Slippage

[SIMid]

Hi everyone,

Finally got my leak fixed and she's holding all her liquids. But I went to a car show over the weekend and on the way home, she started slipping on the uphills close to home. It was a pretty warm day (38 degrees C) and a fairly long drive as well. Maybe 250kms all up.

Usually when she runs low on fluid, she starts to slip. This case, the fluid level was good. Spoke to my mechanic just then and he's guessing that the box may have got a touch too warm, it's shouldn't though, but a possibility. He told me to drive her this comign weekend and see if it plays up again.

Ideas anyone? Would a transmission cooler be worth a modification?

[Bitsyncmaster]

I assume your taking about the auto transmission. Have you checked the fluid when the tranny is warm, engine is on idling in park?

[SIMid]

Have you checked the fluid when the tranny is warm, engine is on idling in park?

I couldn't check it when it was slipping as I got home late at night. I did check it the following day after I had warmed her up, looked okay. I should recheck it when she starts slipping, in daylight.

[David T]

Very bad to dive on a slipping auto trans. You can wear the clutch packs out quickly. The more the clutch packs wear the more junk gets into the filter, the lower the pressure, the more they wear. First, don't drive on a slipping trans. Next, check the level as per the Workshop Manual. Finally check the line pressure. If it is low (and that is what I am guessing) pull the filter and cut it open to clean it. There is a procedure on how to do it and reuse it. If that doesn't get the line pressure up and stop the slipping you will have to pull the transmission and rebuild it.
David Teitelbaum

[deloumis]

Usually when she runs low on fluid, she starts to slip.

You may want to clean your filter as David said. Also if you have ran it multiple times with low fluid could be you burnt out clutches. Not a good idea to run with low fluid.

[Ron]

The only thing useful you might gain by checking it while it is slipping is, when comparing to full when it was warm (at normal operating temperature), you find it reads a lot more...well over the full mark, indicating it is getting too hot (trans fluid expands a lot, relatively). If the fluid looks good (clear and fairly pink, with no minute specks etc when looking at it on white paper, or better yet, through a glass container), I'd check the pressure before I drove it another foot because the clutches are nothing to brag about when new. IMO, the filter has a lot more capacity than it may sound in the above posts, ie if there is enough clutch material in the filter to affect the pressure, it is probably past rebuild time.

[SIMid]

Thanks for the responses. I had the leak fixed several weeks ago and he had also cleaned out the filter. My assumption is the heating of the transfluid to a point where she becomes very low and then, slips on the hills due to the starvation in the box. I'm going to give her another long drive this weekend and re-check the level.

I'm suspecting low fluids in the box which I cannot get an accurate reading till she warms up properly.

[SIMid]

Ok,

Warmed up the engine and transmission, topped up the fluids (minimal) and took her for a drive. After several hours of motoring, she started to slip on the climbs in 3rd gear. I had to slow down for the box to drop a gear so that I could accelerate back up. But then, on some hills, she is fine in 3rd gear with no slippage. I am having problems getting access to the second reservoir to check it as I don't have ramps or a hoist. I'm hoping on the weekend, or the following week to pay my mechanic a visit to stick up up there to check it. But I had the box serviced not long ago by him, so the levels in both should be fine and correct.

Are there other things I need to check or ask a specialists to check/test? I had the filter cleaned out, so all pipes should be clean as well (something about a breather pipe?)

Please don't tell me that I need to rebuild the box. :( If I do, have previous owners had any issues with this box compared to the norms? Will it be a headache for an auto rebuilder or be just a normal box for them to rebuild?

[Jonathan]

Simon,

Barring any wishful thinking, that sounds a lot like the shift computer governor to me. I don't know much about rebuilding them, but I know how to send DMCMW $250 for a new and improved one and after it went in, I never thought about it again.

If you can get your car on a lift, look over the different sections of that wiring harness and see if any of it got melted by the exhaust. That's easy enough to check for now.

[SIMid]

Simon,

Barring any wishful thinking, that sounds a lot like the shift computer governor to me. I don't know much about rebuilding them, but I know how to send DMCMW $250 for a new and improved one and after it went in, I never thought about it again.

If you can get your car on a lift, look over the different sections of that wiring harness and see if any of it got melted by the exhaust. That's easy enough to check for now.

That's what I was thinking Jonathan, but she shifts fine and at the right time when driving normally. With I'm cruising along in 3rd, get to a hill and squeeze the throttle, the revs rise, but no acceleration. So I'm presuming it's mechanical. Toby had replaced the Governor about 5 years ago and she only travelled 3000 miles since. The PO had issues with it shifting. Plus the issue is random, so if it was a wiring issue, it would be happen straight away before the box warms up.

Had a quick conversation on the blower with my mechanic and he said sounds like it's losing pressure when in top gear, possible an "o" ring leakage, but like with anything that's sealed, you need to open it up to check it. :( He couldn't give me a price as no one here in OZ has worked on a Delorean, so it could cost me $2K right up to $5K. :( Fark.

But I should take it to him, stick her on the hoist to take a look at the wiring to check it to be certain.

[DMCMW Dave]

But I should take it to him, stick her on the hoist to take a look at the wiring to check it to be certain.

Have him at least run a line pressure test. Pretty simple and it's in the manual.

[SIMid]

Have him at least run a line pressure test. Pretty simple and it's in the manual.

It's funny you said that, I was browsing through the workshop manual and there's a bolt you remove to test the pressure in the box. I'll ask him if he's got the equipment.

[David T]

If it is slipping it has NOTHING to do with the shift computer. You have to check the line pressure. If it is low you have to find out why. It could be because of a dirty filter, a worn pump, or leaking internal seals. If the line pressure is good and you are slipping then you have worn-out clutch packs and there is nothing you can do except rebuild them.
David Teitelbaum

[SIMid]

If it is slipping it has NOTHING to do with the shift computer. You have to check the line pressure. If it is low you have to find out why. It could be because of a dirty filter, a worn pump, or leaking internal seals. If the line pressure is good and you are slipping then you have worn-out clutch packs and there is nothing you can do except rebuild them.
David Teitelbaum

Exactly what I thought about the computer. I have no experience with autos, so some Qs might sound a little noobish. Is it possible to repair the pump without dropping or opening the box? I'm guessing its the pump as the box is fine at the start, but longer in the drive, she starts to then slip.

I rang my mechanic and he's going to speak to his gearbox friend and see if he can get the equipment to pressure test it.

[Jimmyvonviggle]

One thing for sure, slippage is better than shrinkage.

[David T]

It is unlikely the pump. As the fluid gets hotter and hotter it gets thinner and thinner. If you have internal leaks as the fluid gets thinner and thinner it leaks faster and faster so the pressure gets lower. I question if you really took the filter all apart and cleaned it thoroughly. If you did, then to fix the slippage you are going to have to disassemble the box and replace the seals, steels, and frictions in the clutch packs. The pump CAN be opened without dropping the transmission. It is on the very front and is bolted on. Before doing the pump, do the filter again and fill correctly with the proper fluid. Then check the pressure.
David Teitelbaum

[SIMid]

It is unlikely the pump. As the fluid gets hotter and hotter it gets thinner and thinner. If you have internal leaks as the fluid gets thinner and thinner it leaks faster and faster so the pressure gets lower. I question if you really took the filter all apart and cleaned it thoroughly. If you did, then to fix the slippage you are going to have to disassemble the box and replace the seals, steels, and frictions in the clutch packs. The pump CAN be opened without dropping the transmission. It is on the very front and is bolted on. Before doing the pump, do the filter again and fill correctly with the proper fluid. Then check the pressure.
David Teitelbaum

Thanks for the reply David.

Maybe I need to retop up the second reservoir to the lip of the edge of the bolt, possibly not enough trans fluid? Also, I know that it should have Dex II, but what happens if my mechanic has put in Dex III by mistake? I know it's a no-no for these boxes.

[David T]

Dex III is supposed to be backwards compatible but it is always best to use the correct fluid. They have different friction modifiers in them and the wrong fluid won't work right. The transmission gets the Dexron, the final drive gets 85-90W Hypoid gear oil. It is also VERY important to fill the transmission to the correct level. You really should follow the procedure in the Workshop Manual. Do all of the external On-Car adjustments and check the line pressure.
David Teitelbaum

[SIMid]

Update: Me mechanic has advised me that i will need to go for a rebuild. Question i have, does the motor need to come out to remove the box? Surely it doesnt? Was watching Wheelers Dealers and they seperated the box (manual) from the engine which means they could drop the box? Is there anything else that should get looked at or replaced while shes going through this resto?

Thanks everyone.

[DMCMW Dave]

No. You can drop it from underneath. Replace the engine rear main too!

[SIMid]

It sounded a bit extreme. Is that the Engine rear main seal Dave? Have u got the part number?

[David T]

If the area around the rear main is dry I would not recommend replacing the seal. Dropping the transmission and leaving the engine in the car is no problem. Just properly support the engine. To properly rebuild the transmission requires special tools, not just the right parts.
David Teitelbaum

[DMCMW Dave]

It sounded a bit extreme. Is that the Engine rear main seal Dave? Have u got the part number?

102024 AND 102022

3 AND 4 HERE
http://store.delorean.com/c-267-1-1-1-engine-block.aspx

[SIMid]

If the area around the rear main is dry I would not recommend replacing the seal. Dropping the transmission and leaving the engine in the car is no problem. Just properly support the engine. To properly rebuild the transmission requires special tools, not just the right parts.
David Teitelbaum

Wouldn't it be peace of mind if its pulled apart? Surely a few dollars to replace the seal would be less of a headache if it started to leak down the track?

My mechanice knows an Auto rebuild specialists, so he said I'm in good hands already. :)

[SIMid]

102024 AND 102022

3 AND 4 HERE
http://store.delorean.com/c-267-1-1-1-engine-block.aspx

Thanks Dave. Get Julee to check her emails. ;)

[Nicholas R]

I have an automatic transmission that I've never had a problem with. Pulled it from a my car with 60,000 miles. I only pulled it because I converted the car to a manual. It's for sale in case you're interested.
http://img193.imageshack.us/img193/3669/automaticf.jpg

[deloumis]

Update: Me mechanic has advised me that i will need to go for a rebuild. Question i have, does the motor need to come out to remove the box? Surely it doesnt? Was watching Wheelers Dealers and they seperated the box (manual) from the engine which means they could drop the box? Is there anything else that should get looked at or replaced while shes going through this resto?

Thanks everyone.

The tranny wasn't all that hard to pull out from under the car. I put mine up on jack stands and its all pretty straight forward from there. The one problem I had was trying to figure out how to remove shift cable. I just about finished up with my rebuild. The kit includes everything so it was just pull apart, clean, and reassemble with new parts.

[DMCMW Dave]

I have an automatic transmission that I've never had a problem with. Pulled it from a my car with 60,000 miles. I only pulled it because I converted the car to a manual. It's for sale in case you're interested.


I hate to think about the cost of shipping that to Australia. . . . :jawdrop:

[David T]

There is a LOT more to rebuilding an automatic transmission than just replacing some parts. The torque convertor MUST be rebuilt. The valve body must be disassembled and flushed. All of the gears and bushings must be examined and replaced if necessary. You must measure the pump and replace if worn. The final drive bearing preload must be measured. The end play clearance must be measured and properly set. The filter must be cleaned or replaced. The oil cooler and lines must be flushed. All steels and frictions and clutch pack seals must be replaced. An automatic with 60,000 miles has less than 1/2 it's useful life left, the frictions wear, that is what ultimately determines it's lifespan. The rear main seal seems to be a pretty long-lived part. If it doesn't leak there is no reason to replace it.
David Teitelbaum

[Nicholas R]

I hate to think about the cost of shipping that to Australia. . . . :jawdrop:

http://mominawonders.files.wordpress.com/2010/08/slap-forehead-01_thumb2.jpg

[SIMid]

I hate to think about the cost of shipping that to Australia. . . . :jawdrop:

:lol::lol::lol:

I dare you to walk to your nearest Postoffice Nicholas with the transmission under one arm and lay it on their weighing machine on their desk and go "Padded bag, airmail to Australia please." :lol:

Del, I'll get my mechanic to stick her back up on the hoist to take another look at it. Maybe he wasn't seeing clearly. Maybe he needs to borrow my glasses. :p But I will leave it to the auto experts to rebuild it properly. :)

Definately living the Delorean ownership highs and lows.

[LEVY]

I agree on most of what you say, but not on this. A well kept auto should last a lot more than that!

LEVY


There is a lot more to rebuilding an automatic transmission than just replacing some parts. The torque convertor MUST be rebuilt. The valve body must be disassembled and flushed. All of the gears and bushings must be examined and replaced if necessary. You must measure the pump and replace if worn. The final drive bearing preload must be measured. The end play clearance must be measured and properly set. The filter must be cleaned or replaced. The oil cooler and lines must be flushed. All steels and frictions and clutch pack seals must be replaced. An automatic with 60,000 miles has less than 1/2 it's useful life left, the frictions wear, that is what ultimately determines it's lifespan. The rear main seal seems to be a pretty long-lived part. If it doesn't leak there is no reason to replace it.
David Teitelbaum

[David T]

The friction discs wear from, use, similar to the friction plate in a clutch. They are designed to last around 100,000 miles but of course that can vary depending on how you use the car and take care of it. Friction plates are a wearable item, like spark plugs, filters, brakes, tires, etc. Pull the pan, you will find a good amount of friction materiel, it is loose materiel, worn from the friction plates in the clutch packs and is normal.
David Teitelbaum

[LEVY]

Granted, you should expect normal wear due to friction but if GM recommend transmission fluid change every 160,000 miles on some of their vehicles for normal use or every 80,000 miles for severe service, I would think they expect their transmissions to last more than that.

Some transmission would not last that much, of course but some will. You would also find friction material inside your engine oil pan but still you expect your engine to last well over 200,000 miles.

One member offered his auto transmission for sell, I don't think is right to say it only have less than 1/2 it's useful life left, sure, it would be wise to do a overhaul before installing it but it might work just fine the way it is.

LEVY


The friction discs wear from, use, similar to the friction plate in a clutch. They are designed to last around 100,000 miles but of course that can vary depending on how you use the car and take care of it. Friction plates are a wearable item, like spark plugs, filters, brakes, tires, etc. Pull the pan, you will find a good amount of friction materiel, it is loose materiel, worn from the friction plates in the clutch packs and is normal.
David Teitelbaum

[David T]

I would hope when you drop the pan on your motor you do not find ANY friction materiel. Nothing in the motor to wear like that and between oil changes and filter changes the pan should be relatively clean. Not the case in an automatic transmission. With normal wear an automatic should have friction materiel in the pan with the majority in the filter. What will get your attention is when you find shiny specks of metal. Some brass/bronze would be OK with high mileage but any silvery metal is a cause for concern. Back in the early 80's 100,000 miles on an automatic box is a LOT! Especially if it included a lot of stop-and-go city driving. Automatics today are built a lot better and will last longer.
David Teitelbaum

[LEVY]

OK, OK...

If there is friction, there is wear. Engine and transmission oils are formulated different, motor oil is meant to carry very small partcles so the fillter would remove them, even smaller particles should move with the oil past the filter and then keep mixed in the oil. Transmission oil, however, is not formulated to carry particles that is why "friction material" in automatic transmissions would collect in the oil pan. Have you noticed that automatic transmission oil will not loose it's color even after many, many miles?

Engines produce a lot of "friction material" but you don't see it because, first, you don't take the oil pan every time you change the oil, second, you change the engine oil every 3000 miles or so, third, most of this material is trapped by the oil filter, and I leave the best one for the last:

Change your engine oil only after 100,000 miles (as on your automatic transmission)then pull the oil pan and tell me you don't see any "friction material".

David, engines produce a lot of friction material, believe it or not. You don't see it because of the detergent additives added to motor oil, engines have better oil filters and last, you don't take the oil pan everytime you change the oil.

I believe the purpose of this forum is to help others if we can, ask questions if we have to but not just to prove that I know more than you do!

Have a great day!

LEVY


I would hope when you drop the pan on your motor you do not find ANY friction materiel. Nothing in the motor to wear like that and between oil changes and filter changes the pan should be relatively clean. Not the case in an automatic transmission. With normal wear an automatic should have friction materiel in the pan with the majority in the filter. What will get your attention is when you find shiny specks of metal. Some brass/bronze would be OK with high mileage but any silvery metal is a cause for concern. Back in the early 80's 100,000 miles on an automatic box is a LOT! Especially if it included a lot of stop-and-go city driving. Automatics today are built a lot better and will last longer.
David Teitelbaum

[David T]

What I call "friction materiel" is the dark fiberous junk that collects in the pan and on the filter from the wear of the friction plates in the transmission. There is nothing like that in the motor. Any particles in the motor are going to be carbon or metal. Wearable things in the motor are the soft bushing materiel, brass from thrust washers, and steel from rings, cylinder walls, camshaft, and tappets. When you take anything apart any good mechanic will do a mechanical analog of an autopsy to determine what failed and why so when you reassemble you can correct whatever caused the part to be repaired. The junk that collects in the sump and the filter gives clues to how the part was used, taken care of, how much it was used, and what parts failed. If you do not find much metal and mainly fiberous friction materiel on a high mileage transmission, you can conclude the transmission failed from use-related wear. That would be considered "normal". Finding ANY fiberous friction materiel in a MOTOR would be cause for concern, that is not what is expected to be found.
David Teitelbaum

[DMCMW Dave]

Kind of off topic but DT drifted it to engines....


Is this fibrous enough? :shocked:

9322

There were actually seeds in here too. Any guesses on how they got there?

[jawn101]

Kind of off topic but DT drifted it to engines....


Is this fibrous enough? :shocked:

9322

There were actually seeds in here too. Any guesses on how they got there?

Whoa. Is there a good way to check for/eliminate that mess without dropping the pan? :)

EDIT: stupid question, I know. Maybe an inspection camera in the drain plug hole, but obviously not otherwise.

[David T]

That sludge is mostly congealed oil (carbon), not the friction materiel you would expect to find in an automatic transmission. Cheap oil and/or not changing the oil frequently enough. How many miles on the motor and was it ever overheated? Auto stores do sell "oil flush" but I doubt it would be able to properly clean this mess up without dropping the pan. What were the symptoms that caused you to drop the pan? In this case I would also pull the valve covers and check for excessive wear in the valve train and do a compression test and a leak-down test to get a full picture of the health of the motor. Was there any hint of anti-freeze in the oil? If not then that would indicate the liner seals and head gaskets are probably OK. As for the "seeds", are you sure they are plant seeds? Maybe someone put some kind of additive into the motor and it looks like seeds?
David Teitelbaum

[DMCMW Dave]

EDIT: stupid question, I know. Maybe an inspection camera in the drain plug hole, but obviously not otherwise.

In this particular case, a complete lack of oil pressure was a pretty good sign as this stuff eventually plugged the pickup tube.

Otherwise, yes, drain the oil and go into the drain hole with a cotton swab securely attached to a stiff wire, swipe it around and see what comes out. It should not look gooy.

I'll let a few guesses go on as to the root cause, and I guarantee that they were seeds, much more obvious after they were de-oiled.

[Nicholas R]

Perhaps a squirrel harvesting nuts and seeds for the winter in the airbox. First startup, they get sucked into the valve cover, assuming the screen in the oil fill hole is gone. Just a guess :D

[jawn101]

I'll let a few guesses go on as to the root cause, and I guarantee that they were seeds, much more obvious after they were de-oiled.

Were there any mouse parts in the rest of the engine? We know how much mice love these cars...

[DMCMW Dave]

Were there any mouse parts in the rest of the engine? We know how much mice love these cars...

They were everywhere. Hint - including the valley. . . . .

[jawn101]

They were everywhere. Hint - including the valley. . . . .

Did they eat through the block???

[fnzen]

Uhm have you smelled the fluid? if it smells burnt then its rebuild time

[DMCMW Dave]

Did they eat through the block???

We thought about the oil filler but the screen was still intact there. So - we kept digging.

Yep. Apparently a combination of dirt and mouse pee is pretty corrosive to aluminum. Sorry about the focus but you get the idea.

9335

[jawn101]

We thought about the oil filler but the screen was still intact there. So - we kept digging.

Yep. Apparently a combination of dirt and mouse pee is pretty corrosive to aluminum. Sorry about the focus but you get the idea.

9335

Well, ain't that some s#it. Is this car in your shop now or is this nostalgia? :) I'm guessing a block swap was next.... damn mice.

[David T]

It really is amazing what you see when someone drags their "Barn Fresh" treasure out into the light of day. Bet they didn't bargain for this! Let this be a lesson AGAIN, cars do not store well. On one car I got running, for a while after it started up (not a Delorean) we could smell nuts roasting? When we reved the motor we shot acorns out the tail pipes! The worst was the squirrel piss in the heater box. Once the car warmed up it got REALLY bad! There have been stories of finding snakes in the car, one guy dragged his treasure home and all of the spiders came out and infested his house! You have to treat the car as if it is a biological hazard. There have been cases of Hanta virus in the Southeast and anywhere in the US is the potential for Rabies. Use at least a facemask (a respirator is better), gloves and wet down the car with some kind of disinfectant and remove all biological matter, bag it and dispose of it. Rodents are known to chew on wiring so that can really mess up the electrical system. They seem to like the tool bag too. They take the padding under the seats and use it for nesting materiel in the heater box. In this case if you did have oil pressure you would have found the leak a lot faster!
David Teitelbaum

[DMCMW Dave]

In this case if you did have oil pressure you would have found the leak a lot faster!
David Teitelbaum

Actually in this car the hole is into the crankcase rather than to the oil galley. The car actually drove just fine for about 100 miles untill the crap in the pan plugged up the pickup tube and the oil light went on. The hole in the top was so well-plugged with dirt that there was no "extra" crankcase ventilation leakage at all.

Holes in the high pressure oil galley are admittedly much more dramatic. I had one blow open on a test drive. What a mess.

[QuadcityDMC]

Is this the black delorean I saw last month?

[SIMid]

Updates:

My mechanic pulled out the transmission yesterday morning and the auto specialists had told him that the 2nd Gear Drum had failed. I have no other details to how this has happened. Currently he is looking for a compatible part to replace this, he should be able to find it. I had a look on the online parts listing but did not see this part, unless it's called something else? If I don't hear from him, all is good, but if I do, I will need this part asap.

Auto experts?

[David T]

C1 is usually the one that "goes". Happens because someone drives on a flakey shift computer and it hammers the drivetrain with frequent and hard shifts. It is just a piece of formed sheet metal with some spot welds and is the smallest clutch and all of the power has to go through it. C1 is #26 103620. If your mechanic is calling C2 "second gear" that is #14 103966. You might be able to repair it. Look at 4-5-4 and 4-5-5 in the Parts Manual. DMCH should have it but they may not want to sell individual internal parts. Martin in the UK may be able to get you one, these parts were a lot more popular in Europe, they were used in a lot of Renault cars. It may turn out to be cheaper to buy a rebuilt transmission or another dead one in the hope that the part you need is not bad. While it is apart you should be replacing all of the seals, frictions, steels, springs, and shims and rebuilding the torque converter.
David Teitelbaum




Updates:

My mechanic pulled out the transmission yesterday morning and the auto specialists had told him that the 2nd Gear Drum had failed. I have no other details to how this has happened. Currently he is looking for a compatible part to replace this, he should be able to find it. I had a look on the online parts listing but did not see this part, unless it's called something else? If I don't hear from him, all is good, but if I do, I will need this part asap.

Auto experts?

[EarlHickey]

Tiptronic or Sportamatic if you like them.

Just a locking torque convertor clutch alone will reward you with much longer lasting transmission fluid, less wear and more efficiency.

The tiptronics also aren't made of pricey cheese and it is possible to make them shift with only vacuum and throttle position inputs, sans computer although you'd have to manually lock and unlock the convertor.


I think if I were to stay married to an R30, I'd bump up the line, control and reverse pressures, ditch the shift computer if a vacuum modulator is adaptable and update the lined clutch plates to modern stuff.

At a casual glance it does also look possible to reverse engineer in a modern lock up convertor although it would take some work. I haven't delved into this deeply at all.

Had these cars stayed in production, such changes would have inevitable.


Updates:

My mechanic pulled out the transmission yesterday morning and the auto specialists had told him that the 2nd Gear Drum had failed. I have no other details to how this has happened. Currently he is looking for a compatible part to replace this, he should be able to find it. I had a look on the online parts listing but did not see this part, unless it's called something else? If I don't hear from him, all is good, but if I do, I will need this part asap.

Auto experts?

[David T]

I had spoken with people that were involved with the production of the Delorean and the plans were to get away from Renault. They were not very cooperative and did not want to do any more engineering or improvements on what they considered a product at the end of it's life cycle. The auto was near the limit of it's HP rating anyway. All of the things you mention are probably what would have occurred but not with Renault. Now, to do it "on your own" is very difficult because you can't do it with "off the shelf" parts. You may be able to find parts that can be modified to be made suitable but even that route is expensive. Anyone looking for performance is probably going to want a 5-speed anyway. The only way it makes sense to do it with an automatic is if you use forced aspiration, then an auto with a torque converter can be a good fit, just not the Renault box. Because of the nested design of the clutch packs and the way they are made (stamped sheet metal with spot welds) you have a LOT of work to do to get it to handle more HP.
David Teitelbaum



Tiptronic or Sportamatic if you like them.

Just a locking torque convertor clutch alone will reward you with much longer lasting transmission fluid, less wear and more efficiency.

The tiptronics also aren't made of pricey cheese and it is possible to make them shift with only vacuum and throttle position inputs, sans computer although you'd have to manually lock and unlock the convertor.


I think if I were to stay married to an R30, I'd bump up the line, control and reverse pressures, ditch the shift computer if a vacuum modulator is adaptable and update the lined clutch plates to modern stuff.

At a casual glance it does also look possible to reverse engineer in a modern lock up convertor although it would take some work. I haven't delved into this deeply at all.

Had these cars stayed in production, such changes would have inevitable.

[SIMid]

Auto Trans guy ripped out the box last week and took it all apart and examined why it was slipping. Faulty 2nd Gear Drum or C2.

I went down and had a look.

http://i48.tinypic.com/2ljrzix.jpg

As you can see, there a crack which was causing it to lose pressure. They believe that they might had been a pinhole or a very fine hairline crack. So yeah, poor French manufacturing. :( I wonder how many other boxes have this issue?

[David T]

First time I saw that. I would still guess it was due to a faulty shift computer slamming in and out of gears and over-stressing the parts. Maybe your guy can weld it up and then machine it?
David Teitelbaum




Auto Trans guy ripped out the box last week and took it all apart and examined why it was slipping. Faulty 2nd Gear Drum or C2.

I went down and had a look.

http://i48.tinypic.com/2ljrzix.jpg

As you can see, there a crack which was causing it to lose pressure. They believe that they might had been a pinhole or a very fine hairline crack. So yeah, poor French manufacturing. :( I wonder how many other boxes have this issue?

[SIMid]

First time I saw that. I would still guess it was due to a faulty shift computer slamming in and out of gears and over-stressing the parts. Maybe your guy can weld it up and then machine it?
David Teitelbaum

The Delorean did have a sick computer with the PO. This was replaced by Toby and all was well afterwards. Examining the clutches, he said the slipping was due to loss of oil pressure from the crack in the drum. As you can see the colour of the clutch discs, 3rd was pretty burnt.

http://i47.tinypic.com/33jsr4z.jpg

He did source another drum from a GM Trimatic box. All measured up exactly the same! He said some internal components are used in all boxes due to cost savings. Whish is good news!

I did question regarding if the drum was repairable, but he said he didn't trust it and said that there may be other cracks in the metal that we cannot visually see around the shaft hole. Just told me that it was a bad box. :(