Which Delorean transmission is the most durable?

[Chris Burns]

I know that both transmissions can have their issues, but which do you think is the most durable?

Manual?
or
Auto?

[Massaku]

I believe the manual transmission is more durable than the auto.
The manuals can handle more power than the autos.
the autos from the factory have the transmission governor problem... I could be very wrong though :tongue_stick:

[pezzonovante88]

I would imagine the manual is more durable. I'm far from a mechanic, but from my experience I've gathered that autos in any car are more likely to break and are easier to break AND are more expensive to fix. Not sure about the DeLorean, but I'd assume its the same in general.
Jeez, the auto trans. in my Jag (also used in V8 BMWs of the time) was quite a scary unit that required a full rebuild at ~75kms.

[Chris Burns]

I'm going with the manual on this also (course you usually have to usually replace the clutch at least once) Lotus used a Renualt Transmission on the S4 and V8 Esprits. With the V8 ones they had to do some major beefing up of the clutch and downtune the engine slightly. The engine in the V8 Esprit was capable of 500hp, but was downtuned to 350hp to save the transmission.

The toughest auto transmission I have seen is the Chrysler 727 Tourqeflite used in the 1960's and early 70's. You can put some MAJOR power through that transmission.

Nothing wrong with an automatic Delorean though! They are great for cruising and for horrible traffic:nana1: PLus it gives you an option that most European sportscars at the time didn't have.

[DeLorean]

Frequently the "durability" of a manual trans depends a lot on driver ability. A "can't find em grind em" driver will probably get a lot more life out of an aut, especially with the sorts of faults that seem to typically show up with the Renault trans the Delo uses... where as a driver that drives the manual "properly" may likely get much more life out of a manual.

Typical DeLorean mileages driven, either one will probably last a long time. The most likely fault would be a seal going bad and the car leaking out all it's transmission fluid, ten being driven around till the bearings started making a racket and the car not shifting.

[Nicholas R]

Manual by far, hands down.

I believe the manual can stand up to about twice as much power as the automatics.

This letter from John DeLorean pretty much sums up the automatic transmission. Wanna know why I'm doing a transmission swap? Look no further:
https://fbcdn-sphotos-a.akamaihd.net/hphotos-ak-ash4/430235_636085118446_28500858_33108945_1842745387_n .jpg

[Chris Burns]

Manual by far, hands down.

I believe the manual can stand up to about twice as much power as the automatics.

This letter from John DeLorean pretty much sums up the automatic transmission. Wanna know why I'm doing a transmission swap? Look no further:
https://fbcdn-sphotos-a.akamaihd.net/hphotos-ak-ash4/430235_636085118446_28500858_33108945_1842745387_n .jpg

Where did you get that letter?:eek1:

[Nicholas R]

Where did you get that letter?:eek1:
Part of one of dmcseller's auctions of DMC paperwork and literature on ebay.

I believe the full letter reads:



DELOREAN NYK
12/30/81

TO: GEORGE LACY

FROM: JOHN Z. DE LOREAN

THE RENAULT AUTOMATIC IS A DISASTER -- WE MUST FIND A DIFFERENT
AUTOMATIC. WHAT ABOUT ZF? WHAT UNIT DOES LANCIA GAMMA USE?
ITS FORE AND AFT. HOW ABOUT AUDI -- THEIR UNIT SHOULD WORK.

CC: D.H. LANDER
B. WILLS
C. R. BROWN

[Kenny_Z]

I agree with the manual being the stronger transmission for a Delorean.

However, I think the GM Powerglide is the strongest automatic transmission ever made. There's a reason they bolt those up to 800+lb torque monster drag cars.

[Nicholas R]

I agree with the manual being the stronger transmission for a Delorean.

However, I think the GM Powerglide is the strongest automatic transmission ever made. There's a reason they bolt those up to 800+lb torque monster drag cars.

If you bolt it up to the DeLorean you'd certainly have 2 strong gears in reverse!

[timothymoore]

I agree with the manual being the stronger transmission for a Delorean.

However, I think the GM Powerglide is the strongest automatic transmission ever made. There's a reason they bolt those up to 800+lb torque monster drag cars.

we just talked about auto trannies in class yesterday: and the torqueflite and powerglide were the top 2 transmissions made in auto.

[sean]

This letter from John DeLorean pretty much sums up the automatic transmission. Wanna know why I'm doing a transmission swap? Look no further:


Well I already felt that way about the Auto and for some reason knowing JZD did too makes me smile.:smile:

[Dangermouse]

Well I already felt that way about the Auto and for some reason knowing JZD did too makes me smile.:smile:

:sad30:

[sean]

:sad30:

It took owning one to fully appreciate it though ;-) Still I'd take 5 years of owning an Auto D over not getting to experience a DeLorean.

[stevedmc]

I know that both transmissions can have their issues, but which do you think is the most durable?

Manual?
or
Auto?

The one that has been properly maintained is the most durable.

[Kenny_Z]

If you bolt it up to the DeLorean you'd certainly have 2 strong gears in reverse!

lol, that is true. Maybe I'll rethink the powerglide sitting on my shelf ;)



we just talked about auto trannies in class yesterday: and the torqueflite and powerglide were the top 2 transmissions made in auto.

I've seen pictures where, on a freeway, a Nova's I6 threw a piston before the powerglide failed. Apparently his daughter didn't understand that a 2 speed powerglide and inline 6 combination was not made to go 80 on a freeway.

[DMCMW Dave]

Personally I believe the automatic is less of a problem than people will have you believe. Yes, it's primitive (3 speeds, no converter lock etc.) but in normal use I'd have to say that we see many more service issues with manuals than we do with automatics. I'm not talking about taking on a 400 HP engine etc (hi Nick). just normal everyday use.

I have yet to have to replace or rebuild an automatic for any reason (dropping the pan to fix leaks does not count). The primary service issues on the auto are the computer governor ($300), and leaks (gaskets,hoses, shift cable, and O-rings). I think we've seen one leaky torque converter gasket. There is a very occasional catastrophic hub weld failure but I've not seen one in 8 years.

The manual on the other hand involves replacing the clutch, broken roll pin, hydraulics, and of course the infamous backing-off-nut problem. These are all more common than issues with the automatic. They are generally more expensive to repair than the common automatic issues (A clutch master+slave+line costs more than the governor!)

I have not yet had a failed automatic take someone off the road. Not to say it does not happen (I'm sure someone will post about leaving automatic parts all over the street now!) but it is relatively rare. When they start slipping they will need a rebuild, but honestly they will slip for a very long time if driven gently before final death.

[Chris Burns]

Interesting... Thanks for the post Dave!

I have nothing against the auto Deloreans. I love them in fact. I have driven one and it was fun! You do have to put your foot into it a little more, but it's not that bad. My 1982 BMW 320i I had in HS used a 3 spd auto, and the Delorean felt slightly faster!

I'm not really going to base my Delorean ownership necessarily on the transmission. Just whatever I get the best deal on, because I like BOTH:notworthy:

Hopefully I will win VIN 16559 at DCS this summer! (fingers crossed).

[opethmike]

Personally I believe the automatic is less of a problem than people will have you believe. Yes, it's primitive (3 speeds, no converter lock etc.) but in normal use I'd have to say that we see many more service issues with manuals than we do with automatics. I'm not talking about taking on a 400 HP engine etc (hi Nick). just normal everyday use.

I have yet to have to replace or rebuild an automatic for any reason (dropping the pan to fix leaks does not count). The primary service issues on the auto are the computer governor ($300), and leaks (gaskets,hoses, shift cable, and O-rings). I think we've seen one leaky torque converter gasket. There is a very occasional catastrophic hub weld failure but I've not seen one in 8 years.

The manual on the other hand involves replacing the clutch, broken roll pin, hydraulics, and of course the infamous backing-off-nut problem. These are all more common than issues with the automatic. They are generally more expensive to repair than the common automatic issues (A clutch master+slave+line costs more than the governor!)

I have not yet had a failed automatic take someone off the road. Not to say it does not happen (I'm sure someone will post about leaving automatic parts all over the street now!) but it is relatively rare. When they start slipping they will need a rebuild, but honestly they will slip for a very long time if driven gently before final death.

I sure love that famous output shaft nut.

[DMCVegas]

Personally I believe the automatic is less of a problem than people will have you believe. Yes, it's primitive (3 speeds, no converter lock etc.) but in normal use I'd have to say that we see many more service issues with manuals than we do with automatics. I'm not talking about taking on a 400 HP engine etc (hi Nick). just normal everyday use.

I have yet to have to replace or rebuild an automatic for any reason (dropping the pan to fix leaks does not count). The primary service issues on the auto are the computer governor ($300), and leaks (gaskets,hoses, shift cable, and O-rings). I think we've seen one leaky torque converter gasket. There is a very occasional catastrophic hub weld failure but I've not seen one in 8 years.

The manual on the other hand involves replacing the clutch, broken roll pin, hydraulics, and of course the infamous backing-off-nut problem. These are all more common than issues with the automatic. They are generally more expensive to repair than the common automatic issues (A clutch master+slave+line costs more than the governor!)

I have not yet had a failed automatic take someone off the road. Not to say it does not happen (I'm sure someone will post about leaving automatic parts all over the street now!) but it is relatively rare. When they start slipping they will need a rebuild, but honestly they will slip for a very long time if driven gently before final death.

In comparing the issues between the two and citing normal driving versus abuse, how many of the 5-Speeds problems that you list are incurred with abuse? Likewise what have been the comparable mileage figures between autos and manuals that have required the types of services that you mention?

As for not having to rebuild an automatic, if one did prematurely failed, would that not entail a rebuild of some sort?

From what I've heard over the years (and correct me on any of these if I'm wrong), I've gathered that the Automatic 3-Speed in the DMC-12 is a fine enough transaxle. The biggest factors that have caused premature failure in the units are:

Failed Governors due to Jump starting the car. Whether it's an early VIN that doesn't have the updated ground wire for the starter to engage, or a dead battery due to storage or other issues, jump starting an Automatic can cause too much amperage blow the surge capacitors in the Governor. This leaves the unit vulnerable to normal fluctuations during driving (and subsequent jump starts). What then happens is the other internals get shorted out and proper shifting is lost. Aside from starting out in the wrong gear, you can then have unexpected downshifts at highway speeds and incur internal damage.
Poor Filtration. Old filters can clog easily and apparently don't offer very good flow rates anyhow.
Heat Damage. Heat is the absolute enemy of any automatic transmission. Given things such as problems with otterstat locations in early cars, as well improperly bleeding and neglect over the years, heat is also a big determining factor as well.


Certainly it's true that the 5-Speed Manual had a big problem with the clutch fluid line, and that's certainly an upgrade that needs to be implemented on ANY DeLorean. But something else to consider as well is hydraulics, whether they be clutch or brakes are going to need to be flushed after sitting for a number of years. Same with friction material for Brake Pads and Clutch discs. Something to consider is that to abuse a vehicle you don't have to thrash it. Neglect and improper storage are also outside the scope of normal use and can be just as detrimental to the lifespan of any equipment and/or components.

[Dracula]

I sure love that famous output shaft nut.

Mine failed after 20,000 miles, or so. It looked like there was an additional plug in the transmission end cap and it would've confounded me if I had to fix this myself.

[opethmike]

Mine failed after 20,000 miles, or so. It looked like there was an additional plug in the transmission end cap and it would've confounded me if I had to fix this myself.

Happened to me twice. Unreal.

[DMCMW Dave]

In comparing the issues between the two and citing normal driving versus abuse, how many of the 5-Speeds problems that you list are incurred with abuse? Likewise what have been the comparable mileage figures between autos and manuals that have required the types of services that you mention?

As for not having to rebuild an automatic, if one did prematurely failed, would that not entail a rebuild of some sort?
.

I was basing this on observed cars in the shop. As such I can't really place blame on the driver (since I can't possibly know the 30-year history of the car). (My disclaimer on "abuse" was more pointed at folks doing high-power engine swaps which goes beyond the original design intent, and tends to be done by those intending to actually use the new-found power. )


But there are other kinds of abuse. Some failures may be related to others. For example:

Ignoring the plastic clutch line leads to the rollpin or synchro issues with the manual transmission. A perfect example of putting off a cheap repair (upgrade) and ending up with one that's huge.

Clutch is a wear-out item, I've seen them wear out anywhere from 6000 to 70,000 miles, so I'm guessing the likelihood that for many original owners this was probably their first manual transmission car has a lot to do with it. On an automatic the only wear-out item is the entire transmission.

Ignoring a failed computer governer, causing the clutches to fail in the automatic (from starting out in second gear) is also an example of putting off a cheap repair and ending up with expensive problems. Same with deferring basic maintenance especially on the automatic. Oil changes on the automatic are MUCH more important to long life than on a manual.

Yes, a failed automatic leads to a complete rebuild (or replacement), but compared to a failed manuals the observed rate of occurrence is very low.

Mileage seems to have remarkably little to do with any of this. I actually see very little correlation. Which is pretty strange on the surface!

[sdg3205]

Dave, if you had to guess, how many cars have you seen with a gear nut issue over the years? I've always been worried about this but I've also heard its quite rare.

[Ryan King]

The first that I replaced on my Automatic Transmission was the Computer Governor.

After that, I have had no problems what so ever with it. Yes, it leaks from here and there from time to time, but overall, in the 7 years I've owned the car, the transmission has been incredibly reliable compared to a manual transmission.

[DMCVegas]

I was just wondering about how many failures you'd seen and how the correlated. Especially after this post (http://www.dmchelp.com/archive/index.php/t-2113.html?) caught my eye.

Automatics certainly need their fluid flushed of course, but an oil change in a Manual doesn't hurt either. I remember taking my car in and having the fluid changed out in front of me. It just coasted much, much easier and didn't slow down as fast. You could feel the difference.

[Nicholas R]

I never could get my auto to stop leaking. Replaced the gaskets twice and both hoses to the transmission cooler, still leaked. I finally just accepted it and kept an eye on it. If at some point it wasn't leaking, I'd be worried that it was empty, lol.

[Sidaries]

I never could get my auto to stop leaking. Replaced the gaskets twice and both hoses to the transmission cooler, still leaked. I finally just accepted it and kept an eye on it. If at some point it wasn't leaking, I'd be worried that it was empty, lol.

Same here, only manual. Not much, but always leaks. I changed Lip Seals 2 times, I have to change it again.

[Chris Burns]

Does a Delorean use the same transmissions as a Renault 25?

[DMCVegas]

Yes and no. Same housing but different ratios

http://www.lambolounge.com/chassis/Transmission/ratio/ZF%20alternative.htm

[Victor]

I owned two Ds. An auto, and now a manual. I had to change the governor on the auto. The manual that I have now had required a master cylinder clutch. The slave cylinder, and braided stainless line was changed previously.
For me, I prefer a lot more the manual, simply because I always liked to choose my own gear myself. I also find the acceleration is way better. But as far as durability is concern, maybe they're both strong.

[Chris Burns]

I have friends with both auto and manual Deloreans and both have done well:headbang:

I guess it all boils down to how well the car has been kept up and everything. I have a driven both transmissions and love both:smile: I'd like to have one of each!!

[DeLorean03]

Yes, a failed automatic leads to a complete rebuild (or replacement), but compared to a failed manuals the observed rate of occurrence is very low.


Well, with that being said, looks like auto trannys are more robust.

Isn't it ironic that my car is in your shop right now for a transmission leak ;)?

/end playful sarcasm

[DMCMW Dave]

Automatics leak, need governors, or completely fail. Complete failure is actually pretty rare. We have yet to replace one for failure (other than a prior-shop-induced broken housing :mad2:).

Manuals need clutches, hydraulics leak, roll pins shear, and they unscrew themselves.

I NEVER thought I'd hear myself saying this but repairs are more common on manuals. And tend to be more expensive.

So - buy what you like/can drive.

[Chris Burns]

Well put Dave! I'll buy which ever one is the best deal for me and that I can drive and enjoy:cool1:

[SIMid]

Dave, ever come across a failed 2nd gear drum in the Auto like mine?

I've always had my mind/want for a manual D when I seeking to buy, but I'm liking the Auto a lot. Just slip her in D and cruuuuiiisssssssssssse. :)

[DMCMW Dave]

Dave, ever come across a failed 2nd gear drum in the Auto like mine?



Actually I was test driving a car (a couple of years before we opened) and had that suddenly fail on the road. Went from OK to Nothing but Reverse at at stop light. I have heard of the problem but have not seen one again.

[SIMid]

Actually I was test driving a car (a couple of years before we opened) and had that suddenly fail on the road. Went from OK to Nothing but Reverse at at stop light. I have heard of the problem but have not seen one again.

Hopefully no other Auto will fail like this again. Was a costly rebuild. :(

[David T]

It is not really a question of which is more durable, they both have issues. IMHO it boils down to what kind of driving do you like to do? Driving a 5-speed makes you a lot more involved with the driving of the car but is not good in traffic. An automatic is a lazier way to drive and it is not as "peppy". With a 5-speed, because you are more involved with it, there is more chance for abuse (read clutch replacement). Properly taken care of (flush the clutch fluid every other year, check the fluid in the auto) and don't flog the car, they BOTH can last a long time. My choice was simple, my wife didn't know how to drive stick and didn't want to learn!!!!!!!
David Teitelbaum

[Delorean Industries]

Funny how fast you age in your Twenties. My first D was an auto and I wanted a manual more then anything. Now I want is an auto again. Driving a manual D is labor intensive imo.

[Chris Burns]

Funny how fast you age in your Twenties. My first D was an auto and I wanted a manual more then anything. Now I want is an auto again. Driving a manual D is labor intensive imo.

VIN 16128 got ya hooked on automatics. lol

I commend ya for the great job you did on 16128!!

[Delorean Industries]

Thanks Chris! Darren has a very nice auto.