Input Shaft Play Question

[fmj78]

Started as a clutch job + exhaust upgrade "while i'm in there" ...

I've got the trans on the bench and the input shaft seems to have a TON of play in it.

video:
https://youtu.be/jBnWYyEMojk

I'm planning to take the 5th gear cover off to loctite and re-torque the output shaft nut, but wasn't planning on cracking open the case.

What say the community on the amount of play I'm seeing on that input shaft?

[David T]

Normal. The pilot bearing helps to support the input shaft. Replace the pilot bearing, throwout bearing, pressure plate and friction plate. If the flywheel has blue spots or cracks get it cut or replaced. Use a pilot tool to line up the clutch before replacing the transaxle. If the crank seal is leaking replace it. If the slave cylinder is leaking, replace it. I would open the case and replace the split pins, you are way more than 1/2 way there with the trans out. Other things to check are the little rubber bushings in the shift linkage, motor mounts, and output shaft seals. Also a good time to regrease the C/V joints. Check, lubricate, and readjust the shift linkage if necessary. Have fun!

[RamblinDMC]

that doesn't seem right at all. I'd say your bearings are shot in your transmission. I rebuilt mine earlier this year and the output shaft had next to no play in it. There may be some spec in the shop manual, but I'd say that's abnormal. The transmission isn't hard to take apart at all and the bearings are available from our vendors. There's a video on youtube on transmission disassembly.

[DMC-81]

Without knowing the history, maintenance, or miles on the gearbox, I would say that it is unlikely the nose bearing that's worn. There is a relatively soft input shaft coupler on the other end of that shaft (before the bearing) that is probably wallowed out a bit. I had a little bit of play as well (less than yours). For other reasons, when I tore down my gearbox, I changed the weak coupler to a fully splined one. That solved the play at the same time.

That part of the input shaft is supported by the pilot bearing on the engine side and the couple on the transmission side. Here is my gearbox thread with some pictures and detail:
http://dmctalk.org/showthread.php?14544-5-Speed-gearbox-flaw-repair

Make sure you use a quality pilot bearing. I chose Nachi for my car.

[fmj78]

Normal. The pilot bearing helps to support the input shaft. Replace the pilot bearing, throwout bearing, pressure plate and friction plate. If the flywheel has blue spots or cracks get it cut or replaced. Use a pilot tool to line up the clutch before replacing the transaxle. If the crank seal is leaking replace it. If the slave cylinder is leaking, replace it. I would open the case and replace the split pins, you are way more than 1/2 way there with the trans out. Other things to check are the little rubber bushings in the shift linkage, motor mounts, and output shaft seals. Also a good time to regrease the C/V joints. Check, lubricate, and readjust the shift linkage if necessary. Have fun!

Thanks for the info. I'm going to do the roll pins so I'll be able to take a look at the input shaft. I have the whole clutch kit with main seal, gasket, TO, and Pilot bearings. Planning to have the flywheel done. I did the slave cylinder a few years ago when I had the intake off along with new hydro lines. Definitely need new bushings, trans mounts, and the output shaft seals now that I'm going to open it. I'm thinking I might trade my axels for "new" ones from PJ Grady.

Cheers

[fmj78]

that doesn't seem right at all. I'd say your bearings are shot in your transmission. I rebuilt mine earlier this year and the output shaft had next to no play in it. There may be some spec in the shop manual, but I'd say that's abnormal. The transmission isn't hard to take apart at all and the bearings are available from our vendors. There's a video on youtube on transmission disassembly.

I found Roedl's videos today and watched them all twice. That kind of pushed me over the hump to open it up.

Thanks for the reply.

[fmj78]

Without knowing the history, maintenance, or miles on the gearbox, I would say that it is unlikely the nose bearing that's worn. There is a relatively soft input shaft coupler on the other end of that shaft (before the bearing) that is probably wallowed out a bit. I had a little bit of play as well (less than yours). For other reasons, when I tore down my gearbox, I changed the weak coupler to a fully splined one. That solved the play at the same time.

That part of the input shaft is supported by the pilot bearing on the engine side and the couple on the transmission side. Here is my gearbox thread with some pictures and detail:
http://dmctalk.org/showthread.php?14544-5-Speed-gearbox-flaw-repair

Make sure you use a quality pilot bearing. I chose Nachi for my car.

Hey I read all about your transmission work today on the forum. Nice work and thanks for all the documentation and pictures.

[DMC-81]

Hey I read all about your transmission work today on the forum. Nice work and thanks for all the documentation and pictures.

Thanks, and good luck with the task.

[David T]

Unless the car was driven a lot with bad C/V boots, your half shafts should be very rebuildable. A little bit if time, some new boots, a lick of paint, and a lot of grease and they should be just fine. Unless the grearbox was driven a lot with no oil inside the input bearing should be OK but if it makes you feel better replace it. The Service Manual has all the info you need to open and reassemble the box. The most important thing is the pre-load on the diff carrier bearings. Now that you are going to replace the split pins, get the kit from PJ Grady. He sells a kit where you put the new pin in and then a smaller one inside the bigger one to make it stronger. Not sure if the other vendors offer that. You may also consider buying a new pivot bolt for the linkage (keep the old one as a spare).

[Ethan Rode]

Seems normal to me. You'll need to remove the coupler from the primary shaft to replace the seal, so it'll be a good time to inspect it.

[fmj78]

Unless the car was driven a lot with bad C/V boots, your half shafts should be very rebuildable. A little bit if time, some new boots, a lick of paint, and a lot of grease and they should be just fine. Unless the grearbox was driven a lot with no oil inside the input bearing should be OK but if it makes you feel better replace it. The Service Manual has all the info you need to open and reassemble the box. The most important thing is the pre-load on the diff carrier bearings. Now that you are going to replace the split pins, get the kit from PJ Grady. He sells a kit where you put the new pin in and then a smaller one inside the bigger one to make it stronger. Not sure if the other vendors offer that. You may also consider buying a new pivot bolt for the linkage (keep the old one as a spare).

RGR on the kit from Grady. I already have the new pivot bolt (and new bracket) for the linkage because the old one is seized to the bracket.

going to get the exhaust off today. and get the flywheel to a machine shop on Monday.

[fmj78]

Seems normal to me. You'll need to remove the coupler from the primary shaft to replace the seal, so it'll be a good time to inspect it.

thanks. I'm going into that case next week so I'll report what I find.

[David T]

One thing about the Service Manual. Do not go by the picture. Be really careful which way the diff comes out so you put it back correctly or you will have 5 speeds in reverse! Take pictures as you disassemble to aid in reassembly. Make sure the breather hole is not plugged up, Very common for the little rubber plug to be long gone. If you don't have a magnetic drain plug get one.

[fmj78]

So I got the clutch/pressure plate/fly wheel off yesterday and the pilot bearing just came out with a finger pull. That seems wrong. Anyone else have that experience?

[David T]

The pilot bearing usually comes out without a lot of "drama". Not in Deloreans, but on some cars and trucks it is a real battle to get that bearing out. Especially because it is in a blind hole. The "trick" then is to pack the bearing with as much grease as you can and then hammer a tight fitting punch inside the bearing and, using the hydraulic pressure created by the grease, the bearing is pushed out. The other way is with a slap hammer. The bearing can be *loose* but there should be NO play when fully seated, either in the crank or the input shaft. Be sure the bearing is fully seated into the crank or it will put excessive end thrust on the input shaft. Another thing to watch for. In the Delorean they use hollow dowels to line up the transaxle and motor. Make sure they are both there when you put things back together. It doesn't matter which part they are in as you assemble but they both MUST be there.

[fmj78]

The pilot bearing usually comes out without a lot of "drama". Not in Deloreans, but on some cars and trucks it is a real battle to get that bearing out. Especially because it is in a blind hole. The "trick" then is to pack the bearing with as much grease as you can and then hammer a tight fitting punch inside the bearing and, using the hydraulic pressure created by the grease, the bearing is pushed out. The other way is with a slap hammer. The bearing can be *loose* but there should be NO play when fully seated, either in the crank or the input shaft. Be sure the bearing is fully seated into the crank or it will put excessive end thrust on the input shaft. Another thing to watch for. In the Delorean they use hollow dowels to line up the transaxle and motor. Make sure they are both there when you put things back together. It doesn't matter which part they are in as you assemble but they both MUST be there.

right so if the bearing is not snug in the housing, should I get an oversize bearing or replace the housing?

I think this problem has existed the entire 17 years I've owned the car. When I first got it, there was a "chirp" sound coming from that bearing. I had the clutch replaced straight away (2003) with a new RMS and pilot bearing but the chirp came back pretty quickly and has been there all along. Of other note, one of the four mounting bolts broke when removing the trans. I've damn near melted that thing with heat, welded nuts to it, cursed at it, and soaked it in all kinds of penetrating liquid. It doesn't move. All 3 of the other bolts came out way too easy in my opinion. I think I'll be drilling this one out....

[DMC-81]

right so if the bearing is not snug in the housing, should I get an oversize bearing or replace the housing?

I think this problem has existed the entire 17 years I've owned the car. When I first got it, there was a "chirp" sound coming from that bearing. I had the clutch replaced straight away (2003) with a new RMS and pilot bearing but the chirp came back pretty quickly and has been there all along. Of other note, one of the four mounting bolts broke when removing the trans. I've damn near melted that thing with heat, welded nuts to it, cursed at it, and soaked it in all kinds of penetrating liquid. It doesn't move. All 3 of the other bolts came out way too easy in my opinion. I think I'll be drilling this one out....

The pilot bearing is not tight in the crankshaft holder, but if you are concerned about it slipping, you can use a bearing retainer ( Loctite 648 or similar).

[fmj78]

The pilot bearing is not tight in the crankshaft holder, but if you are concerned about it slipping, you can use a bearing retainer ( Loctite 648 or similar).

thanks for the tip. Once I get this broken bolt out, I should be home free.

[fmj78]

Well... I'm building a new engine now....


https://youtu.be/q4TVESHGyVc

[DMC-81]

Well... I'm building a new engine now....


https://youtu.be/q4TVESHGyVc

Oh man, that's unfortunate. I wonder if the block can be repaired by filling in the boss with aluminum (i.e. welded) and then tapped for a new bolt? I had a larger that a quarter sized hole filled in on my gearbox by a competent aluminum welder.

Still, the engine has to come out.

[David T]

If you can "salvage" the hole and tap it you should be able to get a threaded insert into it. If necessary you can screw a set screw into it deep enough so that you can still use a standard bolt. You may have to use thread sealer on the set screw or the bolt to prevent any leaks. All is not lost, at least not yet. Worst case, you oversize the hole, tap it for an oversize bolt, cut it off flush, and then drill and tap the bolt to get yourself back to standard. No welding. To make sure you are centered you may have to attach the transmission and drill or centerpunch through it with a transfer punch to mark your hole.

[Nicholas R]

Wow, this is a first for me. I've seen plenty of engines with bad rot in the valley, but never seen one leak through a bellhousing hole.

It's certainly possible that this might be able to be salvaged, but if you've got this problem here, it's likely you've got some other gems hiding throughout the engine. It would certainly be worth a thorough inspection.

Had you run this engine before?

[dn010]

Use sealer on the threads of this particular bellhousing bolt and you'll be fine. There are plenty of engines out there, especially old ones, that have bolts that go right into the water jacket.

[Bitsyncmaster]

Wow, this is a first for me. I've seen plenty of engines with bad rot in the valley, but never seen one leak through a bellhousing hole.

It's certainly possible that this might be able to be salvaged, but if you've got this problem here, it's likely you've got some other gems hiding throughout the engine. It would certainly be worth a thorough inspection.

Had you run this engine before?

I think he was drilling out a stuck bolt and went to deep.

[fmj78]

Wow, this is a first for me. I've seen plenty of engines with bad rot in the valley, but never seen one leak through a bellhousing hole.

It's certainly possible that this might be able to be salvaged, but if you've got this problem here, it's likely you've got some other gems hiding throughout the engine. It would certainly be worth a thorough inspection.

Had you run this engine before?

This was self inflicted.

The heater pipe was leaking (probably for a very long time), and made it impossible to free up the top passenger side transmission bolt. Decided to drill it, and had it made until I made the dumbest mistake of my wrenching life by picking up the drill again and trying to "hog" the hole just a weeeeeeeeee bit more.

the hole in the block is not straight back but down and to the left. I believe my only play is to do the tap and time-sert with sealant. I think the time-sert will cover the hole.

That was a really bad day of wrenching.

[fmj78]

I think he was drilling out a stuck bolt and went to deep.

wasn't too far, it was angle of attack. I was trying to knock down a little more from the top side of the bolt hole and the bit tip was pointed down. Very stupid mistake

[fmj78]

Use sealer on the threads of this particular bellhousing bolt and you'll be fine. There are plenty of engines out there, especially old ones, that have bolts that go right into the water jacket.

Definitely going to try that. It needs a tap anyway so I'll probably do a time-sert, sealer on those threads, and decide to use the correct bolt, or put a stud in that side with sealer.

[David T]

Pressure test it before putting the transaxle back together.

[fmj78]

Pressure test it before putting the transaxle back together.

Absolutely

[fmj78]

Thanks everyone for talking me through the problem.

I've brought in professional help on this one. He is going to finish the job of cleaning out the remaining bolt material with a die grinder, re-tap the hole (timesert as a backup), either put a set screw in behind the bolt or simply seal the transmission bolt with the same product he uses for head bolts that go into cooling passage by design.

I'm putting this story together as the most cringeworthy video in all of automotive YouTube.

[82DMC12]

Old thread but I found it on a google search while looking for my own answer to it. I have a similar amount of play in my input shaft after rebuilding the transmission (I know there was some before but I didn't take a video or measure it before disassembly). I sent a similar video Rob Grady who confirmed the play is normal.