Driveshaft Issues?

#1

Today I got the rear crossmember, trailing arms and chassis mounts/bushings out - what a job! Thanks to this board I was edumakated and it went smoother than if I never read the “tips” on how to…

I pulled on the driveshaft and it seems it is two pieces, I have the rear section out and this prompted some questions/concerns.

First of all, has anyone had any issues with the drive shaft U-joints or anything related??

I noticed there is a rubber disc that connects the front section of the driveshaft to the transmission yoke - is this a common failure point?

In summary, while I have the rear end, transmission (clutch job) and drive shaft out, is there anything I should address in the name of making this car more reliable? …or is that driveshaft “bullet proof”??

FWIW, the U-joint in the rear section of the driveshaft seems to be OK.

#2

did you mark re-alignment marks on the two halves of the driveshaft before you separated them? They are matched to be balanced as a pair. I just had mine rebalanced and had the rear U-joint replaced because it was sticking.

check out www.pelicanparts.com and look for the tech articles.
Were you noticing any strange driveline vibrations before you started disassembly?
The rubber donut near the tranny is referred to as a guibo - look for whether it is disintegrating. The center bearing can also degrade and is relatively easy to replace while you have it all apart like this.
cheers,
bruce

#3

Ah crap, no, I didn’t mark anything.

I had gotten the Differential out and figured it would be easier to drop the crossmember with the driveshaft out of the way and assumed I would just pull the whole unit out, sliding the yoke out of the transmission…what I wound up with is the rear section. :ohmy:

So now I should get everything rebalanced as a unit when I have the forward section out then? I have heard of the “guebo” and that’s probably why I asked the question…will probably just replace that thing as I’ve heard others have had issues.

Thanks for the tips on that, will probably get a new driveshaft bearing as well.

WHERE did you get the U-joints for the driveshaft and did you just do them yourself? …if so, I see they are “dinged” into place by several marks around the I.D. of the U-joint sockets - so, are the U-joints fairly easy to take apart with a press and reassemble, then “ding” them to lock them in again??

Thanks again for any more advice/tips you can give…it’s been quite some time since I’ve dealt with a driveshaft. :S

#4

I have always understood the U joints to be non repairable but a driveline shop should be able to replace them in some way.

Do all the seals on the trans and definitely replace the “T” shaped part the connects the shifter rod to the trans selector shaft. make sure you get the little felt piece that fits inside.
since it is all apart replace the center bearing and the guibo. Make sure when you order the guibo, that you make sure of the build date of the car since there are 2 different part numbers.

#5

I had the rear U-joint replaced and then rebalanced by a place called “Driveshaft Doctors” locally - doesn’t look like a DIY job.

Check out a parts picture on realoem.com and make sure a P.O. didn’t scrimp on replacing all the parts (e.g. center bearing dust shields, clamping bit inside the collar at mid-driveshaft, etc) My donor car actually had the wrong center bearing installed, which solved my driveline vibration mystery…
thanks,
bruce

#6

leggwork wrote:

[quote]I had the rear U-joint replaced and then rebalanced by a place called “Driveshaft Doctors” locally - doesn’t look like a DIY job.

Check out a parts picture on realoem.com and make sure a P.O. didn’t scrimp on replacing all the parts (e.g. center bearing dust shields, clamping bit inside the collar at mid-driveshaft, etc) My donor car actually had the wrong center bearing installed, which solved my driveline vibration mystery…
thanks,
bruce[/quote]

Oh yeah…there are also 2 different center bearing part numbers…

#7

The “guibo” is referred to in the Bentley manual as a “flex disk”. (Get the Bentley, by the way. You’ll be glad you did.) When you replace it, you should really order new bolts and nuts. The elliptical thread locking nuts are only intended to be tightened once and the bolts are subject to a lot of shear stress.

When you put the new ones on, check the torque specs in the Bentley - you should get class 10.9 bolts (I got a set from bavauto, I think) but the may send you 12.9’s. Torque 'em right and don’t use class 8.8.

A guibo coming undone at 100mph is not a pretty thing. I know. :wink:

#8

If you have not done so, buy a Bentley manual.

If you replace the rear trans seal, follow the directions in the manual PRECISELY. Be generous with the sealer and put it everywhere on the output shaft flange they tell you to or it WILL leak. Gear oil really stinks when the exhaust burns it off.

:dry:

#9

Thanks again for the tips.

I concentrated on the NASTY job of getting the bushings out of the crossmember and trailing arms this afternoon - while the crossmember was not that fun, being that I had to grind a groove into the steel retaining rings to pop them out, the trailing arm bushings were PURE fun with the help of a Map-gas torch. :laugh:

I think the EPA will have a notice on my door tomorrow though. I figured out a pretty good trick to get them out…the first one took about 15min. the 2nd, 3rd and 4th one took 15min. altogether. :slight_smile:

Sean (AKA NASA Registrar / Buddha) do you have the part#s for each build date? Is there an easy way to tell the build date from the VIN#?

Sorry for so many questions, hopefully I will be the one answering some questions here sometime soon - I just want this car done right the first time.

What transmission gaskets do you all speak of? …just the main shaft and output shaft seals?? If so, no sweat. I have some shifter parts as well, the nylon “ring” bushing and a rubber boot - you say I should replace the “T” mechanism and possibly that swivel connector jobbie? (mini “U-joint”)

I’ll get a chance to checkout the Guibo, center bearing and associated pieces/parts on Friday, tomorrow I have to take another “project” over to the paint shop. :dry: