86 300E - driveshaft rebuild questions
 

Back again with more questions -

I pulled the driveshaft last weekend and looking at the u-joint today I find that it seems to have a "detent" in the central position, i.e. it takes additional effort to deflect it away form center in all four directions. There doesn't appear to be any looseness or roughness, however, throughout the limits of travel. I have noticed a mild low frequency resonant drone at freeway speeds. Could this be due to the u-joint?

Though it's not normally a serviceable part I understand that some driveshaft shops can install a new u-joint in these and rebalance them. Can anyone recommend a place in the L.A area of So. Calif.? Otherwise, are there any recommendations for online suppliers? I've found a couple so far; Driveline Service or Portland rebuilds them with a greasable, replaceable u-joint, and I'm waiting to get a quote from them, as well as some information on lubing requirements and whether the new joint is staked or if they cut a circlip groove or something. They warranty for 5 yrs. or 50K mi.

The other one is Driveshaft Specialist, Inc. and they replace it using a sealed u-joint. They claim that the greasable ones require lubing every 5k mi. to get any useful life out of them which would be impractical on the MB. They have a good comparison of greased vs. sealed u-joints on this page. They warranty theirs for one year, but with unlimited mileage, and state that thier joints typically last upwards of 125k mi. Their price is US $329 - $374, incl. a new center bearing and carrier, UPS ground shipping and the $60 refundable core charge.

Does anyone have any direct experience with either of these firms, or opinions about greaseable vs. sealed u-joints?

Thanks

Gary

Before you go to all that trouble and expense, you can probably get the vibration out of it, by simply putting a washer between the carrier bearing bracket and the body on both bolts. This moves the position of the u-joint just enough to get it away from the worn spot and will usually do away with the vibration.

Good luck,

you didn't say what kind of shape the rubber flex joints were in, I have torn them apart before, my 83 300d I did and used parts from performance probably 10 years ago, a pain but not impossible, my 86 I did the flex joints only at 125000 so far so good now 139000

He didn't talk about the flex disks because he has found the "notch" in the u-joint. That is clearly the cause of the problem.

Have a great day,

The universal joint on my car's driveshaft behaves similarly. It's looser in the center (in the range of angles in which it normally rotates when installed in the car) and tighter if you move it to a greater angle (outside the typical operating range). The transition point between the loose and tight zones is noticeable, but this behaviour doesn't seem to cause any problems or noise that I'm aware of - are you sure it is the source of the noise you mentioned?

Unfortunately, I can't be sure unless I change something and the noise/vibration either goes away or doesn't change. :confused: It's just that I've got it off right now, I'm doing an extensive amount of work on the car and I'd like to take care of as many problems as I can before it goes back together. Pulling it off again at a later time isn't a major obstacle, but I'd rather be driving the car and enjoying it for a change instead of continuing to chase down problems. I think I'll recalibrate my fingertips and go back tonight and wiggle it around some more and try to figure out if there's any discernible play in the bearings. If there is, I'd rather repair/replace it now and not worry about it for another 150K mi. :cool:

I'd still like to hear about anyone's experiences with rebuilt driveshafts or these two specific companies (or any others you might know about) and opinions about sealed vs. greasable u-joints.

Gary

The front was replaced at about 130K mi. and the rear is still in good shape; no rips, tears or looseness that I can detect. I'm planning to replace it during this teardown since I've got it apart anyway.

Gary

I have used driveline service in las vegas for my truck and had good luck, but I don't know if they are related

I would not recommend just any old driveshaft shop for this particular shaft. It needs to be someone who has done them before.

I used a driveshaft shop in Arizona. I think the name was Bejer. They only do work for commercial shops, so if you don't have a shingle hanging outside the door you will need to find a shop to get it done for you. Their work is first rate. Most shops that do the joint on these shaft use an American car u-joint from an early sixties Ford Falcon. Bejer uses a much stronger joint.

Good luck,

I can help...
 

With the finger recalibration - 5 on the left, 5 on the right (LOL) - sorry, had to do it.

This is way over my head, but I'm going to follow it - I learn a lot from you guys - my Indy actually appreciates my having a half-assed understanding of what he goes through to fix a problem I might have. He appreciates that I can understand what he goes through to get there.

Sorry for the hi-jack.

Kevin

Gary,
I don't believe your drone is caused by the driveshaft. I'd look elsewhere. If you are experiencing a slight lock in the center position, it is normal. It means that your driveshaft is on its way out, but still serviceable. A u joint unlike a CV or Rezeppa joint increases and decreases speed as it rotates. This constant speed change dependant on angle hammers on the needle bearings on the sides of the joint and doesn't affect the top and bottom bearings. When you rotate the joint, it is very free from side to side, because the bearings are worn. The bearings on dead center appear stiff, because they are not worn. If you feel a catch anywhere off center you have problem, and the joint needs to be replaced. If you insist on having the joints replaced, PM me and I will supply several #s of top quality driveshaft rebuilders. If you want cheap, I can't help you, because I don't go that way. I also would not fall for the crap about greaseable fittings. Think about it. The first set did about 200k without grease.

Peter

As an addition to my previous post, you need to feel the detents with the front piece removed. If you look carefully, you will see alignment marks which if IRRC are in the shape of triangles so you can reassemble in proper order.


peter

Let's see..um, 1..2..3..4 on this side and, um, 1..2..3..4..5..6...!!! :eek: Damn, no wonder...!!

Don't worry about it Kevin. That's how I learn too; ask a few questions and listen to a lot of answers. I used to turn a wrench for a living when I was younger and I've been doing it on all my own cars and bikes ever since. I know I can always learn something new or a better way to do a job by keeping my eyes, ears and mind open, and I haven't been disappointed in this forum. I often try to post my questions so that (1) they're easily found in a search and (2) they'll get a variety of (hopefully) in-depth answers from people who have had experience with the subject. That way I figure a lot of people can benefit from it now and in the future. I've learned a lot from this forum and I try to contribute when I can, but right now the score is like, forum - 1000, Gary - 10. It's great to have a place with so many knowledgeable people willing to share what they know solely for the purpose of helping out their fellow MB enthusiast/owner. Gee, makes ya feel kind of warm and fuzzy all over, doesn't it?...Oh, wait a minute. That's just the stuffing coming out of my seat cushions! :D

I realise from your description that there is wear in the driveshaft universal joint. I also know from his previous threads that Larry has had considerable experience with driveshaft issues. If however despite this it is not the driveshaft, you may like to consider a situation I had some years ago. Admittedly this was a problem with my 107 not my 124, but I also had a drone or a hum that was obvious only at highway speeds. Everyone suggested a driveshaft problem but I was not convinced. The drone or hum apart from being slightly audible, could be felt slightly through the steering wheel. It certainly was nothing like shimmy due to a wheel balance problem. The problem turned out to be worn front wheel bearing. No wear was apparent with the front of the car raised and rotating the wheel and nor was any vibration noticeable at low speeds. Only when travelling at around 110km/h (70mph) did it become noticeable. New front wheel bearings fixed the problem. This may be worth exploring before diving into the effort and expense of a driveshaft repair.

Thanks for the good info Peter. I'll PM you with my email addy. I think I'll probably go with replacing it now rather than later. I plan to run some Monte Carlo style rallyes when it's back together, and they often involve some rather "spirited" driving, the type where I definitely wouldn't want the driveshaft to be giving me problems. I agree with not going cheap, but I do try for inexpensive when I can. :rolleyes:

Gary