drive shaft (propeller shaft) U-joint rumble?

Looks like I will need to replace at least my front driveshaft U-joint. I get an intermittent rumble from under the car when I let up off the accelerator at 30-50MPH and I notice that the front U-joint has easily visible side-to-side play in it.

It certainly looks like an easy enough job to unbolt the front and rear flanges and drop the whole shaft to do the replacement but seems I recall folks moaning about this chore.

Am I missing something?

Ren
1977 MGB

Dropping the driveshaft is easy.

Changing the U-joint is a different story altogether. :D

However, do NOT put it off, if you have noise and visible movement then total failure is not far away.

I've don't know how many u-joints I've installed in my time but my MGB was the worst I ever tackled. Unlike others I worked with the yokes have no squared off flat surfaces to press against and it makes it shear hell pressing the new caps into them.

Save yourself some grief and take it to an auto parts store's machine shop and let them do it.

Just get a piece of pipe with an inside diameter just larger than the cups and that will sit on the yoke. Cut off a short 3/4" or so lenght of it at a slight angle to match the angle of the yoke. Then chuck that in the vice to keep the yoke square.

What else, besides u-joints could cause the rumble Ren describes? Assuming the u-joints are good....

I just bought two joints from Moss and dropped the shaft off at a local shop. like said above, I tried to do this myself once. Once.

I just pulled the drive shaft off and checked it over. It seems that most of the play is actually in the slip joint/spline :S

I'll bring the drive shaft to the machine shop tomorrow and see what they think, but I am starting to smell a new driveshaft in my near future.

$174 at Moss. Would another supplier be a better bet for this assembly?

Ren

Replaced joints once, not again, next time to a machine shop.

If you have to replace shaft, try Trader forum here, might save some $$.

Just replaced the u-joints in Kathys LE not too long ago and dont have a problem with doing it again if need be. But then again I like root canals too.

Hey Ren, I just so happens that I replaced both my U joints a couple days ago. I can agree with the others here that it is kinda hard, but not too difficult. Its true that one side of the yoke isnt square, which makes pressing the cups in hard. It took me about 1 hour to press in both joints (not including the removal of the shaft). I had to kinda rehearse the assembly though. I am always worried one of the needle bearings are going to fall out before I get the cups in far enough on the joint. I used a 1/2" socket and 4.5" vice for mine . If paying someone extra money to do it for you isnt an issue I would do that. I myself like to save money anyway I can and I usually will try things twice before I learn the hard way. Good luck, Mikek

Just did mine today (yesterday). New shaft assembly from Moss! The joint grease fittings are smaller than I would have liked but they are there.

My front flange was hurt and it sounds like yours may be as well. The joint would move in the yoke as opposed to the joint being bad as in needle bearings shot. The yoke and pline had wobble play in it as well. The fit was perfect and it sure solved several of my pretty obscure problems.

Hi James-


It is not a matter of the slip joint being too tight, but rather too loose.

Unfortunately, it seems that the splines and yoke are just plain worn out from 93,000 miles and very little grease.

Anyhow, I'll just throw money at it and it will get better :eyeroll:


Ren