TR4/4A Changing universal joints in a TR4????

[TR4]

Just thought I would ask this before I do something I shouldn't. How hard is it to change universal joints in a TR4? Getting the drive shaft out, switching the universals and putting it all back together. Mine is starting to clunk when you let off the gas or go from forward to reverse. I am a novice mechanic so please tell of all to watch out for. Your advice is greatly apprecitated.

 

[dan_k]

removing the driveshaft isn't a problem just remember to mark the flanges so it goes back together the same way.

 

[dan_k]

When you start removing the U-joints leave your hammers in the toolbox

 

[TR4]

I was told that the drive shaft can only be removed by taking out seats, carpet and the tunnel cover then going at the forward joint from above. I looked last night from underneath and it does look tight. Can it come out from underneath without all that interior work?

 

[Alan_Myers]

Hi,

Yes, you do have to remove at least one seat, the center dash brace, carpet and the gearbox cover. (I've seen modified, two-piece covers that make it a little easier, but would assume you have a one-piece cover.) It is impossible to get to the nuts and bolts from below. In fact, they are hard to get at in any event, you'll probably need to use open-end wrenches on them.

In fact, during regular service you need to be able to access the front u-joint from above - via a large rubber plug near the rear of the gearbox cover - to grease the u-joint. This doesn't require a lot of disassembly, but also doesn't give enough access to allow removal of the nuts and bolts.

If your drive shaft is clunking, it could be the u-joints or it's also possible the old nuts and bolts have gotten really loose. I found 6 of 8 were less than finger tight on my car not too long ago. Pretty scary, the thought of a drive shaft coming loose on the road and flailing around.

The original nuts were Nylock, and really shouldn't be reused in this application. At the very least, buy eight new 3/8" NF Nylock nuts.

I highly recommend going a little further and getting an upgrade bolt and nut kit that The Roadster Factory offers. It includes all-metal self locking nuts and grade 8 bolts. I found the bolts provided a little long for comfort at the diff and cut them down a few threads to increase clearance slightly. I also used Locktite on them just to be sure.

If you find the old bolts loose, the u-joints should probably be replaced as a precaution. The front splined section can be removed for cleaning, but must be re-installed in the correct orientation. There are arrows stamped into both front and back sections of the drive shaft that should match up when done. Inside the cup that screws on and holds the front drive shaft section to the rear is a cork grease seal that often falls apart during disassmebly. It's not available from any of the major TR vendors, but there was discussion here about it in the past and someone mentioned a source. I ended up making a seal out of sheet rubber that seems to work.

It's not a bad idea, too, to have the rebuilt drive shaft professionally balanced. You can probably find a local shop to do this.

There has been some discussion of good and bad quality u-joints in the past, so you might look in the archives of this forum. I fitted greasable ones, G&K if I remember correctly. Not sure where I got them, though. They had been on my shelf for 4 or 5 years.

They seemed well made and fitted nicely. The factory manual was helpful fitting them. Someone mentioned not using a hammer, probably good advice but unfortunately I didn't really have a choice when removing the 25 year old, non-greasable u-joints from my car! I was very careful to avoid damaging the yokes in any way.

Hope this helps!

Alan

 

[TR4]

Thanks so much for all this detail. This sure lets me plan on how long the job will take. I really appreciate you sharing your experience.

Phil