Had clunking noise on deceleration. Drive shaft hanger bearings both pretty shot. Leaking rear diff pinion flange seal. Removed drive shaft to replace center hanger bearing carriers with OEM. Found both UJ’s had flat spots on them so looked into replacing them as well. Then the problem started…No replacement UJ’s available (never were available, driveshafts are throw away replacement items!).
3 problems: (1) UJ’s are permanently factory “staked” into the yoke housings (no circlip retainers etc);
(2) the UJ’s are solid; (3) the UJ’s are an unusual size (something like 24.8mm give or take) and unobtainable in that size.
So they’re not something that can be swapped out for new ones in your garage.
Solution: Need to find drive shaft specialist that can not only do the re-engineering and replace the parts but also has the equipment to balance the entire multi-part drive shaft complete.
Only UJ’s available that are close to size, are 25mm ones from a Mitsubishi Triton. These are hollow with grease nipple (which long term is probably better concerning wear) but have inherent weakness (due to hollow grease channels running through their core). Engineer was not entirely happy with this, (and the fact that the yoke holes need enlarging which also raises strength concerns) but there is simply no other option, and is likely to be fine for non-modified roadgoing TT’s (could be problem for higher horsepower modded cars and racetrack??).
So, over $1000 later for the driveshaft repair , plus a few more $'s for the parts (including new central CV boot kit because that has to be pulled apart to get to the central carrier) I will put this back in over the next week or two (currently have Covid…real bummer) and get car off the axle stands and road test after 12months off road for various rebuild/restoration jobs, and hopefully the clunking will be sorted. Diff lash looked OK and I can’t see any other obvious rear end problems, but we’ll see…