So a few dumb things have happened:
1. When i lifted the truck a year ago, the driveshaft angle change instantly killed the u joints. No big deal. New joints and a balance, all was well.
2. Drive 10,000 miles and then just recently drive 1500 miles at 70mph going to big bend. On the return trip the truck develops a nasty vibration at speed. I feel around under there and the bolts are finger tight. Two backed out a bit but I didn’t lose anything. Tightened them up but something doesn’t feel right 75% of the vibration is gone.
3. Buy another set of oem u joints and pull the driveshaft. Take it to get rebalanced. They say my matsuba u joints are out of spec, they suggest neapco and I’m not in the mood to argue. He also notices the front flange on the driveshaft is warped. Seems reasonable and i can see obvious wear from where it was loose during the road trip. It had material transferred over and peppered in metal. He suggested that he was able to “straighten” it. I go about my way and he suggests finding a new flange. I Also had 4wp balance and rotate the 33’s. Made a huge difference in noise at speed. Worth the $20 in parts every 5,000 miles to keep the truck quiet and smooth. I have a little bit of regret for not buying the km2’s but not a big deal.
4. The new driveshaft has maybe 3000 miles on it. The front u joint is dead. I’ve got play on both axis. My hum is still there. I try something that a wise man told me and i drop the driveshaft and tighten the output flange down on the tcase. I get a little more than a full turn from the staked nut! Reinstall the driveshaft and things get better. The ds isn’t flopping around as much but there still is a hum at 70mph and doesn’t feel 100%.
5. Purchase a used rear driveshaft from eBay and use the second set of matsuba u joints from the first time. Dropped it off at the Ds shop and asked them for pity. I don’t think that the matsuba joints were bad, I think the flange was out of tolerance from all the fatigue of moving around and it stretched unevenly. Dropped It off yesterday and I’m gone for a week for work, waiting for a call to pick it up later.
I think I left it get loose the first time which killed the u joints, warped the flange and loosened the output shaft bolt. Now let’s see what happens.
I expect to get a DS with no play in the x or y axis and I’m only buying time until I go buy an H55f and t case from Georg in the coming months. 297,500 miles on it with what seems like an original transmission and t case. I’ve got the trans leaking into the t case but it’s a slow leak and Manageable.
Old truck problems rule, no regrets about driving this vibrating heap of rust daily.
