I have a 1991 w250 4wd, 5 speed and I am trying to diagnose two problems, and figure out if they are related. I will try to describe the symptoms with as much detail as needed. Longtime lurker here, great community thanks in advance.

1.) Occasionally, when I am taking a sharp turn (seems to me I usually notice it is a left turn) my steering will come out of alignment and the truck will not drive straight, it will veer left and then veer back to the right and will not track straight. If I stop the truck, turn my steering wheel all the way to the left and back to the right you can feel a very very slight 'pop' and the issue will (mostly) go away. However, the other day it happened in traffic and it was worse than before---not fun, let me tell you! I have inspected all the ball joints, tie rod ends, steering rod to gearbox connections, and everything appears normal to me. I have been unable to recreate the problem in the shop. I am going to make sure all my u-bolts on the axle and every other front end bolt is torqued appropriately and go from there. Any other tips would be appreciated.

2.) As I come to a stop, I hear a groaning noise and vibration. Either depressing the brake pedal or slightly raising the rpm will make the sound go away. I thought it was the rear drum brakes so I just replaced the calipers and got everything adjusted, but no change. It occurred to me recently that a worn front wheel bearing might be responsible for problems 1 and 2. Wouldn't that be lucky?


Thanks for all help,

 

The popping while turning and it veering makes me think that one or both of your D60 4wd axle shaft U-joints are seizing up.

The groaning and Vibration....that's a tough one without being in the vehicle. But when was the last time you had the front hubs off to clean, inspect and repack the bearings...with a new inner hub seal as well.

 

Might want to also check the frame for cracks where the steering box mounts.

 

I agree with both TC and Jugg. I would say you have multiple problems and time for a major maintenance adventure. Start from your transfer case and move forward leaving nothing uninspected thoroughly. Take things apart. Grab and shake doesn't reveal all the problems. Keep in mind that one problem will transfer problems to other items. Check your leaf springs and spring frame mounts. Jugg mentioned the steering gear box. The backing plate is a common fail point, but don't forget the frame its self. You have a lot of work ahead of you. Take your time, take notes.

 

Hello all - late to reply but I hope this helps someone else.

I don’t know how I missed it for so long, but it was the front drive axle universal joints. It was a bit of a pain in the *** rebuilding and repacking the wheel bearings, but the ujoints were fried and binding instead of turning freely. This severely interfered with steering about 50% of the time when the ujoint was in the wrong position on a turn, which explains why it happened sporadically.

one day, I forgot to put the Hubs in the free position and take it out of 4wd and I suspect that’s when the bulk of the damage ocurred.


Remember to grease them regularly!