When I got this truck it had a lot of vibration. I drove it home about 120 miles. Noticed the driveshaft was dented...
I replaced the driveshaft with another from the junkyard. New U joints and it was balanced.
A lot less vibration now but still above 60 mph intermittently.
I'm going to get the tires balanced and change the tie rods, centerlink, swaybar bushings and end links before I take it for an alignment.
Really hope this frame damage isn't the cause of the vibration. Or maybe driving with the dented driveshaft caused some issues as well. I have no idea how many miles were put on it with the dented driveshaft.

Right rear

Probably why there was no rear bumper

Would an alignment shop be able to tell me if my frame is not straight? Obviously it is messed up but looks to only be the very end that is bent.

 

Here is a pic of the left rear for comparison. Looks like the truck might of side swiped something and clipped the bumper on the right rear. Just a guess.

 

You can call around and find somewhere that can put your frame on a machine.

Diy solution, you could get some squares on the good side and figure out good reference points to measure on both sides and compare.

The main issue is if your leaf hanger bracket is cocked, its putting a twisting stress on your axle so youre truck wont be track right.

 

it didn't sideswipe something; somebody wrapped a chain around the frame/shackle mount and pulled, hard. or got pulled out of a "stuck" hard.

 

Truck was probably lightly rear-ended at some point. An alignment shop can tell you if the wheels are still where they need to be. You'd need an auto-body shop with a frame machine to fix it. You can also make things better yourself, if necessary. Just need to get creative with winches, trees, bottle jacks, big pry bars and big hammers.

 

Driving today, I also noticed my shifter is vibrating while in gear. No vibration when I press in the clutch. So it looks I have more than one issue.

Well, I just received all my parts. 555 tie rods and a Proforged centerlink. Looks to be good quality. After replacing those parts I'll get tires balanced and an alignment. I'll ask the shop about the frame.

 

Oh, I already replaced the shifter bushing and changed the fluid in the diff and trans with redline. No change.
Makes me think the dented driveshaft caused a problem. Either with the diff or trans or both. Bearings? Transmission mount?
I'm determined to figure this out!

 

hope you used something other than redline MT-90 in your differentials. it’s great for the transmission, and can be used in the transfer case, but the differentials need a hypoid gear oil because of the contact pressure.

 

You're right. I used Redline MT-90 for the transmission and Mobile One synthetic 75W-90 for the differential.

 

Make sure the slip yoke is still tight in the back of the transmission. An out of balance driveshaft could have wore something there causing it to wobble some. Also check that the rims are still straight with a dial indicator. Something had to hit the driveshaft hard enough to bend it, and being 2wd it was not slow crawling. I would think it took a hit going off the road or something which could have bent a rim. You can also jack up one wheel at a time, spin them while watching carefully to make sure nothing else is out of round. Another thing to check is the transmission mount.

 

Not sure how much the driveshaft should move. I went under there and it rotates about an 1/8 of an inch. The slip yoke seems tight. No sounds from third member when spinning rear tires.
Checked the transmission mount and I don't see any cracks. If I push up on the transmission it moves slightly. Maybe 1/8 of an inch. Is that too much? Can it be tightened?
Haven't checked out the wheels or cheap tires yet. Rotating or balancing. They are new tires..Travelstar UN106 195/75/14. If I check with a dial indicator, how do I know if it is actually the wheels or the axle that is the problem? The rear wheels do make a weird sound. Maybe I need to grease the bearings. On the list.
Co 94 PU mentioned something about light trails and looking in my rear view mirror. Circles =driveline. Vertical =tires or wheel bearings. But my rear view mirror is so floppy that the test might not work. I'll try anyway just to see.
Shifting is smooth. I do have a very slight issue going into 3rd from 2nd but not going from 4th into 3rd.

Slip yoke

Transmission mount

 

that center bolt in the transmission mount is wayyyyy loose. should be snug. could very well be contributing to the vibration.

 

I just tried to tighten that center bolt but I'm worried it will damage something. The bolt sticks out and may be boring a hole in the transmission. Maybe I have use a jack to raise the transmission and then tighten that center bolt? Not clear in the fsm

 

I always thought that large bolt was suppose to be like that to keep things together if the rubber broke, but I could be wrong. I am also trying to fix a vibration on my '88 2wd pickup, so I am going to look into that more. Wallytoo: How would you go about tightening it properly?

If the dial indicator shows something out of round at the wheel, then you will have to keep measuring closer to the hub until you find the problem. I found a flat spot on one of my tires just by holding a yard stick next to the wheel while I spun it. Once you focus on a specific point, like the rim, you can see it holding steady with the nearest line on the yard stick. It looked like my tire was moving up and down, but the rim was not. A dial indicator would be way more accurate, but more time consuming.

I believe the slip yoke will need to be checked with a dial indicator mounted on the transmission, but I am not sure how much play is too much. I was told to do this with the driveshaft disconnected for better accuracy. I have not tried this on my truck since I was going to do a 5 speed swap anyway, so I cannot give much advice there other than I know it can be a problem.

I saw that post by Co 94 Pu on the other thread, and it sounds like an interesting diagnostic trick. I might try it myself. Try removing your mirror and see if you can tighten it up. If not, you can probably get one at the junkyard for cheap. It is worth finding out what the noise is on the rear axle, that might get you closer to the problem. The rear wheel bearings are sealed and need to be pressed on, but the fronts can be greased. Getting the tires balanced is a good idea. You could even try a Road Force balancer to rule out any abnormality with the tires, especially if they were cheap.

 

the bolt is loose, toyota didn’t have it like that from the factory. the reason it’s loose? could be the rubber cushions are deteriorated to the point they’ll no longer support the transmission.

 

I not sure tightening that bolt will help. I purchased a new mount from NAPA and the center bolt is a post.....no threads. When putting weight on the mount it will naturally push the center post out.
Maybe the OEM mount has softened up and compressed over time and I am unable to snug up that center bolt while the mount is being compressed by the transmission. Does anyone else have this exact mount (OEM) and the center bolt is snug? I have the W55 transmission. 2wd manual.

This is the mount from NAPA. It has a post for the center bolt instead of threads. When this mount is compressed, the center post extends out. The area I circled is where the rubber gets pushed down as seen on the OEM mount on my truck.

 

That makes sense. I was wondering about the mount on my transmission since it looks the same as J94's. I had been thinking that maybe the rubber has softened enough to cause a problem, but did not really know a way to test it. It sounds like that bolt could be the wear indicator of a weak mount? I don't think mine will get any tighter, but I will check again.

J94: Now that I am looking at it closer, the picture of your old mount looks like the bolt was torn away from the rubber piece on the bottom, yet the bolt looks like it cannot be any tighter up top. Post a pic of that new mount when it is installed. I am curious to see how far that pin moves, if at all.