First off, a little history.
This 4runner has 242000 miles on the body and axles. Freshly rebuilt 22R performance engine built by me. Transmission and drivelines off of a 1986 4runner with unknown miles from a junk yard. Front end was repacked and aligned when I got some new tires installed after installing the engine and transmission. The tires are used off of a 1993 Jeep Cherokee and have 1/4-1/2 tread left and may be worn to the jeep so that may be causing SOME of my noise.

One ujoint was pretty stiff, and was difficult to turn(like there may be something wrong with it). Some of the other ones were lose and turned super easy, also these could be MORE of the problem.

When I drive down the road, the 4runner runs really well, and is quiet and smooth until I hit about 55-60 and keeps getting worse the faster I go. It is most notable when the truck is going 40-60 and in neutral coasting or when the throttle is not open and not closed, in the middle area when you arent accelerating and not decelerating.

The noise is a rumble type vibration, almost a growl. It is unlike anything I have ever heard before. What ever is wrong with it causes the whole rear of the truck to vibrate really bad, something is definitely wrong. I cant tell for sure if it is coming from the front end and vibrating through the drive shaft and body, or if it is from the rear of the truck. My initial thought was that it was from the rear end, but the last time I drove it it sounded and felt like it could be from either. I also took it up to about 70-75 thinking it was tire balance issues and that maybe it would go away.

The best way to describe the noise is that it is almost like when you drive down the interstate with your hubs in, if not more intense. I also thought that maybe the garage that packed the wheel bearings put my hubs on bass ackwards and that they may be locked but I dont really think that is the case, either.

I think it is the rear wheel bearings because the front ones were completely shot and had to be replaced. There was, however, about a teaspoon of metal shavings in both the front and rear end oils which looked like they hadnt ever been changed. The metal was really really fine shavings, some of it was shiny like it was from bearings and the rest looked like it had been there for a long time. I couldnt tell if all of it was shiny or not because the oil was so dark and the shavings were really really fine. The truck was sitting for about 3 years prior to my purchase as well. The rear pinion seal leaks as well, which worries me that someone ran it outta oil and caused some rear end failure.

Anyone have any suggestions or had any problems with this before? Its a first gen first year 1984 4runner w a 5 speed trans out of a 86.

 

See web page below for some troubleshooting ideas:
- http://www.4crawler.com/4x4/CheapTri...FixingProblems

For sure fix the u-joints. They should move smoothly with no play at all.