I could use some help dignosing a tranny noise.
A little history..
Vehicle is a 1985 4runner, with 3" lift. I put in a used R151F tranny from a wrecking yard and it worked fine with no odd noises or vibrations etc for about a year. Then on a local run I lost 3rd gear (would not stay in).
So I pulled the tranny out and rebuilt it with Marlins HD bearing retainer plate, and all new bearings, seals, and synchros.
Everything was working great. No noises or anything. Quiet, and shifted perfect with redline MTL.
next day I'm driving in 3rd, and I hear a noise, kind of like the sound you hear when your tire kicks a rock up into your fender well. Immediately, I hear a "rattling" noise. I pull over, look everything over, and all looks good.
When I drive away, the tranny drives normally, and I don't think much of it until later I get on the freeway, and notice the "rattling" noise is there when I am not in gear and coasting at highway speed.
Clutch in or out does not make a difference, but when I move the shift lever like I am going to put it in gear, the noise gets quieter.
So I drain the tranny fluid out through a linnen cloth and inspect the drain plug magnet - no excessive debris.
Later in the week I go on a trail/camping run and drive about 50 miles or so in low range, and everything is normal. (not going fast enough to hear the "noise") When I get out on the highway to go home I notice the noise still there when coasting at highway speed, but is also now audible when I am in 4th or 5th gear, when I am barely touching the gas. (not accelerating or decelerating, but in the "middle")
So I drain the tranny fluid out through a linnen cloth and inspect the drain plug magnet - no excessive debris.
I know I am going to have to pull the tranny out and take a look, but I am not sure what I should be looking for. Sonce the trannie still operates "normal", I am not sure I would see anything, especially since I am not that familiar with these trannies.
The only thing I can think of is maybe I have a problem with a needle bearing, since these are not included with the rebuild kit and I used the old ones.
anyone feeling charitable enough to help?
