So, about 1.5 months ago I did a 3inch drivetrain lift on my 87' 4runner. It was fine for a while, then on the way home from my first wheeling trip with it, the tranny started whining in 5th gear. It got worse and worse, and eventually it sounded like a coffee can full of rocks in 2nd, 3rd, and 5th.

At this point I swapped the 5spd/t-case out of my 89' Pickup which never made a single noise. within 25 miles of driving with the "new tranny" 5th gear started whining again. I refilled the tranny with synchromesh and it's still doing the same thing...

Has anyone ever had a problem like this before?

 

Is your driveline too long?

 

3" Drivetrain lift? What did you do about the bad driveline angle it created?

 

Just a thought... I can only assume that you disconnected the driveshafts while you did the work. Is there a possibility that the driveshaft separated at the splines and turned slightly? Have you noticed any unusual vibrations while moving? If the u-joints aren't in line with eachother on both ends of the driveshafts it can tear a tranny apart pretty quick. Even one spline difference could be enough. Just something to check... It definitely seems unusual to have the same issue in 2 different transmissions. You need to look for an external cause. Can you be more specific on what exactly you relocated?

 

yea but wouldnt the vibs just tear up the bearing on the output shaft on the t-case? and not hurt the tranny itself?

 

A drive train lift won't necessarily make the drive shaft angles bad. It will steepen them a few degrees, but if you lift the drive train equally front and rear, the driveshaft alignment is preserved, assuming a stock rear shaft:
- http://www.4crawler.com/4x4/ForSale/MotorMount.shtml

I've run a 3" d/t lift for about 7-8 years now and have not gone through any transmissions yet.

 

yea, i thought about that after I posted. But if only the back of the tcase was lifted and not the engine itself, it can cause a steeper angle than just the 3 extra inches

 

Well You would almost think that the transfer case would let go first, but consider the massive size difference of those bearings. The tiny little needle bearing between the input shaft and output shaft can't take very much abuse compared to that great big bearing on the other end. Once there is any amount of flex between the output shaft and countershaft, synchros don't take long to shred themselves. Like I said just something to consider. We don't know if the engine was lifted as well which could definitely be a factor. Is there anything binding on the shift levers? What else has changed? Was the driveline stock to begin with?

 

But then again, it could just be a completely random coincidence....

 

The input bearings on Toy 5speeds don't last. I think it is just a fluke that they both went at the same time.