When I apply light throttle or smoothly come off of the throttle, I hear a grinding noise that sounds close to the shift assembly, though tat part may be irrelevant. It basically sounds like gears grinding. I thought that it was the tranny, but I replaced it and still have the problem. Any input would be appreciated.

Specs: 1995 4Runner, 3vze, r150f (was auto tranny).

 

Has anybody experienced this? It is only noticable above about 55 - 60 mph.

 

What do you know about the 5 speed used in the swap? May be a transmission bearing or rear diff pinion bearing. If you have oil seeping from the pinion seal, look there. Can always put it on jacks and load it using your brakes as needed to isolate the noise. A really long handle to reach under the truck while things are moving will likely point you to the culprit. Put tip of handle at your ear and listen to those two spots.

 

Both 5-speeds are ok. The first one had some problems with the casing. The second one is fine, not leaks. Same noise with both trannies. There is just a bit of play in the rear u-joint, but not much...

 

Did you ever find out what the problem is? I am having the same problem in two of my vehicles, 85PU and 85 4R. I had an R151F tranny rebuilt and it has made that noise from day 1. I swapped out the tranny for a different R151F with different t-case and same noise. I swapped out the rear, same noise. I swapped the 22r motor for a 93 22re motor, same noise. I’ve changed clutches and flywheels, same noise. I’ve also tried different driveshafts, same noise.

The 4runner, I had the tranny rebuilt by same shop. No noise for 20K miles, now it makes the noise. I would really like to know what is.

Thanks

Chris