Hey all! I'm trying narrow down a noise I'm getting in 4wd. Truck is an 87 4runner with SAS and stock 22re, manual trans. When I'm in 4 low or high and going more than 5-10 mph I start getting a steady grinding noise that will get worse with more speed. It will make the noise if the hubs are locked or free. I pulled the front drive shaft and the noise goes away. I have drained the oil in my t-case and front diff and didn't find any chunks of metal in either one. I put the front of jack stands and with the hubs locked I can spin the tires freely with my hands and nothing feels like it binding up. I'm just trying to see if anyone with much more experience than I have can maybe point me in the right direction before I pull and disassemble my t-case or 3rd member. Thanks in advance for any help.

update with further testing, I have the noise in 2wd with the front hubs locked and the driveshaft installed. If I remove the front driveshaft the noise stops with the hubs locked and unlocked. Im going to replace my ujoints to have that eliminated as a potential problem.

 

Well it is narrowed down to your front differential front drive shaft or the front axles

all parts from the swap ??

Just which front axle are you using and were things rebuilt or at least gone over before the swap??

 

I can't speak for the condition of all the axle internals because I bought the truck like this. Judging by the axle gusseting its probably an 84 85 axle. It has stock locking hubs and when I had the front up on Jack stands the tires would spin in opposite directions indicating an open diff

I'll double check tonight but I don't think I have the noise if I drive in 2wd with the front hubs locked.

 

Updating status. I have inspected the birfs and the front 3rd member and they all seem to be in good shape. I have pulled the t-case and opened that up and everything looks good in there and spinning really smooth. After reading about some things I am now wondering if its my driveline angles in relationship to my axle orientation and no CV shafts. My front pinion is flat but my rear is pointed up to my t-case without a CV.

 

Glad it's gone. I've got just the opposite. Mine goes away when 4H is engaged. Doesn't start until 50mph sounds like I'm driving with mudders on. I hope it's not front differential bearings.