a little bit of background first
its a 1990 4runner 3vze 192100 miles

front: 1.5 bj spacers, aisin manual hubs
rear: crusier coils, panhard drop yada yada
33/12.50 bf goodrich mts that are torn up and out of round

just removed the front sway bar and installed a 4crawler 1 inch diff drop

now at about 15mph there is a loud rattle a lot of vibration and the ocasional grinding feeling that all goes away as i speed up

the hubs are still engaging/dis engaging smoothly

lifted the front off the ground.. tires spin smoothy and there is no back and forth wheel movement that would indicate a bad bearing.. also the hub is warm after driving... not hot

the suspension cycles smoothly without rubing the tires


i cant figure it out.. my best theory is that im just noticing more of the tire vibration because there is a block of aluminum between the diff and the frame.

please gods of yotatech.. guess away.. any ideas you can give me would rock

 

Hmmm I think I have the same problem. Do you get it when acceling in reverse and braking hard? What I've been hearing you can only hear from the cab (my dad stood outside and couldnt hear it outside the vehicle when it was very loud inside). It almost sounds like metal scraping on metal but its a very odd noise. Its almost like my cab is amplifying it from the sheetmetal picking the vibration up...

 

i definately get it when slowing down more than accelerating.. but it makes no difference if im on the brakes or downshifting.. always at 15mph

 

some thoughts... are the diff assembly mounts oval shaped (slop in the mount bracket) that would be used (by service personnel) to align ujoint and cv joint tolerances?

 

i dont believe they are