I recently put 75-90 GL5 gear oil in my transfer case from Redline. Now when I shift from High to Low or low to high I get a chatter/grinding feeling in the shifter on the transfer case. Since the truck is new to me I cant say for sure if it was happening before I changed the transfer case oil.

Should I switch it out for a GL4 oil, like the redline mt-90 or? Any suggestions would be great.

(btw, its a 97 3.4L 4runner 4x4)

 

Not sure about 3rd gens but GL-4 definitely works better in 2nd gen gearboxes and transfer cases. The GL-5 is too slippery for the synchros. I would try the GL-4, Redline MT-90 seems to work well.

 

I've been running Mobil 1 75w90 GL-5 Synthetic gear lube, in the diffs, tranny, and T-case of my '97 4runner, for the last 8 years. No problems.

 

It is normal to get slight grinding when shifting into and out of 4Lo. The amount of grinding will vary with the speed you are driving when you shift. I find it grinds less if I'm rolling forward slightly when I shift (you shouldn't be shifting into 4Lo while moving any more than a couple of MPH anyways). Like 02SE in the above post, I run Mobil 1 75W90 GL5 all around.

 

Its doing it when I am at a complete stop with my foot off the brake. I'll give MT-90 a shot. Its only a $16 experiment.

 

I use Red Line 75W90 for the diffs and transfercase. I get no grinding except when I shift to L4L and the tranny is not in N.

HTH.