Engine/Transmission (1998.5 - 2002) Rear differential shudder

[markgrif]

Hi Guys,



I changed the rear differential lube to Mobil1 75W-90 about 300 miles ago. I've got 5000 miles total now. Yesterday, after driving to work and having the truck sit for 4 hours, I backed out of the parking space (while turning) and got a vibration/shudder from the rear. For about 2 minutes every time I turned I got it, then it quit. This morning same thing. I checked the fluid level and it's correct. I did add the 6. 5% extra stuff DC says to add for a limited slip. I MAY have a vibration all the time. I can't really tell, but the problem when turning does go away in 2 minutes or less. Checked the tire pressure. It was may low yesterday but same thing this morning with correct pressure. Any ideas? Also - I do tow a lot but nothing since the fluid change.

 

[lschultz]

I see you added the modifier so. Trying doing a few figure 8s and see if that helps. Sometimes it just needs to get worked in good. If that don't work trying adding a little more. Just add some and drive it. Keep adding it to it cures it. Is this a synthetic oil?

 

[markgrif]

Yeah - I ordered this from www.mobil.com - only place I could find it. My manual says use 75W-140 but DC said it used the Mobil1, which is 75W-90.

 

[Texasdeere]

I have the Amsoil Series 2000 75w 90 oil in mine, and it shudders the first couple of turns I make when the rear end is cold. I wouldn't think you would need wery much additive with a synthetic oil.

 

[markgrif]

I didn't either but they said they added it so, thinkin warranty, I added it too.

 

[A. Brown]

yea, I added one bottle of the oem friction modifier, no problems at all, got the mobil 75w90 also

 

[Mundgyver]

I am curious as to why the friction modifier would be needed. You put in a synthetic to make a longer life and then add the friction modifier. Does this not defeat the purpose of the synthetic that you just spent $$ on What exactly does this do with the limited slip differential. I'm not running one, but I am curious as to the above. Thanks in advance for the explination.