Engine/Transmission (1994 - 1998) rear end fluid

[gjacobs]

Whats the best fluid for the buck to put into the rear end? I am 99% sure but will find out if I have limited slip!

 

[redram]

If you pull anything over 5000 poiunds, I recommend that you use a GL-5 rated 75W140 gear oil. A synthetic will give you better low temperature flow and better high temperature protection. If you have a limited slip, then the oil should have the proper friction modifiers built in or you can add the Mopar additive.



One such product the fits the above is Royal Purple MaxGear 75W140. You can get it at some Napa's, North Texas Lubricants in Dallas, or on the net at Jegs.com amoung others.



Less than 8 / qt I believe for a fully synthetic with the friction modifier already formulated into it.

Been running it for plus 100K in my 96.

 

[gjacobs]

I appreciate the info redram. That is exactly what I was after!

 

[JJW_ND]

75W90 Full synthetic does just fine.

I don't think any problems would occur with a high quality 75W90 full synthetic like Royal purple, Amsoil, or Mobil.



I have run this for over 200K, changing and oil testing every 40K or so. Hotshotted the first 5 years. Many trips pulling 60+ feet of trailer in summer heat and high winds or -30 and winter snow and ice.



Right rear seal changed at 14K. Changed to synthetic at that time. Seals still all stock, bearings still fine. Wear metals are almost non existent in every sample. LSD is still as tight as the day it was new.



Hotshotting in the deep south with 400+ hp truck would probably require 75W140. But for normal use, normal trailering upto and including the max GVWR, I think 75W90 is more then adequate. It is also much better for us northern users for day to day use.



jjw

ND

 

[Dennis Garrett]

My 3:54 ltd. slip shot craps at 160k. I changed the original fluid at 30k to Amsoil 75-90. At 60k, it still looked clean, but I changed it anyway, again with Amsoil 75-90. I decided to go 100k this time, before I changed it again, but both carrier bearing races & roller desinegrated at 160,000. The fluid looked like it had silver spray paint in it, and the big magnet looked like a grey, metallic donut. Of course it put some wear on the ring gear & pinion, it's bearings, and contaminated all four wheel bearings. I replaced all the bearings, and put all the shims back in the original position. Runs OK now, but has some backlash I need to get adjusted out. I can jack both wheels up off the ground, and put it in drive, and it rumbles up through the bed. I'd put in whatever oil you you want in it, synthetic or real, but change it every 50k. For price, I went with 85-140 Royal Purple this time, with Chrysler additive. The "Purple" says it already has the additive, but mine still chatters with out the Chrysler stuff.

 

[gjacobs]

man jjw-nd what you have driven through sounds like something that you would read of in a Stephen King book!



I am from the land of never getting below 20 degrees, or at least not for more than 2 or 3 days or more. Anyway thanks for the advice on the fluid. For the every once in a while 10,000# towing that I do I looked around and for half the price of royal purple I think that the mobil 1 synthetic will do allright for now.

 

[JJW_ND]

We by no means have the corner on Cold. Just a part of the winter months up here like many other places. Really tests oil, seals and the like with daily temps going from rock stiff when below zero to operating temps in a matter of minutes (well maybe dozens of minutes).



Something that makes us feel good is you can always put another coat on the get warmer but you can only take so many cloths off to cool down. I will take a dry windless -20 over a 90% humidity - 90 degree day anytime!



jjw

ND