Mopar Nats and rear diff fluid....

[JGabl]

Towing one buddy's new trailer and another buddy's tubbed 340 Duster to the Mopar Nats in Columbus, Ohio, the end of next week(about 8 hrs from Ill. ) Going to be loaded with tools, grub, gear and beer. The stock rear diff. still has the stock gear lube(10,000 mi. ). Do you think I need to change this and if so, which brand should I use and why? I do have limeted slip, so I know i need to get the hypoid friction additive. which brand of this and why also... . Any other 'trip tips' would be appreciated besides my usual fluid and safety'once- over'. Thanks in advance, Jim.

PS- MOPARS RULE

 

[Alan Reagan]

You'll probably find that at 10K the diff fluid is pretty black with some filings on the magnet. I changed mine and used the Valvoline 75W-90 synthetic. Based on what I know now I would probably go with 75-140. I only do about 25% towing overall so I'm not to worried. The synthetic doesn't break down and I don't have any leaks.



I have LSD also. With Valvoline I didn't need friction modifier and it works fine with no chatter. Had it loaded in soft sand Friday night and both wheels were pulling.



Trip tips. At 10K, I'd change oil, filter, fuel filter, make sure all hoses including pressure hoses from turbo to intake are tight. Torque intake manifold bolts and check exhaust manifold bolt torques while your are at it. Rotate tires and all the other stuff you do on regular maintenance. If you are towing, don't forget to air up your tires, especially the rears. I normally run front 65/rear 50 empty but bring both to 65 cold when I'm going to tow. Check the trailer brakes and tire pressures there also.

 

[DAWG-1]

Alan great job. I installed a Mag-Hytec cover and filled it with

Royal Purple 75-140 synthetic (8qts). No modifier needed.

 

[Alan Reagan]

Yeah, I wanted to go with 140 but was in a bind and really all I could get was 75-90. Next time I'll plan better.

 

[Jar Head]

Chevron Delo ESI 80W90 is all your truck will ever need. Change it now and leave it. Buy a bottle of limited slip modifier from a dealer ($8. 00) and add a little at a time IF you need it.

 

[Extreme1]

Like they said...

Don't add the modifier unless needed and then a little at a time.