Posted By: Lefty
What's the factory spec for oil in 9.25" axles? - 12/31/08 05:22 PM
Anyone know what weight oil the FSM calls out for 9.25" Mopar axles? it's W I D E so I suspect truck, van or C barge origins. 
What's the factory spec for oil in 9.25" axles?
Posted By: Mopar1
Re: What's the factory spec for oil in 9.25" axles? - 01/01/09 06:05 PM
80W90 will work fine. That's what I have in my '68 Fury (8.75). 
If it's a suregrip you'll need the additive also.
If it's a suregrip you'll need the additive also.
Posted By: MoparJoe
Re: What's the factory spec for oil in 9.25" axles? - 01/01/09 08:10 PM
All the trucks I've had with 9.25's call for 85w140 and the newer ones call for synthetic, It runs about $13 a qt but I havent had any axle problems with it either.
Posted By: ademon
Re: What's the factory spec for oil in 9.25" axles? - 01/01/09 08:48 PM
80/90 for reg duty, 75/140 synthetic for towing and severe duty, This is from my owners manual for my 03 Dakota 9.25 limited slip 3.55. Had my rear end rebuilt at 30k under warranty started to howl bad, Then at 90k it started to growl and howl loudly again, this time i got the rebuild kit from Randys and replaced the carrier, pinion, bearings and races, the pinion seal, and crush sleeve, and axle bearings and seals. BTW i think the axle problems were do to the small vent barbed fitting being clogged i took a drill bit that was just a hair bigger than the original size and drilled it out both times the gear oil was milky because of the pluged vent 
Posted By: ademon
Re: What's the factory spec for oil in 9.25" axles? - 01/01/09 08:51 PM
BTW anyone with the newer 9.25 in their trucks take a few minutes to pull the hose off the axle vent and verify that it and the hose are clear, if it is cloged change the gear oil ASAP.
Posted By: Mopar1
Re: What's the factory spec for oil in 9.25" axles? - 01/02/09 02:38 AM
Quote:
80/90 for reg duty, 75/140 synthetic for towing and severe duty, This is from my owners manual for my 03 Dakota 9.25 limited slip 3.55. Had my rear end rebuilt at 30k under warranty started to howl bad, Then at 90k it started to growl and howl loudly again, this time i got the rebuild kit from Randys and replaced the carrier, pinion, bearings and races, the pinion seal, and crush sleeve, and axle bearings and seals. BTW i think the axle problems were do to the small vent barbed fitting being clogged i took a drill bit that was just a hair bigger than the original size and drilled it out both times the gear oil was milky because of the pluged vent
80W90 IS for heavy and severe duty. Up until about 10 years ago that's what most heavy truck fleets were using. A lot of drivers I know had premature bearing failure using 75W140 syn oil in there diffs and transmissions.
Posted By: J_BODY
Re: What's the factory spec for oil in 9.25" axles? - 01/02/09 04:17 AM
Quote:
80W90 IS for heavy and severe duty. Up until about 10 years ago that's what most heavy truck fleets were using. A lot of drivers I know had premature bearing failure using 75W140 syn oil in there diffs and transmissions.
Working at a dealer I would say that you mixed those two up. We saw a ton of rear gear failures in the 1500 trucks. Nothing tests a rear gear like and overzealous Californian towing his huge boat across the 120+ degree desert to get to the Colorado River. 75-140 worked way better. I know that in my 95 1500 when I would tow my enclosed car trailer in the summer I would get weapage around that lil rubber fill plug from the heat. Switched to 75/140 and it never happened again. ......as always, FWIW.
Posted By: Lefty
Re: What's the factory spec for oil in 9.25" axles? - 01/02/09 06:38 AM
Quote:
80/90 for reg duty, 75/140 synthetic for towing and severe duty, This is from my owners manual for my 03 Dakota 9.25 limited slip 3.55.
Thank you!