I bought my truck at 36,000 miles. Previous owner had it leased, and the dealer performed all maintenance and oil changes. Do you think that the recommended 30,000 mile maintenance was performed? Namely the list below


Change front/rear axle fluid
Check transfer case fluid levels
Replace spark plugs

Would I be able to tell if the differential fluid was 9,000 miles old versus 39,000? Should i just swap to Synthetics to be safe?

 

Check the Carfax. If it's not there, I would assume it wasn't performed.
I would definitely go synthetic

 

i highly doubt the 30k service was done!

 

Wouldn't matter to me if it was done or not, I would convert to Synthetic anyway.

 

That settles it, I have a project this weekend.. Anyone know what to run in the front/back differential? The 6000 page manual referenced on one of the stickies recommends

Mopar Synthetic Gear Lubricant 75w-140 for the rear and 75w-90 for the front. What are you guys running?

 

Great! Do my research for me, I want to do the 15k diffs this weekend along with the trans look all the info up

 

Attached is the fluid volumes needed for all transmissions, cooling systems, transfer case, plus the front and rear axle.

The book suggests Mopar ATF+4 automatic transmission fluid

or G238 Mopar ATF+4 for those rocking the stick shift

Is the attachment legible?

 

Double Check and see if you have the LSD so you can either add the LSD additive or make sure that whatever brand fluid you use can supplement the need for it. My fluid when I changed it out was alot darker than the replacement fluid which was Mobile 1 Synthetic. It did have the ability to supplement the LSD, but I still added a little more of the additive.

It's really easy. I did it around 15K miles. Just pull the covers and clean it out well. I used brakeclean and a lint free rag. Use some RTV on both sides of the covers and then bolt them down gradually tightening down in a star pattern. The front diff is a PITA, so take your time and dry fit how you are going to put on the cover before you add the RTV (a couple of times). Give it about 10-15 minutes to dry well and then pull out the plugs on the covers so you can fill them up. For the rear to make it easier remove the rear tire to get that extra clearance.

Good Luck!!