Don't worry, I searched, but I think something is wrong with my searching or something. I tried searching for about 6 or 7 different terms and nothign came up at all. And I searched on different subjects.

Anyway, I need to replace the fluid in my rear diff, and the front diff. I was going to remove the diff cover and empty it, that way I could look at all of the gears in there, and check for signs of wear. But I don't know how to put a gasket back on the cover. What should I use for that? I have some Form-a-Gasket #1. Is that what I should use?

I know the tourqe spec on the bolts is 30 lbs-ft, but is there any tighting pattern I have to use? Or just opposite bolts like on the wheels?

And finally, I should fill in the fluid using the check plug, correct? There is no other fill plug, right? I was told by the Dodge dealer the correct weight is 75w90. Completely stock drive train, that's the fluid I should use, right?

I really need to get this done. I have a clunk when I change from Park to Reverse and on occation on Park to Drive, or Reverse to Drive, and I've figured out that it's in the rear end somewhere. U-Joints are new, and the transmission is fine. I had it checked out by my mechanic. Also, if I put the e-brake on, it lessens the clunk greatly. Sometimes it doesn't clunk at all.

Thanks.

 

Dodge may or may not sell you the form a gasket they use on diffs. its fast setting..like minutes...

if the dealer told ya 75-90 , then that should be fine. do ya have a haynes or chiltons around? it should also list it there.

some diffs do not have a drain plug. just a fill.

 

I haven't gotten a Haynes yet, but It's on my to-do list. I also have a Haynes for every car I own.

So for the gasket, Dodge will have the fast-setting stuff I should get, got it.

Alright, I'll see if I can't change this fluid soon.

 

go to harbor freight, for 20 bucks you can get a 12volt fluid pump, go to home depot or lowes and get some hard plastic hose. If the fluid is warm it will suck it out in seconds. I do my diffs twice a year with valvoline synthetic gear lube. You may end up leaving a minimal amount of fluid in the diff but like I said I do mine twice a year so it's not that bad

 

Pretty much all dodge trucks will have that "clunk" sound. There isn't much you can do to fix it except put grease around the yoke wich will only fix it for a couple of weeks.

 

Yeah, the "clunk" is a normal noise. Scared me when I first got the truck.

Anyways, I just bought another paper gasket from advanced auto, and ran a nice bead of black RVT sealant the whole way around the differential cover. Put little circles of it around all the screw holes. Set the paper gasket down on top of it (make sure it's lined the right way, they're really easy to tear if you start ****ing around with them. Let the gasket dry on the cover for about 20 minutes (like until it starts to get a skin), then put the cover back on the axel. You don't have to criss cross the cover bolts when you put them back on but I do it anyway. Also doesn't hurt to tighten them all half way the go around and toque them the whole way. That will garuntee a good seal. Also I used 80w90, but it doesn't matter 75w90 will be fine too.

 

Oh yeah, make sure you scrape all the old gasket **** off of the cover and the axel really good or it won't seal right. And when you're draining it try not to get any on yourself cause gear oil stinks.

 

clunk is normal.

do not use a pump to remove oil. do remove cover and clean/inspect the magnet at the bottom, spray out the bottom with brake cleaner to get the residue out. inspect for broken parts especially if you have an limited slip. don't bend or warp the cover when taking it off by muscleing it off with a big screwdriver. use a narrow putty knife and tap it between cover and case and work your way around. do remove the drain plug on front diff before removiing cover. prev owner probably has it way over-torqued. (its just a plug).

ok to use any GL5 gear oil, 75W90, 80W90, 85W90, or 90W, doesn't really matter. do fill it up through the fill hole, up to the bottom of the fill hole. don't overfill.

if you have a limited slip, you need the little bottle of oil additive. if your not sure what you have just ask on here for explanation.

ok to use a real gasket, or ok to just use a bead of rtv all the way around, including around bolt holes. i just use the rtv only. use black. orange, red, or blue is dorky looking. do scrape the cover and case very clean and dry before re-sealing. DON'T use the form-a-gasket as its too hard to get off the next time you do this.

don't over tighten the little cover bolts. its a pain if they break off. also if using rtv only don't overtighten because it squeezes all the rtv out. i put a little dab of rtv on the threads for thread lock.

if you have a white milky oil its a sign of water getting in past your seals. water is very bad on the bearings, so either fix it or change oil regularly or stay out of the water.

nice diy write up ... http://www.pavementsucks.com/tech/diff.php

oh yeah - like killer said, don't get the oil on you, or wife's car, or in the house.. it really stinks.

 

FYI: Dodge does NOT use any paper gaskets when doin diffs. they only use RTV silicone based fast set.


Dodge may not sell it to ya. call first.

otherwise look at napa or autozone for silicone based quick dry rtv. my stuff was orange.

 

Thanks for all the help guys. I went to Advance and got a Felpro Gasket. Feels like a rubber type gasket. I know felpro is good stuff so I think that should work. I will put RTV around the bolt holes as well.

As for over tighting, I have a torque wrench and I will tighten it to 30 ft/lbs as the dodge manual says. I may not need to use a torque wrench but it isn't worth doing unless you do it right.

I have some wedges from Sears. Will those work to get the cover off?

Also, I am not sure if I have a limited slip. Actually, I don't even know what gears I have, but thats because I haven't looked on the diff cover yet. I have Some MMO, will that work if I have the limited slip?

And I got 75w90 gear oil. I used to work at Valvoline, and there were quite a few days I came home covered in ATF and gear oil. I never took the cover off or changed the fluid in a diff, but I was helping my boss and the oil line split and started getting over everything in the pit. It was a fun day, that's for sure.