jlb586

Hello,

I'm going to change the oil in my rear diff. 1998 Jeep XJ 4.0L 4WD.

Just a few questions though...

Do you use both RTV Sealant and a rubber/paper gasket when reassembling?

Or should I just user the Permatex Gasket Maker sealant (http://www.autozone.com/autozone/acc...er=526731_0_0_) minus the paper gasket?

What's the better method?

Also, I read that I should allow some time (5-10 minutes) to let the RTV to cure, the reassmeble, and hand-tighten the bolts. I read that you should allow some time before torqueing the bolts and pumping gear oil back in to the differential.

How long should I allow the RTV to cure after hand tightening?

Any input would be helpful.

THANKS.

excess650

I used Yamabond (Threebond) semi-drying sealant on my trans pan and filled it up immediately, and it hasn't leaked a drop. I can't say that this might be true of other "RTVs". If the diff shows a gasket, use one. Its vertical wheras the trans pan is horizontal.

djb383

Advance Auto Parts (probably others as well) carry a FelPro gasket for the C8.25. We applied a thin film of VersaChem RTV on both sides of gasket, bolted it up and filled it......no leaks. Just snug on the cover bolts.

bigvig

I use just the black RTV high heat stuff and have never run into a problem (read that as leak).

84zmyfavorite

Permatex 1 Minute RTV is my favorite. It really is good to go after 1 minute, especially in this weather, but i do give a full 1 hour cure time before filling with gear oil. How many miles on your 98s odometer? If over 150,000 miles, I usually use a house brand(SuperTech is my favorite) extreme pressure gear oil in a 80w-90 weight in most front differentials, and depending on mileage of rear diff, I usually use 85w-140, because of hard off road use and general severe service. I have mixed 80w-90 and 85w-140 petro gear oils in a 50/50 ratio for rear diffs for a estimated weight of 82.5w-110 that flows better in bitter winter temps. Paper Gaskets are a waste of money in my opinion with a good RTV such as Permatex. I believe Chrysler 8.25 rear axles came from the factory without a paper gasket, just Orange RTV, I know, it dosent sound right, but after servicing many low mileage 8.25s, that were getting their first fluid change, later models, 98 thru 01, have had orange RTV without a gasket.

84zmyfavorite

Oh, and just "Snug" up the bolts when tightening diff plate to differential. Let cure, and then maby 1/8th turn tighten more. Trust instincts and Dont Over Tighten! I broke a bolt from over tightening on my beloved SilverStone Metallic 01s Chrysler 8.25, 3 years ago and have felt like a DumbA$$ ever since. Broke off a bit concave below diff housing surface. Idiot! Hopefully will have a Dana 44 some day, and all will be better.

Carl48

Don't put RTV on a gasket...use either/or. If you use RTV, follow instructions on the tube regarding set-up time and make sure the diff and cover mating surfaces are absolutely clean and free of oil or you will have a leak. Don't over-torque the cover bolts.

mrfajita

On my D35 I used some red high temp RTV, has not leaked a single drop in a year and a half since I did it.

huntsman

yup i used a versachem gasket maker sealent and a felpro gasket, once i put it together i hand tighten all the screws and torqued them. I let the sealant dry for 12-24hr and then i filled my diffs up. I actually filled them up today and no leaks.I used 75w90 valvoline full synthetic gear oil.

be sure to clean the surface from the old sealant. I also wire brushed my diff cover from all the rust and primed and painted it with pasti dip that way it shouldnt rust anymore.

jlb586

Thanks for the input.

I got under there this weekend, didn't actually get it done. Sprayed the cover down with PBlaster, as most of the bolts are in pretty rough shape. Wire brushed the cover as well to know all the lose rust/paint.

It appears to only have gasket sealant on it at this point - no trace of paper/rubber gasket that I could see. I'm thinking I'll try that 1 minute gasket maker and let it cure for a few hours.

My XJ is my DD, no off-roading involved. Got ~136k on the odometer. Was just gonna put in the recommended 75w-90.

CherokeeCountry

I use permatex RTV, no paper, never have any problems from either of my diffs, and I swap the oil in front and rear after every wheeling excursion or if they're underwater. Excessive, but safe on the equipment rather than sorry. I usually put a good bead on, spread it out with my fingers, let it dry 1 minutes, put the cover on pretty tight, wait 60 seconds, snug them again, then wait till the morning after before work to fill er up.

briansgarage

I used the red high temp RTV. Got a big caulking tube of it cheaper than the little tubes. Changed front and rear oil with 80/90 and that RTV and have been absolutely good. No drips at all. I only let it sit maybe an hour before filling up.

Bstrom650

I second that - all of it. Wait a bit for the RTV to cure before refilling. SuperTech is $3.95/qt here for - cheap as you can get out of it.

metaldemon7

I have a LubeLocker gasket. It has been on, and off four times since the powertrax mistake. I just torque it to 35 ft lbs, and it is good to go. It is made to be reused. I got it at OK 4WD.

Evil Drew M

I do the same. Quick, easy and effective.

I haven't ever used any sort of paper/cork/rubber gasket on a diff cover in almost 20 years.

And as an added data point the black RTV is high temp as well as the most oil resistant of the Permatex line.