Differentail fluid efficacy

If they are limited slip differentials you want to follow the change intervals religiously. If they are not the fluid may last the life of the vehicle---but who wants to take chances?

I would recommend synthetic next time, to cut down on friction losses in the winter. This is one place where synthetic might be economically viable.

In addition to viscosity you care about something called "shear strength", which is a function of additives. I don't know how you would determine that in used differential oil. You also care about water contamination. If you even suspect that you put the rear axle under water, at least check it for milkshake consistency. If it rains a lot where you are, level and consistency checks should be somewhat more frequent.

Cheers,

Earle

Normally, axle fluid is not changed on a regular basis. If you have a posi-type differential, then there may be a change schedule to follow. The owners manual and D-C Factory Shop Manaul call for 80W90 (dino) and recommend synthetic 75W90 for trailer towing....and there may be a schedule if you tow on a regular basis. If you submerge the axle in water (water has entered the diff) then you need to change the fluid ASAP. Other than that, the stuff is supposed to last the life of the vehicle....but there's nothing stopping you from changing it on a regular basis.

mike

00XJ

Hi Mike, FYI You might want to look at your manual and see what qualifies your wagon to use the lube maintenance schedule "B":

I've never owned a car thatthe axle didn't have to be changed every twelve, or twenty four thousandmiles. God Bless America, Bill O|||||||O mailto: snipped-for-privacy@aol.com

It is a big oversite to never change the lube LSD based or not. It gets dirty too and it is a bigger concern than viscosity breakdown. As far as grade, people seem to be SYN crazy these days but 80w90 dino works fine as does 75w90 dino in colder climates. IF you tow hard in warm or haot weather I would not use 75w90 though and would lean towards 85w140 as it does well in extreme towing.

----------------- TheSnoMan.com

"B":

've never owned a car that> the axle didn't have to be changed every twelve, or twenty four thousand> miles.

Hi Bill,

Ooops....ya got me. I guess I should've looked at the "B" schedule.....figured the original poster was like a lot of Jeep owners in that they rarely, if ever, take their ride off into the boonies. Thanks for the info :-)

mike ooxj

"B":

'venever owned a car that> > the axle didn't have to be changed every twelve, or twenty four thousand> > miles.

Mike, you are right - I have never taken the Jeep in the boonies...yet. I changed the differential fluids just to be safe, and for the experience. I opened up the front axle cover, cleaned, sealed using rtv selant, and refilled. However, for the rear axle, the spare wheel was coming in the way so I tried the easy way out - I sucked out the fluid through the drain plug and refilled via a tube screwed on the fluid bottle - even then the process is tedious - the fluid takes forever to come out of the bottle.

Thanks all for your comments.

I have been changing axle lub for over 30 years by loosen the cover bolt enough to let fluid drain out and then retorquing them. I have had no trouble with any of them leaking. Sure, you can remove cover completely if you want to but 99% of the time there is no need too. I have done this 3 times to wifes Cherokee so far and no leaks even today.

----------------- TheSnoMan.com

I prefer to take the cover all the way off. Then you can get the magnet out and see what kinda shavings are on it.

-- Old Crow "Yol Bolsun!" '82 FLTC-P "Miss Pearl" '95 YJ Rio Grande BS#133, SENS, TOMKAT, MAMBM

"B":

'venever owned a car that>>> the axle didn't have to be changed every twelve, or twenty four thousand>>> miles.

A couple other comments.

When you mess around with today's vehicles, you need to be sure you use 'sensor safe' RTV because the regular stuff will take out the O2 sensor instantly. More than one person on this group has taken out the O2 by using regular RTV on their front diff cover.

If you believe as I do that Jeeps shouldn't be 'marking their territory' every time they stop by dripping oil all over, then it is 'highly' recommended you use the directions on the RTV and let it cure before adding fluid to it. For most of them, this cure time is about 24 hours.

The 'only' leak under my 86 CJ7 was caused by a shop that filled my back diff right after RTVing the cover on.... That diff has been wet on the bottom ever since. Grrr....

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 88 Cherokee 235 BFG AT's Canadian Off Road Trips Photos: Non members can still view! Jan/06 (More Off Road album links at bottom of the view page)

You can but the point is, I would lossen cover and drain ol and sediment before I would try to suck the oil out through fill plug.

----------------- TheSnoMan.com

Kinda strange that someone that acts like a Jeep expert on advise does not even know how to fix their own leak and actually fix it themselves. No surprize though because he beleives in stock tall gears with oversized tires too and burning rubber or spinning tires in reverse to "relieve" driveline torque stress in 4x4 drive.

----------------- TheSnoMan.com

Listen you insane idiot, I will say once again stalking my posts across Usenet will only get you grief. Usenet Stalking is really frowned on these days, you will only get so many warnings....

I was badly injured as a passenger in a passenger side T-bone hit about

4 years ago and haven't been able to do my own maintenance since then.

There can be no one stupider or more insane than someone like you who states it is safe to stop on the highway in a snowstorm to shift gears, that is just pure insanity when our Jeeps have a shift on the fly into 4 high feature and 'we' use it.

We also don't stop on the highway and jack up a wheel to unbind a drivetrain like you advocate because we don't drive beaters that will explode if you spin the tires. LOL! Man that poor guy you suckered into doing that....

Now Screw Off!

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 88 Cherokee 235 BFG AT's Canadian Off Road Trips Photos: Non members can still view! Jan/06 (More Off Road album links at bottom of the view page)

Ditto. God Bless America, Bill O|||||||O mailto: snipped-for-privacy@aol.com