Transmission & Transfer Case Lubricant Questions ???

I have a 2000 Jeep Grand Cherokee, and my son has a 1997 JGC. We are doing some lube changes for his car (which he just acquired), and we are comparing some of the specifications in both of the Jeep manuals. We have come up with some basic questions.

  1. The 1997 book says for the *transmission oil*, it should be ATF+2 or ATF+2 7176. The 2000 book says it should be ATF+3 or ATF+3 7176.

QUESTION-- is the ATF+3 just the updated spec for ATF+2 ? If so, I should use ATF+3 in the 1997 like in the 2000 model ?

  1. For the *transfer case* oil, both books say to use :

"automatic transmission fluid or equivalent, labeled Dextron III"

QUESTION-- is it literally true that the transfer case uses regular transmission fluid ? IF SO, then why doesn't the book say use ATF+3, which is the spec given for the transmission fluid ? Perhaps ATF+3 is the same as Dextron III ??

  1. For the *differentials*, the book says to use SAE 80w-90 gear lube in the front axle, and SAE 75w-140 synthetic in the rear axle. They say IF the car has Trac-Loc, to use a friction modifier in the rear axle.

QUESTION-- How can we know if this used vehicle has Trac-Loc ? (The transmission type is Quadra-trac) We see no markings or other indication if this vehicle had that option (Trac-Loc) and we don't have the original invoice so we don't know how we would know. I don't know how much difference it would make. I do have the friction modifier on hand as I used it in my 2000, but I don't know if I should add it.

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We will appreciate any comments and advice on these questions !!

Thank You very much !!

--James---

Reply to
James Nipper
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1) ATF +3 and Dexron III are the same thing, and backward compatible with +2 and Dex II. The difference in verbiage proabably has to do with the transmission being manufactured by one outfit and the tcase by another. Each writing and supplying their own maintenance instructions. 2) If the axle is trac lok it will have 2 tags on the cover, and /or the tag that shows the ratio will show it with an L where the decimal would go. I.E. 3L55 is a 3.55 axle with trac lok. If in the slightest doubt add the modifier compound, it hurts nothing if in fact the axle is the regular kind. If you are going to drain the old fuid anyway, the cover will be coming off, and you will see that a trac-lok diff has a drum arrangement with just visible clutch packs. A regular set will have clearly visible side and spider gears, with no evidence of a clutch pack.
Reply to
John Garrison

John, what an informative reply. Thanks !!

--James--

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1) ATF +3 and Dexron III are the same thing, and backward compatible with +2 and Dex II. The difference in verbiage proabably has to do with the transmission being manufactured by one outfit and the tcase by another. Each writing and supplying their own maintenance instructions.

2) If the axle is trac lok it will have 2 tags on the cover, and /or the tag that shows the ratio will show it with an L where the decimal would go. I.E.

3L55 is a 3.55 axle with trac lok. If in the slightest doubt add the modifier compound, it hurts nothing if in fact the axle is the regular kind. If you are going to drain the old fuid anyway, the cover will be coming off, and you will see that a trac-lok diff has a drum arrangement with just visible clutch packs. A regular set will have clearly visible side and spider gears, with no evidence of a clutch pack.
Reply to
James Nipper

Yeah, except that it is WRONG!!!! ATF +3 aka 7176 is NOT THE SAME THING AS Dexron III!!!!

ATF +2 and ATF +3 are needed for compatibility with the friction materials in your Chrysler-built transmission. (The reason you only need Dexron III in the transfer case is that it doesn't have friction materials in it.)

Earle

Reply to
Earle Horton

For the transfer case, literally any good grade of ATF can be used so whatever you're putting into your automatic transmission can also be used in the transfer case.

It would be hard to find a GL-5 Gear Lube of the viscosities you're looking at that did not already have the additive required for Tracloc. I've yet to see any gear lube on a store shelf that did not have the friction modifier already. The reason is that the friction modifier addtive is compatible for axles with or without Traclocl.

Jerry

Reply to
Jerry Bransford

Yes, absolutely it can hurt the Tracloc to add additional friction modifier if its already present in sufficient quantity. Too much friction modifier is as bad as not enough. IF there is a little chatter with the amount contained in the gear lube, then a little friction modifier can be added a little at a time until it stop... but it can definitely screw the Tracloc if you just add friction modifier if there's enough already present in the gear lube.

Jerry

-- Jerry Bransford To email, remove 'me' from my email address KC6TAY, PP-ASEL See the Geezer Jeep at

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Reply to
Jerry Bransford

Sorry this is so long...start of rant....

Earle is right. ATF+2 and +3 both contain the additive MS7176 which is what you need in the transmission. Most Chrysler automatic transaxles require this fluid. Whenever I change the transmission oil, I check that the additive is specifically mentioned (ie. in a case where the fluid label says ok for chrysler vehicles, if the label doesn't specifically state additive MS7176 I won't buy it). This is also a problem when having your fluid changed by a non-Chrysler savvy mechanic. Dexron III will eat away at the clutch packs linings and ultimately destroy them. All that being said, the ATF+3 should go find in the Transfer case. When I changed my fluids last, I used Dexron III in the transfer case (i have a 94 JGC) This is one of the toughest things about Chrysler cars in general. I bought my 94 about 4 months ago, and was very leary about buying a used Chrysler automatic transmission. You have no way of knowing what fluid was used in past fluid changes. I immediately changed the fluid after I bought it, but it would not make too much difference if 'regular' ATF was used previously. I had a Mits. Galant (Chrysler transmission) before this. I had to change the tranny at 55K. I suspect that the person who changed the fluid at 30K used the wrong type. I will never make that mistake again! Sorry this is so long, but I this is a subject that really bugs me especially since there is a lot of misinformation out there at auto parts stores, some mechanics, and even some publications. PS: Not sure for your year, but you may want to make sure that you know the correct way to check the transmission level. Many times chrysler transmissions need to be checked with the gear shift in Neutral vice Park (like almost every other automatic transmission). I honestly can't remember on my JGC, but if I checked the transmission in P on the Galant, it would be about a quart and a half low. So, that should be a rough guage when refilling. If it looks full but you haven't added as much as you took out then check it in N and see where the level is (in absence of the correct procedure). NOTE: Chilton's published procedure was wrong for the Galant. The only place I saw it correctly was in the transmission rebuild manual. (I never got the service manual for the Galant)

Bottom line, treat any Chrysler automatic with care and be meticulous with the service, and it should be fine.

Sorry for the long rant,

Phil Rynn

"James Nipper" wrote in message news: snipped-for-privacy@comcast.com...

Reply to
phil.rynn

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