Small reminder: transfer case fluid

For anyone else who may be wondering if it's worth changing out the fluid in their transfer case, here's a small case study from today. This is on a 2000 Limited, 4.0, AW4, NP242, 94,000 miles and change on the clock.

This vehicle was purchased last February with about 73,000 on the odometer. Shortly after buying it I changed out the coolant, engine oil, gear oil in the axles, and tranny fluid; never touched the transfer case up until today. Every time I drained a particular fluid, it had the look of having been factory-original. No signs of abuse as such - just a lack of regular maintenance.

Over time I gradually noticed more and more that when in 4FT on solid surfaces with the steering pointed anywhere but straight ahead, more and more front axle axle hop was making itself felt - at times, I was almost convinced only 4PT had been engaged. Noting that the case worked more or less as expected in all ranges, the assumption at this point was that that there was no mechanical issue but rather that the fluid in it was shot. And dear God, was it ever. Viscosity aside, there was no good way to tell it apart visually from engine oil that was at least twice past its change interval. If it had come out of a transmission, I'd probably be debating replacing the tranny about now.

1.3 litres of fresh ATF (I used Valvoline MaxLife Dexron-III/Mercon formula; THIS MAY NOT WORK FOR YOUR PARTICULAR CASE) and a hundred miles later, I've noticed three very interesting things:

1) The transfer case shifts into and out of 4WD ranges far more easily than it has in the entire time I've owned this Jeep.

2) Cabin noise is *majorly* reduced. I'm going to make an entirely non-scientific guess here and say it's somewhere in the region of 30%.

3) About a 1mpg improvement in fuel consumption. This is without any fuel additives.

So, the moral of the story: don't neglect to change your transfer case fluid. It's easy, prolongs the life of your XJ, and improves living with it. Your transfer case is in use all the time (even in 2WD!), so if you can unscrew two bolts and pour ATF in a hole, you can do this job. Hell, even the $6 expense for fresh ATF is about $103 less than the (in my case) local dealer charges for essentially the same service.

Pick up a wrench and do it. You'll be amazed at how easy it is.

casm said:

Pick up a wrench and do it. You'll be amazed at how easy it is.

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There ya go...saved a good amount of money doing it yourself too. Good findings as well.

Jim

ok let me get this straight. you did coolant, oil, trannsmission and then the diffs.

so why did you skip the transfer case to begin with? you passed it on the way from the tranny to the rear diff. just wondering.

whenever i get a vehicle(regardless of how new or used it is), i make it a habit of immediately changing ALL the fluids. that way you know exactly when it's been done last and wether or not it's full and has the correct fluid. and you'll never wonder about it.

Yucca-Man said:

There ya go...saved a good amount of money doing it yourself too. Good findings as well.

Jim

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Ayuh - that's why I do my fluids myself. Not only do I get to keep track of actual maintenance, but I save a bundle, and if there's problem that can be indicated by the fluid, I'll catch it straight away (and that saves me a BUNDLE in repair bills!)

And, here's the best $10 I've ever spent on maintenance:

http://www.plews.com/brochure.cfm?brochure=2238&location_id=2724

Use this to easily (and not messily!) fill your transfer case, axles, and manual transmissions. It holds a pint at a time, you can change the hose (if you need one longer or shorter,) and it works much better than those silly bottle pumps! Check your local - if they don't have it, they should be able to get it...

Buy two - the spare is worth the bucks!

5-90

Yucca-Man said:

There ya go...saved a good amount of money doing it yourself too. Good findings as well.

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Thanks I've always tried to do as much work myself as I can, though I know I'm by no means a mechanic. It just annoys me when I can look at something, know it's a straightforward job, and then see how much either the dealer or local oily simian chain charges to do the same thing. Rebuilding engines or transmissions may be out of my league right now, but I can at least change out things like fluids, sensors, and ancillary parts like fuel pumps and alternators.

For anyone else wondering what was involved in doing this, I required the following:

- PB Blaster
- 2 litres ATF (CHECK YOUR OWNER'S MANUAL FOR SPECIFIC REQUIREMENTS)
- Tool to remove drain plugs with (this may or may not be a 10mm male Allen-head socket depending on year)
- Plastic handbrush with stiff bristles
- Drain pan
- Funnel

Here's how complicated it was:

- The night before you do this, crawl under the Jeep. Look at the rear of the transfer case. Notice that there are two bolts (either Hex- or Allen-head) on it. Clean any dirt on or around them off with the stiff-bristled plastic brush and give them both a couple shots of PB Blaster. Go to bed and let the PB Blaster do its job.

- The next day, when you go out to buy your two litres of ATF, hit them with PB Blaster again.

- At home, find some level ground, place your drain pan below the transfer case, and slowly remove the lower bolt. I say slowly because if you try to do this fast it'll end up in the drain pan with several hundred cc's of crappy transfer case fluid on top of it. Think of finding it in this instance as a Zen exercise. Oh, and yeah, it'll probably pee all over you if you're not ready for it.

- Remove the top bolt as well while the case drains; this is a good time to get it out of the way.

- Sit around and wait until the flow of fluid from the transfer case to the drain pan has gone from a steady stream to an occasional dribble; every few seconds is probably about right. A couple of cigarettes and/or a beer are long enough if the fluid's already warm and you don't live in Siberia.

- Now that all the fluid's out, put the lower drain plug back in. When you removed it, you probably noticed that it was sticking out a thread or two. DO NOT OVER-TIGHTEN IT; YOU RISK SCREWING UP THE TRANSFER CASE HOUSING IF YOU DO SO. Tighten it back down to where it was, which was probably NOT biting into or level with the back of the case. If you've got a torque wrench, 15-20lb/ft. would be just dandy.

- Pour your new fluid in through the top hole. A funnel or hose may help here, but take care to not knock dirt from the underside of the XJ into it - the idea is to keep it clean.

- Following the same caveats above for the lower drain plug, replace the upper one.

- Drive around a bit (be sure to work through the ranges as prescribed in the manual) to make sure everything works.

Assuming your transfer case isn't shot, you should be good to go for the next several thousand miles. Please dispose of your used case fluid at a recycling centre. I did this in 38 minutes with no prior experience of transfer case maintenance; you can too, and feel free to beat my record and post your time that entirely humiliates my efforts.

Basic maintenance - it's nothing to be scared of, folks. If I can do this, you can.

so why did you skip the transfer case to begin with? you passed it on the way from the tranny to the rear diff. just wondering.

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Because I didn't do everything in one pass. One weekend was coolant, a couple later was the tranny, a couple later were the axles. Time constraints meant doing things bit-by-bit, and the transfer case ended up being put on the back burner.

whenever i get a vehicle(regardless of how new or used it is), i make it a habit of immediately changing ALL the fluids. that way you know exactly when it's been done last and wether or not it's full and has the correct fluid. and you'll never wonder about it.

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Totally agreed - but it's still easy to overlook. People (and I'll admit that this includes me) don't necessarily remember the t-case as an always-on drivetrain component.

5-90 said:

Ayuh - that's why I do my fluids myself.

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You and me both, just that this was virgin territory for me. Honestly, the main motivation behind posting this thread was to put something in OEM Tech that could let new folks know that doing these things aren't scary or difficult, get you better acquianted with your XJ, and let you use money that otherwise would've gone towards maintenance costs to improve your Jeep.

The ony change I'd make is to make sure you take the fill plug out first. That way you always know you can refill it before draining it.

My gear oil comes with fill spouts on the bottles; I keep those handy and use them to refill the tranny and t-case from 1-quart bottles.

Jim

Yucca-Man said:

The ony change I'd make is to make sure you take the fill plug out first. That way you always know you can refill it before draining it.

My gear oil comes with fill spouts on the bottles; I keep those handy and use them to refill the tranny and t-case from 1-quart bottles.

Jim

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X2. Also on the older ones the fill & drain plugs are 30mm. JIM.

Yucca-Man said:

The ony change I'd make is to make sure you take the fill plug out first. That way you always know you can refill it before draining it.

My gear oil comes with fill spouts on the bottles; I keep those handy and use them to refill the tranny and t-case from 1-quart bottles.

Jim

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That, and you've got more control over the drain stream. I've had the tcase "burp" sometimes if I didn't pull the fill plug first - now I do it as a matter of course.

To prevent "plug stiction," I like to apply a little Teflon "pipe dope" (available at your hardware store - look in the plumbing section. I use Harvey's because it's available,) to the threads, which both helps with sealing and prevents rust, crud, and general "crapping up" while running. Wipe it off and reapply when you change fluids again. I'll use this stuff on ALL plugs - oil drain, axle fill, transmission/transfer case drain/fill plugs, what-have-you.

Failing that, a little RTV won't go amiss, and gives much the same results.

And, if you change from the steel pipe plugs in the axle covers to brass plugs, you'll save yourself a power of headaches (they're 1/2" pipe, as I recall.) I keep a number of spares in the toolbox, in case I lose one or run into one I haven't changed yet. For the most part, using brass hardware undercar is a GOOD thing!

5-90

i guess you got a point how that might possibly be overlooked if you just do a little here and there. i always forget that not everybody is like me and spends more time in the garage than they do in the house and at work combined. LOL

about your remark of not being a mechanic, don't worry about it. in my opinion that's just a title. i've worked at several dealerships, and have seen mechanics that were smarter and better than any robot down to mechanics that were fully certified and were asking me (no school of any kind and no mechanic certs) for help/advice every day. i'll agree that at first almost every "new" job on a vehicle seems a little overwhelming at first, but you'll get used to it. i'm about to start a complete 1 weekend (at least i hope so) project in which everything i'll have to do is new to me. replace/rebuild front axle and suspension, install suspension lift, rebuild/modify transfer case, etc...etc.... there is plenty of information on the net and on various jeep forums. with a little patience and research and common sense you can usually get most things done yourself.

x2 what 5-90 said. A suction gun is an invaluable tool. At $10, its the most useful tool I've ever owned and 300 times better than all of those plastic pumps that cost half as much. NAPA has them.

Second, I wonder why I never had any of those problems when I let my t-case go dry? :laugh3: Seriously I have some seepage and once I did let it get pretty far down. They're pretty tuff but keeping fluid in it is obviously the preferred method.

Yeah doing the your self is a big help. Some guy on another board i frequent jeepin or maybe it was here said that the stealer wanted like over 300 bucks I think to change all his fluids. I mean were talking about maybe 40 bucks worth of fluids counting engine oil and a few bucks for some RTV for the diffs. The labor rate must be out of this world.

Yea the labor rate is really what you are paying so much for at a dealership. The Jeep dealer I've worked for the past 2 summers charged $96/hour!

devildog0 said:

Yeah doing the your self is a big help. Some guy on another board i frequent jeepin or maybe it was here said that the stealer wanted like over 300 bucks I think to change all his fluids. I mean were talking about maybe 40 bucks worth of fluids counting engine oil and a few bucks for some RTV for the diffs. The labor rate must be out of this world.

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I hate to say it but I think you're being generous. How many places do you think actually remove the diff covers anymore as opposed to just sucking the old lube out?

How many places do you think actually remove the diff covers anymore

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believe it or not that's one thing i have to give all the mechanics i ever worked with credit for. i never saw one suck it out. they always took off the cover.

i personally don't use rtv. i use a gasket. it's cleaner in my opinion.

thats not an opinion that is a fact. but in using it 4 diffrent vehicles diffs never had a leak with regular changes (except the time the rock tryed to pry the rear diff cover off for me).

scorpio_vette said:

i personally don't use rtv. i use a gasket. it's cleaner in my opinion.

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Yeah, but RTV is less likely to leak should you do something to your cover on the trail.

devildog0 said:

Yeah doing the your self is a big help. Some guy on another board i frequent jeepin or maybe it was here said that the stealer wanted like over 300 bucks I think to change all his fluids. I mean were talking about maybe 40 bucks worth of fluids counting engine oil and a few bucks for some RTV for the diffs. The labor rate must be out of this world.

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My mom got a quote for $350 out the door for the front and rear diffs. on her KJ....I did it this weekend for much much cheaper than that..lol. And it wasn't just us....out neighbor who also has a KJ was quoted $375...still can't figure out the two different prices. It was super easy to do....although the rear cover was a PITA to get off.

Two diff. people at the stealer figuring it up. :?

by the way. since you seem so excited about doing your own work. here's a very very often overlooked fluid. Powersteering. mine looked like chocolate pudding when i got my xj. it might not drive your vehicle but it's turning heavy tires and if your offroad it has to turn even harder trying to turn through mud and other stuff. something to keep in mind.