Transmission flush on automatic Jeep Liberty 04

Ok, I learned to care for my cars in an oil rich country where costs of labour are next to zero. Oil changes, fluid flushes, tyre alignment were things you did on a whim and paid very little for. I am now in the US and paying for everything.

I have a 2004 automatic Jeep Liberty with 43,000 miles on it. I drive about half on highway and half on very steep hills (I drive up 3 miles on first gear everyday to take my kids to care, and then to pick them up). I am fairly responsible caring for it and it isn’t showing any symptoms of trouble.

I would have done a transmission flush (drain all the oil and replenish) a long time ago if I were back in Venezuela. When I ask my garage about it, they weasel on it (I understand that it takes some fancy machine that broke and they have no plans to replace). The manual ends all sentences on the topic with the dreaded “if needed” which does nothing to answer my question.

Should I worry about a transmission flush or no? If the answer is yes, how does that go? This is my first automatic vehicle. In a standard you just open the plug, drain it and replenish it. Does it take a special machine to do this in an automatic? (because of the fact that there are all kinds of pressurized channels in there)

Please advise.

Look at the maintenance schedule in your owner’s manual. Does it list a service interval for your transmission? Look under severe duty, does it list one there?

My guess is that there is a drain and refill interval listed, not a flush listed. Here in the states, transmission flushes are way over sold as they are easy and profitable.

My suggestion is do what the factory suggests.

The conditions that are condsidered “severe service” for an automatic transmission are towing a trailer and driving in hilly/mountainous terrain. I would say your driving qualifies, so service is “needed” in this case.

The traditional service includes draining and refilling the fluid and replacing the filter. Unfortunately, only about 2/3 of the fluid will drain out. Flushing involves replacing virtually all the fluid, but doesn’t address the filter. Neither is perfect. Doing both is, but isn’t really cost-effective. My advice is to do a traditional service the first time, a flush the second time, and continue alternating between the two. A 30,000 mile interval is probably appropriate.

I have qualms about a garage that won’t service your transmission because their flushing machine is broken. A traditional service requires no special equipment. I also wonder why they don’t want to repair or replace the machine. I suspect you’d be better served elsewhere.

I didn’t even know there was a filter in there! What for? There is no input of foreign substances to the tranny (as there is to the engine). Why won’t the flushing include a filter change?

My garage is generally ok, my BIL worked there for years and they treat me as family and give me some discounts. It also means they try to “save me money” and seem to be always preventing me from following my tendency to do unnecessary maintenance. I often feel they err on the side of putting off stuff. I often have to buy the air filter and change it myself since when I ask them to do it they just say it is ok.

I am the kind of guy who can change his own engine oil (and I do half the times when there is no need to rotate the tyres which I can’t be arsed to do). Can I change the transmission oil myself? Is it a similar process to changing the engine oil? (unplug, drain, change filter, plug, replenish). Will I need special tools? (I use the FRAM filters with suregrip so I can do it with bare hands)

Thanks for the help.

I recently researched oil filters. Fram’s used to be quite good, but several experts (real experts) who have done cross-sectional comparative analysis (all major models) say they are among the worst–even the extended-wear models. I don’t have a handy cite, but Mobil 1 filters were said to be among the top 3. I think Wix was another top performer.

The drive-up oil change places, Jiffy Lube etc. offer these services at a reasonable cost. Why not ask the dealer what they recommend, and then go to Jiffy for the service.

The filter isn’t for external foreign substances, it’s for internal debris that is inevitable from normal wear. Some parts of an automatic transmission (valves in the valve body) are VERY susceptible to even tiny particles. It’s common practice to have one or more magnets in the bottom of the pan to collect dust-sized “iron filings,” as a supplement to the filter.

In most* automatics, access to the filter is by removing the transmission’s bottom pan. Obviously, this drains the fluid. American-design pans almost never have a drain plug, but even if they did, the pan still has to come off to replace the filter. This is the essence of a traditional service - remove the pan, drain the fluid, replace the filter, replace the pan with a new pan gasket, replace the fluid with new.

Flushing is accomplished by disconnecting a joint in a transmission cooler line, pumping fresh fluid into one part of the line while collecting old fluid from the other. When only fresh fluid comes out of the exit line, virtually all of the fluid has been changed. Since the pan isn’t removed to do this, the filter is not accessed.

To change all of the fluid AND change the filter, both processes must be done. This is superior to doing just one or the other, but obviously costs more than either process alone. Many (too many) shops push the flush, touting its benefit of replacing all the fluid, while overlooking filter replacement. This is probably because they have an expensive flushing machine whose cost they want to justify, and flushing is quicker and easier than a traditional service. There is more money to be made by flushing, particularly once the machine has been paid off. There’s nothing wrong with flushing, and it does have a real benefit, but never changing the filter can be a problem. And of course if they try to sell both services together, they appear too expensive compared to selling just one service like everybody else does.

Hence my recommendation to alternate the types of transmission servicing. For decades, only traditional services were done, so not changing ALL the fluid isn’t awful. And filters can last many tens of thousands of miles, so not ALWAYS replacing the filter isn’t awful. But the maximum benefit comes from covering both bases. I suggest the first service be a traditional one, because the break-in of a new transmission produces more debris than normal operation after break-in.

A traditional tranny service is a lot messier than an engine oil change, especially if there’s no pan drain plug. Draining is accomplished by removing most of the pan bolts and letting the pan drop on one side. This sends a big splash of fluid over a wide area. Special oversized tranny drain pans are made for this purpose. After the fluid is drained and the pan completely removed, fluid will drip from anywhere in the pan coverage area. Pans are attached with hex-head bolts, requiring normal socket wrenches. Filters are attached with hex-head bolts, Phillips-head screws, or just pressed in.

Care must be taken to note any gasket or seal associated with the filter - leave the old one or install the new one, but don’t put a new one in on top of the old one. Clean all the debris off the magnet(s), and wipe the inside of the pan clean. If the new pan gasket is cork, tighten it in several stages allowing 5+ minutes “rest” between each stage for the cork to settle, and DON’T OVERTIGHTEN. Refilling is done through the tranny dipstick tube, and requires a special narrow-necked transmission funnel. Often it’s impossible to read the dipstick right after adding fluid - you get a false high reading from fluid working its way down. Time must be allowed for the fluid to settle from the dipstick tube.


*There are some exceptions. A few designs have an external spin-on filter, like an engine oil filter. In these cases flush plus filter replacement makes sense, and the pan doesn’t have to be removed. And some (only Honda and Acura to my knowledge) have no pan - the filter can only be removed by disassembling the tranny, and thus is not changed as maintenance.

Gary T I don’t want to hijack this but you seem to be very knowledgeable regarding transmissions.

I have a Jeep Grand Cherokee, 1996 with about 220,000 Kms on it. I bought it used and as far as I know the transmission has never been serviced. About two years ago the transmission started slipping when it was cold. I checked the fluid and it was down a pint or two, so I topped it up and everything seemed fine.

A few months later it started doing the same thing, but the fluid was, and still is within the right range. In fact I think it’s right at the top of the acceptable range. With the really cold weather hitting us now, I need to drive for 5 minutes or so before the transmission will shift into 3rd and overdrive. So I’m stuck with first or second gear only until it warms a bit, and then I’m OK to go, although sometimes from a standing stop I might have to back off on the accelerator and then re-accelerate to find third.

Here’s the really weird part; my driveway is sloped about maybe about 20 degrees where I park the Jeep. If I park facing uphill, I’m more apt to find third gear when the transmission is cold. If I park level, or especially facing downhill it takes longer to shift into third.

What the heck is going on with this thing? You help is appreciated!

A very typical problem with automatics is delayed engagement when cold caused by worn internal seals. The seals lose their flexibility and don’t allow pressure to build up in certain hydraulic circuits. Driving, or even running the engine, for a few minutes generates enough heat through fluid friction to restore their function. For a while. This is my armchair guess as to what’s happening with yours. I would further speculate that when parked at the right angle the affected seals are bathed in fluid and don’t stiffen up so much when cold (that’s a WAG).

If this is the case, the cure is a transmission overhaul. There are some additives - I believe Trans-X is one - that might alleviate the problem temporarily, buts there’s always a risk using additives (could make things worse), and at best it will buy some time before the inevitable repair is required.

Occasionally a fluid service will help with such things, but it’s by no means a sure bet. And if it hasn’t been serviced in a long time, there’s a good chance that adding fresh fluid will dissolve the varnish that’s allowing worn parts to seal and result in immediate total failure. If the fluid is dark, brown or nearly black, I wouldn’t change it.

I’m afraid my best guess is that you’re on the verge of having to get the tranny overhauled. My suggestion would be to visit a reputable transmission shop (not a franchise), preferably a member of ATRA (Automatic Transmission Rebuilders Association), for evaluation.

Thanks!

good, now stop hijacking my thread! :wink:

oh wait, I was already done myself. Carry on.

Thanks Gary T

A filter change requires dropping the transmission pan. This means replacing the pan gasket too. Pain in the ass for a do-it-yourselfer (like myself).
Probably takes a garage an hour to do and an additional $100 (labor and parts) or so.

Oops, should have previewed, left browser window open since this morning.

thanks anyways. I had reached the PITA conclusion myself. Sounds like a job for the garage. If I can’t be arsed to rotate tyres, much less chance to see me splashing oil and replacing gaskets.

I have a 2004 Liberty. The owner’s manual has two schedules, “A” for lightly-used cars & “B” for more typical use / heavy use.

Schedule “A” extends to 120,00 miles and never recommends any transmission maintenance.

Schedule “B” recommends “Drain & refill the automatic transmission fluid and replace the main sump filter” at 60,000 miles and again at 120,000 miles.

Schedule “A” wants transfer case fluid inspection & top-up at 30,000 mile intervals with a drain / refill at 120,000 miles.

Schedule “B” wants transfer case fluid inspection & top-up at 30,000 mile intervals with a drain / refill every 60,000 miles.

For sustained offroad or heavy load use (ie not you), schedule “B” also wants front & rear axle fluid drain/refill every 12,000 miles.

ok, that’s sounding better. Mine is not 4x4, btw.

The wife has had the truck for the last few days which means I only have access to the manual at night when I am not even thinking about this. Thanks for the reference. Sounds like I still have about a year to worry about this.