Advice on Transmission Fluid Flush / Filter Swap

[Not_Invented_Here_]

Sorry for the essay!

2004 4.0 - 42RLE, purchased with 94k miles on 12/26/18, currently sitting at just over 96k today. I'm trying to make a decision based on limited time/space and necessity. I can't say with any certainty when the last transmission fluid change + filter swap occurred and am feeling some urgency to get that particular box checked, especially with summer temps on their way. So, with that said, I'm looking for advice.

I read Chris' walkthrough and believe I could do this job myself. However, I have limited access to the necessary tools and space at this time due to my in-laws being the in process of moving. It would maybe be another 1-2 months (at most) before I can get to this.

Are there any disadvantages to going the cheapest route (Jiffy Lube)? Having read Chris' description, it sounds like they don't drop the pan or anything like that, just use a machine to pump in/out and flush/swap fluid. Around $155 + tax - don't think that includes filter swap.

Pricier option is a local trusted shop that quoted me around $300 - he's wary of doing this on higher mileage transmissions though as I guess he's been burned before (the old debate over waiting too long to change fluids and then you end up wrecking the transmission) - won't get into that debate but it's an option and I assume would include the full service, filter change, drop/cleaning around pan area etc...

Last option is to wait until I have the time/tools to properly do it myself - obviously the best option due to cheaper cost, knowledge gained, can scope out other stuff while working in that area, can clean, peace of mind knowing how well job was done.

At my mileage and without knowing the service history on my 42RLE transmission, is it maybe urgent enough that I should go the quick/cheap option for the time being and next time around I can do the work myself?

 

[Steel City 06]

I would not trust Jiffy Lube with any car. If you have to flush the transmission, there is a redneck way to do it. I’ve done it on my f150 before.

Simply disconnect the transmission cooler line. Run a hose to a bucket. Turn on the engine and pump out a few quarts. Refill the transmission and repeat. Between refills and dumps cycle the transmission between forward, 2nd, 1st, and reverse. Basically you’re diluting the old fluid.

When dumping the fluid, shut off the engine as soon as air starts to come out of the line. Don’t let it pump air.

You would need a significant amount of fluid on hand. The more fluid you put through the flush, the more diluted the old fluid will get. I personally would run 16-20 quarts through with this method

 

[cliffish]

I avoid Jiffy lube places like the plague. There is no reason you can't wait unless you have some major rock climbing or an across the country drive. I dropped the pan and changed the filter, then followed @Jerry Bransford write up and flushed the rest of the fluid out of the cooler lines...took about 10-12 quarts of ATF+4 and a little time. That way you get the best of both worlds a new filter and a complete flush, there is some discussion about the commercial flushing machines causing issues...I will leave that discussion to others.

 

[Not_Invented_Here_]

I would not trust Jiffy Lube with any car. If you have to flush the transmission, there is a redneck way to do it. I’ve done it on my f150 before.

Simply disconnect the transmission cooler line. Run a hose to a bucket. Turn on the engine and pump out a few quarts. Refill the transmission and repeat. Between refills and dumps cycle the transmission between forward, 2nd, 1st, and reverse. Basically you’re diluting the old fluid.

You would need a significant amount of fluid on hand. The more fluid you put through the flush, the more diluted the old fluid will get. I personally would run 16-20 quarts through with this method

Basically how I feel too - I've been there once in my life when I was a kid and didn't know any better. They needed to replace a battery and had trouble with the cage brackets that fastened it in place. Just bent them to get it out, didn't tell me and hoped I wouldn't notice

I'll consider the option you described. Need to price out that much ATF4

 

[cliffish]

I would not trust Jiffy Lube with any car. If you have to flush the transmission, there is a redneck way to do it. I’ve done it on my f150 before.

Simply disconnect the transmission cooler line. Run a hose to a bucket. Turn on the engine and pump out a few quarts. Refill the transmission and repeat. Between refills and dumps cycle the transmission between forward, 2nd, 1st, and reverse. Basically you’re diluting the old fluid.

When dumping the fluid, shut off the engine as soon as air starts to come out of the line. Don’t let it pump air.

You would need a significant amount of fluid on hand. The more fluid you put through the flush, the more diluted the old fluid will get. I personally would run 16-20 quarts through with this method

I am not sure you would need that many quarts as the fluid in the tranny is already new after a filter change...the flush will pull the old fluid from the torque converter and cooler first. Just look and when the fluid changes to the light red you are done.

 

[Not_Invented_Here_]

I avoid Jiffy lube places like the plague. There is no reason you can't wait unless you have some major rock climbing or an across the country drive. I dropped the pan and changed the filter, then followed @Jerry Bransford write up and flushed the rest of the fluid out of the cooler lines...took about 10-12 quarts of ATF+4 and a little time. That way you get the best of both worlds a new filter and a complete flush, there is some discussion about the commercial flushing machines causing issues...I will leave that discussion to others.

Heard - yeah not planning wheeling or CC trips... It's my DD for short trips between schools, it sees a little highway driving a couple times a week at most. This summer though, I'd like to be able to drive it with confidence on camping trips to destinations within a couple hours of home. I've got time before that happens though.

 

[Steel City 06]

Honestly dropping the pan really is the better option.

You can pump out the fluid like I described so you don’t get a crimson shower when you drop the pan. Pumping it out before pulling the pan will only leave about half a quart in the pan on most transmissions

 

[cliffish]

best I have found so far

https://www.amazon.com/dp/B01MD18HUR/?tag=wranglerorg-20

 

[Steel City 06]

I am not sure you would need that many quarts as the fluid in the tranny is already new after a filter change...the flush will pull the old fluid from the torque converter and cooler first. Just look and when the fluid changes to the light red you are done.

Yeah that might be a bit high. I don’t have experience with the 32RH or 42RLE, only the 4R70E

 

[Not_Invented_Here_]

best I have found so far

https://www.amazon.com/dp/B01MD18HUR/?tag=wranglerorg-20

Awesome thanks for the link - got it bookmarked

 

[pagrey]

It is not urgent that you flush your transmission fluid. There is a reason why the procedure is not in the factory service manual.

If you want some extra security or piece of mind until you can change the filter you can add an extra quart of ATF+4, many of us run 1qt extra for off-road use.

If you want to know the condition of your transmission the computer stores the wear parameters in it's memory, a good shop can tell you how it's doing. Jiffly lube can't, the dealership probably wont but a good transmission shop will.

The filter should be changed when you are able. The only extra fluid you need to add is what was lost during the filter change.

A flush will do one thing, drain your pocketbook. If that makes you feel better then go for it.

 

[JLLJ]

For what it's worth the off road shop I talked to and some of the things I've read say don't flush the trans, do a fluid change instead. Unless it's burnt or there's more than normal debris, most of the recommendations have been to drain the pan and change the filter. I believe the owners manual says the same thing. I know this speaks more to GM transmissions but it's a good short read. https://www.700r4transmissionhq.com/transmission-fluid-change-vs-flush/

 

[cliffish]

The flush we are talking about is not the flush you get a shop. They use a pressurized machine that can have some ill effects on the seals and valves, especially in older units. The one you do per @Jerry Bransford method is disconnecting the output on the trans cooler and pour fluid into the dip stick hole while the engine uses its own tranny pump to send out the old fluid.

 

[mgroeger]

It is not urgent that you flush your transmission fluid. There is a reason why the procedure is not in the factory service manual.

If you want some extra security or piece of mind until you can change the filter you can add an extra quart of ATF+4, many of us run 1qt extra for off-road use.

If you want to know the condition of your transmission the computer stores the wear parameters in it's memory, a good shop can tell you how it's doing. Jiffly lube can't, the dealership probably wont but a good transmission shop will.

The filter should be changed when you are able. The only extra fluid you need to add is what was lost during the filter change.

A flush will do one thing, drain your pocketbook. If that makes you feel better then go for it.

I've never heard of running an extra quart... why? I've read that too much fluid (overfill) is not good.

 

[pagrey]

The 42RLE can starve off-road.

Seriously, the flush, no matter how you do it is a total waste of ATF+4. Such a silly old wives tale.

 

[toximus]

best I have found so far

https://www.amazon.com/dp/B01MD18HUR/?tag=wranglerorg-20

If you have one near you, Menards has Valvoline ATF+4 for just over $4/qt.

 

[toximus]

Seriously, the flush, no matter how you do it is a total waste of ATF+4. Such a silly old wives tale.

How? Old fluid out, new fluid in. No mixing.

The one you do per @Jerry Bransford method is disconnecting the output on the trans cooler and pour fluid into the dip stick hole while the engine uses its own tranny pump to send out the old fluid.

I have done this, if you mark the bucket you are using with a line at every quart you know exactly how much is flowing out so you can match that rate with new.

 

[Not_Invented_Here_]

It is not urgent that you flush your transmission fluid. There is a reason why the procedure is not in the factory service manual.

If you want some extra security or piece of mind until you can change the filter you can add an extra quart of ATF+4, many of us run 1qt extra for off-road use.

If you want to know the condition of your transmission the computer stores the wear parameters in it's memory, a good shop can tell you how it's doing. Jiffly lube can't, the dealership probably wont but a good transmission shop will.

The filter should be changed when you are able. The only extra fluid you need to add is what was lost during the filter change.

A flush will do one thing, drain your pocketbook. If that makes you feel better then go for it.

Nah, longevity is the goal. It doesn't need anything except to be well taken care of so it can last for many many years to come

 

[Not_Invented_Here_]

The 42RLE can starve off-road.

Seriously, the flush, no matter how you do it is a total waste of ATF+4. Such a silly old wives tale.

To be clear, I may be misusing or confusing different terms for different procedures. I simply want to perform the proper maintenance and upkeep to ensure a healthy transmission and keep my Jeep in good running shape.

 

[pagrey]

A flush wont hurt a thing, it's just over and above what Chrysler suggests (which is totally fine).

The regular procedure is just to change the filter every 60K.

You'll be fine either way.