I have a 99 jeep xj 4.0 with 174K. I have seen so many diff opinions and really to get this fixed. Should I be useing atf+4 or dex-3. Should I change a little at a time? Change filter? Flush the entire system. What do you guys thinks. I really need someone with the exp to help me out. I dont want to ruin my tranny or make it start slipping. So what do you think?

 

when fluid gets old it better to not change it unless you want problems, if it aint broke dont fix it

 

First and foremost... Dex III. Nothing else. If someone tries to point to that TSB.. Ask them to show you one from Aisin-Warner or Toyota that says the same thing.

Now.. Is the fluid burnt??(black,stinky).. or just very worn(brown, dirty)?

There have been issues when flushing AW-4's that have been running on burnt tranny fluid. If it is burnt, drop the pan, change the filter, refill with whatever Dex III you get and keep on trucking. Realize that you are probably on borrowed time in this situation.

If it is dirty and worn, this becomes a bit more of complicated answer. Normally a flush would not hurt the transmission, but if you do not know its service history. You cannot rely on it not becoming an issue.

 

My Cherokee has 130,000 miles on it (I just bought it) and I don't know it's history. The tranny fluid is red / brown, but more on the brown side. It does not smell burned. I've heard stories about "don't change it" and "just change the fluid and don't flush", etc. I emailed a friend of mine who once ran his own car repair shops for a lot of years and asked him the question. He responded:
We started doing flushes in our shops because they involved a cleaner and then removed all the old fluid and was actually a better cleaning. Flushes remove fluid from the torque converter and all of the valve body passages and I never had a problem with the hundreds of cars I flushed. I did have a few problems with some of the vehicles I did a filter and pan change on due to the mingling of the old and new fluids.
This still didn't answer my question about just draining the fluid and replacing it with new fluid... okay or not okay? So, I'm still VERY CONFUSED. HELP!

 

I would drain the fluid. about 4 qts should come out. Add fresh fluid.

A filter would not hurt either.

Do drain & refill of the fluid 2-3 weeks later.


Use DEx/merc fluid only..

Valvoline & castrol make some fluid.

 

+1 This is the accepted way of doing things. If the fluid is straight burnt and stinky well start looking around junk yards for an AW4

 

I have done the fluid and filter change five years ago and have had no problems to date.I also change the fluid at recommended times and filter when its do.Remember if the fluid is bad all ready what is clean fluid going to really hurt????This is everyone with there own take on it you have to figure out the thing to do.I use castrol high mileage fluid.

 

The fluid is burnt. The tranny runs perfect as of now and I hope it stays that way. Thanks for all the input guys. I will also be installing a transmission cooler so this doesn't happen again

 

I owned a transmission shop and rebuilt transmissions for more then 25 years and I will tell you that when the salesman came by to try and sell a fluid change machine they are not saying that it is better for the customer, it makes the shop more money because they don't drop the pan and change the filter, I know that some shops do do that but not most of them.

GM put out a TSB about Dextron 3 smelling burnt and looking brown, They said that it is a normal condition and that it did not mean that the tranmission was bad.

If you pull out the dipstick and wipe it on some white paper and it is clean then you can change the fluid and filter if you want to.

I have seen flushing cause more problems.......during normal operation the transmission will have small particals wear off of parts in the transmission and lodge in little nooks and cranies, when you flush the system they will be dilodged and start moving around but this time in large quanities often sticking valves and clogging solinoids.

Have you ever spilled transmission fluid on the floor....it is a great cleaner and it can dislodge the particals just by doing a fluid change.

My opinion is if it hasn't had the fluid changed on a regular basis and you have 100,000+ on the vehical, leave it alone.

Just my 2cents

 

Repair... thanks so much for the input. What you state validates what I've heard the most over the years. In my situation, the fluid is more brown than red but not burned. I understand the solvent ability of the tranny fluid, so just replacing old with new, why would this be a problem? Unless the old fluid is no longer acting much as a solvent. Here I'm just referring to removing the drain plug, left it empty what's in the pan, and replacing it with an equal amount of new. Why? I just get concerned that, like any lubricant, over time it loses its lubricity. If it is not lubricating the tranny as it should, that isn't a good thing either. Comments???? Thanks!

 

Do the partial change method. DO NOT have the tranny flushed, Old tranny seals especially XJ trannies don't like this. Drain and fill the fluid every 2-3 weeks over the next couple of months. Change the filter, ONLY, after you have drained and filled 2-3 times.

 

ive done probably more the 500+ trans flushes. never seen a failure or issue(even on vehicles with over 300k miles). i got my jeep at 114k. flushed it, added a cooler and changed my filter. no problems.

if draining and filling makes YOU feel better then great. if flushing does great. but leaving crap floating around and diluted fluid control your hydrolics , seals, clutch packs seams foolish to me.... just my opinion.

however i work for toyota, no need to change the filter, there isnt one... (in toyota trannys)

 

I have made more money from repairing transmissions that were flushed but to each his own.

If you have particals floating around that you can see you have a lot more problems then trying to decide how to change the fluid.

 

The main reason that you have to change motor oil is because of the acids that form from the combustion vapors getting mixed with the oil.

The main killer of transmission fluid is the heat but it does reach a point that it is unable to dilute and absorb sludge and varnish causing contaminants and at this point it loses it's ability to act as a solvent.

 

ive heard that from people before, and it is a general thing people quote. I've just never seen it. not saying it doesnt happen, or is VERY unlikely. i would never suggest putting the "flush" cleaner threw a trans no matter the mileage, jus a fluid exchange. the machine we use, uses the trannys pump pressure to perform the exchange. i wouldnt think a "power flush" is good either... idk. to each there own. but i dont like tranny addatives/cleaners or "power flushing".

but either way i am not saying your wrong. just stating what i have seen...