Touchy subject..no arguing please

[dmc80]

I have a 99 x 4.0. It has 157K on it that have all been put on by me. The trans fluid has not been changed at all. I know i'm not going to flush it, but what would be better, drop pan and change filter, or leave it alone. Fluid isnt red but def isnt as bad as motor oil, its somewhere in between(orangeybrown?) I havent had any trans issues because i have only towed a handful of times and dont take off road. So what is it. Leave it be, or drop pan/filter change. let me hear it, and no dont let me hear it about letting go so long.

 

[inh]

Drop the pan and change it. Let as much drain as possible. I might even go so far as to put in some generic trans fluid for awhile, and then change it again in a couple thousand miles with something nice like Amsoil (preferred) or mobil1.

While the pan is down, clean all the crap out of it that you can, it will probably be nasty. Then look in to installing an external trans filter =]

 

[jmakdisi]

I would not change it if I was you. If you have waited this long it might not be a good idea to change it because of the viscosity of this fluid compared to a new fluid. (example) Me and my friend both have the same year chevy c1500 truck. Our driving conditions are about the same (no hot dogging or offroading) and he decided to change his trans fluid. Mind you I had 199,000 miles and he had 159,000 then he decided to change the fluid. Within 6 months his trans was damaged and mine was still running fine ( now with 252,000 miles that is with original trans and engine). I'm not saying listen to me,but i would ask some advice from general mechanics as well as transmission specialists and make a decision for yourself. If the transmission has a lot of metal debris this could also ruin a transmission and a filter change would be necessary to do.

 

[YountExplr]

I had a little bit of slipping in my trans earlier this year and I had it flushed around march. The slipping went away and my trans has been great since then. At the time I had 223,000 miles on it and had no idea when the last time the fluid had been changed. makes me think all that stuff about old trans fluid is bs, but thats just me.

 

[inh]

Makes sense, I mean might as well not change the engine oil either.. Its not like trans fluid gets dirty and contaminated..oh wait..

Change the fluid!

 

[Rick]

I'm still from the school of thought that says if you haven't changed it for 100k + don't. I used to work at a tranny shop. The shop always recommended changing fluid on high mileage vehicles. Many of the vehicles came in with functional trannies, had the fluid changed and came back a few months later with toasted trannies.

When I pulled them apart the pans and valve body were filled with sludge, and the friction discs were nearly bare of any friction material. Transmission fluid is very high in detergents which work to disintegrate old clutch material.

 

[ZNathan130]

Changing tranny fluid after that long is a hit-n-miss deal. Sometimes it improves your tranny, sometimes it kills it. I was at 110k and had to drop the pan on my tranny and changed all the fluid except in the tc, and mine is running quite a bit better (still have the darn flare, though). However, in my parents' Chrysler 300, they changed the fluid and had to go get a new tranny 3k later...

If you aren't having any problems, I would leave it alone.
Or, as inh said, drain it, throw some generic fluid in there, and then drop it again and clean out the pan and filter. Then replace it with some higher quality fluid. I recommend Amsoil as well.

 

[thannon]

change the tranny fluid but look in ur owner manuel and make sure u put the recomended amount in there thats the number one way to fry it...i also had sliping on my explo at 125,000 miles about a month ago my dad recomended changen the tranny fluid and a new filter and it runs like a charm no problems with any thing!!! so i would change...

 

[dmc80]

Thanks for the opinions and keep em coming. I just feel like it hasnt been a problem yet, and amazingly i havent had an issue, it just something that came to mind cuz i'm not working, and it give me time to think about this stuff.

 

[bluestream1]

Change it. Drop pan, change filter and add the 4-5 liters that came out. Still leaves 8 liters in the tranny, so very mild change for a high milage unit. That oil breaks down over time and shears down to very thin viscosity, and is hard on the unit.

 

[inh]

I bought my truck with 150k on it, and the trans fluid looked and smelled like it had never been changed. I had a 6+ hour drive ahead of me from the dealer I bought it from, so I took it to jiffy lube and them flush it. A couple thousand miles later I put an external filter on it, which noticeably improved the shifting (not a LOT but enough to feel.) A few thousand after that I dropped the pan for a drain plug, temp sender, and installed a sonnax boost valve and increased pressure spring. Trans still runs fine, with just a slight 2-3 flare. If you would have seen the amount of super fine baby-powder like sludge that came out of the pan and off the valve body, a slight 2-3 flare is to be expected.

 

[jseabolt]

OK guys but I can't understand how changing transmission fluid would damage the transmission unless you put the wrong fluid in it. Enlighten me.

My Explorer has 82,000 miles on it. I have no idea if the lady who owned it before me ever had it changed or not. It looks red but that's all I can tell about. I thought I'd change it when I got back from Pennsylvania next week.

So should I change it? I'm sort of scared to now.

I changed the transmission fluid in my C4 68 Fairlane about 10 years ago. My grandmother drove this car so it probably hadn't seen a fluid change since it was new 30 years prior. It had 47,000 miles on it when I got it 10 years ago.

It hadn't ran in about 8 years and most of the fluid had leaked out so it wouldn't shift after I got it running. I dropped the pan, put new fluid in it and it still leaked.

I put some Trans-X transmission leak stop in it and it leaks just a drop or so now. I was told this would crap out a transmission but it did the trick and the car still shifts fine.

 

[pwtsvwt]

Here's a little info that might help answer a couple of questions & concerns.....

High mileage ATF has lost most, if not all, of its detergent. It is no longer "washing" the tranny internals.

Do a full flush and now there's plenty of detergent in the tranny. The detergent does its job and cleans the crud build up from all the internals. Now there's all this junk suspended in the fluid. Before long the filter is clogged, and likely some of the smaller passages, too. One toasted tranny is the possible result.

The are a couple of ways to get fresh fluid while reducing the possiblilty of the tranny choking itself to death.
One way is to do two full flushes with filters with one to three thousand miles between flushes.
The other way is what I'm doing. Drop only the fluid in the pan and replace filter, and add a pan drain bolt at the same time. Over the course of the next two thousand miles, change the fluid in the pan four more times, changing the filter again on the last change.

Either method should prevent any clogging. The second method is slightly less expensive (if you're doing it yourself) because a little less fluid is needed. I'm doing the second method because, in my opinion, it is less of a shock to the tranny.

This is what I'm doing. I'm sure other will disagree.

 

[bluestream1]

pwtsswt, your post pretty much nail it. That's why I suggested a partial flush to start. Then partial flush 6-12 months later. Drain plug is always a good idea. Keep in mind the crud that may be in there is from not changing the fluid in the first place. I have changed mine at regular intervals, and my tranny has been spotless inside each time I did it. Leaving the fluid in there and not changing will cause more problems in time

 

[bluestream1]

Here is a reply to a simialr question about a F-150. Responses are from Ford Techs..

http://www.flatratetech.com/community/index.php?showtopic=30782

 

[jseabolt]

Here's a little info that might help answer a couple of questions & concerns.....

High mileage ATF has lost most, if not all, of its detergent. It is no longer "washing" the tranny internals.

Do a full flush and now there's plenty of detergent in the tranny. The detergent does its job and cleans the crud build up from all the internals. Now there's all this junk suspended in the fluid. Before long the filter is clogged, and likely some of the smaller passages, too. One toasted tranny is the possible result.

The are a couple of ways to get fresh fluid while reducing the possiblilty of the tranny choking itself to death.
One way is to do two full flushes with filters with one to three thousand miles between flushes.
The other way is what I'm doing. Drop only the fluid in the pan and replace filter, and add a pan drain bolt at the same time. Over the course of the next two thousand miles, change the fluid in the pan four more times, changing the filter again on the last change.

Either method should prevent any clogging. The second method is slightly less expensive (if you're doing it yourself) because a little less fluid is needed. I'm doing the second method because, in my opinion, it is less of a shock to the tranny.

This is what I'm doing. I'm sure other will disagree.

OK that makes sense now.

My boss took his Dodge Intreped into some shop and they hooked it up to a machine that completely gave the transmission, the cooler and torque converter an enema. So he ended up with a completely flushed system and pretty much 100% new fluid.

I'm not sure how this machine works but I imagine they disconnect one of the lines at the cooler and the machine goes between it and the transmission. Then it pumps some sort of detergent through the system and which does the pumping and has a filter on it. Then I guess once all was said and done they pump fresh fluid into the system and install a new filter.

From what I rememeber he said the reason he did was the transmission was slipping and the shop recommended this rather than just doing a filter and fluid change.

Once they hooked it up to the machine and did a flush he said the transmission shifts like new again.

 

[sidneyhop]

grabbed this from another site and it seems to explain it pretty well, although I think the double fluid/filter change 3k miles apart makes a lot of sense too.

"If your vehicle has high mileage (> 80,000 miles) and the transmission has not been maintained, I would not recommend replacing the fluid and filter. The fluid that has been in the transmission all this time has become dirty and gritty. This gritty fluid is actually providing needed friction for the worn internal parts of the transmission. Changing the fluid and replacing the filter would remove this friction that the internal transmission parts have become dependent on. If you have not been regularly maintaining the transmission throughout the life of the car, you might actually be doing more harm than good if you replace the transmission fluid at this point. For example, putting new clean slick transmission fluid in an older high mileage vehicle could cause the transmission to slip.

If you are not experiencing a problem, have over 80,000 miles on your car, and have not kept up regular maintenance on the transmission, my advice would be to leave the transmission fluid and filter alone. If you are experiencing a transmission problem like those listed above, seek the advice of a qualified transmission shop before allowing your regular mechanic to service the transmission.

I learned about this problem several years ago...the hard way. We had two cars in our shop with these "minor" transmission symptoms that I have listed above, and both of them had to be towed out to the transmission shop after servicing. The old fluid was gritty due to metal shavings caused by normal internal wear and tear on the transmission clutches and was acting like liquid sandpaper. This "sandpaper" was producing the friction needed for the transmission to pull itself. When we changed the filter and replaced the old fluid with new fluid, the clutches inside the transmission had nothing to grab on to. Sometimes even the best of us learn lessons the hard (and expensive) way"

 

[Xplorer82]

Here's a little info that might help answer a couple of questions & concerns.....

High mileage ATF has lost most, if not all, of its detergent. It is no longer "washing" the tranny internals.

Do a full flush and now there's plenty of detergent in the tranny. The detergent does its job and cleans the crud build up from all the internals. Now there's all this junk suspended in the fluid. Before long the filter is clogged, and likely some of the smaller passages, too. One toasted tranny is the possible result.

The are a couple of ways to get fresh fluid while reducing the possiblilty of the tranny choking itself to death.
One way is to do two full flushes with filters with one to three thousand miles between flushes.
The other way is what I'm doing. Drop only the fluid in the pan and replace filter, and add a pan drain bolt at the same time. Over the course of the next two thousand miles, change the fluid in the pan four more times, changing the filter again on the last change.

Either method should prevent any clogging. The second method is slightly less expensive (if you're doing it yourself) because a little less fluid is needed. I'm doing the second method because, in my opinion, it is less of a shock to the tranny.

This is what I'm doing. I'm sure other will disagree.

looks like another project for my Ex. the fluid in there has about 100k on it since the last time it was changed (family friend/shop owner did it). looks like i'll be doing it this time, and this way. thanks.

 

[gijoecam]

DO NOT FLUSH!!! Simply do a pan drop and filter change; nothing more. Several changes roughly 10k apart would probably help clear out the old gunk without clogging the filter in the process, but IMHO, just avoid a FLUSH. By doing the pan drop, you're only changing out about 1/4 to 1/4 of the fluid at a time, and adding a little bit of the detergent with the fresh fluid every time. That should be enough to stop the new fluid from stripping all the gunk out and clogging the filter.

Obviously the best solution is regular maintenance, but we won't get into that discussion here.

 

[BrianDye]

I'm gonna design a no liquid, no mantenience transmission LOL. I have 139k, don't know diddly squat about previous owners fluid changes or anything, and planned on dropping my pan and getting as much old fluid out as possible, the. A new seal and filter and new fluid, but now I'm reconsidering, I have a hard shift from 1-2 once a week maybe and on occasion a harder shift into reverse but everything else is good, sadly to say though I have yet to even check the tranny fluid