on alot of forums here as well, i;ve seen posts about, if you have old transmission fluid, let it stay in there, changing it will do harm...

so in my spare time i;ve called around to a few places

amsoil, levelten.com, royal purple, aamaco and a few places on the web to find out whats up with that cause personally it sounds remedial at best....

Quote:

Tom: This guy is also perpetuating the myth that "disturbing" an older transmission will somehow cause irreversible problems (this is also known as the "let sleeping transmissions lie" theory). This myth is based on the belief that the transmission has gotten used to its old, dirty fluid. And if you drain out that loving, old, comfortable, familiar fluid and introduce new, clean, uncaring, unfamiliar fluid, the transmission will be upset and won't remember how to work right. This, of course, is complete horse-droppings. A transmission fluid and filter change is never harmful, no matter how many zillions of miles you have on the car or how many fish scales you have in there.

http://www.cartalk.com/content/columns/Archive/1997/August/10.html

Quote:

Ok, Well I did some research into the matter. I called 4 local trans shops in my area. It seemed that they knew exactly what I was talking about right away and were eager to nip this in the butt.

Just as I suspected, this was a horrible myth. Just cause a trans has not been serviced, doesn’t mean it shouldn’t. It should still have the filter and fluid replaced. The new fluid is not going to dislodge the particles or cause to much pressure or any of that non-sense. Theirs no reason that a transmission even with 150,000 miles that never been serviced, not be serviced. The only thing that may happen is it may start leaking cause the new fluid may break down anything clogging a already bad gasket. This is what I thought as well. Obviously if theirs a lot of mileage, then yes, don’t just slap it on the machine, but pull the pan and replace the filter and fluid.

http://forums.automotive.com/community/70/3086/maintenance-repair/transmission/tech-recommening-not-to-change-atf/


http://www3.bc.sympatico.ca/Volvo_Books/faqtrans.html



also both levelten.com and amsoil said, that the additives that are added in todays fluids, have the ability to attempt to recondition the seals internally to minimize leaks. also levelten stated that logically, old oil has less viscosity when its burnt, however new oil has more viscousity (thats pretty much common sense ) so the larger the molecules, the less likely to leak. tranny fluid is more a hydraulic fluid, but still should work at a certain level of viscousity... not to mention newer fluid that isnt worn will produce LESS oxidation.


so really after 3 days of calling around the country, and looking up articles, the main consensus is that, even if it is high mileage, change the oil and the filter.... no need to flush it, but atleast change it. things have evolved fluid wise and transmission parts quality wise.

Nice find, Event. Very informative..

What does duct tape and this thread have in common? STICKY

regardless of what a trans fluid company says (their interest lies in selling trans fluid) there is truth to be told. if your fluid is brown and smells burnt and shows no sign of damage (metal or clutch in the pan) doing a service is obviously good. on the otherhand having been in the trans business for 11 years and counting, if you drop the pan and find black broken down fluid along with metal and clutch you bolt it back up and "let it lie". reason is, if you put fresh fluid( even just 5 quarts) into that trans, the high detergent level in the new fluid along with the different viscosity wreaks havoc on that trans. it wont shift and it recirculates sediment thats previously tucked itself into areas causing no harm.no service in the world will fix that trans, its shot. this is and has been general knowledge in the trans industry for decades. if a shop services this type of trans and gives it back to the customer it will fail quickly if it hasnt failed already. then you are stuck with a customer who thinks your responsible for their trans failure, because "you serviced it and it was fine before you did the service!" if on the otherhand your a DIYer go ahead and do the service, if it fails its noone elses fault. and yes trans fluid technology today is awesome!! oil companies have done wonders with ATF.

The Key for the Isuzu Manual, just GM Syncromesh? My tranny has a slight leak, and was wondering if theres anything out there that could reseal it that i could put in.

no. there is no sustitute for properly repairing the leak. change the gasket or the seal whichever it is. every product on the market that claims it reconditions seals and gaskets and stops leaks, doesnt work. most additives are nothing more than zinc and alchohol. you never know it may be something real simple, like an axle seal.

kyle 102565 wrote:regardless of what a trans fluid company says (their interest lies in selling trans fluid) there is truth to be told. if your fluid is brown and smells burnt and shows no sign of damage (metal or clutch in the pan) doing a service is obviously good. on the otherhand having been in the trans business for 11 years and counting, if you drop the pan and find black broken down fluid along with metal and clutch you bolt it back up and "let it lie". reason is, if you put fresh fluid( even just 5 quarts) into that trans, the high detergent level in the new fluid along with the different viscosity wreaks havoc on that trans. it wont shift and it recirculates sediment thats previously tucked itself into areas causing no harm.no service in the world will fix that trans, its shot. this is and has been general knowledge in the trans industry for decades. if a shop services this type of trans and gives it back to the customer it will fail quickly if it hasnt failed already. then you are stuck with a customer who thinks your responsible for their trans failure, because "you serviced it and it was fine before you did the service!" if on the otherhand your a DIYer go ahead and do the service, if it fails its noone elses fault. and yes trans fluid technology today is awesome!! oil companies have done wonders with ATF.

thats what i did with my stock one...

i raced on the fluid, traffic, it was burnt... gm even showed me how burnt it was after 70,000 miles WITHOUT sufficient cooling.

i changed it, filter and all, no leaks and went well into 104,000 miles with no problems, besides the time i changed it again and didnt fill it back fully.

technically most suggested i didnt bother, and just "let it die" but personally, didnt seem right....

i never had a problem with that transmission before i upgraded to a built one. even with the conditions you just described.


also some of the myth advice above was NOT transmission fluid companies... but actual transmission building companies.

one happens to be one of the most well known transmission building companies US and in Europe but based in europe...





just saying that alot of the things that have been known for decades doesnt exactly hold true in newer times. its no different than cutting/heating springs, not changing to synthetics, etc...

would you be talking about ZF in Europe?