Transmission Fluid/filter change request turned bizarre!!

[Electrician4you]

Originally Posted by X-Greensboro Resident

I own a 97 Toyota Corolla DX (1.8 L, automatic tranny) with 120K miles that I've posted about on here before.

Anyway, I asked my mechanic for an automatic transmission fluid/filter change which is due at this mileage (a flush has been done at 30K, 60K and 90K at the dealer), he tells me that I should not do anything like that to my transmission since the car is so old with so many miles. He says, the fluid is clean and a fluid change may cause problems down the road. He basically said not to change the fluid and just drive the car! He also said that new transmission fluid has alot of detergents in it and it may create some serious problems on an old car.

Has anyone ever heard of such a thing? I was shocked! I have always thought that the tranny fluid should be changed regularly. I am thinking about taking it somewhere else to have this done!! Basically, I want the tranny fluid drained, drop the pan, clean it, change or clean the screen/strainer/filter, put the pan back and put new fluid in it or flush it, whichever. By the way, this shop's been working on my cars for some time now, they do a great job and I completely trust them... well, until now! Any thoughts?

His advice is good for vehicles that NEVER had a service. Since you did yours at the required intervals I would keep doing it. Lots of imports don't have filters. It's a drain and refill or a specific procedure. Most don't recommend flushes with a flush machine. In fact most manufacturers warn against such service

[Don in Austin]

Originally Posted by X-Greensboro Resident

I own a 97 Toyota Corolla DX (1.8 L, automatic tranny) with 120K miles that I've posted about on here before.

Anyway, I asked my mechanic for an automatic transmission fluid/filter change which is due at this mileage (a flush has been done at 30K, 60K and 90K at the dealer), he tells me that I should not do anything like that to my transmission since the car is so old with so many miles. He says, the fluid is clean and a fluid change may cause problems down the road. He basically said not to change the fluid and just drive the car! He also said that new transmission fluid has alot of detergents in it and it may create some serious problems on an old car.

Has anyone ever heard of such a thing? I was shocked! I have always thought that the tranny fluid should be changed regularly. I am thinking about taking it somewhere else to have this done!! Basically, I want the tranny fluid drained, drop the pan, clean it, change or clean the screen/strainer/filter, put the pan back and put new fluid in it or flush it, whichever. By the way, this shop's been working on my cars for some time now, they do a great job and I completely trust them... well, until now! Any thoughts?

Did anybody consider looking up the factory recommendation for this? I did and for normal service 30k, 60k, 89, 120k calls for INSPECT transmission fluid.

Don in Austin

[UpstateJohn]

Maybe by now the Corolla is in the scrap yard, (The OP did post this in 2010) but still, if the OP requested it, it should have been done.

[AlaskaErik]

Originally Posted by Lux Hauler

Your mechanic is a moron. The only time the AT fluid should not be changed is if the same fluid has been run for high mileage. If you have been diligent in changing the fluid at those intervals then it will be fine to continue changing it out.

What happens when the same fluid is run in the transmission for high miles and is not maintained, all of the clutches and seals become acclimated to that old, seasoned fluid. If it is suddenly changed out then you induce a shock factor to those components and they begin to fail. Think of it like a blood transfusion, you just don't flush out someone's blood instantaneously.

What he said.