should I get a transmission flush?

[Louster38]

I've got an '84 t-type. The body has 130 some thousand miles on it, but the guy I bought it from had it rebuilt about 30k miles ago and it has a rebuilt drivetrain from an '87 grand national. Anyway, the gasket on the bottom pan of the transmission is leaking and I wanted to just get a complete flush so they would replace the gaskets. The guy at Pep boys said that on older high mileage cars like mine that once they flush the transmission it "starts to shift funny" I dont know if he knows what he is talking about. Has anyone heard anything like this before? Would you recommend getting a transmission flush or not? I'm going to try and call Aamco tomorrow because they might know what they are talking about more, but they put me on hold twice today so I got fed up. Any information is appreciated.

 

[Lee Thompson]

Gasket

Her is my take on this!!! You ask for advice---Stay away from AAMCO and PEP BOYS. If you own one of these $ PITS you better be able to change your own pan gasket. Forget the flush. Buy a pan gasket, some new fluid and change it your self---save your self some $.

 

[STP]

Do not flush a high mileage good working tranny. You will have shift issues afterwards. The flush will loosen up any debris collected in the valve body, cooler lines, etc. Been there done that. A friend of mine owns a quick oil change and offered to flush a 1/2 ton Chevy of mine. Transmission shifted fine before I flushed, never shifted the same after. Steer clear....as Lee said get some fluid, filter, and a gasket and do it yourself.

 

[Louster38]

Thanks, I'll try and figure out how to do it myself. I'm just getting into these cars and I don't know nearly as much as I would like to about them. I've always loved them but never (until recently) had my own, or the opportunity to work on em, so I'm kind of learning as I go along. Plus I'm going through college and I have a part time job so I don't have too much daylight to work on it like I want to.

P.S. 401 nailhead, nice. My dad has a '63 lesabre with a 401 that sits in the driveway. The interior is real clean and the engine runs really nicely, but the body needs a little work and the paint is pathetic. He was planning on working on it but he's a busy man (there's five kids in my family). We'll see what happens with it. We'll sell it if anyone wants it, but we aren't pursuing it.

 

[IrvJr]

I flush all my vehicles, my 96 Tahoe has 1801k on the orig tranny. I say do it and do it often. I am lucky cause i can borrow a machine whenever i want. I think all these instances of "wierd shifting" is coincidence. More people have better results then not, you just hear about the bad ones.

Scott

 

[XLR8]

There is a good write-up on gnttype.org under Spring Cleaning for changing the tranny fluid. That is what I followed.

 

[HOTSIX]

Shifting

Its one thing to change and flush often - then you will have no problems.

BUT if you dont do it often - then you decide to do it - chances are you will run into problems due to the reasons stated above.

 

[GNeric]

I get to rebuild somewhere between 20-25 a year after people have them flushed at the local Jiffy Lube's. A few because they cut the hard line and then put them back together with a piece of fuel line and after it ruptures and looses fluid, then they get pissed and bring it to us. It is mostly the higher mileage, never been flushed ones that this happens to, but I still just do the "once a year fluid change whether it needs it or not" to my cars. No flush.