: 99...thinking of doing a transmission exchange AND seafoam cleaning... you recommend?

07-28-05, 04:57 PM
My 99 runs pretty darn good but every once in a while I'll notice a little shimmy or knock in idle.

I had the pan dropped about 10,000 miles ago and it smoothed out the transmission a bit but it is now back to how it was before the service since the new fluid is now thouroughly mixed with the old.

I have 89,000 miles and everything is going pretty bullet proof.

I've been told by the guy that dropped the pan that doing the transmission exchange is not a good idea because it can stir up deposits in the transmission creating problems in an older transmission...

However, I've had several people swear by the fluid exchange in their older transmissions well beyond the miles on mine.

Any opinion on exchange? Probably going to have it done after work.

Then, I'm also considering doing the seafoam cleaning.

How much should I put in the gas and am I hearing you guys right about putting some in the crank case where you add oil?

I'll then need to change the oil, right? It's about due for an oil change and I do as much as I can myself, but dropping the pan over and over seems like time better spent doing other things and the fluid exchange sounds great in theory old school mechanic advice nothwithstanding.


07-28-05, 06:17 PM
Not only might the tranny exchange stir up deposits and cause the seals to let go, you don't know what kind of vehicle was hooked up to the machine previous to yours....those machines don't drain completely, so there might be a ton of crap in there from the last time it was used....fire the machine up and all that crap ends up in your tranny somewhere. Just do what you did last time, drop the pan, change the filter and gasket, and top 'er off.

07-28-05, 11:16 PM
Actually the car before me was a chevy late model ext type truck... at least an 03 if not 05...

I had it done at Kwik Kar and so far...

Went ahead and did the fluid exchange after speaking to the dealership service department who said they do not have issues and they do them all the time.

I'd bet that the tranny's been serviced (calm down GD) before because the fluid looked decent and di'nt smell like poo before... I've had a great maintenance record on baby girl since I got her at 50k... my buddy drove her for about 12k before I bought it and had it looked at a couple of times as he had it under contract as a promotion for the dealership... she get around a bit but has been loyal to me... as far as I know... she's in the driveway by the time I get up in the morning anyway.

No problems with the transmission after the exchange and no real significant difference in the feel of the transmission before/after...a leetle' bit smoother but still a little clunky going from R to D but as I understand that is a trait shared with the 99s and 2000 model 'lade.

I did (gasp) add some Slick 50 to shore up seals and bushings in leu of the new tranny fluid and prospect of possible leaking bushings and seals... so I hope to be good to go for a long time with my tranny... errr transmission. Gimmick or not, I bought the ***** at Walmart for a tenner... no big loss.

I've haven't seen such a clean dipstick in moist pink fluid in a looooong time.

Added 93 octane and a treatment of seafoam to the crank case and gas tank intended to reduce carbon deposits and improve fuel consumption (the cadillac forum dudes are pushing this on a dude experiencing a loss of power).

The engine seems to sound and feel a 'leeeetle' smoother in idle and when giving it a little stomp.

Ready for an oil change again in another 500 miles or so... and I've been feeding her the synthetic stuff and doing it myself with the mid-range fram filter since the 70k when I paid over fi-ty dolla for a shop to change it... huh??? How much? Whew... went and got a creeper and change kit the next time.

I guess you already know to change your plugs, fuel filter, air filter and coolant.
Yeppers new sparks, wires, and distributer about 4k back... new rear end has less than 10k on it.

I did a lot of long distance towing for the TGSA the last two years with a double axle 6k lb trailer... It had to be ready for a 'swap meat' by now...