Thread: Downshifting an automatic trans

Originally Posted by TDCRacing

Down shifting an automatic tranmission at normal driving....down a hill ect ect will not hurt anything. Holding it in a particular gear at wot will hurt it.

well yeah i dont leave it in first gear. i will shift it when the rpms get too high or when it would normally shift. i just get bored of leaving it in drive the whole time so i downshift every now and then. thank you for not leaving a smart a** reply.

Originally Posted by Sabrewings

I hope you know you're hurting your transmission. Those lower gears are for engine braking, not hot-dogging it. Use them going down a hill when you don't want to get brake fade by heat soaking (riding) your brakes. Don't use them like your car is a manual.

actually the lower gears were made for climbing up a steep hill or towing(although i dont know who would put a hitch on a GTP). and how would i be hurting my transmission if i shift the car rather than the car shift itself? im not trying to be an a**, im just asking a question

Originally Posted by Sabrewings

3 is for towing. 1 and 2 are for engine braking. When you pull it down into those gears, it uses different internal mechanisms called manual bands instead of the clutch packs. They are designed to provide engine braking with higher line pressure than you could use the standard clutch packs for.

When you leave it in D or 3, the tranny uses its first or second gear clutch packs to use those gears instead of the manual bands.

Trannyman probably has a more eloquent way of putting it, and he can surely show you pictures of toasted manual bands from people doing like you're doing.

sounds pretty complicated. lol. would this apply to every car or only GTPs? cuz i did this with my old grand am and never had a problem.

Originally Posted by Sabrewings

Depends on the transmission. This for sure applies to any car with the 4T65E. Grand Prixs, Impalas, Monte Carlos, Regals, etc. I think the Grand Am has the 4T40E, which I haven't paid much attention to.

oh. and it was a 93 grand am with a 4cyl. lol. wasnt the quickest car

Originally Posted by projectGTP

well yeah i dont leave it in first gear. i will shift it when the rpms get too high or when it would normally shift. i just get bored of leaving it in drive the whole time so i downshift every now and then. thank you for not leaving a smart a** reply.

No problem

Umm..dumb question...What's PCM? I'm trying to learn the terms and my learning curve is massive.

[QUOTE=Sabrewings;144890]Powertrain Control Module. The computer that controls the engine and transmission.[/QUOTE

Much appreciated! Thanks!