Thread: Downshifting an automatic trans

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

Ya know i'm really not sure why you are not suppose to do this I just know the well known Trannyman (transmission ''expert'') told me he voids peoples warranty's if they do this. So I don't do it. I'll email him and get him to respond.

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

I have never roasted a tranny doing this.

Its actually better to shift it like that, working thru the gears instead of letting them slip into place on their own.

The MPH will also depend on your final drive ratio as well.

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 WhiteDevil

I have never roasted a tranny doing this.

Its actually better to shift it like that, working thru the gears instead of letting them slip into place on their own.

The MPH will also depend on your final drive ratio as well.

i agree

Originally Posted by GTPJOE90

go 65 and throw it in 1st gear...... lmao jk haha =epic fail ha

lol. theres a safety feature that wont let it drop into first at higher speeds

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 blowfishRus6

the auto tranny is designed to slip, makes for a smooth shift. even if you shift it your self it still slips.

IMO the auto tranny works best when left in drive (unless trying to down shift) your right foot can controll all the shifts and compared with stall converters everything works together. get up on a stall and you dont even have to downshift. keep going into the throttle and it will hold the gear. let off the throttle and it will unlock the lock up. an auto tranny can be controlled like a manual just with using your foot.

if you feel the need to manual shift, by all means go for, but you can do all that with your right foot (except downshift for engine breaking)

It is designed to slip, however if you hold line pressures higher the shift is much firmer thus better for the tranny.

if you have a RPM limiter( factory set), dont bother.

I had a heavily modified TH350 that had all the goodies in it, that specific automatic worked best when manually shifted. I know these trannys cant even come close to comparing what the th350 is however that is most of my driving life expeirence**. I do understand its apples to oranges but if all you are speaking of is stock FWD,its a very narrow opinion to work with.

I have manually shifted the FWD auto's I have driven/owned and have never had a tranny issue until the engine was tweaked and the tranny was left stock, all GM's all 3100 and 3800 series powerplants. You just cant be stupid, it takes time and a good set of ears to know exactly when to manumatic the auto.

Originally Posted by blowfishRus6

and with downshifting it to first and nailing it. its just more of a jerk, makes it feel faster. but its not

ok but i raced my friend with a 00 GTP with the same mods i have and i put mine in 1st gear and he left his in drive, when he honked three times i pulled about 8 lengths on him. im not making this up, it was really around 8. and he asked how i took off so fast. i told him and he tried it but from a 55 roll so we were in 2nd gear, and it was a much closer race than with him leaving it in drive. i have a 3.4 pully, 180 thermo, plugs, msd wires, AC delete, and resonator delete. he didnt have the AC delete which i heard is only a 2hp difference

Originally Posted by blowfishRus6

shift kit FTW??

this is a stupid question, but what does "FTW" mean? lol. and "FTL". i always see these in messages but i dont know what they mean