I drive my iroc all the time, i have a th400 w/ tranny brake, the question i have is about the transmission. Is it ok to downshift either when your on the fly or when you wanna climb up to speed or whatever the situation might be.

I called my tranny builder, asked him about it and he told me NO absolutely not, do not downshift unless you come to a stop. I gave him a quick senario which was if i'm in 3rd gear cruising and comming up to a light slowing down to make a right hand turn, light is green so i'm gonna coast around the turn, can i downshift to 1st or 2nd and continue on my way, he thought about it and said i better not because when u downshift a turbo tranny with a brake the fluids do not circulate backwards the same way they do forward. But really, what if a pesky viper pulls up to me while i'm cruising 45mph, i wanna give him the old 2nd gear drop and plaster him

I do not no trannys and i dont understand why i can't downshift the car, its a street car!. I have done it b4, when i downshift to 2nd gear it clicks right into gear, now if there was a lack of fluid there it simply would not go into gear and of course that would be bad.

Any explanations, whether you do or do not do it and if its ok to do? And does anyone have any reasoning on this and can explain it to me?? His whole answer seemed based around the tranny brake, but still, when i did it there was no lag, it goes into gear so there is enough fluid present, PLUS its a th400! they arn't supposed to brake!!!haha

Please help..
Mike

 

Downshift whenever you want. When you break the tranny, pay your builder to make another.

 

The main idea with a manual is not to downshift to slow the car down... If you are lugging the motor then by all means downshift, just make sure your foot is on the go pedal..

 

I think your builder may have been talking about fluid getting to the clutches themselfs, not the shifter valvebody. If you want to shift the trans yourself get a manual, otherwise id suggest listening to your trans builder.

 

Humm... what would be different between using a kickdown switch and just dropping it into a lower gear yourself? I've dropped mine into a lower gear plenty of times and nothing has happend. I don't have a transbrake though so there might be something different with the way things work.

I burnt up one 3 times behind my old 305 damn thing was cursed so I bought a different TH400, the one I've been beating on for a couple years now

 

I downshift mine ONLY when my foot is on the gas. If i'm slowing down to come to a light, i leave it in 3rd and let it coast. To my knowledge, if you downshift and let the car "engine brake" then it can hurt the tranny.

<-- built 700R4

 

Lots of great info here guyz! thanks. well since i broke the transmission the first time i haven't downshifted it since, i realyl baby the thing on the street, i only downshift it when i come to a complete stop and put it in first. I'm not sure i mentioned but the reason for all the manual shifting talk is because i have a manual valve body in it so i have to shift, there is no put it in drive and go..

So you guyz are thinking that downshifting to slow the car down is what hurts the tranny? makes sense. I mean when i'm doing say 45mph for example and i put it in 2nd gear it doesnt lug it down at all, mainly becuase i have a 4500stall converter..