BBBBadSS

iTrader: (16)

This is a fresh rebuilt tranny with about 4,000 miles on. I can manualy hold 1st, 2nd, and drive but when I let off the gas it wont engine brake the car, its like I pushed in a clutch and rpms go to idle until car is about ready to come to a stop then it will engage again or will engage again at any time if I hit the gas again. If I downshift from OD to D to 2nd to 1st it wont engine brake the car! Its like I pushed in a clutch or will engage again if I touch the gas again or when the car just about comes to a stop it will engage again and pull its self. This is a level 4 built tranny with I belive a transgo shift kit.
Any ideas or theories on this, tranny or torque converter???

performabuilt

iTrader: (25)

something has happened to your overun clutch in the input drum , Its not coming on or the clutches have burned or gone bad. There are only two overun clutches and they are right under the forward clutch set and only come on in the lower manual gears ,Not in OD.

BBBBadSS

iTrader: (16)

That makes sense because in OD it will engine brake. Is there heavy duty clutches I can have put in there?

performabuilt

iTrader: (25)

No because they are not and upshift clutch they really are only intended for intermitant use for instance coming down a mountain and using engine braking to reduce wear and heat on the cars brakes. But more thanlikley unless you spend alot of time downshifting to slow the car there is some issue that caused them to burn up such as a cross leak keeping them partially applied during the 4th shift or a cracked forward clutch piston feeding the overrun piston through the crack, which with the aluminum forward piston this is a common issue. Another possibility is a cut or damaged center seal in the forward clutch piston feeding it and causing partial apply, You will have to take the trans down to really figure out what happened,

BBBBadSS

iTrader: (16)

Cool, thanks man. I do down shift it some but mostly between OD and D. Does that hurt it? Dropping the tranny tomarrow. I think I will get the torque converter rebuilt right away.

performabuilt

iTrader: (25)

That really shouldnt hurt it , Its probably gonna be one of the other issues I mentioned.

BBBBadSS

iTrader: (16)

Is this hurting the performance in say the 1/4 mile? It seems to shift fine if I put it in D and stand on it, or I can manualy shift it under wot and it seems fine.

performabuilt

iTrader: (25)

No Its Not Hurting Performance But Now If They Are Burning Or Grinding On Each Other It Will Make Debris

BBBBadSS

iTrader: (16)

I dont plan on running it, like I said tranny is coming out tomarrow.
Does it hurt a tranny to manualy shift it? Down shifting or upshifting?

performabuilt

iTrader: (25)

Thats a hot topic lol , Personally I dont see any issue with it . There are actually several reasons I wont go into right now as to why it may actually be benificial .

BBBBadSS

iTrader: (16)

Benificial? Must tell.

performabuilt

iTrader: (25)

Maybe later this eve or tomorow , Ill do that

BBBBadSS

iTrader: (16)

Cool, lol. Thanks again for your help.

Predator T/A

iTrader: (7)

manual shifting doesnt hurt it applies more clutches and raises the pressure manual low instead of the low rolller clutch doing the work the roller and the L/R clutches work together and the overrun clutches come on to assist the forward..and if you have the hd clutch kit for 3-4 you will have 17 clutches applied in 3rd and 15 applied in 4th (along with a band)

performabuilt

iTrader: (25)

Heres what happens during a manual shift
1st gear manual = low/reverse clutch set is on supporting the low roller clutch its near indestructable in this mode, Also the overun clutch is on helping support the input sprag not so much as the low cluthes do the low sprag but every little bit helps
2nd gear manual= the overrun clutch is on helping support the input sprag
3rd= equals the same as 2nd
And in all the manual gears the line presure is boosed slightly , Now in whats called roll racing its a real advanatage to pull down to first not only for power but you increase the support for the low and in put sprags .
This is also the reason a full manual valve body appears to make for a stronger trans not so much because its manual but because you have to shift manually engaging these clutches

nomoneyz

iTrader: (15)

My tranny does the this also (along with other problems). I could go into first at 30 and it the rpm's just drop like its in neutral. If i punch it the rpms jump up and catch and the tranny just grinds and slips and i dont move any where.