harsh downshift to low

[z-ya]

This is a conversion to a 2001 camaro with a 2004r and a 911 converter. I
bought the setup used and it was built by century transmission. Everything
seems to wok fine ,except when comming to a stop when the trans shifts to
low, it bangs the car violently.Does any one have an idea what is going on here? Idle speed is set to 850 rpm.I have a pressure gauge permenetly mounted in the car and the tv cable seems to be set correctly.Right around
100lbs at idle and rises instantly with throttle.TIA
whitey

 

[Lee Thompson]

Imo

Probably missing the large cushion spring in the servo. Some people do this in an attempt to firm up shifts.

 

[mikestertwo]

Is it harsh 2-1 or 3-2? At what speed is the downshift?

 

[z-ya]

It's harsh 2-1 at low speeds and no throttle comming to a stop.

 

[mikestertwo]

At what speed is it downshifting 2-1? It shouldn't downshift until you are almost stopped.

 

[turbo nasty]

I second the no cushion spring as well

 

[77 cruiser]

When trans downshifts itself to LO with the shifter in anything but manual Lo you shouldn't even feel it. It would feel like neutral because when coasting you would be overunning the roller clutch.
Pull the shifter into manual Lo & see if their's another gear. I think it's going clunk on the 3-2.

 

[z-ya]

Mr Kurtz verified that the spring is not in the servo so you guys were right as usual. Yes the car is nearly stopped , about 10mph or there abouts when this occurs.All the suspension is rod ended chrome moly so that doesn't help either.It has a stage rite transbrake in it so there won't be any pulling it in to
low while moving ( I HOPE ) .

 

[z-ya]

So if I replace the missing spring in the servo this problem will be solved?