telling tranny mods by driving

[green67cuda]

first....not originally a mopar guy...i'm new to them....

are there any obvious ways to tell to what level, if any, a 727 has been modified....besides, obviously, the firmness of the shifts.....

i've never had a car that wouldn't, but apparently there are stock trannies that will not let you downshift to first above a certain speed or sutomatically shift out of first anyway....

guess i'm getting the notion from kits that claim "allows you to hold in first to any rpm" and "can downshift to first at any speed"

 

[Guitar Jones]

Most stock TorqueFlites will not allow a shift to 1st from anything higher than about 30 mph. Other than that I don't know how you could really tell just by driving it how far it's been modified.

 

[Duster346]

Hey green67,

I like your notchback!

Try putting your computer controlled car in park, or down to 1st while at speed, it will most likely shut the car off. Actually, don't try this in case it really doesn't!

With a stock torqueflite you are correct; it will not let you go into 1st at speed. You can move the selector to first, but the transmission will downshift to 2nd, and then 1st as you slow down. The transmission has a pretty good idea of road speed by receiving pressure from the centrifically activated governor that is mounted on the output shaft.

Full manual valve bodies will go into any gear you select at any speed. As governor pressure has no influence on the shifts.

It would be hard to tell what type of modifications are done to a certain transmission just from driving it. Some shift kits don't work properly, and some are installed incorrectly. A lot of times the shift kit will not address the "shift overlap" situation that plagues this transmission. A HARD shift may indicate "shift overlap", where the transmission is momentarily in two gears at once. This is what we want to avoid.

Hope this helps a little bit, thanks for writing.

Chris

 

[Mopower71]

Shift overlap. I had that in one of the valve bodies I have. I installed it brand new, and withthe car in the air I was just shifting thru the gears. When I pulled it into second, it locked up. Third gear was fine.
Sent it back and they fixed it, but it was very slow shifting from 2nd to 3rd. I thought it was my rebuild.
I put a different valeve body in and the tranny shifted hard into all gears. That is untill reverse left one day.