Difference between shift kit and bad tranny?

[C0DY1921]

So i am looking to get a car and the guy told me it had a shift kit in it. This worries me because it has high miles and I dont want it to be the tranny going bad. Is there a way to tell the difference between a tranny going out and a shift kit by test driving it?

[thebeewantsboost]

Re: Difference between shift kit and bad tranny?

well i'm not a transmission guy really. but i'll throw in what i think i know... if a transmission has a trouble code. (i don't think they will always set the CEL). it will raise the pressure in a limp mode sort of a deal in an effort to save the transmission. higher pressure will cause harder shifts. if that's the only symptom you have. i would try to get it scanned with a good scanner that shows transmission codes. somebody else may have better info for ya.

[ssms5411]

Re: Difference between shift kit and bad tranny?

A shift kit and corvette servo with make the trans firmer and shift harder, suppose to extend the life of the tranny. You should have nice firm shifts when you drive it. If your in a high heat state where its warm you might add a trans cooler to help out. You can have it scanned for trouble codes and see if any come up , usually its a 1870 code that shows up when the valve is going out. How many miles is on it and when was the shift kit done and how many times was the trans fluid changed? I would ask these questions.

[thebeewantsboost]

Re: Difference between shift kit and bad tranny?

some things i just thought of. obviously look to see if the transmission is slipping. but also... if there is a 1870 code stored (the light may not have come on yet) it will stop the tcc from locking up. so get it up to about 45 and see if the torque converter locks up. the rpms should drop quite a bit, if you're still unsure tap the brake. you just have to tap it enough to hit the brake light switch, it will unlock the tcc and the rpms will go back up. The transmisison will have to be atleast halfway warmed up before the TCC will lockup. an 1870 code isn't to bad to fix. i replaced the valve body on my dads s10. and it still runs :D i second ssms' on the tranny cooler, heat kills autos.