my buddy just bought a small block race car. trans was bad so he bought a new Trans from a reputable guy,almost 3k. took it to track and made 1 pass,went great 10.79. thats what it was suppose to do. went to pits ready for another run and NO reverse. Any guesses? still has 1 st. 2nd n 3rd.what could of went wrong?

First thing to check would be the shifter cable but I assume that was already checked, just to make sure it's engaging reverse correctly. After that I'll leave it to the trans experts, hopefully it just needs a band adjustment or something.

wouldn't band adjustment affect 2nd gear also?

Sounds like a planetary...I used to strip the splines
Check for metal in the pan

Check the pressure on the rear servo first. Pressure tap is on the passenger side back of the case.

Rear servo probably let go, There's a retainer in there that was probably never changed out to a good billet one. You're losing pressure now. You can replace it in the car but it is messy an a real pain. Check the new billet rear servos from
A & A Transmissions

Rear band, strut or servo. Sounds like the reputable guy will be getting it back to fix tomorrow. Stuff happens. Not a big deal, unless the band is broken it should be able to be fixed without coming apart. 1 run old, I would expect he'd take care of it.

Does it have a brake in it? Does it still work? Mine won't back up if the brake won't apply.

I would think either the servo or the strut..if the
strut bent.. it might have fallen out.. or the servo
itself... both can be checked from the pan.. I would
find it hard to be the band adjustment unless he didnt
tighten the lock nut

Servo

he dropped the pan , fluid is Cooked!

What did the servo and the strut look like... was the servo cocked
or the strut bent

The lack of reverse while still having all 3 forward gears still indicates a problem with the rear band or it's hardware. Cooked fluid will still make it go until the burnt up element is done eating itself up. If the pan is off, look at the that to try to get an idea, but at this point I expect it needs to come apart. Any broken parts in the pan? Rear servo failed and jammed the band on?

904's are always good for breaking rev band, should be piece's in pan

$3000.00 for a 10.79 904???


Should be an overkill by a ton type of trans and should have had all the good billet everything, transbrake and good bands... and a nice profit for the builder to boot. Certainly sounds like a rear band issue. If I charged someone that much for a trans for that car I would offer him cash to pay for his trouble and fix it for free. Even the best stuff can break I guess.

I know plenty of guys in the 9s with a 904 and never
broke a band... I would think its the piston is cocked
and didnt release

Hellooooo...is this thing on? We want to know what broke.

The one reason I don't like high idling engines, when put in reverse, that's a lot of pump pressure. It takes a toll after awile.

trans is on its way back to builder. my buddy builds his own tranny's
this time he decided to have one professionally built. he doesn't even know whats wrong.or what could of went wrong. we'll know in a few days, i'll post it.

UPDATE! builder found band cooked off all material and ate into drum
when car went across finish line my guy thew it into 1st. gear which is a no no.