i have a 1997 pontiac grand prix gtp that i recently put a 2001-2002 GTP transmission in, the problem is i have no reverse i have all other gears and they work flawless just no reverse. is this a valve body/solenoid issue or is my sun gear screwed, the transmission was fresh rebuild

thanks for your help

No reverse can be a few problems, but since all of your other forward gears work fine then it rules out a handful of possibilities. Commonly no reverse is a seal problem on the reverse apply servo. It may have been installed incorrectly or an older short-style lip seal was used instead of an updated long-style lip seal. Also the reverse band may have broke which will give you no reverse.

__________________
www.TripleEdgePerformance.com
http://www.tripleedgeperformance.com...ssion_Info.php tranny info page

so basically i should be getting a new transmission

how hard is it to rebuild these things? lol

also my car has the thread in style transmission cooler lines, but the transmission itself was a quick release style, so i used an adapter fitting on the smaller hole and reused my style lines (threaded) could that be a problem?

The mid 99 and newer cases had a larger fitting thread, the one that points straight down, to accept a fitting that has a checkball and spring and is larger in diameter than the early fittings. The function of this checkball and spring is to retain fluid in the torque converter when the vehicle is shut off, hence its name an anit-drainback ball. The earlier models had this inside the transmission, mid 99 to jan 04 had it in the fitting, then jan 04 to present has it inside the trans again. You may experience a long delayed engagement on cold startup but otherwise shouldnt case any major problems, however this really does need to be in the loop. There were thread in style fittings with this that were used in late 99 before they switched to the quick connect lines.

__________________
www.TripleEdgePerformance.com
http://www.tripleedgeperformance.com...ssion_Info.php tranny info page

so basically this transmission is junk for my application. whats your recommendation. once upon a time i was GM technician could do most any work thrown my way but never had the opportunity to learn how to rebuild these trannys even though i really want to learn them, and now i work on british cars ( land rover, and jaguars, aston martins etc.) primarily, still love GM and grand prix's, ive had 3 GP's now, 2002 gtp coupe, 2000 gtx sedan (black as seen in pic) and my 1997 gtx sedan ( as currently out of commission in my driveway with a a brand spankin new 3.8 and SC just needs a tranny now ..... again lol

do you think it would be wise to at least check the reverse servo, to see if anythings missing or has a bad seal? who knows it may be something that simple and after that IF it works i'll fix my cooler lines


thanks

Is the no reverse problem on your original trans or in the newer one you mention? Sorry I guess I took your original post as you installed a newer trans and it has no reverse. If its your original trans did it show any signs of slippage? Does it make any attempt at all hot or cold? It is worth checking out the seal but if the band is broken you wont know without taking the trans apart.

__________________
www.TripleEdgePerformance.com
http://www.tripleedgeperformance.com...ssion_Info.php tranny info page

i installed a new transmission, and right out the box it has no reverse, when you put the transmission in reverse the engine/trans slightly (very softly) shift but no movement with acceleration

Gotcha, I would check out the seal on the reverse apply servo-piston but you may also have a broken band.

__________________
www.TripleEdgePerformance.com
http://www.tripleedgeperformance.com...ssion_Info.php tranny info page