No Reverse
 

ok I searched and just read 20 pages but the other day while i ewas backing out of a parking space some guy decides to whip out of the one directly behind me so i hit the brakes and then stepped on the gas and the car would not move it would just rev like its in Neutral...but there was no signs of the gear slipping before, it just happened out the blue it does drive forward perfectly fine and no codes...I was wondering if anyone had any ideas 2002 4.4 or am i gonna be looking into a rebuld with faulty F clutches

This is a common problem with the GM 5L40-E transmission used in the 3.0 litre models (generally caused by the reverse lockout valve sticking) but it’s unusual in the later ZF 5HP24s used with the M62 engine.

Early 5HP24s had problems with the F-brake piston seals which would wear and leak preventing pressure building up behind the piston and hence reverse was lost (the C-clutch & F-brake being engaged for reverse) but this was sorted in the late 90s.

http://i260.photobucket.com/albums/i...tchFPiston.jpg

The only 5HP24 that I’ve rebuilt specifically for losing reverse was caused by the O-rings failing on the C-clutch support bush (the sleeve having rotated in its housing). However there was still some pressure build-up and the vehicle would just about move backwards if gently nursed.

http://i260.photobucket.com/albums/i...clutchfeed.jpg
http://i260.photobucket.com/albums/i...ledO-Rings.jpg

The fact that your failure happened so quickly though is curious. The 5HP24, like the 5L40-E and any other modern transmission for that matter, has a reverse lockout which prevents reverse being engaged at forward speeds above 5mph if the shift lever is moved (accidentally) into reverse while the vehicle’s travelling at speed. The 5HP24 has a shift solenoid (solenoid #3) in the valve block specifically to perform this task but it seems unlikely that it would just suddenly develop a fault in the situation you described. I guess it’s possible that the lockout valve has become stuck?

It makes no difference whether the transmission fluid is hot or cold?

Phil

hanks for the input but it doesnt matter if its hot or cold either way stillo o reverse

Can your shift linkage be out of whack, and your car is not even engaging reverse? Do your reverse lights turn on?

the reverse lights come on and the mirror dips down just no movement

Wow, well now, that is kind of freaky. Have you tried flooring it? Make sure no one is behind just in case it kicks in.

I've tried to floor it but it acts like its in neutral

Time to go to a transmission shop. Sounds like a solenoid to me. Could be something else in the valve body

Yea I'm with JCL on this at this point. Maybe GT1 will be able to read the code.