reverse issue with th350

[82k20]

okay so ive finally got the k20 running my problem is that i dont have reverse. I have all my foward gears ive drop the pan there wasnt any metal chunks in the pan and the fluid was clean. ive put a new filter in i still dont have reverse. could the problem be in the valve body im not a huge transmission guy the trannys a th350. thanks for any help yall can give.

 

[crazy4offroad]

Are you sure you have L1? The clutch pack for reverse also controls L1.

 

[82k20]

yes i do have l1 it shifts in and drives in all the foward gears but reverse does not its got me totally lost the reason why i mentioned the valve bodies because thats what a transmission guy up here told me but like i said i know very little about transmissions.

 

[crazy4offroad]

This pic...
http://pages.suddenlink.net/crazy4offroad/storage/TH350 Valve Body Exploded View.jpg
from here:
http://www.gmsquarebody.com/forum/showthread.php?t=3823
might help. I know it's hard to see but just hold your Control key on the keyboard and press the plus sign (+) to make it bigger.

EDIT: one other note, if you go pulling those valve assemblies apart be sure to put them back the way they came out! I put 1 spring back wrong, it had a large end and a small end, and it burned up my forward clutch pack.

 

[82k20]

thanks for the info ill look at my valve body soon as i can. the pic will help alot

 

[HotRodPC]

Yep, if you put it in Manual 1st gear and it still has a solid 1st gear, then it's NOT the low/reverse clutch pack. If you have 1st Gear in D, it can still be the low/reverse clutch pack. Low/Revers clutch pack issues, whether it be seals to the piston, or the clutches themselves is the most common reason for loss of Reverse. If you do have Manually seleced 1st gear with the shifter all the way down, then I'd agree the issue is likely in the valve body, but it could also be a pump bleed issue, or a clog in an artery of the transmission itself from the front pump.

 

[82k20]

thanks for the help guys it was the valve body i put a manual/automatic valve body in shifted in perfect now all ive got to do is fix the brakes on the front and put tires and its done i know it took me a while to respond i had honestly forgot about the post