1984 f150 4x4 302 c6. 1,2,d all work fine but netrual is like drive and reverse feels like it is stuck in drive an reverse at the same time same with park.so there is no gear i can rev the motor up in. valvebody? thank for any help Tim

 

Linkage under the truck might be misaligned or loose....that's my first thought..

Have you ran over something recently? I have seen things hit linkage and bend it. Imagine a skunk being ran over, bouncing up and hitting linkage.....bending it and then the skunk exploding all over the underside of the the car and onto the hot exhaust. Yeah...I had to deal with this once! Other time I had a customer run over a piece of wood and it did the same thing...bending the selector linkage....

Have you had the transmission out recently? The linkage might be installed incorrectly or it may be loose.

if linkage is not bent...sounds like the gear selector might be misaligned. Have you had issues starting the truck in park or nuetral? (nuetral safety switch is a common related issue) Check the linkage going the the transmission. Does the linkage feel sloppy? Adjust if needed and replace worn bushings if the linkage has them.

if linkage feels tight..adjust by loosening adjustment nut. then wiggling the gear selector inside truck and letting linkage move naturally to appropriate position then re-tightening. Check again and then adjust again if needed. Sometimes this takes a few attempts to get it right....

if all else fails......jack the rear wheels up and disconnect the linkage and manually change the selector position on the side of the tranny to double check proper operation. BE CAREFULL!!! chock the wheels securely and don't change selector between forward/reverse/park when wheels are spinning..you could break the parking pawl.....have someone in the cab while you are underneath checking...

If linkage is good........

if unit does not go into reverse after manually checking operation described in previous paragraph...drop the pan and check for metal or clutch material....

if you find metal or clutch material....either valve body may be hanging due to particles making valves stick....or you have a more serious issue...this would indicate an overhaul is probably needed.

Three things can cause no reverse. The sun shell broken, the rev. input clutches are toast, or the low/rev clutches are toast. If the sun shell is gone then you have no 2nd and no rev. If the low/rev clutch is gone, then the trans will free wheel when you let off of the throttle and drop it to manual low when going around 25-30mph.

if you get to this point and there is nothing in the pan besides the normal fine metal mud on magnet(smaller than grains of table salt)...then could be valve body issue...but this is rare...

hope that helps narrow down your issue.....

good luck..

 

THANKS ILL check all that when i get home.

 

ok i know this is a old post. but im having the same problem with my c6 tranny
heres what i have a 77 460 with a c6 tranny
park neutral and reverse all seem to be the same. but the motor also will not rev all the way up seems like its bogging down a little or the 4 barrel is not opening up.
i believe its all tranny related

how did you fix yours if you happen to see this post what did u do to fix yours anyone else with some helpful info would be greatly appreicated as well


thanks alot.

 

I would replace tranny in either case but that's just me

 

As with any trans problem, a little diag goes a really long way. At least to me (since I cut my teeth on these tranmssions), they are a very well known quantity, and a very easy rebuild. And if you think these are hard, try a 6F50N.
Does the trans creep (either direction) in neutral? Does it 'kinda want' to move, like a clutch engages, but it 'won't move' because a band isn't?
Does it shift normally in 1-2, but not have 3rd?
Do the manual 1 and 2 work normally?
Is is the same hot or cold?
When did the problems occur, and what was happening right before things went haywire?
Please let us know. This won't be hard to figure out.

 

Thank you For help forward clutches seized up
It's rebuilt now