Transmission lost reverse ?

[davidistotheone]

Transmission lost reverse. What should I do? Just swap out for a rebuilt transmissions or take it to a shop and try to have them rebuild it ?

 

[snarl95]

Need year,make,model and engine of truck.

 

[davidistotheone]

1996./3500 Chevy..6.5 l diesel

 

[Will L.]

Rebuild yours, not an off the shelf rebuild imo. Changes from year to year can create issues. Then your “core” transmission is rebuilt and sold to someone else before all your detailed issues arise.

Outside of that, if you are buying a highly upgraded transmission from someplace like TCI or the like- then you would be ok.
Something many people dont look at is the cost of a factory new transmission. Some dealerships actually sell them for a descent price- at least a couple here in Vegas used to and the warranty that came with added some security blanket effect.

In either case when the want a core you are better off waiting a week or two before getting back them cash- that holds true with most parts.

Depending where you’re at there might be folks that can recommend a shop.

 

[davidistotheone]

I'm in Jacksonville Florida.....
Thank you for the advice

I'm still trying to figure out the best thing to do.... There's a shop here in town offering rebuilt transmissions for $1,400 and 350 to install.... I think this is a good deal if I try to have my transmission rebuilt it could run a lot more than I have...

 

[denata]

You can simply change the reverse pin to a longer one.

 

[denata]

This is done without removing the transmission. You just need to remove the cover. I could tell you more if necessary.

 

[WarWagon]

I'm in Jacksonville Florida.....
Thank you for the advice

I'm still trying to figure out the best thing to do.... There's a shop here in town offering rebuilt transmissions for $1,400 and 350 to install.... I think this is a good deal if I try to have my transmission rebuilt it could run a lot more than I have...

They can't rebuild YOURS? Then keep looking! FWIW I get mine rebuilt for $1,100.00 installed (plus oddball hard parts like gears).

 

[MrMarty51]

YUP, I`m kind of partial to My core no matter if it does cost a few bucks more. Ask the rebuilder what the recommended up rated components are and if they install those without asking. If they dont install them without asking and just throw run of the mill components at it, then, keep looking for a better shop.

 

[snarl95]

Probably just the reverse pin worn down.

 

[EWC]

When I rebuilt my 91 4L80E , I couldn't find anything wrong with the internals . Trans just had no reverse . Nothing was burned , broken or cracked . What I did do was to replace all the bushings and the seals . I got GM rebuilding tools off Ebay and checked the reverse pin . That was the correct size , or length , for my trans . Later I found that the 4L80E will take out the bushings and lose oil pressure . I am not a trans guy but that is what worked for me .

 

[denata]

When the friction coating on the reverser band is worn by 1 millimeter, the servo pin must be extended by 3 millimeters so that it clamps the tape with the same force.
(1 millimeter is equal to 1/24 inch)

 

[THEFERMANATOR]

If the trans suddenly lost reverse, you have a hard part issue somewhere. A worn band will gradually show itself, not be perfect one day, and gone the next. And putting in a longer apply pin is a short term bandaid at best. If it is a worn band, why is it so worn? If you don't fix the root problem, it will be out again in short order. The biggest issues with the 4l80e are either low line pressure from wear letting fluid just go to sump, worn afl valve bore that doesn't provide adequate control pressure through the valve body, or high line pressure from a sticking regulator that cracks apply pistons and servos.

 

[denata]

when reversed - the pressure regulator delivers the maximum possible pressure.

 

[THEFERMANATOR]

when reversed - the pressure regulator delivers the maximum possible pressure.

When in reverse the boost valve increases line pressure to about 50% more of what it would be in forward(increase from roughly 40 in fwd to 65 in reverse). Max line pressure spikes is a common problem in 4l80e's due to the boost valve design and is a common cause of loss of reverse from cracked hard parts from the shock of max line pressure.

 

[Husker6.5]

Yeah, max line pressure blew the face out of the Reverse Apply Piston in the 4L80E in my 94. Then it wouldn't shift into 3 or OD after that because it couldn't build enough pressure to shift.