FZJ 80 Tranny Problem

[Banfinson]

My 80 pops out of reverse when reversed for more than 25 yds or so and then re-engages. The shift lever doesn't move. It has 137k mls and has been well maintained and is not low on AT fluid. Any thoughts.
Cheers, Brent

 

[GXO]

What makes you think it is disengaging from reverse? Does it coast? speed up? Clunk?

Sounds like the normal slack when you back up and ease off the gas and have the truck lurch a bit....

Solution....drive in D not R

 

[Banfinson]

Good thought But seriously, it disengages under constant throttle and re-engages when it stops...not a good thing!!

 

[Brentbba]

Oh man, I don't know if this board can handle two Brent's at one time.

Welcome newbie (2 posts). Tell us all about your truck.

 

[IdahoDoug]

I think Dan attempted to steer you into actually telling us what happens, and you didn't take the hint. So I'll repeat his kind attempt a little more directly:

WHAT DOES THE TRUCK DO? REV? LURCH? WHISTLE? HOWL? CLUNK? COME TO A FULL STOP FOR 5 MINUTES WHILE YOUR FOOT IS ON THE FLOOR AND THE ENGINE'S REDLINED AT 5500 AND THEN EASE OFF WHILE PUTTING OUT CLOUDS OF SMOKE? WHAT??????????

Ahem. Thenk yew....

Doug

 

[Banfinson]

OK!! While driving in reverse (without reving the hell out of it)the tranny just stops reversing and finds (a false??) neutral at which time I ease off and the vehicle stops...it then re-engages reverse. I'll try to get it to do it again today and listen/ feel for more clues.
Cheers, Brent

 

[GXO]

hmmm, sounds like a reverse rev limiter vs a real disengagement...

When you hit the "disengage point"...if you keep on the gas will it rev up more?

oh yeah...would you say you are going fast? How fast are you going in reverse when this happens?

 

[Beowulf]

>> when reversed for more than 25 yds <<

That seems like a long way... how fast are you trying to go in reverse?

-B-

 

[Rich]

Hey, let's take it easy on the new guy . Based on Brent's first post it is reasonable to suspect that his tranny is not maintaining the line pressure necessary to keep reverse gear engaged.

Based on recent posts regarding the occasional need to replace shift solenoids in the older style tranny it is reasonable to suggest this as a possible cure.

I expect any decent tranny shop can quickly diagnose the problem. The tricky part is to know which are decent.

Brent, check out https://forum.ih8mud.com/index.php?board=2;action=display;threadid=7203 , and then search for more topics regarding shift solenoids. If you wish to tackle the repair yourself consider talking to crusierdan about getting parts.

Rich

 

[Banfinson]

Thanks to all for your responses. To answer a few of the questions; I don't reverse faster than 5mph or so, I have a 100yd driveway that must be driven in reverse upon occation.
I will try to find a reputable tranny shop to diagnose the problem, thanks Rich for the insight.
Brent

 

[GXO]

a little trail blazing should remedy that big reverse issue in the driveway

 

[drexx]

13Nov2003 (UTC -7)

Banfinson, I just checked the factory service manuals. Suspect areas can be:
transmission control rod, or oil strainer, or presure relief valve...

*disclaimer: I've never had a problem like yours before