I know this has probably been covered but I tried to search and couldn't find anything too helpfull... so here it goes.
My 91 has trouble fully engaging reverse, you have to go to 1st first and then reverse most of the time and it still sometimes wont be fully engaged, making a painful and embarassing grinding sound, or popping out when I let off the pedal.
So, I assumed it was the R syncro but I've read R and 5th share a syncro? I've never had any problem with 5th or any other gear. Now I'm thinking more like bent shift fork, mb?
Anyone else had this problem? is it the syncro? I think I'll live with it for now if thats the problem, But mb a bent shift fork would be easier? I've pulled apart older 4spds but never messed with the zf.
Thanks in advance
Dave McGuire

 

the zf is one of the hardest transmissions to pull apart and put back together because everything is loads in from the tail shaft end. not impossible though.

 

Probably worn shift forks or syncros....... http://www.zf-group.com/pdf/S5-42.pdf

 

On the older trannies, they never synchronized reverse because you should be at a complete stop and wait for the tranny guts to stop turning when you push in on the clutch, before shifting into reverse. On the older trannies, grinding in reverse was usually a sign the clutch was not disengaging, so the guts of the tranny had not stopped turning. And this also overworked the forward gear synchronizers, but you really couldn't tell this was happening in those gears unless you noticed it took just a little longer to get into gear.

So I am wondering if it's a clutch problem?

 

Thanks for the suggestions, I dont think its a clutch problem, it only grinds if im still rolling or after the clutch is released, if its not all the way in gear. It just feels like reverse has no syncro. I guess I was just asking in case there was an easy fix I was missing. worth a try right?
Dave McGuire

 

Guppy, sounds like your input shaft is still turning, causing this apparant problem.
When I had enough of the grinding gear syndrome, I put in a LUK clutch. The shop found that most of the factory Dual-mass flywheel had fallen apart. No more problems except I now feel that the 1-2 synchro has been worn some in the ZF. BUT... I am gonna leave that one alone.
Eric

 

check a couple of things before you go snaching out the ole zf. check the plastic bushing on the clutch master cyl. rod under the dash. and also the spline on the small lever the rod hooks to

 

This is most common problem in a zf 5 speed, besides cracked bellhousings. I would run until there is no reverse. Because the gear has to changed anyhow. I've rebuilt hundreds of these things. Every one of them I've put a gear in it. The gear/sliding collar/syncro ring are worn. If the clutch wasn't releasing completely, it would rake going into gear or hard shift. It's not fully engaging because the small cluthing teeth on gear are wearing down. This is not a tranny I would tackle without somebodies experienced hand. It's not impossible by no means, but parts are not exactly cheap for these things. If have any questions on these trannies 5 or 6, I'll be glad to help.

 

Rebuildman,
Welcome to FTE and the IDI diesel forum.

 

Thanks for welcoming me. I've been rebuilding trannies and rears for some time now, but always enjoy learning something new. Especially with these older diesels. There hard to beat when it comes to maintence and cost, compared to the newer ones.

 

So where in Pa are you located?

 

Hi Dave. I'm about 25 minutes north of Pittsburgh. Cranberry/Zelienople, if anybody familiar with the area.

 

good morning please I have a problem no my zf transmission cluster the neutral is not coming on the cluster board so the car is not starting in the bucket not listen to is not working