It's been a whie since I've posted to the boards, but that is mainly b/c I just haven't been driving my truck at all lately. I have a 94' F250 with the ZF tranny. When I bought the truck I noticed that 2nd and 3rd gear synchros were a bit worn, and there was a slight leak at the shifter linkage. Niether has been a big deal. Everything else worked well.

Lately though I've had two thing begin to come up and they sound expensive. The first is that I get a "whine", almost like a whistle when I am accelerating. It's loudest in gears 1-3 so I'm assuming it's probably an input shaft bearing? Shifting has also become very difficult in cold weather in gears 1 and 2 but that could be temperature related as well.

The other problem is that I have a symptom just like a clutch master cylinder going out. After driving for a bit the pedal pressure on the first press is VERY poor. Pumping it brings the feeling back to normal, and when I was almost home I actually had to pull it off the floor with my foot! The only problem with that is that there does not appear to be a fluid leak(I guess the slave could be bypassing?). It's almost as if the clutch is hanging up or something. I'm getting a burning smell too, and that just makes me all the more suspicious.

Does my prognosis sound fair, or do you think I should be checking something else first. I'm going to bleed the slave to see if that is the problem, either way I think I need to detach the transmission from the engine since it's an internal slave cylinder. Is this a tough job? I've pulled FWD trannys and this looks no more difficult at first glance.


Thanks,

Bryan

 

While this may be a little obvious.. check the clutch pedal fluid. My ZF was fine for years and all of a sudden I had to pump it once or twice for it to feel right, and my fluid was alarmingly low. I refilled it, and it's still at the level so obviously in my case, the leak is very very slow.

Your prognosis sounds fair, and you can save the tranny by purchasing a master rebuilder kit, which includes the hard parts and such. I bought such a kit on ebay by searching for "zf rebuild" then "ZF rebuilder" then "ZF parts". After a few weeks a tranny shop posted a suitable kit for a little less than $200 by the time shipping was done, and I rebuilt my ZF (with 340K at the time) on my workbench in a day with no special tools. The "trickiest" part is reassembly... lining everything up is difficult, but if you put two long wire ties around the shafts to hold them together, you can wiggle it back in no problem.

 

Thanks for the advice. I did check the fluid, which was fine. After coing home today I found I had NO pedal pressure....truck has been sitting all day. I DID find, however, alot of brake fluid residue running along the firewall inside the truck, so I am assuming that my master clutch cylinder must be on the fritz. Nothing wet under the truck or bellhousing. When I pushed in the clutch, it "stuck" at the floor and I found the reservoir level was actually higher then with the clutch pedal released. That suggests to me that it's bypassing?

If I can fix that without pulling the trans, I'll at least have some more time to find a suitable rebuild kit.

Did you replace your synchronizers when you rebuilt it, and was that part of the $200?