hey all. first post in the trans portion of FTE.

i have a 90 f250 with a 5.8 and a zf s5-42. it doesnt like to go into 2nd or 3rd and grinds if i dont have the revs just right. is that bad synchros? time for a rebuild? can the synchros be replaced relatively easy without a total teardown? the trans doesnt make noise or clunk or anything or come out of gear. im pretty new with manual trans so sorry if i seem a little slow.

ive read that the rebuilds on these are pretty straightforward. any advice?

thanks

 

Could be synchros.

Does it go into gear easily when stopped? If not, check your clutch master cylinder mount for flex. That eats a lot of travel and can cause hard engagement and shifting.

As for the rebuild, you can get kits at:

Ford Pickup Truck Manual transmission parts, quality rebuild kits and overhaul parts - Drivetrain.com

 

You'll have to do a full tear-down to get at the synchros. ZF has a copy of the Ford service manual section on the ZF transmission on their website. http://www.zf.com/na/content/media/u...ce_manual_.pdf That will give you an idea of what is involved. They also have a troubleshooting guide to help you figure out the issue with the engagement too.

ZF Friedrichshafen AG | Service Portfolio

 

it doesnt like to go into 1, 2, or 3rd very well even when standing still...4th and 5th are smooth standing and driving.

now that you mention it, the clutch doesnt "feel" quite right. feels like it gives too easy too soon. my engagement is only like 2 inches of pedal travel.

wheres the clutch cylinder mount? like i said im a newb to manuals. i can switch out a 350 in 2 hrs but this is greek to me

 

Follow the linkage path under the dash. The clutch master should be on the engine side of the firewall. Check for rust, flex and cracks. '80s trucks had these issues and Ford even sold a reinforcement part. Not sure when it was "fixed", but your symptoms warrant a full clutch linkage, master, line and slave inspection.

 

roger, ill check it. is it just a replacement then if its weak? what exactly am i looking for on the other components?

thanks for responding and helping me out.

 

On the master, you are looking for movement of the master itself. If the firewall is cracked or weakened, the master will move instead of the piston in the master. Thus, it's like you didn't push the pedal all the way down.

The line should be inspected for bulges and leaks.

The slave, if external, should be inspected for movement. My '85 was external, and the mount flexed a little for example.

 

Hydraulic Clutch Troubleshooting .: Articles Have a read through this also.

 

Sounds like you're not getting full disengagement. My money is on cracked firewall flexing. If this is the case you need one of the 3 different kits available to repair/reinforce. '80-'86 is definitely E3TZ-7K509-A. I believe E3TZ-7K509-B is the larger kit for '80-'86. There is another kit for the newer trucks, I think the cutoff was after '86, I want to say it was when they were to the rounded '90s body style that take the other kit.

 

Definitely get the clutch linkage and hydraulics gone through before you try a rebuild. I had issues with my ZF, replacing the hydraulics helped, but still didn't fix it. Turns out the pilot bearing was shot so the input shaft was dragging even when the clutch was on the floor. Also the throw-out bearing was gummed up so it didn't slide well along the input shaft.

I don't know where you read that rebuilds are straight forward. I guess they are in some points, but without the proper tools its a royal pain in the rear. Unless you have access to the right gear pullers, you're not going to be able to get it all apart.