1997 F250 ZF5

[csdwarf11]

Hey guys, this has been somewhat of a problem from the day i bought the truck.

It runs and goes great, I love it a lot, but heres the problem. The transmission is obviously tender, something isnt 100%, i have driven tons of truck and equipment and this one is picky. It grinds when shifting for about everyone, I have gotten used to it and can rev match and keep it from griding, but if you shift fast, or are not going the right speed for the gear it will grind. Sounds like syncros to me?

Also, I havn't had it to me but my buddy was driving one day because I was sick of driving on a trip and it popped out of 4th gear on him, I havn't been able to get it to do it in about 10k miles but I was there, and it did pop out.

Im expecting to have to pull the tranny and give it some TLC with 200k miles on it, probably got ground a few to many times and just needs it. Supposedly the PO put a single disc clutch in it because the old one was bad, cant imagine why he wouldn't have addressed this problem, oh well.

thanks a ton guys, let me know what you think

[csdwarf11]

downshifts from 5th to 4th flawlessly as far as i can tell.

[Patrick Feeley]

It's probably the synchros, especially if it's popping out of gear (although only one time so far). Make sure you check the clutch/brake pedal mainshaft bushings for wear as well as the bushing where the clutch pedal linkage connects to the clutch master rod. You can also try changing the fluid to 4 quarts (through the shifter hole) of the RedLine MTL which sometimes helps (it did on mine). Cheers!

[csdwarf11]

Yeah I read something about redline, sounds like good stuff heard great things about it.

you drain it through the inspection covers? or is there a drain ( havn't looked), but I still might just drop it and go through it because it has 200k on it.

Ill let you guys know how it goes, maybe grab a few pictures show whats up, this should be happening in the next week or so.


thanks a ton!

[Patrick Feeley]

There's a big drain plug on the bottom and a fill plug on the side (lots of folks just add through the shifter hole so they can slightly overfill it. Cheers!

[fordboy2]

Well what ever happened with this, mine seems fussy to not bad you just gotta watch that your not going too fast for th e gear when you down shift, I assumed mine was normal and I just learned how to drive it this way. maybe not now that I read this.

[csdwarf11]

Originally Posted by fordboy2

Well what ever happened with this, mine seems fussy to not bad you just gotta watch that your not going too fast for th e gear when you down shift, I assumed mine was normal and I just learned how to drive it this way. maybe not now that I read this.

Its not normal at all, I do think its syncro issues. Ive driven many trucks with zf5's and they for the most part shift like a car, very smooth.

Im running it with the bad syncros for now until I decide to rebuild the tranny, I will probably do it myself to save the cash. They arn't that complex despite what people say sometimes. Just have to be organized, My dad has done a few before and is going to help me.

Ill let you know. I havn't even changed the oil to MTL so i will do that soon here, ill also report back and let you know if that helped and how much.

thanks everyone!

[csdwarf11]

i have looked for mtl redline while browsing the shelfs at a few stores, havn't seen it yet. Online its like 15 bucks a quart? is that actually how much it goes for?

Where should I pick some up, thanks again!

[Diesel_brad]

Syncros are your grinding issue

Popping out of gear is bad bearings typically or a bad shift fork OR it wasnt all the way in gear.

All the syncros, All the bearings and ALL the seals are about $250

And about a day to tear it apart and reassemble. You will want a press and bearing splitter to take the collars off

[7.3 on 40s]

Zf5 needs motorcraft synthetic atf part number xt5qsm. Also i have had a few obs fords with zf5s and they would all grind when shifting fast.