Hey guys,

I have recently finished a zf5 swap on my 1994 f250 460 4wd.

first 800 miles I had almost 0 trans issues and everything seemed fine trans wise.

after putting in my new ecu this weekend, I noticed my trans has become very noisy. I would call it gear rollover. But I’m not sure that that is the proper term.

It ONLY happens when I am letting my clutch pedal out. I don’t hear it with clutch fully disengaged, or engaged. And it does not happen every time.

Much more apparent in the lower gears. Especially 1-2, and 2-3.

Trans shifts like you would expect a zf5 to, as it is relatively newly rebuilt, but this intense rattling sound between every shift makes it sound pretty bad and it honestly seems like the clutch grabs a lot harder and tougher since I’ve heard the noise. And I don’t beat the crap out of it. I shift like a grandpa. I’m trying to restore this truck.

I towed about 650 miles this weekend and the noise is more apparent when there is a trailer, and when the rpm’s drop more between a shift, for example, shifting while driving up hill.


My questions are, is this gear rollover, or is it possibly a clutch issue? The truck got a brand new clutch, pressure plate, and flywheel 800 miles ago.

Is gear rollover harmful, and why does it happen,

Is there any way to fix this?

Is this normal,

is this something a different type of atf would fix?

Let me know what you guys think. I’m 18, and just recently getting into the mechanics of these trucks. So any insight would be great.

Thanks,

 

Who rebuilt it and when?

Gear rollover is more common with the Diesel trucks. We just add an extra quart of ATF to help some, but they are noisy with a single mass flywheel.

 

The trans was rebuilt by a shop in New York 6-7 years ago. The original owner died, and the truck sat. I picked it up for my parts truck. Roughly 10k on trans.

does my problem sound like gear rollover?

 

Does it make sense that it only happens when the clutch is grabbing?

I will note that my transfer case shifter hole is still open. So I’m sure that accounts for a little noise. But it is very loud when it happens!

 

My dually was real loud inside without the shifter boot there...plus heat was immense from the floor. Like blazes of hell and damnation itself!

I would start with the boot and go from there. I have zero experience with the noise of a gasser with the ZF S5-4x behind it, sorry. Ours spec 4qt of ATF, we do 5qt and fill through shifter hole. You may want to verify fluid is at proper level. I broke mine in with cheapo ATF then swapped to Redline D4. Shifts about as good as that tank will shift I believe, I also do have the Midwest Trans short shifter in mine.

 

Oh yea it gets rediculously hot in there. I will start with over filling the trans. Will that jack up my shift tower seals?

 

It did not mess up my seals.

 

Ok I’ll give it a try thanks