ZF6 Hydraulic Failure Symptoms

HaysKSFirefighter · Oct 2, 2012

Some of you trans gurus out there help me out. I've been having some shifting issues lately with my pickup. I'm sure the clutch is worn out with 126k on it, I've got a new SB in the garage. My issue is, the past 4k or so it has gotten hard to get into gear. From a stop it can be a challenge to get it into L or 1, then after I take off, you really have to match the rpms or it grinds and fights ya...some say these are the symptoms of a worn clutch, others say its the hydros....I don't really want to drop $150 on hydraulics if I don't need to.

hiniker88 · Oct 2, 2012

I think there are some bushings that can wear under the dash. Might want to check them

TrailerHauler · Oct 2, 2012

Hydraulics.

From ford they are all plastic, plastic that gets hot and swells is no good for hydraulics. They don't last very long, so your clutch probably isn't releasing all the way.

Here's a good read on hydraulics http://powerstrokearmy.com/forums/showthread.php?t=22328&highlight=slave+cylinder

stroker2 · Oct 2, 2012

If the clutch was just worn then symptoms would be it slipping under load. Hard to put into gear and shift smoothly to me means the clutch isnt fully releasing meaning the hydraulics are getting bad. Buddy had the same problems on his zf5 and a new hydro system fixed it. Another possiblility is a bent clutch fork but i highly doubt thats the issue if its a factory clutch

HaysKSFirefighter · Oct 2, 2012

stroker2 said:
If the clutch was just worn then symptoms would be it slipping under load. Hard to put into gear and shift smoothly to me means the clutch isnt fully releasing meaning the hydraulics are getting bad. Buddy had the same problems on his zf5 and a new hydro system fixed it. Another possiblility is a bent clutch fork but i highly doubt thats the issue if its a factory clutch

Oh, it slips under load too LOL...been babying it for a while till I got the new clutch. I'll have to look into the metal master/slave cylinders...possibly also finding some sort of steel line to tie them together.

Thanks guys...It's been driving me crazy. Guess this will be added to the project when I replace the clutch. I'll try to get it done before though to see if it makes a difference.

HaysKSFirefighter · Oct 2, 2012

I'm going to try and track down the metal slave/master tomorrow. Another question, lots of people were talking about the upgraded clutch fork, was that only for the weak 99s, or did they upgrade them again, so should I worry about a new one in my 07?

stroker2 · Oct 3, 2012

Not sure but my 00 had a weak one and i didnt realize that until i had to take the tranny out again a couple months after putting in the new Valair :doh:

TrailerHauler · Oct 3, 2012

I think that the clutch fork prone to bending was either early 99 or all of 99, and after that it was revised and strengthened. I don't remember the specific dates for sure though.

HaysKSFirefighter · Oct 3, 2012

TrailerHauler said:
I think that the clutch fork prone to bending was either early 99 or all of 99, and after that it was revised and strengthened. I don't remember the specific dates for sure though.

I knew that but I thought they might have revised it again. Either way I'll see when the tranny comes out. I'll compare the factory 07 one to the new one I've got waiting with the clutch.

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