Thread: Nooooo, gearbox is dying!

DJ does the zip kit not include the orings for the solenoids ?

Originally Posted by DiscoJeffster

Sure.
Note: I have the 6HP28 gearbox so internal parts are different to the 26 used on the 2.7L engines.

1 x Sonnax Zip Kit.
The Zip kit is a freshen up for the valve block and fixes most of the common internal leaks that occur from age related wear. It’s installable without and special tool and does not require reaming of bores etc. consider it DIY.

1 x Duraprene gasket. Obviously a new gasket to seal the pan. I have a steel pan.

2 x valve body separator plates. The 28 box had two models of separator plates (plates that seal the two halves of the valve block together. These generally need to be replaced as the rubber seal layered on them will be worn/brittle. I bought the two types so once I have it apart I’d have both alternatives and wouldn’t need to head out to find the one it uses. You can’t tell which one you need until it’s apart.

1 x mechatronic kit. Includes four seals plus the square seal, plus the external mechatronic seal. These should all be replaced as they go brittle, break and leak.

1 x Solenoids (not shown here). These are pulse width modulated (PWM) solenoids that control the oil flows. They do wear out, can leak and flow outside the parameters of the gearbox adaptations where it then impacts performance.

1 x filter. Obvious.


So the only issue this rebuild cannot help is if there is too much wear in any bushes causing fluid loss. Also cannot fix a worn out torque converter. The idea of this is that if the valve body is able to properly control the gearbox then there is less compensated wear in other components.

Where did you source your parts in Perth?

Originally Posted by loanrangie

DJ does the zip kit not include the orings for the solenoids ?

Yes it includes new o-rings for the solenoids but that’s not what goes wrong with them. They internally wear out. Even if their resistance is of spec, commonly vacuum testing will show they leak etc.

Originally Posted by DiscoJeffster

Yes it includes new o-rings for the solenoids but that’s not what goes wrong with them. They internally wear out. Even if their resistance is of spec, commonly vacuum testing will show they leak etc.

Look forward to pics and hope goes easier than thermostat replacement

Originally Posted by PerthDisco

Look forward to pics and hope goes easier than thermostat replacement

Take care when you prise the two halves of the VB apart as mine fell apart when I picked it up after removing the bolts.

Originally Posted by DiscoJeffster

Yes it includes new o-rings for the solenoids but that’s not what goes wrong with them. They internally wear out. Even if their resistance is of spec, commonly vacuum testing will show they leak etc.

They would only leak if the orings have failed, i'd test them before replacing.

Originally Posted by loanrangie

They would only leak if the orings have failed, i'd test them before replacing.

No. There is a specific vacuum test that is performed to detect wear inside the solenoid which is nothing to do with the o-rings. The solenoids are a well known fault domain for poor shift control. Sure, stick with them but if you do all the work and it’s still not behaving, pulling it apart again to replace them? Stuff that. It’s also cheaper to buy a new set than three types of solenoid test kits plus a vacuum tester.

Originally Posted by loanrangie

They would only leak if the orings have failed, i'd test them before replacing.

Sonnax Solenoid Test Manifold Kit - 95430-VTK


“The leading cause of solenoid failure in Ford 6R60, 6R75, 6R80, ZF6HP19/26/32 (Gen. 1) and ZF6HP21/28/34 (Gen. 2) units is an inability to maintain an internal mechanical seal, resulting in a multitude of drivability concerns. Since it is not an electrical failure, it can be difficult to evaluate whether a solenoid is the cause of a particular problem.
Sonnax solenoid test manifold kit 95430-VTK allows quick, easy, cost-effective pass/fail verification of the solenoid's internal sealing integrity, taking the guess work out of replacing solenoids.”