New solenoids/Zip kit and plate for valve body 6HP26

piria33 · September 17, 2018

I have just completed a challenging but fun project.

I was suspecting worn parts in my vlave body due to a slight flare/delay (not surge) when upshifting. Before looking at the bushings in the tranmission the first place to revise is the valve body as this is the control centre for the pressure control for shitfing.

Spending several evenings carefully dissasembling the valve body and cleaning I proceeded to vacuum test the different ports and solenoids. Several weak points were found. The inner seals on the soleoids were all worn. Also some of the areas on the valve body. The separator plate was quite worn also. These can erode over time.

So Sonnax provide a zip kit tor restore certain areas of the valve body without the need for reaming.

New end plugs, o-rings, 6 accumulators, A clutch valve sleeve and pressure valve end sleeve installed. New plate and new ZF original solenoids.

(ESD cable was used at all times when touching the TCM)

Everything was spotless. Had an Oil change in March but wasn't happy with the shifting quality.

All installed and torqued up correctly, double checking everything.

New Oil went in again.

SDD to check for codes - adaptions reset.

After some initial hard shifts due to the adaptions adjusting all gears 2-6 felt vastly improved. No shift flare and faster smoother shifting.

1-2 was still harsh.

But after about 90 miles 1-2 is now smoothing out. Re-checked Oil level after 2 weeks. Added just 200ml . All good now.

I can say this box still has a lot of life left in it (currently at 141k). The new parts on the valve body has injected new life into it without the need for a full rebuild.

Let me know if you want to view some photos.

Thanks