5HP18 Valve Body rebuild question

[632 Regal]

It must be valve body related. Old sloppy valve body gives me a good 2-1 downshift. Completely overhauled valve body gives me a bad 2-1 downshift.

Which leads me to question other partially related items.

[whiskychaser]

The springs in the SK01 kit replace springs 0732042581 and 0732042115 (numbers for the 088 valve body). They are the 2-3 traction valve and F brake control valve springs. If you have flare from 2-3, the engine revs increase but your speed doesn't. The effect is similar to driving a manual with a clutch which is slipping slightly on hills

Great news that the box seems to be working fine. Of course you will want to find out why the problem remains on your 'spare' valve body. While you can't really bench test the gearbox, you could test the solenoids for operation. I'd also be taking a look at traction/shift valves 1056327028 and 1056327029. I don't imagine you want to take parts from a working gearbox so I may be able to help if you don't have spares for testing.

[Frank87]

If I could get my hands on all the springs brand new, I'd slot them all in. Just to be sure.

Problem is that ZF over here delivers 80% of the springs x10 when ordering. Basically, you are looking at a valve body kit of over 600 euro's. Thats a little steep.

I'll be re-opening that spare valve body. The 20% of the springs I could order per piece, have all been slotted into that valve body. I'd like a fully rebuilt valve body in my almost-completely-overhauled spare transmission.

[whiskychaser]

Automatic Choice in the UK are still showing the full valve body kit (5HP18.VBK) in their catalogue so it may be worth contacting them. I found they are pretty good at responding on the phone but a little slow if you use email. Link is below:
https://www.automaticchoice.com/en/catalogue

[Frank87]

I have ordered my overhaul parts from them. Even they said the vbk is no longer available.

I have used: http://eshop.original-teile.de/index.php?

To order valve body parts piece by piece. All original ZF.

[whiskychaser]

I have ordered my overhaul parts from them. Even they said the vbk is no longer available.

I have used: http://eshop.original-teile.de/index.php?

To order valve body parts piece by piece. All original ZF.

I have not bought one for a while. You would think they would remove it from the catalogue.

[shogun]

Which paper gasket did you use between the valve body plates and which one was originally installed? Did you check the new one by cross checking it with the old one coming out of the valve body? identical holes and channels? Usually I lay one over the other to compare.
There are 2 different ones. According to my expert info from a ZF repair shop there are
gasket 1056 327 100 5HP18 old version
gasket 1056 327 110 5HP18 new version

I bought both of them as I do that more often on other cars and according to this expert, the new gasket can replace an old gasket (originally installed) but a old gasket version cannot be installed in a valve body originally equipped with a new version.

Same is with the 5HP30
paper gasket 1055 327 093 5HP30 old Version
paper gasket 1055 327 102 5HP30 new Version

[Frank87]

I used the newer gasket. I ordered 5 of both part numbers "just in case" as they dont cost anything.

The older gasket has 1 big hole where the filterneck connects with the valve body.
The newer gasket has 1 big hole where the filterneck connects with the valve body and a small rectangle shaped hole right next to it.

I have used that newer style gasket with 2 big holes more often in the past without issues.

[Frank87]

For those of you who are interested in the outcome, I had 2 of my 3 valve bodies measured by a specialist who has 3D equipment. The 2 valve bodies who shift excellent but have a 2-1 jerk both suffer from bore wear in the exact same housing. Bore wear leads to too little or too much pressure causing bad shifting. He said there are generally 3 options:
- Fabricate the exact same piston but oversized from a block of anodized metal to compensate bore wear
- Buy new housings and fit the old pistons and springs (pistons were fine)
- Buy a used valve body which measures correct pressures in every mode on his test bench

Option 1 would cost $$$ due to the price of the anodized material and the engineering work in measuring the old pistons, estimating the increase in bore and refining the raw material

Option 2 would cost $$$ due to single housings for valve bodies being expensive. ZF prefers to sell entire valve bodies and take back your old used one

Option 3 was a cheap and easy option as he had access to all kinds of vendors we individuals don't. He came up with the exact same used valve body from a 088 transmission, measured it, slotted in the improved selector piston and sold it to me as the solution.

I fit this valve body and after a thorough reset of the entire car (DME, AGS etc.), the transmission started shifting better and better.

The box is now excellent and the 2-1 jerk was explained by bore wear in valve housings.

Since I fit a used valve body, it will last perhaps up to 150.000km instead of 300.000. I already put about 20.000km on the box so in 30.000 km, after a good 50.000, I will probably do an oil change and may even fit a factory new valve body to see if that makes the box shift even better. This would cost me about 1000 euros. The fine shifting valve body I have now, will be held in reserve. I am going to overhaul the 5HP18 box that came out of the car after my previous overhaul as I plan on buying a 3.0 V8 sedan or touring for my girlfriend in about a year or so. That car can then be fitted with this overhauled box with the used but "ok" valve body. This makes it possible to specifically look for a car with autobox damage meaning the price goes down.

[genphreak]

Nice, Frank87- thanks you for updating and clarifying the verified causes, symptoms. Not easy to do but once you get into ATs they become a challenge one can't set aside. You've done well, and not left anyone out by sharing a lot of insights.