4HP20 Hydraulic Unit

toh · Post by **toh** » 04 Sep 2010, 06:51

To PUG lover.
i got PUG 406 D8 year 1999 or may be 1998.

i dismantled the gearbox ZF 4HP20.
and i also dismantled the hydraulic unit.

i opened the side cover as in thelink

the problem is that, when i opened the upper side cover.
all spring and valve fall out. i can not remember its position.

Can someone take a real picture of those all spring on side cover of
hydraulic Unit. ? Please..

Post by **CitroJim** » 04 Sep 2010, 07:58

No worries Toh!

As soon as the CXM rally is done and dusted, I can get the camera busy. problem is, my 4HP20 spares are well-stored and not easy to get at

toh · Post by **toh** » 04 Sep 2010, 14:28

CitroJim wrote:No worries Toh!

As soon as the CXM rally is done and dusted, I can get the camera busy. problem is, my 4HP20 spares are well-stored and not easy to get at

Appreciate Jim. i want to help you Dont wanna get u in very busy

Ok ok. i am waiting.

Post by **CitroJim** » 07 Sep 2010, 21:39

Toh,

I have brought my spares gearbox out from its hiding-place and its valve block is now sitting on my bench ready for taking apart and photographing.

Sadly, I ran out of time today (much else to be done) and all being well, tomorrow I'll have the necessary information for you.

Post by **CitroJim** » 08 Sep 2010, 21:45

Hi Toh,

Here are the spring details:

With reference to this diagram:

Spring 50.060 measures 39mm long by 10mm dia.

Spring 50.090 measures 43.5mm long by 10mm dia.

Spring 50.120 measures 51mm long by 10.5mm dia.

Spring 50.150 measures 40mm long by 9mm dia.

Here is a picture of the springs and valves:

Note that Springs 50.060 and 50.150 are nearly the same length but 50.150 is made of thinner wire and has more coils.

I hope that helps sort out the confusion

toh · Post by **toh** » 11 Sep 2010, 14:24

Perfectly done Jim. everything is very clear.

compare with my photo,

my longest Spring was put at 50.030. Hahaha.

Thank you So much JiM

after re-arrange them all, My gearBox still jerk on every gear changing.

Hm i need to find more what wrong with mine..

toh · Post by **toh** » 19 Sep 2010, 16:20

This my Car CetroJim..

Hope it's not too Big.

Clogzz · Post by **Clogzz** » 21 Sep 2010, 13:11

Too big, no, but it looks like it’s too hot there.

toh · Post by **toh** » 22 Sep 2010, 16:33

Clogzz wrote:Too big, no, but it looks like it’s too hot there.

Thank you Clogzz,. nextime will be better.

it's hot because of my car

Post by **CitroJim** » 22 Sep 2010, 19:19

Your car is the only thing not melting Toh

It must be one very cool car!

Now, what is the current state of platy with your gearbox? Is it still jerky? Is it jerky in all gears? Do you have the sport and snow lights flashing? Can you only get reverse and third emergency gear in D?

I'm still trying to get to the bottom of what is wrong with yours.

toh · Post by **toh** » 24 Sep 2010, 11:54

Hi Jim.,

my gearBox is no flashing light of snow and sport.

i can do every gear P R N D 3 2 1( using snow mode, i can do every gear) every gear work fine.

but on every step up/down of gear, it is jerky( harder on step down 4/3, 3/2,2/1). but no jerk for N/1 or N/R also 1/N and R/N.

jerk is happen both manual changing gear(snow mode) and automatic(normal mode)

appreciate for your help Jim.

i still wonder what is the cause of this jerk.

now a day i go anywhere by 3rd gear

i am looking for info what the root cause of this problem.

toh · Post by **toh** » 12 Oct 2010, 06:15

Dear All who wanna overhaul by themself.

i think it's better to replace only clutch pack, gasket ect.

please dont play with the Hydrawlic unit. i mean, should not open it's cover.

it's hi precision.

just wanna share something