C5 4HP20

[Hell Razor5543]

It looks like this query has come up before;

http://www.frenchcarforum.co.uk/forum/v ... 27&start=0" onclick="window.open(this.href);return false;

[pavlebo]

After two months of driving, a new problem. Oil below the transmission, at the junction of the engine - gearbox. Probably bad seal. ZF 4HP20 Drive Shaft Seal Peugeot/Citroen 0734319537?

[CitroJim]

Give the area a really good clean-up and then the source of the leak should be revealed...

Hope it's not the valve block cover seal...

[pavlebo]

I'll check again out a leak around valve block seal. It seems to me that yesterday was not oil around valve block seal.

[CitroJim]

I see you have borrowed one of my pictures there

A leak there suggests the torque converter neck seal may have failed...

That is bad news as it means removing the gearbox to replace it

I hope it is not that seal

Removing the 'half moon' plate on the bottom of the gearbox bellhousing may make diagnosis a little easier...

[pavlebo]

Today I looked again. Oil leaking slowly at the place as displayed in this picture.
At the bottom of the gearbox.
I have to replace neck seal. Whether you can help to get part number for the oil ring?
Would leak stopped after long drive?

[CitroJim]

And it is definitely ATF and not engine oil?

The seal should be available from any good ZF spares agents. In the UK http://www.automaticchoice.co.uk" onclick="window.open(this.href);return false; will be able to advise and supply...

[pavlebo]

I really don't know.
Before changing gearbox there has never been traces of oil.
Someone wrote that ATF oil has strong smell, but this does not?
And color of oil under gearbox is not so black as motor oil, as you can see on the picture.
Gearbox is second hand, and perhaps has long be out of use, and o-ring harden and leak.
My fault that I did not immediately changed, but it is the fate of the owner Citroën in Montenegro, no spare parts.
I am gonna to dismantle gearbox again and I find out, and I do it as part of my hobby and I do not mind.
Do you have oil ring part number?
Thank you for providing the requested information.

[pavlebo]

refresh

[pavlebo]

O'ring part number : ZF 0734310316

[1997V6]

Yes it sounds like the box has expired and will need replacment or rebuild.. Had it ever had a Fluid change at all?

What sort of miles,? Which engine petrol or diesel? Diesel 2.0 hdi use AL4 and 2.2 HDi use the HP4 20.

ZF claim a sealed for life gearbox, but none are really. A fluid change always helps a gearbox work for longer.

I received the following reply from ZF Services UK Ltd, Technical Support, to my question about their 4HP20 gearbox:
"Your 4HP20 transmission takes ZF Lifeguradfluid5. Although the gearbox is "filled for life" we recommend an oil change at 60,000 miles. I have attached an oil specification sheet and a list of our aftermarket car parts centres where you can buy genuine oil and service parts for your transmission. To prevent damage and premature transmission failure you should only use the specified ZF oil in your gearbox."

[CitroJim]

To prevent damage and premature transmission failure you should only use the specified ZF oil in your gearbox."

Precisely and always what we say on here...

Now from the horse's mouth as it were...

[pavlebo]

Some mechanic here told me that I can not change only oil seal,
that I must change oil pump and repaired converter?
If it is true, that is too expensive and I will stop fixing gearbox/C5!

[CitroJim]

Some mechanic here told me that I can not change only oil seal,
that I must change oil pump and repaired converter?

It is common sense to have the converter overhauled whist it is out. To not do so risks trouble later..

The oil pump should be ok, it all depends if what has caused the seal to fail has caused any further damage as the converter neck bearing sits in the oil pump housing and if this bearing seized it spins in its housing and indirectly damages the oil pump...

[lexi]

Jim: Have you ever seen the main clutches wear in the 4hp20? Not the lock up in the TC. I think there are another two clutch packs,maybe forward and reverse..........A and B?