Part 1 [ Ссылка ]
Part 3 [ Ссылка ]

Part 4
Installing the ZF4 HP18 governor unit
[ Ссылка ]

Part two (of four videos) showing how to access and remove the governor unit on the front wheel drive version of the ZF4 HP18 transmission. Actual example is from my 1995 Citroen XM 2.1 TD (XUD11) which started to show signs of governor-unit seal failure - a common fault on the ZF4 HP18 according to several forums such as those for the Saab 9000, Alfa Romeo, Citroen and Peugeot. Several US manufacturers also fitted this transmission in rear wheel drive form.
Symptoms of seal failure are bad gear shifts but the main one is a feeling that the car wants to stall as it comes to a stop. This is normally accompanied by vibration.
My XM had all these symptoms. Luckily the governor seal repair is fairly simple as it can be carried out with the gearbox in situ. Lucky really considering that a gearbox swap on a Citroen XM is an 'engine-out' job due to lack of room in the engine bay. Worth noting that these 'old generation' transmissions are actually strong but don't tolerate wrong type of ATF or extended drain intervals. These transmissions need Dextron II mineral based fluid - NOT the later synthetic based ATF. Synthetic base fluids will cause rapid wear of the non-metallic parts of the box such as friction surfaces and any rubber, plastic material found in the gearbox. Many an owner has found to their cost of filling their 4HP18 with the wrong fluid. Also worth noting that they tend to run hot - especially in the Citroen XM so the cooling system and the fluid exchanger and ATF radiator have to be in perfect order.
Tools & parts needed;
Trolley jack
Axle stands
Drain pan
Two-legged puller
Socket set
Torx-bit set
Fine tipped probe to remove the two square-section rubber seals
New governor seal kit
Dextron II mineral based ATF (auto transmission fluid)
End cover gasket (reuse old one if perfect and NOT torn)
Pinion bolt.

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