E28 – ZF4HP22 Torque Convertor Neck Seal Replacement

Note from James Copp-Taylor:-

Another blast from the past. I was given an E28 528i, that, I really should’ve kept. I hardly drove the thing, and spent most of my time, repairing it!

Not a job for the faint hearted. With the help of a couple of mates I have managed to change the front oil seal on my 528i transmission. The symptoms, the car was getting through a large amount of auto trans fluid, leaking it from the torque convertor housing and burning it off the exhaust, I purchased the seal, BMW had this in stock and I was informed that this is a common fault area, the job can be done at home but it will take a long time, but the end satisfaction of knowing you’ve only spent a few quid on a seal is good. It should take a total of 16/20 hours to do the job. Tools that are needed.


Nut breaker

Selection of sockets, mainly 10mm, 13mm and 17mm

Selection of extender bars, to make at least a two foot extension

A flexible extender joint

A breaker bar is useful

A flat blade to lock up the fly wheel

An E12 star shaped socket

At least three jacks and some axle stands


The seal, always quote the chassis number when ordering, ZF made a number of different seals to suit different appilcations, don’t forget, Jaguar used this box on the XJ40 models as well.


A number of items need to be removed for easy access.

-Steering cross bar, 4x 17mm bolts, get a 17mm spanner on one end, socket on the other.

-Front anti-roll bar, 2x 17mm bolts, get a 17mm socket on to remove.

-Drain the Gearbox fluid into a suitable container

-Obviously you have jacked the car and placed axle stands under the front end of the chassis leg, before the wheelarches……


-Remove the three bolts holding on the exhaust downpipes, you may have to apply some penertrating oil. 17mm

-Remove the 10/13mm bolts at the rear of the front pipes.

-Remove the 10mm bolts on the gearbox holding the exhaust on, support the centre section with a jack you can slowly remove the front pipe.

-Using your E12 sockets and a 13 mm bolts remove the bolts and remove the cover from the front of the torque convertor housing.


-Remove the heatsheild under the centre pipe

-This is where it gets fun. Support the box with a jack.

-Using a 10mm socket remove the rear gearbox/engine mount, the gearbox shall drop slightly, take the slack up on the jack and raise to the previous level, score the area left by the mounting to remind you where it should be replaced.

-Not to sure of the bolt size but make sure the box is in Neutral, get a jack under the the right hand drive shaft and jack till the rear wheel is off the ground, with the help of an assistant moving the wheel, rotate and remove each bolt in turn, if needed, lower the wheel each time, get a closed spanner on the bolt and push like hell from the side of the car with your foot to remove the bolts.

-The driveshaft will drop to the floor.

-Lower the centre bracket, couple of 10mm bolts, this will lower the prop nicely to the floor.

-Lower the jack under the box slightly.

-Remove the sparkplugs

-Turn the flywheel till each torque convertor bolt is in view, get a 17mm spanner on each one in turn, lock the fly wheel, have an assistant wedge a couple of spanners in the way, a top the 17mm spanner, you must push bloody hard on the spanner to crack each bolt off. Do this till three have been removed and the torque convertor flies freely.

-Lower the box a little, remove each 13/17mm bolt in turn, using the massive extender where needed, it’s best to attack this from the rear of the box…MAKE SURE THE BOX IS WELL SUPPORTED.

-The very top bolt will need a 13mm spanner and removal from the engine bay, at the back of the engine, once removed your box is free.

-Make sure its supported by a couple of jacks and shake it till it’s free, the Torque Convertor will piss fluid everywhere.

-Remove the box from the car and re-cover the torque convertor.

-Replace the seal, applying a little new Dextron II on the new seal, and tapping with a hammer handle, the seal into place.

-Drain the torque convertor and fit into the bellhousing, make sure the dogs link into the oil pump, the convertor will click back into the box once this have been meet.

-Lift the box and raise a jack under it, takes two people to lift it.

-Get a couple of jacks under it, and jack up, line up with the engine, using a brace, a Rover 800 series jack is good for this, wedge the engine against the inner wing to stop it moving.

-Line the dowels up with the engine, insert the two 17mm bolts and slowing tighten so the box comes together with the engine.

-The torque convertor will not spin freely, don’t worry, making sure the box is well supported, shake it and make sure it’s lined up with the engine.

-Get everyone away from under the car, turn the starter, this will get the torque convertor spinning freely as it now links in with the flywheel.

-Fit the rest of the bolts to the gear box.

-Feed the kickdown cable to the throttle linkage.

-Jack the gearbox up, refit the prop, using that jack the wheel up trick I talked about earlier.

-Refit the rear engine/gearbox mount, lower the jack off and remove.

-Refit the exhaust frontpipe

-Refit the anti-roll bar

-Refit the steering bar thingy.

-Lower the vehicle, put the spark plugs back in, and refill with 5ltrs of DextronII.

-Start the vehicle, leave for a minute of so, allow the oil to circulate in the box.

-Take for a short 5 mile test drive, return and park for five minutes.

-Move the vehicle, check for leaks.

-If all is well, you should be fine, don’t thrash it for a while, treat it carefully and you should be fine.