The 'box is in bits. What follows are possibly the very first pictures of a stripped 4HP20 anywhere on the web...
I started by hoisting the 'box on a block and tackle to drain the oil from it after cleaning it up.
Whilst it was draining I removed all the ancillary items, including the transmission cooler.
I slipped off the valve block cover next
And inside the cover I found some magnets to collect swarf. The cover had been dented in the accident this donor vehicle sustained and one of the magnets was broken. Bits were stuck to the valve block.
Next to come off was the rear circular cover but first the oil pipe needed to be removed.
Then the cover to expose the front clutch drum.
I thn found the front clutch drum would move forward but was stopped by the input speed sensor. The sensor was removed.
Then the whole front clutch and input shaft could be withdrawn!
Along with the first epicyclic gearset..
The 'box could now be tipped on its back, resting on a slab of foam and the bolts holding the two halves together removed. The two halves could then be carefully separated, leaving this...
This view shows the oil pump and filter in the bellhousing half of the case.
Here is the other half containing the diff and second epicyclic gearset..
Here is a close-up of the oil filter. It has two magnets on it and the filter media looks like a piece of felt. The magnets are very "furry" with swarf.
The filter cannot be dismantled and needs replacement I reckon.
And finally, here is a picture of the front clutch and epicyclic gearset up close...
Tomorrow, I shall pull the oil pump to bits and have a look at that.
Then I shall reassemble it and then get the 'box off the car and dismantle that.
The 'box came apart tremarkably easily really but it is heavy and a block and tackle is really essential to lift it around. Most of the weight is the diff and transfer gear.
This box has done about 40K. It'll be interesting to see how my 150K 'box compares..