Easy – just put it back in the same order you took it out!
Make sure you've got the correct order of friction discs and steel plates. Also make sure you buy new friction discs from a supplier who needs your chassis number to make sure you get the correct friction discs. The ATSG manual does state that some parts are not compatible – apparently there was a change in design. For more information see page 79 (in the ATSG manual).
The cover for the clutch pack – which is actually a piston – has two seals that should be replaced. It is easy pulling the two parts of this piston assembly apart but it is pretty difficult getting them to go back together once you've fitted the seal.
Note the position of the lip of the old seal before you remove it for replacement. You'll notice that it goes in a direction that makes it especially difficult to get the two parts back together.
I don't have any snazzy tricks for getting this stubborn bit back together other than to use lots of ATF to lubricate it; and to take your time. Do not force the seal. Do not try and push it in with a sharp object such as a thin screwdriver. You will probably rip the seal or worse damage the piston assembly.
The ATSG manual states that the circlip used in the “bottom” of the B2 brake drum is different in diesel engine gearboxes (such as the 722.118) than the petrol engine gearboxes. The diesel gearboxes have a rigid circlip; the petrol gearboxes an undulated. If you are chopping and changing parts you might come a cropper – so watch out.
Before you reassemble the return pressure springs in the B2 brake drum you need to check the clearance of the K2 clutch pack. This needs to be between 0.7mm and 1.2mm.
Place the clutch pack in the B2 drake drum and measure the depth (with your depth gauge) from the “top” of the B2 brake drum to the “top” solid plate in the clutch pack...
...make a note of this measurement and call it “measurement A”. Then measure the thickness of the K2 clutch piston assembly...
...make a note of it and call it “measurement B”. Then place the K2 piston assembly in position and measure from the “top” of the B2 brake drum to the “top” of the K2 piston assembly...
...make a note of this measurement and call it “measurement C”.
The clearance is A – B – C This value should be between 0.8mm and 1.2mm – and can be visualised as the gap between the “bottom” of the K2 piston assembly and the “top” of the K2 clutch pack.
Adjustment of the clearance is made by introducing different steel clutch plates with different thickness’s.
Please note:- the information shown above is the clearance for a 722.118 K2 clutch =>
From the information in the ATSG manual other transmissions look somewhat different. If you know that other transmissions are different please let me know as this chapter in the ATSG manual just looks confused and not in the correct order to me.
Fit the return springs on the pins positioned around the inner circumference of the B2 brake drum. I decided to fit them back in their original positions although the ATSG manual says to distribute uniformly. I'm in no position to recommend one way or the other so it is up to you to choose what you want to do.
Place the K2 piston assembly on top of the return springs and push it into position with the help of a woodworking clamp. Please note the K2 piston assembly only fits on one way. Compress the woodworking clamp so that you can fit the circlip ring in position.
