just had the 4.44 crown wheel & pinion swapped to 3.9, the drive pinion is all built up, i've bolted the crown wheel gear to the front diff, fitted into the casing and then i thought i'd read the PDF to make sure all was going according to plan.

Now it mentions in the PDF about the drive pinion shims and altering the amount you put in to get the proper contact area between the two gears which i understand, question is, is it going to have changed from the 2 sets of gears? i've got 3 shims from the 4.44 set up which was obviously correct, is this going to of changed or is it pretty much the same from gearbox to gearbox?

 

It could be different, but more than likely it will be about the same, or as close as makes no difference. You will almost certainly have to adjust the diff offset to get the correct mesh. On a CWP swap you can do this by feel initially, confirmed by marking blue/chalk on the CWP to check the mesh. you will need to torque down the two casing halves, and put a couple of the thrust bearing bolts in to check.

Paul

 

okay, that's what i thought, adjusting the diff offset, i can't find anything to tell me how to do this in the PDF (think they're using different terminology) i'm presuming you mean altering how close the bevel gear comes into contact with the pinion shaft, how's this done?

 

Front diff offset is adjusted by winding in and out of the diff bearing carriers in the two halves of the gearbox casing. (where the front shafts exit the box)

 

thought so, the PDF confused things by mentioning hypoid gear backlash adjustment by tightening the bearing carriers will give it a go in a minute

 

I left that bit for Paul to do on mine, Hope it all goes together well Kev

 

some engineer's blue later and it's perfect as it is