I have bougrth some time ago a series III diff in an unknow estate to replace the one of my series 2. The main reason of this change is to improve braking with the dual cylinder shoes and bigger diameterer.of drums.
When i dismanled the unit, it was in a yard for years, I discovered that water has entered the casing. Crown and pinion where useless because corrosion has heavily affected both parts.

I have bougth new crown and pinion set, and new bearings and crown bolts. When I reasembled the unit I have a big doubt about pinion heigth or in other words, distance between pinion head and crown axle. In some part in the internet, for a more modern diferential, a 39.5 mm gauge is used to chek the distance between front of the pinion and botom of the crown bearing housing. According Series Workshop manual it is necessary to use a heigth gauje and a special axle in place of the crown and differential. I don't have these tools.
Could someone give me the distace between pinion head and crown axle. With this I could adjudt the pinion heigth. Thanks in advance. Any other suggestion will be welcome

 

I don't have specific knowledge of the Series differential rebuild, but generally speaking, there won't be a magic dimension that sets your ring and pinion correctly. This is a function of the gear lash between the two parts, and so changes ever so slightly between every two parts. The proper (again, generic) method for doing this is to install the ring gear and torque it properly, then "pseudo-install" the pinion gear (this is usually done with a bearing that is a couple thousands too large on the inside diameter so it will slide onto the pinion shaft without having to be pressed on and off like the correct bearing-- some ring and pinion kits come with this special bearing included, others do not. Then using this temporary bearing, you install the pinion with an approximate number of shims to get it in the right place, and then paint ring and pinion marking compound onto several of the ring gears so you can see how the two gears mesh. If your mesh pattern is out of whack, you add or subtract spacers on the pinion shaft until it is in the correct location... this is the reason for the temporary bearing, otherwise you'd have to press the pinion shaft into the bearing after each test fit, which would be a hassle. Here's an example of a pretty decent mesh pattern (not a LR gearset)...



I hope this helps.

 

Hello XXL,

Many thanks for your answer.

I tried to search the distance between pinnion head and crown axle because the Series workshop manual specifies to use an special crown axle and a heigth gauge to adjust distance. Off course I haven't these tools and I'm triying to replicate this method.

Your proposal looks really practical. In this differential shims for this adjustment are placed between outer bearing ring and case. I will put the old outher rings of the bearings in a lathe and reduce a bit the diameter using sand paper. In this way assembly and disasembly will be a lot less tedious.

I will report the results.

Thanks again