Diff fluid level after pinion angle change

[Kent]

I've 4 linked the rear and I pointed the rear pinion towards the transfer case and plan to use a double cardan driveshaft. My fill plug is now much lower. How do I correctly compensate for this? I plan to move the fill plug up but to what level?

Does the diff fluid level need to be at axle level or above? Is there a danger of overfilling the diff?

Thanks

Kent

 

[Poser]

The fluid level needs to be enough to have the outer pinion bearing, the one right by the companion flange where the drive shaft attaches, partially immersed in oil.

Failure to have the proper oil level will lead to bearing failure and ring and pinion damage.

 

[Kent]

Thanks Poser,

Is there any danger of me slightly overfilling this? How critical is it that the level be perfect as long as that bearing is partially immersed?

 

[Poser]

Not really; you may get oil out the breather if you really go crazy with the oil level, but I know folks that have cut the fill hole out of the rear cover and moved it two-plus inches higher and are not having issues.

 

[Cruiserdrew]

I fill it through the breather hole with an extra couple of quarts. No problem so far, but admittedly it isn't very scientific. I do this front and rear since they are both tipped up.

I think in the rear running forward, the motion of the ring gear actually will supply the front pinion bearing. The problem is in the front diff, where the diff runs "backwards" so oil supply to the pinion bearing can be compromised.

 

[rusty_tlc]

I fill it through the breather hole with an extra couple of quarts. No problem so far, but admittedly it isn't very scientific. I do this front and rear since they are both tipped up.

I think in the rear running forward, the motion of the ring gear actually will supply the front of the pinion bearing. The problem is in the front diff, where the diff runs "backwards" that oil supply to the pinion bearing can be compromised.

I used that trick Sunday. Thanks for sharing it with me the other day.

I use to park with the front down hill to top up the rear. Andy's way is much easier.

 

[Kent]

Great info, thanks guys!