front axle pinion shims; how much is too much?

[big dan]

Before anyone asks, I am building a front axle and the inner Cs have already been cut off so I am going to set my castor angle after everything is lined out.

Now Im going to be clocking my t-case and raising it for a flat belly at the same time Im building this axle. I want to turn my pinion up for better u-joint angles as well as getting the pinion higher off the ground.

Now my question is how much can you shim a front axle before it starts to mess with other things such as oiling the pinion bearings?

With large shims does stability become an issue? Ive done some searching and read about people welding large shims to spring perches instead of bolting them into the spring pack. Which is better? I know that with larger shims the centering pin will not engage the hole in the spring perch very well but there are ways of getting around that if bolting it into the spring pack is better.

So basically I want to shim my pinion up as high as I can safely and reasonably go. (I dont want it straight up)

And reference pics would be great from those that used shims to turn up their pinion. Im not talking about those that use long shackles or other spring hanger arrangements that messed up your pinion/castor, just general pics of how much the pinion is raised by different degree shims.

 

[sweetk30]

if me and going this far why not start with a ford high pinion housing and solve all the possible problems with no shims.

but yes if shims and tilt way up you will run in to pinion bearing oil problems and also center pin alignment problems.

you can have a machine shop angle mill the stock leaf pad cast in the pumkin to make up the angle you need and redrill the center hole. and also remove the weak stock spring perch and get a diy4x http://diy4x.com/cart/index.php?route=product/product&path=24&product_id=123 he sells singles for this idea. then weld it on to match the angle needed for the build and get beefy perch in the end.

 

[blazinzuk]

As far as oiling goes just get a hi pinion diff cover, the oil hole is higher up in a low pinion you should not have much problem at all oiling the upper bearing.

I agree though that the best thing to do would be to take the bare housing to a machine shop have the orginal holes plugged and then the perch milled and new holes drilled.

To much shims and you will break your center pin alot

 

[big dan]

Ive considered a ford high pinion but it seems that they are rather difficult to find around here and I would also have to find a drivers drop transfer case

Thought about machining the housing as well but was curious about the easy way out.

I guess when you think about it though, for the cost of shims it really wont cost that much more to have the housing machined and get a new spring perch

High pinion diff cover is something Ill have to check into. Already found the cover I want but that may change.

Thanks for the info

 

[big dan]

I am still curious on what you guys think is too much.