Cutting/turning knuckles...

[5spd_xj]

I searched some on the subject, but all I found was people mentioning that they had done this, but didn't really find much on a how-to type deal... Just wondering, when you go to do this, what exactly are you cutting, and how? What do you use, what's the process, etc...

TIA

 

[asp]

is your intent is to make a low pinion a high pinion or to adjust caster?

i can't think of another reason one would want to turn the knuckles on the tubes...

 

[cal]

I cut and turned my knuckles.

You may have to remove some other bracketry (on a dana 30, the coil buckets).

Look for the obvious weld between the knuckle and axle tube, grind at that weld, all the way around, until you have gotten down to the 'tube' level and are just barely into the knuckle itself. Once you are there, get a BIG Fn HAMMER. I don't mean a 20 ounce ball peen, I'm talking a 7 pound sledge.

Make sure the axle is well secured. I had 3 friends holding mine. Give the knuckle your best two handed swing, hitting it at a motion that will rotate it. Then do the same the other direction, and then a swing towards 'out'. After a couple of good hits, you should start to see a hairline appear between the knuckle and tube - if you don't, you havent ground enough. Be careful not to grind too far into the tube, that can weaken it for reassembly.

They are press fit and really on there. Don't be afraid to swing hard.

 

[5spd_xj]

oh yay. haha, thanks for the tips... I'll be doing it on the LP 44 I have, just want to be able to turn the pinion up, I figure at 6.5" it's a good idea. Plus, now would be the time to do it, the housing is bare of brackets, so before I start on those this would probably be a worthwhile project... and by the way cal, thank you for describing the required BFH haha...not a 20 oz ball peen. got it. LOL. What did ya use, just cut-off wheels on a 4.5" angle grinder? seems like it would be tough to just get at the weld and not the tube/knuckle...

 

[gorman]

On the subject of cutting and turning and especially a LP housing - how many degrees would one want to point the pinion upward or turning the knuckles on the tubes for say a 6" lift? On Go-Jeep's site in the alignment section he mentions that the caster/pinion relationship of a LP D30 is 12 degrees and on a HP D30, 9 degrees. I'm building a LP diff, similar to a LP D44, my stock LP D30 has about a 5 degree difference between pinion and propshaft with around 5 degree caster sitting at 6" lift. I was thinking of turning the knuckles 5 degrees to have a total difference of 17 degrees between pinion and caster - that should give me about 7 degrees caster with a 2 degree difference between pinion and propshaft. Does this sound about right?