Topic: 30 Spline 4340 Upgrade Question

[blazen487]

I was just wondering, when I replace my stock shafts with the 30 spline 4340's will they go into my differential?  I have a detroit truetrac in my '85 front end with .529 gearing that I really do not want to replace.  Are the very inner splines 27 and then neck out to 30 on the upgrade shafts? Or is the stock spline count on the inner shaft 30 making this upgrade viable?

[mudmaster]

Yes, the inner axle is 30 spline. Do it!

[blazen487 [OP]]

Can you think of anything else that will need replaced in the assembly to put it all back together after installation of these B.A. shafts?

[blazen487 [OP]]

I do not have manual hubs anymore since my truck is off-road only, I have competition flanges that keep it locked up all of the time (this saves a few steps in the servicing process as well lol).  Will those need replaced or anything else in the assembly, is what I am curious about now?

[Joey88RUNR]

Can you think of anything else that will need replaced in the assembly to put it all back together after installation of these B.A. shafts?

I would check and repack knuckle bearings and wheel bearings while doing the job. maybe new felt gaskets so your knuckles wont leak. reccommend HD marlin inner axle seals!

[blazen487 [OP]]

Oh ya, I have the entire rebuild kit waiting, its just that I have done this job over and over again about 3 years ago and this time I am waiting until I get the 30 splines, then the HD seals are getting sealed in with cat green and I am hoping that I never have to go back into this axle.  I do not understand how the flanges that replaced my manual hubs which are on the stock shafts now will fit the new 30 upgrades.

[mudmaster]

I believe they should still work. Give Bobby a call, he'll be able to answer any question you have. 253-847-8254

[blazen487 [OP]]

Thanks a lot, axle is about to get a little Toyota tougher, and..... I'm pumped about it!!

[kneedownnate]

I do not understand how the flanges that replaced my manual hubs which are on the stock shafts now will fit the new 30 upgrades.

The same way your stock locking hubs would fit if you still had them.