8.8" IRS, measuring for half shaft end clearance.

Ant · #1 (**permalink**) 04-01-2007, 04:41 AM

I am after information on what is the general axle end clearance, from axle (half-shaft) end to where it bottoms out inside the Inner CV Plunge joint, this measurement taken when the axle slides to its maximum length with the suspension travel??

Also if ordering axles any tips on where to measure?
maybe a total measurement might be safer, than measuring with CV Joints installed, as the widths of aftermarket joints may differ!

LMH · #2 (**permalink**) 04-01-2007, 08:14 AM

Hey A J
The inner CV joint has about 1.5" of total travel, measured from full compression to full extension.
When ordering axles, I'd call the shop you're using to build them and ask them. That way, everybody is on the same page.
HTH
Larry

Ant · #3 (**permalink**) 04-01-2007, 03:22 PM

Hi Larry,

I have had a couple of vague answers, and in my mind further in is better due to less side loading, closer to the support bearing, and I reckon if I end up with some clearance eg 1/4 - 1/2" when the axle is at its innner most point, it will be okay. Famous last words I will give them a call.

LMH · #4 (**permalink**) 04-01-2007, 04:41 PM

Hey A J
I measured one of my axles with the shaft compressed into the CV joint, then fully extended. Total travel is about 1.5" or slightly more. That's on a 31 spline 2004 Mustang Cobra axle. I don't know if the more common 28 spline is different or not but I doubt it.
I agree that further in is better. (read "makes me FEEL better"!) I'm sure that total shaft extension isn't going to reach 1.5" throughout the range of the rear suspension travel. So setting it up to the "inside" would be better than to the "outside".
Larry

Ant · #5 (**permalink**) 04-01-2007, 05:48 PM

Hey Larry,

What I have got here is almost 700bhp on 12" slicks for road racing, and as I am a fussy person with the build, I can be a bit hard on components at the race track, so like you say there is a fair bit of compliance in the joints and I dont think I really have to go to extremes, but if I get it wrong it will try and load the inner plunge joint and that may have an adverse affect on handling.

I am looking at The Driveshaft Shops 28 spline inner/outer Chrome moly 4340 uprated CV joints and their 300M axles! I have been trying to get some GKN race style joints like the late model mustang guys use which come with hollow axles etc but its more of a kit, and to date have had no success sourcing those.
I have read where a lot of guys use DSS with good success and they have heavy cars launching off on the drag strip, and use the 31 spline inners/outers but that is overkill for my car, 28spline will be good for road racing, plus I have an Eaton carbon posi which I have machined the side gears to accept the axle retaining clips, and have on the outer new Mustang Cobra 4.5 pcd bearing flangle hubs, on it goes....!

LMH · #6 (**permalink**) 04-01-2007, 07:02 PM

I have one thing to say... "WOW"!

I'm having axles made using the same shafts from The Driveshaft Shop. Or rather, I will be. Haven't sent them my stuff yet but it's in the works.
I have the same outer hubs as well. Over-kill tends to be my middle name.
Let me know if you need any other measurments.
Larry