I have a shop quoting me billet stub axles for my car. They will made of chromoly or 300M and should be able to withstand ANYTHING someone wants to throw at them.

Preliminary cost estimates are they will be around 400 dollars each....but we will have to wait and see. Qty of units might help spread the initial costs out and allow for cheaper individual costs.

Just testing the water. Have some other creative thoughts for these cars also that will GREATLY increase the strength of the IRS.....stay tuned

 

Me, me! I'm going to a 500hp 412 this year, and worried about my stock IRS rear.

 

Maybe a stupid question but isn't it more likely the u-joints would break first, regardless of the strength of the axles?

 

I was looking at the carbon fiber ones, and thought the same exact thing. Not to mention on those I don't think there is any way to replace the u-joints

 

No the 1350 series u-joints take a pounding. Not to double talk myself but I was having some issues with ruining the u-joints this past season (actually crushing the needle bearings after as little as 1 run) but I found that the problem was I was not correctly, or rather I was not paying attention to the torque spec. After calling around for stronger ones and talking to people about option - two of the guys asked me if I was using the torque specs as listed......after paying attention to it, my problems disappeared! They only need 20ft/lbs...I must have been putting too much on them and they said it concentrates the load too much and you get my results.

Also I am talking about the stub axles, not the 1/2 shafts. THey have carbon fiber 1/2 shafts already. When you really start making power the stub axles are a weak spot. Broke both mine on this launch the last day out of the season!

http://media.putfile.com/spindles

I spent some more time on the design today and I think I have come up with a pretty crafty way to lower the price dramatically and make things VERY strong......

Going to the shop tomorrow to get a more firm cost estimate.

 

OUCH!!

 

I'm already working on a redesign, with bigger replaceable bearing and larger diameter axles.

http://forums.corvetteforum.com/show....php?t=1552588

Here's some pics of a Coleman Wide-5 which takes the same bearing as their Grand National hubs.

Here are the bearings next to the hub. Here you can see how much bigger the subaxle could be.



The part that's failing is ~1in in diameter, I want to crank it up all the way to 2in. I figure that should do it.

 

Brian,

Cool, and thought I saw you were working on something with the hubs...But I think your failure mode is different than that of mine. You are failing in the bearing area, due to excessive side loads associated with the autocross, whereas my bearing and stuff have held up terriffic (still stock 89s) but the spindles due to the excessive power and brutality of 1.3 60' times are failing.

Your upgrade with the larger axles would definately solve my problem, in this case bigger would be better, but with better material and a standard diameter stub axle it will hold up fine for me and my power, thus satisfying 99% of the people's needs....and should be a direct bolt in and be very cost competitive. I would imagine that replacement of the hubs and axles will get pretty expensive, but you guys need both upgrades, whereas I only need the strength added in the stub axles....

Keep cranking away with your project...as it will solve some of you guy's problems.

 

But isn't the cryo guy, forgot the name/link, already doing subaxles in 300m?

 

Not sure what Jeb is up to......We usually chat on the phone about things, but he has been pretty elusive lately....or maybe I have been....at any rate, we have not spoken in a few months.

 

I'm in. just snapped my third axle thanksgiving weekend. This is perfect, I haven't done anything because I was waiting to see if anyone made billet axles.

 

ttt

 

i want some! hurry it up lol... think they will be ready by the end of january? I am ready to do moly half shafts and some billet/300m stubs... think we can get some for the differential as well? or are you guys keeping them alive and if so could it be the next week link?

CChris

 

Guys I spoke to the shop on Friday and they are going to be more expensive than I thought. They would be machined from billet 4130 and look nearly idential to the OEMs, with slight changes to areas where they can be larger. In other words you could just stick them in and they would bolt right up. But like I said they will be more expensive than I originally had hoped.......They quoted me for the first ones $775.00 each. Just the chunk of billet is 98 dollars, but the 775 included that cost.

When you do look at them there is a LOT of machine time to take a chunk of billet and machine it down into what the OEM looks like. I honestly was hoping for a OEM version to come in around 400-450 range.......the guy did say after they do a set if things are cheaper then he would adjust the price down accordingly. My father and the guy work together and run the place....so I have no doubt that he is telling me straight up what something like that would cost to machine...and would stick to his word about adjusting the price downward if the cost did come in under what he quoted.

My initial thoughts were that is too much, but when you look at new cold stabalized ones from TOMs Differential which are no stronger than one out of a junkyard for 100 dollars, maybe its worth it.

These units would also be cryo treated upon completion of the machining to relieve any stresses.....I am sure they would hold up to some SERIOUS abuse....and yes the inners might be the next week link, but for some reason,....knock on wood, i don't see many people breaking the inner - and I have yet to hurt one and mine have at least 400-500 runs on them under some pretty brutal conditions.

What do you fellas that were interested think....I am still mulling it over, but if you guys are interested maybe with a few sets on order the guy might lower the price some more......

Give me your thoughts...I would really like to have a solution to this weak spot in the rear of these cars.

 

I had these made years ago. Heat treated, cryo, and clad plated $325.00 each.

 

That's a nice beefy looking piece!

 

Thats what she said!!!