Ok is the 8 1/4 axle strong enough for demo derby?

[chryslerfat]

I have not had an 8 3/4 axle shaft break in the years I have run them. This time we are running a 78 Magnum with the stock axle and I was wondering if the shaft diameter was close to the old ones or small and easy to break?

 

[QKFSH67]

It will be fine.

 

[Bodyperson]

You tell us. You are gonna weld the spiders anyway.

 

[chryslerfat]

You tell us. You are gonna weld the spiders anyway.

Yup spiders will be welded just didnt want to take a wheel shot and have the wheel and part of the shaft roll away.

 

[QKFSH67]

Yup spiders will be welded just didnt want to take a wheel shot and have the wheel and part of the shaft roll away.

When you weld the spiders, weld the ends of the axles in there too….it helps the clips then…

 

[Bodyperson]

I have not had an 8 3/4 axle shaft break in the years I have run them. This time we are running a 78 Magnum with the stock axle and I was wondering if the shaft diameter was close to the old ones or small and easy to break?

This picture here shows the smallest diameter of the shaft at 1.055". Now the rest of the shaft is much larger as you move out towards housing ends(1.480). Does anyone have a a-body 8-3/4 shaft to measure the smallest point?or a 7-1/4? Just curious, got to say I started pulling out axle shaft thinking wow this looks stout. Then it necked down a bit. I still have no doubt this should be a strong setup. But with some MT sportsmans and eventually a stroker, the axle shafts do seem like they would be the weakest link. Only time will tell..

 

[Bodyperson]

I wanted to link that whole discussion but I lost it. It was a 8.25 discussion with dial indicator pictures of the measurements. I now know, because I am interested too, that in 1979 they went to a 29 spline from the 27 spline. Your 78 might be on the fence of that change.

 

[Professor Fate]

I wanted to link that whole discussion but I lost it. It was a 8.25 discussion with dial indicator pictures of the measurements. I now know, because I am interested too, that in 1979 they went to a 29 spline from the 27 spline. Your 78 might be on the fence of that change.

Hmmm... the 8.25 in my '88 Dakota is 27 spline- catalog lists them as 27 up through '96, then going to 29 in 1997?

 

[Bodyperson]

Hmmm... the 8.25 in my '88 Dakota is 27 spline- catalog lists them as 27 up through '96, then going to 29 in 1997?

I may have transposed some numbers there. LOL I am getting old. Probably changed different times for different models.

 

[Professor Fate]

79...97...
Wish I was 16 instead of 61!