Axle spline Q

[MudFrog]

What is the big difference in a 28 spline 10-bolt and a 30 spline 10-bolt. I was reading the specification page bout my blazer and it said my 10-bolt started using a 30 spline, is it any stronger?

89 K5 Silverado
http://mudfrog.coloradok5.com

 

[6.2Blazer]

The 30 spline axleshafts should be approximately 20% stronger than the 28 spline versions. However, this is just the axleshaft themselves and not the entire rear axle.

 

[89K5]

I saw that too. I here alot of guys saying that their 10 bolts blew. Does anyone know if these were pre-89 10 bolts with the 28 spline or the gearing in all 10 bolts?

 

[ken]

The thing that grenades in 10 bolts is usually not hte axle shaft but the ring & pinion itself.

ken

 

[Blazer1970]

It's not normally the axle shafts that will break in a 10 bolt failure. For instance, the one in my Brother's '95 Yukon made a big bang, and then started making noise. We pulled the cover, and found that one of the carrier bearing cap bolts had broken. Found the bolt in the bottom of the case, and the cap was loosely held on with the other bolt. He even drove it like that for a little while, amazing that it did not eat the bolt and grenade completely.

Tim

1970 Blazer CST 4X4 350 SM465 NP205
1987 Suburban 4X4 350
1988 Chevy Pickup 4X4 350

 

[6.2Blazer]

It seems as if most 10-bolt failures are due to the differential (especially the Gov-Lok) blowing up. I think this is do to the fact that most 10-bolts see mostly pavement and the diff is what goes due to the stress of heavy acceleration. In off-road conditions with larger tires there is a better chance of the axleshaft breaking due to the extra stress (such as climbing hills) and the shock loads caused by bouncing tires over rough terrain and the constant "spin and grab" conditions. I have also read that the 30 spline differentials (or carriers) are weaker than the 28 spline versions, this is because the carriers were just bored out to accomodate the larger axles which meant less material in the carrier.

 

[MudFrog]

If thats true... I'm screwed
I have the 30 spline and a Gov Loc

89 K5 Silverado
http://mudfrog.coloradok5.com