7200# rear axle (HO72) extreme application

[stillsmokin]

Hi everyone, I'm new on this forum, but not new to old 4 wheel drives.



I have a 7200# axle (ho72) question thats a little different than most. I have seen many 7200# axles in hot gas sled pulling trucks. I have a 4.57 ratio7200# axle coming my way from a 67 2 wheel. If I were to put a 7200# axle under say a 92 dodge diesel (anticipating the pinion dislocating on the current dana 70U) how will it hold up? I was thinking of trussing the axle tubes, using a 14 bolt mini spool/welded to the carrier for reinforcement and 14 bolt axle shafts. Or can I get something even stronger? The yoke is too small for the dodge u joint so I need to do something there, think it's a 1410 joint.

It would be alot more cost effective vs. a dana 80 and would be more of the correct width and look for the dodge. Plus used parts are everywhere and fairly inexpensive which is not the case with a dana 80.

The 7200# axle is pretty similar to the 80. Both have 2" pinion shafts, they have similar sized axle shafts 1.5" although the 80 has 35-37 spline axles vs. the 30 spline 14 bolt shafts, the 80 has a little more in the ring gear and it's bolt circle is a little larger.

[DieselEater]

I'm running a 14-bolt in a 700ish HP super stock puller.....Unless you're making more than 800 HP and your rules allow it, you can't beat the 14-bolt!!! they're everywhere, the pinion style is stronger than the D80, they're cheap, and easy to get parts for, like yokes to match your driveline.

A........

[DieselEater]

[stillsmokin]

Originally Posted by DieselEater

I'm running a 14-bolt in a 700ish HP super stock puller.....Unless you're making more than 800 HP and your rules allow it, you can't beat the 14-bolt!!! they're everywhere, the pinion style is stronger than the D80, they're cheap, and easy to get parts for, like yokes to match your driveline.

A........

Well a pinion design supported by 3 bearings is stronger than one with 2. But, in a diesel competition application we don't worry about HP, it is torque that shreds drivetrain components. The 14 bolts I have around here are 1.75" at the pinion splines. The dana 80 and 7200lb axle have 2" pinion splines, these cummins pulling engines produce 1400 torque fairly easily. The pinions on dana 60/70 axles just can't handle the torque surge and snap little little girl toys on street trucks. My new axle has to have a 2" pinion.

Nice truck by the way!

[DieselEater]

There are a large number of modified diesel 4x4's in our club, but, I've never looked to see what rears they are running??? Most are newer vehicles, so I'd say they are probably factory D80's.....

The H110 may be an option also, if rules allow.


A..........

[stillsmokin]

Originally Posted by DieselEater

There are a large number of modified diesel 4x4's in our club, but, I've never looked to see what rears they are running??? Most are newer vehicles, so I'd say they are probably factory D80's.....

The H110 may be an option also, if rules allow.


A..........

The 80 wasn't available till 96 I believe, then it's standard behind cummins and v10 w/5 speed manuals. Every other dodge diesel came stock with a 70 or 70U.

I have a H110 third here but it's a 6.17 ratio, besides can't run it anyway (1 ton or smaller axle rule), I need to be at 4.56 anyway.

I did a little fooling around with the truck the other day, a friend did some video....

YouTube - Playin' with a VE cummins

[FROSTBITE406]

Im pretty sure i have been told the HO72 EATON comparable to the 14 bolt. The 14 bolt is a newer design that replaced the HO72. The only real problem with the HO72 is there is not really any aftermarket products. I run the HO72 but i have not had the hp to put it to the full test. With my planned 472 big block hopefully going in this comming spring i will see how she holds up.