[Formulajones]

Originally Posted by FrankieT/A

3.5 vs. 3.0 makes a big difference in critical speed...

The thing that worries me about aluminum is the strength of the ears where the U joints mount. They look like they would break right off doing a hole shot.

They are good for 1000 hp so if you break one with a hole shot you're doing something.

In fact GM still uses them on their duramax's, as well as the other OEM's on their diesels and look at the power those things are making these days. Especially the torque. Couple that with the fact that they weigh over 3 tons.

My Duramax is making over 700 ft lbs. at the tire (newer models are more now) and it weighs 7000 lbs. empty with no one in it. That aluminum shaft is holding up fine. So I had no qualms putting one in my 600hp Chevelle. I'll never break it.

[ta man]

Originally Posted by Formulajones

They are good for 1000 hp so if you break one with a hole shot you're doing something.

In fact GM still uses them on their duramax's, as well as the other OEM's on their diesels and look at the power those things are making these days. Especially the torque. Couple that with the fact that they weigh over 3 tons.

My Duramax is making over 700 ft lbs. at the tire (newer models are more now) and it weighs 7000 lbs. empty with no one in it. That aluminum shaft is holding up fine. So I had no qualms putting one in my 600hp Chevelle. I'll never break it.

Not really apples to apples comparison ...Trucks have 5 inch diameter aluminum shafts to handle the torque..I would guess your Chevelle has a 3.5?

[FrankieT/A]

I have one out of a chevy truck that just needs to be shortened to fit my car. Its 4" diameter and would clear everything no problem. It already accepts 1350 U joints which is what is in my car now. My local driveshaft place wants $350.00 to shorten and balance it which is not bad. In my case, I would only be trying decrease inertial load. My current DS is 3.5" and has 1350 U joints and I have no issues. So, its sort of a "get around to it" upgrade.

[Formulajones]

Originally Posted by ta man

Not really apples to apples comparison ...Trucks have 5 inch diameter aluminum shafts to handle the torque..I would guess your Chevelle has a 3.5?

Chevelle has a 4" shaft and I believe they build it with thicker wall tube as well. Got it through PEM if you want to check out details. Prices aren't bad either.

Considering what those trucks put those shafts through with towing 15,000+ lbs and the torque the diesels make, they'll take some abuse for sure. I've seen the inside of those aluminum shafts for the trucks too, they aren't very thick wall tubing at all.

I'm not going to break it.

[Formulajones]

Originally Posted by FrankieT/A

I have one out of a chevy truck that just needs to be shortened to fit my car. Its 4" diameter and would clear everything no problem. It already accepts 1350 U joints which is what is in my car now. My local driveshaft place wants $350.00 to shorten and balance it which is not bad. In my case, I would only be trying decrease inertial load. My current DS is 3.5" and has 1350 U joints and I have no issues. So, its sort of a "get around to it" upgrade.

That's a great way to get into one for very little money if you really want the aluminum.

[Formulabruce]

Torque and shift kits destroy u joints and floors.
You don't need 500 hp.
I have updated a bunch of axle yokes without a rear down.
Lock the wheels and torque to 165 lbft. Of Torque And check the rotation of the yoke with rotational torque, wheels, drums off. 99% of the time its all good.

[Formulajones]

Just a word of caution if wanting to check pinion rotational torque without disassembling the rear.

The rotational torque measurements given in books and ring/pinion setup instructions is just for the "pinion gear only" That means the posi unit with ring gear and the axles are not in the housing. It was never meant to be a measurement with other components in place, it's just pinion bearing preload measurement. Interference with other rearend components in place will skew those numbers.

What I do in these situations where I just want to change a yoke, is the same procedure when I am fixing a pinion seal leak. I mark the nut and the pinion gear and then count the turns it takes to remove the nut.

On reassembly I count the turns on the nut and as I get to my mark I make sure I'm at a point that all the slack in the pinion bearings are gone, no more play. I then want to give the bearings a pinch of preload again, because remember at that mark they had preload from the crush sleeve, which has now been lost, so I'll turn the nut maybe 1/8" past my mark and leave it at that. Since we are reusing the old nut, which generally isn't recommended but that's how this repair goes, I'll peen the nut in 3-4 places for good measure so it doesn't move.

[AG]

I always remove the axles and differential when changing a pinion yoke to remove the guess work and get the exact rotational resistance measurement. Not the only way, but I know it is correct and it's not that much more work.

[Formulajones]

Originally Posted by AG

I always remove the axles and differential when changing a pinion yoke to remove the guess work and get the exact rotational resistance measurement. Not the only way, but I know it is correct and it's not that much more work.

[Formulabruce]

Originally Posted by Formulajones

Just a word of caution if wanting to check pinion rotational torque without disassembling the rear.

The rotational torque measurements given in books and ring/pinion setup instructions is just for the "pinion gear only" That means the posi unit with ring gear and the axles are not in the housing. It was never meant to be a measurement with other components in place, it's just pinion bearing preload measurement. Interference with other rearend components in place will skew those numbers.

What I do in these situations where I just want to change a yoke, is the same procedure when I am fixing a pinion seal leak. I mark the nut and the pinion gear and then count the turns it takes to remove the nut.

On reassembly I count the turns on the nut and as I get to my mark I make sure I'm at a point that all the slack in the pinion bearings are gone, no more play. I then want to give the bearings a pinch of preload again, because remember at that mark they had preload from the crush sleeve, which has now been lost, so I'll turn the nut maybe 1/8" past my mark and leave it at that. Since we are reusing the old nut, which generally isn't recommended but that's how this repair goes, I'll peen the nut in 3-4 places for good measure so it doesn't move.

All this is excellent advice and correct.
Marking the nut to the pinion is good, but that assumes the yoke is same thickness at the nut area.
I guess my point is that you can change the yoke and seal, without a rear end tear down. Everything I do has NO crush seals, which makes my life easier.
Formulajones, you are On the Money...

[Schurkey]

Originally Posted by Formulabruce

Marking the nut to the pinion is good, but that assumes the yoke is same thickness at the nut area.

Given the current state of Made-In-China and/or sloppy-built "everything", that's probably not a good assumption.

Originally Posted by Formulabruce

Everything I do has NO crush seals, which makes my life easier.

I never understood the purpose of the crush sleeve. God bless Loctite thread-locker.

[Formulajones]

I'll use loctite on it as well but when reusing an old nut, I find loctite isn't enough. Darn things will loosen up. I end up peening the nut in 3-4 places for safe insurance, on top of the loctite. Never had one back off like that.

However really should be replacing the nut any time it comes off. It's just that on a repair like a seal replacement, that is seldom ever done.

[grivera]

So I ended up buying the Strange 3” CM drive shaft from Strange for $279 with their forged slip yoke. It has 1350 u-joint at slip yoke and a 1350/3R conversion joint at pinion yoke. I plan to upgrade pinion yoke to 1350 size.

[ta man]

Originally Posted by grivera

So I ended up buying the Strange 3” CM drive shaft from Strange for $279 with their forged slip yoke. It has 1350 u-joint at slip yoke and a 1350/3R conversion joint at pinion yoke. I plan to upgrade pinion yoke to 1350 size.

Good parts! I know when I swapped mine I wondered why it took me so long!

[FrankieT/A]

When I had my 10 bolt in my car I needed a 1350 rear end yoke for my F body I went to the junk yard and took one off a '90's pick up truck and it went right on my rear. Turns out 10 and 12 bolt yokes are interchangeable and apparently trucks all the way into at least '90's.

If looking for a inexpensive temporary solution to get away from the conversion joint.