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Roasted u-joint
#1
I think I've logged a few thousand miles on my car since performing the 4R70W upgrade with EEC-V injection. The car makes ridiculous amounts of power and torque, it's completely overkill. I don't drive abusively, but I've discovered that I've totally roasted my rear u-joint. The shaft was built new at the time of the conversion to accomodate the yoke needed for the 4R70W. I'm not really sure what size the joints are, but I'm going to assume they're 1310s or 1330s. They were Neapco, which I've had good luck with in my other vehicles. I think the power level is killing them in my case. Any suggestions for replacing the u-joints? I was considering maybe stepping up the yoke to a larger size as well, not sure yet.

1971 Mustang fastback: 10.3:1 C90E 408W hydroller - CDAN4 EEC-V w/EDIS8, girdled, lowered and caged
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#2
I'd check your driveline angle and make sure it isn't causing the failure. U joints don't work when they are straight, there has to be some angularity in the set up or they won't properly lubricate.

Not sying this is your problem, but you may need to check.

[Image: 1_01_07_15_8_53_18.png]

"I love my Hookers!" and "Get some Strange" probably have a different connotation to non automotive enthusiasts!
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#3
Shaft builder is replacing the Neapco u-joint under warranty and rebalancing. The yoke will need to be replaced however, there's a little bit of damage to it from the first u-joint going out. My friend has a transmission shop so I'll ask him to replace the yoke and take a look at the angles. Thanks for the advice.

1971 Mustang fastback: 10.3:1 C90E 408W hydroller - CDAN4 EEC-V w/EDIS8, girdled, lowered and caged
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#4
Gonna need to order a new yoke... any favorites out there? I see Summit lists Keyser, Currie, Inland Empire, Yukon Gear, and Moser... all about the same pricepoint. I see forged steel, nodular iron, and ductile iron as materials.

1971 Mustang fastback: 10.3:1 C90E 408W hydroller - CDAN4 EEC-V w/EDIS8, girdled, lowered and caged
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#5
The "ANGLE" is the relationship between the trans output shaft
and the yoke on the differential.

Chin

[Image: o089qe.jpg]


Paul
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#6
The way our U-joints mate up sucks with just the little u-bolts. If you had the flange like the newer cars they would last much longer. I broke three rear u-joints in my bone stock 73 Mach 1 when new and were replaced under warranty. When factory guy checked they had put the yoke, driveshaft and u-joint in for a 2-V application not the Q 4 speed I had ordered so they changed out everything and did not break another but did not drive 6,000 miles either.
Like others have said the angle is important. If you are running at strip or some runs on the street you will find if you have a manual that you cannot power brake. A Hurst Line Loc will help more than anything on snapping u-joints and axles along with the trans. You get all the slack out before you drop the clutch.
With power comes failure.
David


When a man is in the woods and talks and no women are there is he still wrong??
Tongue
David
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#7
Yup, with power comes failure, but I have a high angle driveshaft with CV in my '79 Bronco with Neapco greasable joints and they seem to be surviving just fine despite a major increase in power and abusive driving. I think I might've overtightened the U-bolts on the bearing straps and killed them myself.

1971 Mustang fastback: 10.3:1 C90E 408W hydroller - CDAN4 EEC-V w/EDIS8, girdled, lowered and caged
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#8
Mesozoic;249180 Wrote:Yup, with power comes failure, but I have a high angle driveshaft with CV in my '79 Bronco with Neapco greasable joints and they seem to be surviving just fine despite a major increase in power and abusive driving. I think I might've overtightened the U-bolts on the bearing straps and killed them myself.

Humm don't think I have ever used a torque wrench there, will it fit?


When a man is in the woods and talks and no women are there is he still wrong??
Tongue
David
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#9
Carolina_Mountain_Mustangs;249193 Wrote:
Mesozoic;249180 Wrote:Yup, with power comes failure, but I have a high angle driveshaft with CV in my '79 Bronco with Neapco greasable joints and they seem to be surviving just fine despite a major increase in power and abusive driving. I think I might've overtightened the U-bolts on the bearing straps and killed them myself.

Humm don't think I have ever used a torque wrench there, will it fit?

Good question. I have a smaller compact wrench that might. I believe the fasteners call for no more than 15 ft-lbs.

1971 Mustang fastback: 10.3:1 C90E 408W hydroller - CDAN4 EEC-V w/EDIS8, girdled, lowered and caged
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#10
I know on my 67' with an 8" rear end, there is not way to get a socket wrench or torque wrench on them, only a regular wrench
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