Roasted u-joint

[Mesozoic]

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.

 

[Jeff73Mach1]

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.

 

[Mesozoic]

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.

 

[Mesozoic]

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.

 

[rocket366]

The "ANGLE" is the relationship between the trans output shaft

and the yoke on the differential.

:chin:

Paul

 

[Carolina_Mountain_Mustangs]

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

 

[Mesozoic]

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.

 

[Carolina_Mountain_Mustangs]

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?

 

[Mesozoic]

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.

 

[nickstewartroc]

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

 

[72HCODE]

on my 72 its impossible to get a torque wrench on those nuts for the u bolts. i would have to take the driveshaft out of the transmission and move it to the hard left or hard right to even access the nuts to get a hex over it.

 

[Mesozoic]

I've been able to tighten things down using a 1/4" drive ratchet and 1/2" deep socket, but there's definitely not a lot of space there.

 

[rocket366]

I must be way old school?

When I was wrenching/Racing in the 70's and 80's the only time

I got out a torque wrench out was to tighten...

Head Bolts

Rod Nuts

Main Cap Bolts

Everything else was feel and experience and

I never had anything come loose or fail.

I support guys that don't trust an impact gun on lug-nuts and use a torque wrench!

Back when... I didn't either I just chased the nuts with a breaker bar and laid into them.

Anyway tighten the U-joint cap U-bolts with a wrench and "Job Done"

Paul

 

[Mesozoic]

I used a wrench on my U-bolts and "job done" resulted in a failure. The failure is more likely due to the fact that the engine puts out over 550 ft-lbs of torque.

 

[Mister 4x4]

I tightened mine a LONG time ago when I put the rear axle and driveshaft back in (as in - 2.5 years ago), and when I took it for a drive (didn't get above 30mph) it slung the bearing caps right out of the yoke and dropped the driveshaft shortly after. I'm beyond extremely thankful that it happened on one of the neighborhood streets, and not the Loop (interstate-like freeway that circles San Angelo).

When I was repairing the U-joint after I got the car home, I noticed the U-bolts were still attached and still pretty much in their tightened down position. The only thing I can think of is that maybe I hadn't gotten the bearing caps seated properly in the yoke, since there are retainer tabs built into the yokes. Maybe I installed the U-joint improperly, since there's really no way for the bearing caps to be slung out of the yoke if there were seated between the retainer tabs and secured with the U-bolts.

Regardless, I'm paranoid to drive it right now. I thought I'd done everything right when I put it all back together, and then I dropped the 'shaft just trying to get it over to get inspected. I'm planning on driving it through the neighborhood a few more times and inspect the rear U-joint area again before I'll trust it on any of the main streets or the Loop for sure.

 

[Mesozoic]

I tightened mine a LONG time ago when I put the rear axle and driveshaft back in (as in - 2.5 years ago), and when I took it for a drive (didn't get above 30mph) it slung the bearing caps right out of the yoke and dropped the driveshaft shortly after. I'm beyond extremely thankful that it happened on one of the neighborhood streets, and not the Loop (interstate-like freeway that circles San Angelo).

When I was repairing the U-joint after I got the car home, I noticed the U-bolts were still attached and still pretty much in their tightened down position. The only thing I can think of is that maybe I hadn't gotten the bearing caps seated properly in the yoke, since there are retainer tabs built into the yokes. Maybe I installed the U-joint improperly, since there's really no way for the bearing caps to be slung out of the yoke if there were seated between the retainer tabs and secured with the U-bolts.

Regardless, I'm paranoid to drive it right now. I thought I'd done everything right when I put it all back together, and then I dropped the 'shaft just trying to get it over to get inspected. I'm planning on driving it through the neighborhood a few more times and inspect the rear U-joint area again before I'll trust it on any of the main streets or the Loop for sure.

Wow, that's scary. What transmission and type of driveshaft are you running? Mine is a custom made aluminum shaft with 1310 joints at the rear diff, U-bolt style. I had to get a custom made shaft after I installed the 4R70W transmission.

Might want to install a shaft loop underneath your car... I have an X-pipe exhaust system that prevents the shaft from dropping right out of the car, serving as a sort of shaft loop!

 

[Jeff73Mach1]

Loops not only prevent the drive shaft from dropping, they also keep it from coming through the floor of the car if the front u joint shears-It is a very deadly failure without one.

 

[Carolina_Mountain_Mustangs]

Amen to the driveshaft loop. I had a front joint come apart on the interstate at about 70 in a 1950 ford hotrod I have. The emergency brake cables saved me but I could not see the car was shaping so bad. It broke the cast iron tail shaft housing on the transmission and the hood popped open but caught on the safety. Back in the 60's I saw a friends circle track car do three end overs on the front stretch at the New Asheville Speedway. He left in ambulance and woke up in hospital. Front u-joint let go and no loop required back then and it stuck the shaft in the asphalt and did a pole vault.

I have been pulling cars on dollys for the last couple weeks and pulling driveshaft's. Only one was really tight of the 5 I pulled and just used a short 1/2" boxed wrench. These are cars I recently purchased.

Like Rocket says we use feel a lot when working on a car. I use a torque wrench in one more place than he does the wheel lugs to prevent warping the rotors. When I get tires I take my torque wrench and when they tighten them with their silly twist shaft torque air wrenches I go and loosen them and do them with a good torque wrench. My last tires I got at Discount tire and to my amazement the last thing they did was bring out a real torque wrench and finish off the lugs. That impressed me first time anyone has ever done that after buying tires over 50 years of burning rubber.

David

 

[TommyK]

I tightened mine a LONG time ago when I put the rear axle and driveshaft back in (as in - 2.5 years ago), and when I took it for a drive (didn't get above 30mph) it slung the bearing caps right out of the yoke and dropped the driveshaft shortly after. I'm beyond extremely thankful that it happened on one of the neighborhood streets, and not the Loop (interstate-like freeway that circles San Angelo).

When I was repairing the U-joint after I got the car home, I noticed the U-bolts were still attached and still pretty much in their tightened down position. The only thing I can think of is that maybe I hadn't gotten the bearing caps seated properly in the yoke, since there are retainer tabs built into the yokes. Maybe I installed the U-joint improperly, since there's really no way for the bearing caps to be slung out of the yoke if there were seated between the retainer tabs and secured with the U-bolts.

Regardless, I'm paranoid to drive it right now. I thought I'd done everything right when I put it all back together, and then I dropped the 'shaft just trying to get it over to get inspected. I'm planning on driving it through the neighborhood a few more times and inspect the rear U-joint area again before I'll trust it on any of the main streets or the Loop for sure.

Wow, that's scary. What transmission and type of driveshaft are you running? Mine is a custom made aluminum shaft with 1310 joints at the rear diff, U-bolt style. I had to get a custom made shaft after I installed the 4R70W transmission.

Might want to install a shaft loop underneath your car... I have an X-pipe exhaust system that prevents the shaft from dropping right out of the car, serving as a sort of shaft loop!

You might want to consider upgrading to a 1350 joint. IMO you are making way to much power for a 1310.