Topic: Damage from U-Joint Separation
in Forum: C3 Driveline Components
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I've been told that there isn't really a torque spec on the rear shaft
nut, but to tighten it until it is tight but not too tight.
Anyone got any more insight of a slightly more technical manner?
Anyone got any more insight of a slightly more technical manner?
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Duncanville, TX - USA
Joined: 11/8/2003
Posts: 20219
Vette(s): #1-1974 L-48 4spd Cp Med Red Metallic/Black deluxe int w/AC/tilt/tele./p/w-p/b/
Am-Fm/map light National/Regional/Chapter NCRS "Top Flight"
#2-1985 Bright Red/Carmine Cp.L-98/auto
Member: NCRS, NCRS Texas, Corvette Legends of Texas
[QUOTE=dnv] I've been told that there isn't really a torque spec on the rear shaft
nut, but to tighten it until it is tight but not too tight.
Anyone got any more insight of a slightly more technical manner?
[/QUOTE]
Uh...well...just before it breaks ain't gonna do it either then, huh?
It's hard to give an exact figure on a "used" bearing set-up, plus, you still have the half-shafts attatched. If it's too tight, it will wipe the pinion brngs out quick...if it's too loose...well, you'll be doing all this same stuff before long, again!
The nut is normally tightened until there is a specific amount of "drag" on the pinion, measured in inch/pounds.
With new bearings it is 20-25 inch/pounds. With used bearings, 10-15 inch/pounds. You would need to disconnect the half-shafts to measure this correctly, and, it would really need to be "dry", with no fluid in the diff. That's not gonna be realistic, tho, so we'll give it a good "precision guesstimate"!
You will need an inch/pound torque wrench, tho. Tighten the pinion nut down slowly(with a regular socket/ratchet), until you can feel no play(frt/rearward) on the yoke. Then, with the torque wrench, check to see how much force it takes to turn the pinion with the torque wrench. For your purpose, I would say probably 15-20 inch/pounds, taking into consideration the gear lube in the diff. will add some resistance, as well as the seal.(I hope you planned on replacing the seal?) This figure is simply measuring the amount of force, in inch/pounds, to turn the shaft, not tighten the nut.
This make any sense?Adams' Apple 2006-10-17 19:58:39
nut, but to tighten it until it is tight but not too tight.
Anyone got any more insight of a slightly more technical manner?
[/QUOTE]
Uh...well...just before it breaks ain't gonna do it either then, huh?



It's hard to give an exact figure on a "used" bearing set-up, plus, you still have the half-shafts attatched. If it's too tight, it will wipe the pinion brngs out quick...if it's too loose...well, you'll be doing all this same stuff before long, again!

The nut is normally tightened until there is a specific amount of "drag" on the pinion, measured in inch/pounds.
With new bearings it is 20-25 inch/pounds. With used bearings, 10-15 inch/pounds. You would need to disconnect the half-shafts to measure this correctly, and, it would really need to be "dry", with no fluid in the diff. That's not gonna be realistic, tho, so we'll give it a good "precision guesstimate"!
You will need an inch/pound torque wrench, tho. Tighten the pinion nut down slowly(with a regular socket/ratchet), until you can feel no play(frt/rearward) on the yoke. Then, with the torque wrench, check to see how much force it takes to turn the pinion with the torque wrench. For your purpose, I would say probably 15-20 inch/pounds, taking into consideration the gear lube in the diff. will add some resistance, as well as the seal.(I hope you planned on replacing the seal?) This figure is simply measuring the amount of force, in inch/pounds, to turn the shaft, not tighten the nut.
This make any sense?
Joel Adams
C3VR Lifetime Member #56
My Link
(click for Texas-sized view!) NCRS
"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"
Joel;
Makes sense to me. We'll give it a try. We tried to re-assemble last night and found that the driveline guy didn't pay attention to the old shaft, which has two different size u-joints. He put two small (81 standard rearend) ends on the shaft so the front u-joint was way too small. It'll be going back today.
I guess I should have suspected as much when I saw on his business card, "Happiness is a good joint" and saw the 1976 Orange Chevy Van done Cheech & Chong style in his shop.

Makes sense to me. We'll give it a try. We tried to re-assemble last night and found that the driveline guy didn't pay attention to the old shaft, which has two different size u-joints. He put two small (81 standard rearend) ends on the shaft so the front u-joint was way too small. It'll be going back today.
I guess I should have suspected as much when I saw on his business card, "Happiness is a good joint" and saw the 1976 Orange Chevy Van done Cheech & Chong style in his shop.


Doooz, I need to move to the midwest. My ujoint job was 4000.00 when we were finished! As looooong as we were in there...

Moderator
Duncanville, TX - USA
Joined: 11/8/2003
Posts: 20219
Vette(s): #1-1974 L-48 4spd Cp Med Red Metallic/Black deluxe int w/AC/tilt/tele./p/w-p/b/
Am-Fm/map light National/Regional/Chapter NCRS "Top Flight"
#2-1985 Bright Red/Carmine Cp.L-98/auto
Member: NCRS, NCRS Texas, Corvette Legends of Texas
That's whut youse gits fah being up theah wid dos GUIDOS!!!! 

Joel Adams
C3VR Lifetime Member #56
My Link
(click for Texas-sized view!) NCRS
"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"
Born in Brooklyn, Raised in Staten Island, Hey wait, I iza gweeeedo? capesche?
Smokin Kenny managed to fix the shaft and I actually got to drive her home last nite!!! He put a u-joint in that was longer on two sides than on the other. Seems strange but it works ok.
It took a full 32oz of fluid to top off. Anybody know how much it holds??
Even though it's 34 degrees and rainy, I had to drive her to work today!
It took a full 32oz of fluid to top off. Anybody know how much it holds??
Even though it's 34 degrees and rainy, I had to drive her to work today!
UPDATE:
Two estimates for the wrecker driver damage.
$3,850
$2,850
The guy for $2,850 says he will work with me on a complete paint job. He just painted one of our club guy's baby's and you should see the overspray and the underside of the nose that wasn't painted. Funny thing is, he paints almost all the street rods for 3 counties around here.
I guess I'm just too picky.
Time will tell what AAA will do.
Two estimates for the wrecker driver damage.
$3,850
$2,850
The guy for $2,850 says he will work with me on a complete paint job. He just painted one of our club guy's baby's and you should see the overspray and the underside of the nose that wasn't painted. Funny thing is, he paints almost all the street rods for 3 counties around here.
I guess I'm just too picky.
Time will tell what AAA will do.

Joined: 9/8/2005
Posts: 241
Vette(s): 1980 with a Banks Twin Turbo
1969 Convert Big Block
1996 Grand Sport Convert
I know that the 80 to 81's had a Lot of Half Shaft U-joint Changes depending on when they were produced. Looking at Replacment Catologes it would appear that all the 82's were the same. That might just be because Borg Warner was pissed at Gm and wouldn't sell any 4 Speeds so if they were all Autos then it made it simpler. Dose anybody Know if One Setup or another is much Stronger than another? As I have a High HP Car I am above and Beyond anything the Engineers ever Planned on. I would assume that Bigger is better and that 4 Speed Cars in 81 ? had the Heavy Duty Parts ??? Richard...
in Forum: C3 Driveline Components
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