U joints
11-04-2018, 05:26 PM
#1
U joints
For the second time, my u joint is failing. The clunking is back when I let out the clutch. I upgraded my driveshaft to a 3 inch during my ls swap. Maybe the shaft is bent?
11-14-2018, 07:46 AM
#3
Re: U joints
I used a Herman LS swap kit. I wonder if the crossmember wasn’t designed properly. I read this article:
http://www.superchevy.com/how-to/eng...ap-muscle-car/
“All you have to do is slide the crossmember back on the framerails, and lower or raise it to get the driveshaft angle correct. We usually recommend a driveshaft angle of -0.5 to 2 degrees. Otherwise, you’ll have driveshaft problems and wear out the U-joints.”
http://www.superchevy.com/how-to/eng...ap-muscle-car/
“All you have to do is slide the crossmember back on the framerails, and lower or raise it to get the driveshaft angle correct. We usually recommend a driveshaft angle of -0.5 to 2 degrees. Otherwise, you’ll have driveshaft problems and wear out the U-joints.”
11-14-2018, 10:32 AM
#5
Re: U joints
I had an installer mount the new engine and transmission. The Herman kit bolts into existing holes in the subframe. Their crossmember “maintains the proper drive-line angle”. Measuring the angle wasn’t part of the instructions, but I should do that now that I’ve gone through 2 U-joints. So...how does one measure the angle?
11-14-2018, 09:28 PM
#6
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Car: '89 Firebird
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Transmission: T56
Re: U joints
You want equal operating angles on both ends of the drive shaft (relative to the driveshaft tube) so that both ends are parallel to each other.
Perhaps more likely your issue, are the driveshaft ends phased correctly when the drive shaft was built? The yokes at the ends should be straight in line with each other.
Perhaps more likely your issue, are the driveshaft ends phased correctly when the drive shaft was built? The yokes at the ends should be straight in line with each other.
Last edited by QwkTrip; 11-14-2018 at 09:47 PM.
11-16-2018, 01:22 PM
#7
Re: U joints
I watched the video and found it quite informative. I took the Trans Am to Grapevine Automatic. The guy there knows his trade and checked the driveshaft, angles, etc. Turns out the rear u-joint was bad. I replaced the front u-joint at a different shop less than a year ago, but I should have had both replaced. Everything else looked good. He replaced that u-joint, and the car drove great when I picked it up.
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11-16-2018, 05:38 PM
#8
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Car: '89 Firebird
Engine: 7.0L
Transmission: T56
Re: U joints
Ya, that's a sweet little video. And best of all you don't have to listen to someone who can't teach or get to the point ramble on for 15 minutes and leave you with "be sure to like me."
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