- Location
- Reno, Nevada
Talking Spicer driveshafts here...
So who has discovered they have reached the limitations of the stock front driveshaft here? How tall were you? What were the symptoms?
After reaching 6.5" lift (true lift height) a year ago (and yes I have a HP30...) I started getting a clunking sound after being in 4wd a while. It would clunk at very slow speeds but in sync with speed. On the Rubicon run, Richard suggested my CV was worn, which seemed to be the most likely cause of the clunking, after all I had that shaft for 2 years at 5" lift with a LP30 and the new height of 6.5" and HP30 for a few months. It was also mostly a daily driver, so I could see why all that turning (non-disco axle) could eventually wear down the CV. Took the DS off and it doesn't feel bad at all turning it by hand... But I picked up a fresh DS from a 2001 XJ in the junkyard. Oh BTW, I figured it should be long enough, I have about 1" of extension left in the slip joint. I was also upgrading to manual hubs, so I figured this shaft should last me for a long time since it won't be spinning when the hubs are not locked. Well... after less than 6 months, the clunking has returned and again I can't feel it being bad when I turn it by hand.
After visiting Tom Woods site and reading his tech, I think I found the problem. He states:
Most drive shafts will, depending on components used, incur a binding interference at about 30 degrees. You DO NOT , I repeat DO NOT want to run a drive shaft at any where near this angle. you need to allow for axle droop, frame flexing and differential roll. All of which can momentarily alter the operating angle of the "U " joint to the point that it will cause what I refer to as an IMMEDIATE & CATASTROPHIC FAILURE. Ultimately you need to be certain that your driveline will rotate freely under full axle droop.
So I think at full droop it may be causing damage to the CV or at least causing it to clunk when back at "level" ground in 4wd. I don't hear clunking when flexed but do on just regular trails, after I have flexed. Just FYI, at full droop I can unseat the RE5.5" coils about 2 - 3". I wonder what angle that CV is operating at?
I was going to try and rebuild the shaft with greasable joints but now I don't think that will help much. Is an aftermarket shaft the only true solution?
So who has discovered they have reached the limitations of the stock front driveshaft here? How tall were you? What were the symptoms?
After reaching 6.5" lift (true lift height) a year ago (and yes I have a HP30...) I started getting a clunking sound after being in 4wd a while. It would clunk at very slow speeds but in sync with speed. On the Rubicon run, Richard suggested my CV was worn, which seemed to be the most likely cause of the clunking, after all I had that shaft for 2 years at 5" lift with a LP30 and the new height of 6.5" and HP30 for a few months. It was also mostly a daily driver, so I could see why all that turning (non-disco axle) could eventually wear down the CV. Took the DS off and it doesn't feel bad at all turning it by hand... But I picked up a fresh DS from a 2001 XJ in the junkyard. Oh BTW, I figured it should be long enough, I have about 1" of extension left in the slip joint. I was also upgrading to manual hubs, so I figured this shaft should last me for a long time since it won't be spinning when the hubs are not locked. Well... after less than 6 months, the clunking has returned and again I can't feel it being bad when I turn it by hand.
After visiting Tom Woods site and reading his tech, I think I found the problem. He states:
Most drive shafts will, depending on components used, incur a binding interference at about 30 degrees. You DO NOT , I repeat DO NOT want to run a drive shaft at any where near this angle. you need to allow for axle droop, frame flexing and differential roll. All of which can momentarily alter the operating angle of the "U " joint to the point that it will cause what I refer to as an IMMEDIATE & CATASTROPHIC FAILURE. Ultimately you need to be certain that your driveline will rotate freely under full axle droop.
So I think at full droop it may be causing damage to the CV or at least causing it to clunk when back at "level" ground in 4wd. I don't hear clunking when flexed but do on just regular trails, after I have flexed. Just FYI, at full droop I can unseat the RE5.5" coils about 2 - 3". I wonder what angle that CV is operating at?
I was going to try and rebuild the shaft with greasable joints but now I don't think that will help much. Is an aftermarket shaft the only true solution?