I have a 68 Camaro that has an M-22 in it. I swapped the 10 bolt for a 66-77 Bronco big bearing 9 inch (they fit perfect and it's a cheaper fix than trying to find a 12 bolt these days). It looked like I was going to be able to get away with using the existing driveline. When I really get on the low end without spinning the tires (375hp/396), I notice a very slight vibration. When I tore the car apart this fall, I was able to see where the rear seal has been riding on the yolk. Based on this Photobucket pic link below, is there enough yoke going into the tailshaft or should I have the driveline lengthened??? http://i120.photobucket.com/albums/o182/agentjdub/driveline002.jpg

Question #2........If it's not long enough, would this at all cause tire hop?? I was told because I'm using a 2" lowering block, I'm getting axle rap easier and need a slide-a-link or build a little 2 link off the top of the axle and tie it into the frame. What do you experts think???? Thanks so much!!!!!!

I have a 68 Camaro that has an M-22 in it. I swapped the 10 bolt for a 66-77 Bronco big bearing 9 inch (they fit perfect and it's a cheaper fix than trying to find a 12 bolt these days). It looked like I was going to be able to get away with using the existing driveline. When I really get on the low end without spinning the tires (375hp/396), I notice a very slight vibration. When I tore the car apart this fall, I was able to see where the rear seal has been riding on the yolk. Based on this Photobucket pic link below, is there enough yoke going into the tailshaft or should I have the driveline lengthened??? http://i120.photobucket.com/albums/o182/agentjdub/driveline002.jpg

Question #2........If it's not long enough, would this at all cause tire hop?? I was told because I'm using a 2" lowering block, I'm getting axle rap easier and need a slide-a-link or build a little 2 link off the top of the axle and tie it into the frame. What do you experts think???? Thanks so much!!!!!!

Hard for me to tell from the picture, but typically if you measure from the rear face of the tailhousing to the center of the FRONT u-joint, you should get a measurement of 3" What does yours measure? If you have more than that, I don't think you would get tire hop but you would experience a driveline vibration.
Richard
Tech Support

I would want it further in than that.Not causing wheel hop but could be the vibration issue.Slida-a-Links or Caltracs will stop the wheel hop.I have Caltracs and they work great.

Wheel hop is caused by spring wrap-up. Simple traction bars will stop that. Or, as stated, you can use the more expensive Slid-a-Links or Caltracs. I tried clamping my leaf springs to get rid of wheel hop, but it just didn't work all that well. If you want nice, smooth tire-spinning with no wheel hop, then you'll need traction bars of some sort.

I can't tell where the seal is contacting the yoke. Looks like a large area is wiped clean from in/out action of yoke on tailshaft. I suppose that could be partially caused by the spring wrapping (wheel hop) as well as normal suspension movement...................

I think if you had the driveshaft in the car and then took a pic from underneath, someone might be able to ascertain if driveshaft length is appropriate. Also might help if you positioned a ruler or tape measure (in the pic) so that folks could see the depth that yoke is actually in/out.


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Usually 3/4 -1'' or two small fingers , is enuff yoke to trans clearance providing the seal is flush with the exten housing. I would get some fine emory cloth and polish up the bushing and seal section on the yoke.

When I use to build drive shafts I always used the width of my thumb for the distance from the end of the seal surface to the seal. Basically the same as what zdld17 said 3/4-1"