Just curious if anyone else has experienced this. No pictures of the driveline set up as it's out of the vehicle right now. Got a picture of what happened though.
78 fj40 2f
Orion Transfer Case
97 Fzj80 axles
37.5" tires
Double-Cardan Joint at t-case (Out of a 4 runner 80's can't remember the year)
leaf springs (rear)
anti-wrap bar
90 deg transfer case
68 deg at pinion
Working on it the other day so the youngest daughter could take it to prom (See "What have you done to your 40 this weekend"). Finished up and was jacking around in the gravel parking lot as I was feeling pretty good to drive it since I had not had a chance in two weeks. We've all been there. Stuck it in reverse and gave it some skinny pedal. ugh!!! Twisted rear drive shaft. (Pulled the drive shaft, stuck in 4wd and let her drive it to the prom!)
1st thought was the drive shaft had to have been dented from the last time on the trails, thus weakened. Just happy it didn't happen on the trails.
Took it down to a buddy machine shop to have him weld me up a new one. Our version of a driveline shop around here. Started looking at it closer as we were discussing the distances and angles. Started to make me think a little.
I've set the antiwrap up so that it squats vs. hopping when climbing. When I stuck it in reverse it was hopping. Seems to me that would be what is expected in reverse if you have it set up to squat in forward. (LOGIC MAY BE ALL WRONG HERE but it seems to make sense)
My thinking is that the rear of the vehicle lifted up creating a greater angle than what can be handled by the double-cardan and this is what caused a bind in the drive line. Weakest link was the shaft. I almost welded it up but I started to think about the rear axle drop. When it drops either in reverse or forward it's going to drop and travel towards the transfer case creating a greater angle.
90 - 68 = 22 deg angle front cardan has to make. I read some where that they don't want to go over 30 deg. The most I can get out of this cardan is 30 deg. (I might go back and check to make sure I can get 30 deg.) Stopped right there and wanted to think about it. I've been running this way for 2 years and had no problem, I'm quite sure I've nailed it in reverse like this before and never had an issue. Tempted at this point to weld it up and lift the rear end up by the body to get full flex and see if I have any issues, but I stopped as I would like not to saw sawdust 2 years from now on the trail!!
Anyone experience something similar?
78 fj40 2f
Orion Transfer Case
97 Fzj80 axles
37.5" tires
Double-Cardan Joint at t-case (Out of a 4 runner 80's can't remember the year)
leaf springs (rear)
anti-wrap bar
90 deg transfer case
68 deg at pinion
Working on it the other day so the youngest daughter could take it to prom (See "What have you done to your 40 this weekend"). Finished up and was jacking around in the gravel parking lot as I was feeling pretty good to drive it since I had not had a chance in two weeks. We've all been there. Stuck it in reverse and gave it some skinny pedal. ugh!!! Twisted rear drive shaft. (Pulled the drive shaft, stuck in 4wd and let her drive it to the prom!)
1st thought was the drive shaft had to have been dented from the last time on the trails, thus weakened. Just happy it didn't happen on the trails.
Took it down to a buddy machine shop to have him weld me up a new one. Our version of a driveline shop around here. Started looking at it closer as we were discussing the distances and angles. Started to make me think a little.
I've set the antiwrap up so that it squats vs. hopping when climbing. When I stuck it in reverse it was hopping. Seems to me that would be what is expected in reverse if you have it set up to squat in forward. (LOGIC MAY BE ALL WRONG HERE but it seems to make sense)
My thinking is that the rear of the vehicle lifted up creating a greater angle than what can be handled by the double-cardan and this is what caused a bind in the drive line. Weakest link was the shaft. I almost welded it up but I started to think about the rear axle drop. When it drops either in reverse or forward it's going to drop and travel towards the transfer case creating a greater angle.
90 - 68 = 22 deg angle front cardan has to make. I read some where that they don't want to go over 30 deg. The most I can get out of this cardan is 30 deg. (I might go back and check to make sure I can get 30 deg.) Stopped right there and wanted to think about it. I've been running this way for 2 years and had no problem, I'm quite sure I've nailed it in reverse like this before and never had an issue. Tempted at this point to weld it up and lift the rear end up by the body to get full flex and see if I have any issues, but I stopped as I would like not to saw sawdust 2 years from now on the trail!!
Anyone experience something similar?
