700r4 driveshaft angle / rear axle issues, help!!!!!!!

[cronic]

Ok, guys, I had recently noticed that I had a roar when letting off the gas from the rear axle. It was the same noise I was getting a few years ago (way less than 10k miles) when I had the rear end "rebuilt". The noise went away until recently. While I was home last weekend I decided to tighten the pinion nut up and see if that helped. It was loose and I tighten to 120l ft lbs. It did help for about 3 miles and then it was back. So this weekend while home finishing up the cooling system I decieded to try and tighten it a little more, 150 ft lbs. No good, too tight whiich didn't seem right per some of the torque ranges I had read, so I loosened it up. It got better at 80 ft lbs, and tried it at 70, 60, 90, and then back at 80. When I went back to 80 the issue was bad, so bad that it shuttered at 15 miles per hour. So I figured it was screwed and decieded to check the plug for metal. Yep, it was full of small metal flakes, similar to a low viscosity pumice soap, but no big chunks. I should mention that I have checked the pinion and universals for play, and they are in great shape. This got me to thinking that the driveshaft angle could be the cause of the premature rear end failure. The transfer case has about .5" between the top and the floor of the cab, so I really can't go any higher with it. What is optimal for the angle and how can I get it? I am going to have to have the rear end completly gone through, any reccomendations for someone in the US that can do this and do it the right way? I have to figure out if the drive line is causing the rear end issues and fix it so I don't have to deal with this in the future. Any help would be greatly appreciated.

 

[Cruisertime]

Driveshaft angle for ujoints is 4 deg of tailshaft angle .... so if your tcase is set up at 11 deg. from flat ground. Pinion should be 7 deg. from flat ground. Looks like your joints are in phase, so youre ok.

 

[green71fj]

wow

First off,What tcase is that? second from the pic it looks like the out put on the t case is way low.could just be the pic but it looks like the drive shaft goes up to the rear end, i believe i read some where that the angles on the front and rear drive shaft should be the same 12degrees. post up some more pics, any floor modifications,stuff like that.

 

[cronic]

First off,What tcase is that? second from the pic it looks like the out put on the t case is way low.could just be the pic but it looks like the drive shaft goes up to the rear end, i believe i read some where that the angles on the front and rear drive shaft should be the same 12degrees. post up some more pics, any floor modifications,stuff like that.

Is a 73 3 speed transfer case. The case is within a 1/2" of the stock floor pan, so going higher would be very difficult without hacking up the floor pan, which I do not plan on doing.

 

[cronic]

Driveshaft angle for ujoints is 4 deg of tailshaft angle .... so if your tcase is set up at 11 deg. from flat ground. Pinion should be 7 deg. from flat ground. Looks like your joints are in phase, so youre ok.

Ok, so is the 4 degrees a max amount of angle or optimal angle?
Here is a pic of what I think you are explaining, Is this correct?

 

[Texican]

Your driveshaft u joints are out of phase, the flats on the u joints should be in line for instance

 

[Texican]

DRIVE LINE PHASING

 

[Cruisertime]

Sorry man, just coming back to this thread, big tex is right. I was def wrong on the phase thing.

 

[cronic]

DRIVE LINE PHASING

Ok, great link with good info, thanks. I will defiantly fix this. Could this cause the rear end to screw up to the point of needing a major rebuild. I haven't noticed any odd vibrations and the u joints are in great shape.

 

[cronic]

Any recommendations on a place I can by rebuilt thirds?

 

[Texican]

Iron Pig off road is kinda close to ya, any shop that does dirt track 9'' Fords can do LC thirds once they know they are damn near identical
That said if you are running 4.11 many times you can purchase used fronts with no miles to speak of cheap

What have ya got going on?
A 3rd will rarely cause vibration.......usually they will grind whine or moan

 

[cronic]

Iron Pig off road is kinda close to ya, any shop that does dirt track 9'' Fords can do LC thirds once they know they are damn near identical
That said if you are running 4.11 many times you can purchase used fronts with no miles to speak of cheap

What have ya got going on?
A 3rd will rarely cause vibration.......usually they will grind whine or moan

whine on the coast side and metal flakes in gear oil. I have order a few fab pieces from iron pig in the past and been very happy. I will give them a call tomorrow and see what they have to say.

 

[cronic]

Ok, I decided to pick up a rebuilt third member from Iron Pig. Hopefully I will have it in a week or so. I got the third member out today and the housing all cleaned up. My axle shafts have grooves worn in the shafts at the axle seals, so they are leaking a little. Can I use a speedi sleeve or do I need to pick up another set of good used axles? I measured the angles today on the transfer case and the third member. The transfer case is angled down at 6 degrees and the third member is angled up at 5 degrees, so they are off by 1 degree of being in line. Is this an issue?