Driveshaft problems

[ken74amx]

My truck is a 91 F-350 cc Dually 7.3 zf 5 speed and no matter what I have done I keep blowing the rear section of the driveshaft out of it. This was now the third time now. for some reason it has small u joints in it. I'm worried if I can't find a better set up that my compound turbo set up will be a complete waste of money. I'm wondering if I can put a flange from a super duty on the pinion. That would open up a new world of options. Has anyone else had this issue? Any thoughts of what I can do to beef this up?

 

[dsltech83]

Can't you get a 1410 yoke for the pinion and have the end on the shaft changed at a driveshaft shop??

 

[gatorman21218]

You mean the u-joint keeps breaking or something else?

 

[ken74amx]

The u joint at the diff kept breaking. This time that one and the one at the center bearing broke too. The shaft also twisted this time. I have a shop that will build a complete new shaft to my specs but I need to figure out a new pinion flange.

 

[gatorman21218]

dont know a whole lot about drivetrains but is there a problem in the differential? It sounds like something is binding up

 

[towcat]

is the truck lifted?
also...check out this thread. you need the angle gauge in the thread to figure out if your angles are good or bad.
http://www.oilburners.net/forums/showthread.php?55946-pitching-driveline-angles

 

[hce]

Does your truck power hop when you try to spin the wheels. Nothing will kill a drivetrain faster.

 

[riotwarrior]

seems peculiar ....

watching this one!

 

[Agnem]

Twisted the shaft? Better pull your diff cover and see if you've got loose metal in there.

 

[Black dawg]

what part # u joint are you using? I have been around lots of these truck that were beat on hard without that issue.

 

[ken74amx]

The rear end is fine. The driveshaft angles are also good. Everytime this happens I have to replace the pinion yoke. The truck is 2wd and stock height. I'm an ase certified tech with 15 years in the industry. I can only determine that the joints are to small. This has even stumped my father who is a Ford tech of 34 yrs now. I'm wanting to have a bigger shaft made with bigger joints. I can't remember off hand what the part number is for these joints. The truck was an auto that someone started to convert and gave up on. I cut up two other trucks to build this one. The trans and driveshaft are from a 91 F-450. I had the shaft lengthened to make it work. Every thing in this truck has been rebuilt. I put a Hypermax turbo on it and then started having these problems. I'm worried about doing the new turbo set up I built. I just need to figure out what to do with the pinion yoke so I can run a bigger joint. Need Ideas!

 

[ken74amx]

Oh yeah, I couldn't even think of spinning the tires as it blows the driveshaft! !

 

[mobilemech]

are the shafts in time, if not that could be your problem. Something had to change in the drive train, just adding a turbo will not put that much stress on the u-joints. You said that when it breaks it takes the rear diff yoke out, I think it's a drive line timin g issue

 

[towcat]

The rear end is fine. The driveshaft angles are also good. Everytime this happens I have to replace the pinion yoke. The truck is 2wd and stock height. I'm an ase certified tech with 15 years in the industry. I can only determine that the joints are to small. This has even stumped my father who is a Ford tech of 34 yrs now. I'm wanting to have a bigger shaft made with bigger joints. I can't remember off hand what the part number is for these joints. The truck was an auto that someone started to convert and gave up on. I cut up two other trucks to build this one. The trans and driveshaft are from a 91 F-450. I had the shaft lengthened to make it work. Every thing in this truck has been rebuilt. I put a Hypermax turbo on it and then started having these problems. I'm worried about doing the new turbo set up I built. I just need to figure out what to do with the pinion yoke so I can run a bigger joint. Need Ideas!

if you already have the F450 trans and driveshaft, do you have the F450 parking brake too? if so, why not just go up to a dana 80 out of the same vintage truck. your parking brake issues are already taken care of.

 

[ken74amx]

Towcat that's the plan. I found a yard with a few of them. The timing is good. The last time it blew I took it to a Driveline shop n had the shaft completely re done. The yoke gets destroyed because the joint explodes. Its a stupid strap type yoke! Towcat what size joint does the dana 80 use? And yes i have the 450 driveline brake and it's operational. If it uses a bigger one then this might be the answer I'm looking for. The next issue would then be the ten lug wheels.