Front drive shaft

[Whips 17]

I have a 80 CJ-7 with a 350 engine and a turbo 400 Transmission. It has a Dana 30 front axles. And I have Brocken 2 drive shafts now!! Has anyone had problems with this site up. There is not much room between the transmission pan and drive shaft, for a bigger one. Thks

 

[69jeepcj]

Did you brake the shaft or the ujoint? I assume this has happend off road as your front shaft shouldnt spin in 2wd, and hubs unlocked. Is your jeep lifted??..Your driveshaft angle may be steep for normal operation. We probably need a little more info on your jeep to help. lifted, lockers, tire size, gear ratio, is the egine stock or modified?
PS.. quadra-trac equiped jeeps didnt have the lockout hubs did they?

 

[Whips 17]

Yes it happened 1 off road and the ofter time in a mud bog. I have a stock 350 engine with a Th400 trany the Dana 30 has a detroit true trac in it. It has Broke 3/4 of the length towards the transfer case side. Never had a u-joint problem.

 

[808CJ7]

You said there isn't much room for a bigger shaft. Could it be the driveshaft is hitting something while your off road?

 

[Whips 17]

It is very close to the transmission pan. But if that was the problem then I should have a dent in it. No?

 

[808CJ7]

Not necessarily a dent. But even just a scrape can grenade a driveshaft.

 

[big_o_tom]

The fella that always does my drive shafts says that the front shaft, although smaller has thicker walls than the rear. Ive had 304's, 360's and a 401 in cj's and I think the only time I ever had a drive shaft problem was on my first cj. I ended up having a front shaft cut down to use in the rear and it ended up getting warped.

 

[69jeepcj]

What 808 said is the first thing that came to my mind. You are breaking it 3/4 of the way up to the case, which is about where the oil pan hangs down. You have a chevy engine in your jeep, the oil pans are dif. when someone installed the engine they may have gotten a deep sump pan for high volume oil pumps and it hangs down lower than a norm pan. I just looked at mine and my pan cant even hit my driveshaft but the bellhousing could possibly. Is the shaft pulling apart and twisting, or just breaking in half? with your jeep on level ground and looking at the front shaft, can you see splines where the shaft slides into itself. If so your shaft may be too short and pulling apart.