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So this weekend Installed a 6 inch suspension lift on my 1984 f350 crew cab. with the drop of the front axle my front drive shaft is hitting on the transmission cross member and wont match up to pinion on the pumpkin. Any Ideas on how to get the drive shaft to drop?
You just found out why tall lifts are not all they crack up to be.
With that much lift you got to go with longer drive shafts.
Then you have to check for Ujoint bind. Because of the lift the joint flexes more and can bottom out.
You also get what you have, shaft hitting a cross member or skid pan.
Sometimes you can trim them for clearance. The other way is to drop the cross member or pan from the frame. May be 1/2" to 1" may work?
Now remember you have weight on the suspension now so when check everything (joint bind/shaft clearance) do it with the suspension hanging.
Dave ----
Are you still running the TTB front axle? The later f350's that had the dana 60 used a double cardan front driveshaft. The double cardan is up near the transfer case and gives you a little bit more room for the crossmember, as well as being more forgiving on driveshaft angles. I ended up putting this shaft in my truck, even though it's a TTB. With the 4 inch lift it always vibrated really bad in 4x4. With the shaft conversion, the vibration is gone. I did have to change out the front yoke on the transfer case to make the f350 driveshaft fit.
The front drive shaft is spring loaded and I have pulled back with the ratchet strap. I have enough length on it but it is hitting the crossmember and not letting it drop enough to meet the yoke. I was wondering if there was someone who makes a custom crossmember with a drop enough to allow the driveshaft to drop or a good way to modify it? I have never heard of the double cardan front driveshaft. I will have to look into it. I have done some research and found a bunch of guys just cut a U shape in the crossmember, but I hear doing that will weaken it. I would love to put a Dana 60 under it but the budget does not allow for it now, but maybe later.
Might have to run a transfer case drop which will put your engine at more of a angle under the hood. We've had to do that to a bunch of short wheel based four wheel drive vehicles to get the driveshaft aligned properly without U joint bind.
Even with a dana 60, you will still have the interference problem. And with all that lift, you would be better off getting the f350 driveshaft. They make several depending on what trans you have (different lengths, you probably need the longest one regardless). The only problem you will run into will be finding one of those transfer case yokes to fit. They are getting harder to find, I found one in a junkyard in New York state and they shipped it to me.
Autozone sells new drivehshafts. I punched in a 1989 f350. They sell one for $259.99 and another for $309.99. The first one is for a manual trans and the 2nd is for a automatic. I am going to guess the one for the automatic is longer if the auto trans is longer and pushes the transfer case back farther. Here's what they look like.
You can see the double cardan on the end that might push it out beyond the crossmember enough to clear. You may also need it to relieve the u-joint angles on your high lift.
