4* C bushings or double cardan driveshaft

[msmith]

I have my front axle ready to reinstall with Duff's 2.5 inch springs and 7* C bushings. When I originally removed the radius arms, some of the bolts had been cross threaded so I chased them with a tap. I got a little worried about how well they were going to hold so I bit the bullet and ordered a set of T Rex arms.

So my question is...what would be the best route to take, keep the 7* bushings and go with a double cardan drive shaft or keep the stock shaft and replace the bushings with 4*? Is the extra camber worth the $$ of another drive shaft?

Thanks in advance,

Mike

 

[Spaggyroe]

Personally, I'd probably run the 4 deg bushings with a 2-1/2" lift and t-rex arms.

Doesn't your Bronco already have a double cardan driveshaft from the factory?

 

[Broncobowsher]

Probably talking about a double cardon at the pumpkin. I have seen that once before. Pretty sure you will also need to change the yoke on the pinion to use a CV there.

 

[Apogee]

It's a compromise...whatever you do with the C-bushings to improve your caster is most likely going to exacerbate your pinion to driveshaft angle issue. You fix the pinion angle, and you reduce your caster numbers.

My '77 with CAGE arms and 3.5" lift needed an offset u-joint at the pinion to alleviate binding at partial droop just so it could get to full droop, though I'm not really a fan. My current project is cutting and rotating the knuckles and wedges on a HP D44 so that I can put the pinion and caster angles where I want them.

Tobin

 

[msmith]

Probably talking about a double cardon at the pumpkin. I have seen that once before. Pretty sure you will also need to change the yoke on the pinion to use a CV there.

Yes. I probably should have clarified, at the pumpkin. 4* bushings are the more affordable option. I didn’t know if a cv at the Punkin would help eliminate bind with extra caster, if it would even be feasible or if 7* would ok as is. I’m not real good at wording my questions.


Sent from my iPhone using Tapatalk

 

[Slednut10]

I have the T-rex arms and 7* bushings on my 76 with a 2.5” lift and I have no issues with the ujoint angle or binding at full droop.

 

[msmith]

I have the T-rex arms and 7* bushings on my 76 with a 2.5” lift and I have no issues with the ujoint angle or binding at full droop.

Perfect info! Thank you!

 

[Broncobowsher]

Remember that not all modifications are the same. 2.5 lift does not state how much droop is allowed with that lift. You could have a little or a lot. I know when I was running my 3.5 lift I had the rear shocks limiting down travel to prevent the CV from binding. Same thing can be done in the front.

Also have to consider transmission swaps. If a longer transmission has been installed, the front driveshaft can be longer, and that helps with the angles.

'76 and '77 axles are rumored to have a little more factory caster in them even if the published spec never changed from the earlier years.

 

[omureebe]

I have a 3.5 lift, t-rex arms, and put in the 4*. I have positive caster, something like +1.5 each side, so when there's a rainy weekend I'm going to swap to the 7* and see if that's better. Certainly an improvement over the factory arms and 2*, but the t-rex arms really didn't add much caster at all. Good luck, and please post some alignment numbers when you're done!
Omar

PS - I should add that if I were to do this again, I would bring my front axle to a professional welder (vs myself) and have them cut and reweld the knuckles. It's the down time I don't want!

 

[msmith]

I should have mentioned, factory 3 speed with no intentions of swapping in the near future. I'm almost sure that the front D44 has been swapped out at some time.

This Bronco will be mostly a DD, back roads, and maybe some mild trails so it's not likely to see much droop. If it gets to that point I will consider a cut and turn.

I'm going to try the 7* bushings and see how it drives and have the alignment checked. I can't use 4x4 until I regear and rebuild the rear anyway. I hope to finish that in a couple of months.

I really appreciate all of the info. Lots of experience here for sure.

 

[Spaggyroe]

I'm going to try the 7* bushings and see how it drives and have the alignment checked.

Would you mind posting your caster numbers after your trip to the alignment shop?

Thanks

 

[msmith]

Would you mind posting your caster numbers after your trip to the alignment shop?

Thanks

Absolutely