Driveshaft angles and extending the driveline

[RnrdTheFox]

I have a 3 1/2" lift and added a 4R70W tranny which extended the driveline back a few inches. When I mounted it to the brace, I moved the brace back the appropriate amount by moving the brackets on the frame back 2".

What I'm wondering is should I have lowered the brackets down at the same time, or will the CV joints handle the additional angles? If this question makes sense.... I'm wondering if I should drop the x-fer down a few inches.

Thoughts?

 

[slyjki]

i did kinda the same thing with an atlas. the angle was a little much so i cut off the spring purches and rotated the rearend just a tad. Dont know if it was the right thing to to but it has worked so far. I asked a few people before i did it and they said it would be fine. I didnt want to lower the tcase any cause it already seamed too low.

 

[Broncobowsher]

When I installd my 4R70W I tried lowering it a little just to clear the floor without cutting. Ran into major problems with the engine rocking back and putting the valve covers into the firewall.

I finally cut the floor to get the engine to roll forward enough to line up the fan, clear the firewall, etc.

As for the driveshaft, mine is a normal one. Lots of miles on it (3 trips from Phoenix to Vegas) and normal driving. 3½” lift. The pinion angle has been raised. Mine was done by angle milling the lift block due to the worn nature of the used springs I have. At full droop I can unbolt the driveshaft and lower it another couple inches before the CV binds. Shocks act as limiting straps. If I did some fancy shock thing to get more droop (that I don’t need) I could easily exceed the angle limit of the driveshaft’s CV.

Remember to rotate the driveshaft as you are looking for the CV’s limit, it is different at as it rotates.

 

[RnrdTheFox]

Thanks. That's the info I was looking for.

 

[76Broncofromhell]

I did the same thing with my ZF swap. My rear driveshaft is around 31" long and the optimum angle for the CV is less than 10 degrees operating range. That's not saying it won't work at higher angles, but it will take far more maintanence to keep it alive for over 30,000 miles. I'm at right around 10 degrees on the EB and I haven't had to touch my driveshaft for a long time.

 

[tsmustangs]

It will work

You might want to add the 6 degree shims that Wild horses sells. Puts the pinion angle about right with a 3 1/2 in lift. I didn't change my trans but did the 3 1/2in lift. Had my drive shaft lenghtened 2 1/2 in and installed the shims.

Terry

 

[68 Broncoholic]

I lowered my NP435/205 set up to help the rear but this caused the front yoke to start heading up hill causing a bad bind in the CV. I raised it slightly to a happy medium and it seems to work.

 

[Broncobowsher]

I lowered my NP435/205 set up to help the rear but this caused the front yoke to start heading up hill causing a bad bind in the CV. I raised it slightly to a happy medium and it seems to work.

Good point about the front CV. I never checked mine since I didn't have a front shaft to even consider mocking up when I built my crossmember. I guess I just got luckey on the front.