Stock Engine and Drive line angles

[RamblerRob]

Hey guys.
I'm getting set to finalize the engine mounts in my project. I've got a lot of uncertainty around the Drive line angles and transfer case output angles that's making me gunshy about locking in the vertical position of the engine mounts.

I think I've roughly simulated the unlaiden ride height with the engine weight on the chassis and a couple of stout friends of mine sitting on the front of the chassis.
(That wouldn't include any cargo or passengers)

My rear pinion angle is 4.3 degrees and my front is 12.8 degrees. I'm trying to decide whether to try to angle the output angle by adjusting the engine height or not.

It seems to me that anything I do to try to match the rear angle will put the front angle even further out of whack.

I understand the basic premise that the output angles and pinion angles ought to match. I'm also aware that the stock front shaft is phased to account for the variant angle between front pinion and front output but I'm not clear on how much angle that phasing accounts for.

I've been trying to find info on the stock configuration but coming up dry.

Can anyone tell me what the stock configuration looks like. Is the engine typically level? or tilted rearward or forwards? How much difference is normal between the front and rear pinion angles?

The chassis is originally from a LWB RRC but is sitting under a 109 2a. I'm not sure if it has stock defender springs or lifted. (My best guess at unlaiden ride height gave me about 21" from center of wheel to top of wheel arch). Transfer case mounting is rearward from "stock" by about 5".

Thanks for any info you can offer!

 

[Red90]

The front does not use parallel flanges. It is meant to point at the transfer case.

 

[RamblerRob]

Ah I see so even though it's not a DC shaft it uses the same geometry as one.
Mine is about 4 degrees off of pointing at the transfer case

 

[Red90]

They offset the u-joints to reduce the vibrations. They changed to a DC shaft with the disco 2s.

 

[chris snell]

My rule of thumb is to run single cardan shafts wherever possible and only put a DC in if there is vibration. Every truck is different and the only test is to run a single and see if it works. In a decade of long, multi-state desert trips in my Defenders, the #1 mechanical failure I've seen is the centering ball on the DC shafts. Literally every regular on my trips has blown one up. Regular greasing of the centering ball is imperative. The only trail fix for a failed centering ball is to pull the shaft and lock the center diff.

 

[RamblerRob]

So am I putting way too much thought into the vertical position of the engine mounts at this point? Should I just pick a height that gives me the hood clearance I need and deal with pinion angle later? I mean I'm probably quibbling over a couple of inches in possible height adjustment at the engine end.
How much pinion angle change can you get without it becoming a big hassle?

 

[chris snell]

I would go out and measure mine but it won't make much of a difference for you. You can have two identical trucks and get two different results from two identical driveshafts. I'm sure that Jimmy or Red90 can quote the spec on the angles from a manual if needed.