6" Rough Country Lift 1982 Flareside

A quick way to find your drive line angle is to use a magnetic angle finder, make sure the truck is level then put the weight on the suspention and put the angle finder on top of the drive line and the other side to the top of the yoke where the u joint cap sits in. It is my understanding that u joints were only ment to run for a short peroid of time at 17 or over degrese and will start binding.  This is why the shorter wheel base Broncos have a double cardigan( spelling) joint at the t case.

ArdWrknTrk wrote

Ray,
You didn't space the transfer case down 6".

If A remains the same
And B increases 6"
Then C has to increase in accordance *with Pythagorean theorem.

I understand that the "C" or hypotenuese gets longer. This driveshaft has a slip joint long enough to account for the change (I think/hope).

What we are really concerned about is not C. We are concerned with the pinion angle at the front diff, and at the tcase. Once I have it all together I will find a flat spot somewhere and measure the angle of the dangle. Ha

I guess I misinterpreted What Dave was saying about limit straps.

If this conversation has gone to drive angles, be aware that the universals at each end should be at the same angle or they will be out of phase and binding.(minutely, a couple of times every revolution)
Not that it will stop them, but it will wear them prematurely.
This is why CV joints have gained popularity.

Gary can offer a bit of background, from when he was questioning why he needed (wanted) the double cardan front driveshaft that comes with a D60.

There is really no way to change the transfer case output, so that double cardan is used to bisect the angle.  Also in the driveshaft of Broncos...

Edit: We've all seen mall crawlers and brodozers with the pinion pointing right at the TC output.
This is exactly what you DON'T want.
Zero angle in one joint and all the angle in the other.
You would be better off with full angle in both (to the limit) because at least both ends of the shaft would be trying to go the same speed.

I guess what I should do is call Rough Country, and ask them about the design.

Just inspecting the rear, the lift blocks have corrected the diff pinion angle.

I highly doubt that the radius arm brackets and the pivot brackets all have dropped straight down 6". How else will they have accounted for the pinion angle? Im willing to bet the radius arm brackets are where the magic happens with the geometry. Looking at the control arm pivot brackets, they do appear straight down from the original position.

Limiting straps might be a good idea if I go wheeling, probably not necessary for the street though.

Dave did some off-road racing so I'm sure he knows about droop while airborne.

Pinion angles are simple geometry.

Since you have access to powerful and dynamic CAD you could model the U-joints and fixed yokes at each end of a ridgid shaft and watch the acceleration and deceleration as the shaft and yokes rotate.

I'm sure you have a library full of this stuff?

I wish I had time to play with CAD like that. But yeah, I could do it. Too many other things going on.

Maybe you have a little time to read what experts have to say?

https://4xshaft.com/blogs/general-tech-info-articles/tail-shaft-conversion-kits

https://www.hotrodhotline.com/md/html/drive_shaft_harmonics.php

https://www.therangerstation.com/tech_library/pinionangles.shtml

Spicer/Dana also have pages and pages, but I can't link pdf's from my phone.

Jim, thanks for the links, I'll check them out.

I did some measuring. The axle pivots are 6" straight down drop. That makes sense.

The radius arm pivot brackets are closer to 5" lower than stock. This must be how the kit corrects the pinion angle. However, this effects caster. Which is why they recommend new adjustable ball joint bushings to correct this.

The rear drive shaft has extended about 1.5", just eyeballing the slip joint. I have no idea how long the splines are.there is no slop in the joint.

I was succesfull removing the 1st eccentric bushing without removing the knuckle. I made a quick Youtube vid to show yall.

https://youtu.be/71LgMp_0NCU

Well that's real cool how your pitman arm puller fits nicely when you relieve the octagon (?) at the top of the bushing.  

You can also hear it coming right out of there.
I can almost guarantee that if Angelo or I tried that we'd be there with a torch and a hammer.  

Looking good.
Hope you enjoy the additional ride height!

I like that, Ray.  Worked very nicely.  

ArdWrknTrk wrote

Dave did some off-road racing so I'm sure he knows about droop while airborne.

Pinion angles are simple geometry.

Yes it was the drop of the suspension when airborne and Ujoint bind, nothing about the Ujoint angles.

Now you may think "I will not be getting airborne" but it is not that hard to check in the safety of the garage and let the axles hang and see if the Ujoints go into bind. If so then you add axle limit straps.
They are made from seat belt webbing. You bolt 1 end to the frame and the other to the axle and should be just long enough to let it hang but not go in to bind.

BTW shocks should not top out as a axle hang stop, that a good way to pop the top off shocks & break mounts.
If you have that happening you need to run shock extensions and then you have to check you don't bottom out the shocks as that is a good way to break shock mounts and is not good for the shocks.

What we had issues with was bottoming out the front drive shaft on landing a jump.
It would bottom out pushing the transfer case back and breaking the adaptor between trans (auto) and transfer ending the day of racing unless you had a spare and did different type of racing later that dayas not to break the replacement before you could adjust the drive shaft.

We had been known to rebuild a Toyota LC rear because it snapped the pinion going across the finish line.
Also replaced a steering box on a 65 Jeep CJ, both taken out racing in the woods.
 Sent a team to a yard down the road to pull the parts and the others stayed to pull the bad parts off the trucks. Both trucks were ready to run their class in 100 yd drags that same day.
Dave ----

Dave, thanks for that. Yeah, Im not worried about ujoint angles. Rough Country is probably the most well known lift manufacturer, and they have tons of reviews. No one has mentioned lowering the tcase, or having issues with driveline angles on this lift.

Here is a little entertainment for the Southerners on the forum:

https://youtu.be/gmtG8y5qfkc

So, that 2nd eccentric bushing didnt come out as easy as the first. In fact, I gave up. I guess I will have to go get a hub socket for that nut, then remove the diff and driveshaft, then pull the knuckle. Hopefully I dont destroy the ball joint boots dropping the knuckle.

The other eccentric was shaped much differently, much less the grab onto. The pitman puller wouldnt work. Neither would my other 2 jaw pullers.

Ray, if it comes to the worst, I just posted some eccentrics in the marketplace.

Thanks Jim. I already have two of the Moog eccentrics that adjust caster and chamber. I have one i stalled on the passenger side already.

I had my oldest helping me today. He installed the axle pivot bolt, while I strained to hold it in place for him....hahaha

If I am looking at Garys diagram exploded view drawing correctly, in order to remove the steering knuckle on the drivers side, I need to remove the differential, pull the driveshaft out of the wheel hub, then I will be able to pickle fork the ball joints free.

Any tips on doing this without a pickle fork messing up the ball joint boots? Ball joints are nice and tight. I dont want to replace them if I dont have to.

I think I'd just buy some new boots and get on with it.

Well, my friend down the street had the spindle nut socket. I got the hubs/rotors off and pressed out the lugs. Picking up some new rotors and pads tonight.

I removed the diff from the swingarm. Man, I still cant get that stubborn driveshaft out of the swingarm. I think the lower bolt for the radius arm has to be backed out. I got the upper bolt out, but that lower bolt wont budge with an impact or a 4' cheater!!! I guess I'll let it soak in PB and take it through a few heat cycles with the propane before attempting again. IT IS ON THERE!!

I like to quench the bolt with PB Blaster after I've heated it.  The shock sometimes breaks it loose.  Good luck!

Ray, did you remove the axle clip from inside the diff housing?

What exactly do you mean by "lower bolt from the radius arm"
Where it bolts to the beam?

Sorry if I'm asking a stupid question.
I don't usually work on the light duty 150's