Static Pinion Angle Thoughts?

[RickTheEngineer]

Hey all, hope you're all gearing up for a great 4th of July soon! I had a quick question in regards to my pinion angle. I bought a Rough Country lift kit (4" new leafs all around) and it was a botched kit. I was on the phone with a few reps and they told me about how after they "revised" the springs the angles from the pinion to the Tcase just don't line up at all. I am 7 degrees off, from what should have been a bolt on kit, so I am going to be adding shims and getting this all figured out. Now here are my 2 questions.

Should I do a Tcase drop to extend the life of the U joint or is it not worth it/harmful?

What difference should the static pinion angle be? I know the pinion will point up slightly under acceleration, so I was thinking 1-2 degrees below the Tcase angle? Any thoughts on that?

Thanks folks!!

 

[Chaski]

The M1009 is so short that with that much lift I would bite the bullet and buy a cv rear driveshaft. Point the pinion at your transfer case and run a driveshaft with a CV at the transfer case end. Not saying you can't make the stock setup work, but it is an idea. Personally I run a stock rear driveshaft on my 1008 clone, but I only have a 2.5" shackle flip and it is a lot longer. My static angle is about 1 degree tipped up in comparison to the transfer case and it works well. I would not drop the transfer case, just consider a CV driveshaft. A local shop, High angle driveline, or Tom Woods could make you something.

 

[RickTheEngineer]

A very good point indeed. I am trying to figure out if I can make the stock setup work, but I do want to upgrade one day, but with money being a bit tight at the moment, I think it can be done since I do not believe I am exceeding 15 degrees on the driveshaft. Thanks for the input, it is highly valued. I was going to make this a poll to try to expose this post to all the folks who have experience lifting their rigs, but I definitely could use suggestions!

 

[86m1028]

DO NOT do the tcase drop it only makes things worse !

with single ujoints at each end you will want the angles same or within 1 degree.

 

[RickTheEngineer]

^Roger that! Rough country kept telling me to do so but I really felt like it was not so necessary for only a 4" lift!

 

[86m1028]

^Roger that! Rough country kept telling me to do so but I really felt like it was not so necessary for only a 4" lift!

When you drop the tcase your "tilting" it.
It makes the frt shaft point that much higher (counter productive)

 

[RickTheEngineer]

That's what I was thinking... It seemed a little strange to me because I thought I would be throwing the front off. Plus in the instructions for my lift kit, they suggest grinding the U-joint stops, but I don't even think they are close to stopping? http://s3.amazonaws.com/roughcountry/install/92114500.pdf seems excessive, but I guess it wouldn't hurt to do so. I found these instructions to be so much more different than that of the other manufacturers. If they didn't include shims on the leaf packs it might have been pretty close. I will take those off, and add my own if needed. With the pinion pointing 1-2 degrees below the tcase output shaft

 

[86m1028]

You did make sure you didn't install the springs backwards ?

 

[RickTheEngineer]

Yessir, I called, double checked, and triple checked. there is a clear stamp that shows which side was front too. Problem was that they added shims when they shouldn't have. When I called they admitted to it being the manufacturers fault, but they will put a $100 loss on my end for shipping if I wanted to return it, so I have to fab up some solutions. Mainly taking their shims off, adding my own and checking all my angles. I have installed lifts before ranging from 2-6 inches, but I never had a headache quite like I do now haha

 

[86m1028]

Wow sounds like they should send you the CORRECT parts.

 

[RickTheEngineer]

Yeah and get this, they admitted that I was not the only complaint. The "revised" their parts about 3 weeks ago, and in that time 2 other folks needed the same lift kit, and they all complained of the same problem, but they are leaving me in the dust. I have about 10 buddies that have their kits and never had a problem, but they really left me in a cruddy situation. They said the most they would do for me is offer to pay for shipping back, but I am still out $100 for when it got to me. And they refused correction shims or other parts to make it right. On the phone their words were "Dude it's a lift kit, get ready to do some fab work." But this is more than 6 degrees off, I can literally see how bad it looks. None the less, enough of my complaining, I'll just fix it and move on. But to anyone else that wanted to lift their M1009, be wary of their lift kits, they have problems to sort out

 

[Ilikemtb999]

Next time don't buy China garbage.


The pinion angle should be 1ish degree less than the yoke to driveshaft angle because under accel it'll increase. Best case solution indeed is a cv style axle. Shouldn't cost more than a few hundred bucks to get made.

 

[RickTheEngineer]

Alright folks, this is going to be a cringefest so brace yourselves. I finally got my angles just right, but reversing the shim from the springs they shipped me and was getting it within a half degree. I was thinking that I was in the clear. I moved my truck a little forwards, and it binded the heck out of the driveshaft and ate away at the u joint bolts on the yoke but didn't break anything per se. Unless that can be qualified as breaking. So I called rough country and they asked to send a whole bunch of pics. I sent everything I had, and they concluded and I quote "hmmm, something is screwey with your truck. You probably have a shorter than average driveshaft or maybe you had a super weird production." Am I missing something? If I am I am totally open to all your humble and wise suggestions. But seriously, I just have no idea what I'm missing. The driveshaft does seem a bit steep (18°) I am interesting in a SYE. But incredibly disappointed that rough country advertised it as a 4" bolt up kit and I'm having this many problems with it. Thoughts?

 

[Ilikemtb999]

Post said pics

 

[RickTheEngineer]

here y'all are!

 

[Ilikemtb999]

That yoke looks like it's about to fall out. Yikes.


What about shackle angle (pic), total length of spring and eye to pin length?


something is certainly off but not quite sure what. I only have a 2" lift on my m1009 and I used a zero lift shackle flip and then an extended shackle to get mine so I could get the most flex out of it.

 

[Ilikemtb999]

Also, so what angles are you getting? Yoke to driveshaft and then pinion to driveshaft

 

[RickTheEngineer]

I know, I feel like this is probably really bad for the tcase. It really makes me wonder if my driveshaft was too short or something. The shackle looks like it's not being stressed in any way, and it's a 52 inch spring with the pin right in the center. Yoke to driveshaft works out to be about 20° which I don't feel very comfortable about. It's more like 18° though. There has to be something I am missing because I've heard if folks buying this kit and bolting it up with no problems. Sadly I can't say I know anyone around me that knows much about these rigs haha

 

[RickTheEngineer]

Also, do you know how I would go about removing the U joint from the tcase side?

 

[Ilikemtb999]

I can measure my old shaft center to center if that helps. A longer shaft is currently needed as yours sits. I'd bet any major or sudden droop would let your yoke come out of the t case.


If its a factory u joint then you just put heat on it till the plastic worms out around the caps. If it's aftermarket then there are clips on the inside that clip on each cap. Just pop those out and then press or hammer the joint out.