Front driveshaft pinion to transfer case help

[NewGladdyOWNR]

So I have the @Clayton Off Road 2.5” overland + lift installed, in addition, I went overkill and installed the Teraflex control arm drop brackets to help with the control arm geometry (probably a waste of money?). While I was under the truck, I noticed the front driveshaft pinion that goes into the transfer case (?) does not angle straight/level into the transfer case, but is pointed down due to lifting the truck. Is this normal? Will this affect how my 4 wheel drive operates? I assume the only solution to fixing this is to lower the truck back to stock height or at least a 1.5” lift. Any one else have this issue?

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[kevman65]

Have a watch and quit worrying. I believe the cut off lift for having to change out shafts is 3 1/2".

 

[NewGladdyOWNR]

Have a watch and quit worrying. I believe the cut off lift for having to change out shafts is 3 1/2".

That video just proved my point. Steep angle on the pinion from transfer case to drive shaft will cause premature wear.

 

[rharr]

RCV driveshafts (oem) have a smaller range of movement/angle. The aftermarket u-joint style shafts using a DOUBLE CARDAN SHAFT to divide the angle between 2 u-joints allows a greater angle for the driveshaft and less wear on each u-joint.

Lifts with 3.5" or more generally need a DOUBLE CARDAN style shaft. A 2.5" lift at full droop you should see the inner shaft of the oem drive shaft just kissing the metal gasket flange of the RCV joint at the transfer case. Problems happen when you have more droop and the inner shaft is now prying on the metal gasket flange.

Jack your jeep up, support the frame and let the axle hang unsupported floating in air. Can you still turn the front drive shaft by hand (transfer case in N) with out a notchy feeling? Does the inner shaft jam hard into the metal flange?

If yes with no notchy when turning by hand and no about jamming then worry about something else.

My ruby with a rock krawler 3" and their shocks puts the front OEM drive shaft at it's extreme range at full droop and may shorten it's life but rarely does my jeep see full droop in the front, usually one tire is pushing up which impacts angle. I had to add 1/2" alum spacers to my cross bar skid plate after my lift because the drive shaft would bottom out on it before it got to full droop.

drive it till it breaks, then replace with a DOUBLE CARDAN SHAFT.

 

[sass JT]

Question for the op… did you get an alignment? If you did , can you post your alignment sheet?

 

[Gren71]

I went overkill and installed the Teraflex control arm drop brackets to help with the control arm geometry (probably a waste of money?).

Not at all overkill or a waste. I put these on my 2in lift, in addition to the MPP LCAs, and it made a HUGE improvement in my steering. You made the right choice with them.

as far as your drive shaft, ive seen the angles for front and rear posted somewhere on here. But im sure you could reach out to @Clayton Off Road and see what deive shaft angles they want in conjunction with their lifts.

 

[ShadowsPapa]

So I have the @Clayton Off Road 2.5” overland + lift installed, in addition, I went overkill and installed the Teraflex control arm drop brackets to help with the control arm geometry (probably a waste of money?). While I was under the truck, I noticed the front driveshaft pinion that goes into the transfer case (?) does not angle straight/level into the transfer case, but is pointed down due to lifting the truck. Is this normal? Will this affect how my 4 wheel drive operates? I assume the only solution to fixing this is to lower the truck back to stock height or at least a 1.5” lift. Any one else have this issue?

Are you saying you changed the pinion angle (and thus your caster is really changed) or, is it that the front axle dropped straight down (compared to the truck) without tilting or changing the pinion and there's a matching angle at the rear of the shaft, at the transfer case?

With conventional u-joints you want the front and rear joint angle on a shaft to be matching but opposite, or within a certain amount, with CV joints, that's not the case because there's no velocity change through the joints.

 

[NewGladdyOWNR]

Not at all overkill or a waste. I put these on my 2in lift, in addition to the MPP LCAs, and it made a HUGE improvement in my steering. You made the right choice with them.

as far as your drive shaft, ive seen the angles for front and rear posted somewhere on here. But im sure you could reach out to @Clayton Off Road and see what deive shaft angles they want in conjunction with their lifts.

Yea I’m hoping once i get everything dialed in with the front suspension, I’ll notice a difference for the better.

 

[NewGladdyOWNR]

Question for the op… did you get an alignment? If you did , can you post your alignment sheet?

I have alignment specs with the Clayton lift, without the control arm drop brackets if you want me to post those. If not, I’ll have specs with the brackets tomorrow after I get yet another alignment.

 

[NewGladdyOWNR]

Are you saying you changed the pinion angle (and thus your caster is really changed) or, is it that the front axle dropped straight down (compared to the truck) without tilting or changing the pinion and there's a matching angle at the rear of the shaft, at the transfer case?

With conventional u-joints you want the front and rear joint angle on a shaft to be matching but opposite, or within a certain amount, with CV joints, that's not the case because there's no velocity change through the joints.

Yea so I adjusted the U joint to be straight with the driveshaft, but when I did that it moved my knuckles to 0 degrees caster on the verge of negative castor. When I have my upper control arms completely disconnected from the axle and frame, the differential is almost parallel with ground and my knuckles are at 4.9 degrees positive caster. Which is great for castor, however what about the U joint not being completely straight with the drive shaft? It seems as though I cannot align my U joint with my driveshaft without affecting castor in a negative way. My question is with the U joint not being aligned is that a potential problem? Hope that makes sense.

 

[Renegade]

Yea so I adjusted the U joint to be straight with the driveshaft, but when I did that it moved my knuckles to 0 degrees caster on the verge of negative castor. When I have my upper control arms completely disconnected from the axle and frame, the differential is almost parallel with ground and my knuckles are at 4.9 degrees positive caster. Which is great for castor, however what about the U joint not being completely straight with the drive shaft? It seems as though I cannot align my U joint with my driveshaft without affecting castor in a negative way. My question is with the U joint not being aligned is that a potential problem? Hope that makes sense.

Forget about your u-joint. Set the caster correctly and drive. Your driveshaft doesn't even turn unless you're in 4wd, and even then, there is a CV joint at the t-case. This isn't a TJ...

 

[Zachattack50]

For sure do NOT get hung up on the ujoint angle. As long as your caster is set right your good to go. Any time you lift a vehicle the driveshaft operates at a greater angle, its part of it. With the amount a lift your describing, you wont prematurely wear out your joints. Caviat beiing, if you wheel the ever loving crap out of it, you may see accelerated wear. Don't sweat it, get a good alignment and go rip it.

 

[ShadowsPapa]

Forget about your u-joint. Set the caster correctly and drive. Your driveshaft doesn't even turn unless you're in 4wd, and even then, there is a CV joint at the t-case. This isn't a TJ...

Yeah, that was my point - on a CV joint there's no speed change across joints so I'd not worry about it. Caster is the primary concern.

Conventional joints are a problem IF one has quite an angle and the second one does not. The angles need to cancel each other out IF it's conventional joints in the drive shaft.
CV joints - don't sweat it. People should see some of the extreme angles a CV can run (and do run)

 

[Gren71]

Yea I’m hoping once i get everything dialed in with the front suspension, I’ll notice a difference for the better.

after you get an alignment done I would double check your toe measurements yourself. I had my alignment done three times and still had loose wandering feeling steering. Once I checked myself the toe was equal front and rear… So I watched a few YouTube videos… got some encouragement from @ShadowsPapa … And did my own alignment by making sure I was toe’d in. After I did it myself, night and day improvement.

here is a pic I used for drive shaft stuff. I’m definitely not an expert with this though, And I’m not sure if this helps or not. But it helped me understand my driveshaft a little better.

 

[Renegade]

after you get an alignment done I would double check your toe measurements yourself. I had my alignment done three times and still had loose wandering feeling steering. Once I checked myself the toe was equal front and rear… So I watched a few YouTube videos… got some encouragement from @ShadowsPapa … And did my own alignment by making sure I was toe’d in. After I did it myself, night and day improvement.

here is a pic I used for drive shaft stuff. I’m definitely not an expert with this though, And I’m not sure if this helps or not. But it helped me understand my driveshaft a little better.

Those are "conventional" driveshafts with a u-joint at each end. Our front shafts come with a CV joint at the upper end, and don't spin unless 4wd is engaged (the optional full-time transfer case is an exception, but it still has a CV). Those old rules don't apply to us.

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