opinions on drive line degree wedges

[1986cj7]

I've put a 4 inch lift on my 86 when i first bought it some 10 years ago and put the Transfer Case lowering kit in for drive line angle issues. Now i'm finely getting around to do the complete restoration on it that I've been wanting to and want to take the lowering kit out. Was wondering if degree wedges under the spring and axle would be a way to go. Thank you for your time.

 

[hole]

Yes on the wedges, steel are best.

 

[Lumpy Grits]

110%
LG

 

[PistolDave]

If you are removing the drop kit, even though the wedges can get your u-joint operating angles back in spec., you still want to check for binding at full droop. Probably ok on a CJ7 with 4" lift, but it never hurts to be sure. Tom Woods considers 15 degrees to be the maximum allowable angle to operate a traditional u-joint at. Here is a link to that article.


Tom Wood's Custom Drive Shafts - Driveline 101

Dave

 

[Lumpy Grits]

Info and links like that should be a permanent 'sticky' on this forum.

LG

 

[1986cj7]

Thank you all for your responses and also thanks for the link Pistoldave. I'll be sure to get steel also cause I remember something about aluminum breaking?

 

[Torxhead]

I am not a fan of using wedges, especially up front. When rotating the front diff to line up the front driveshaft to it, the castor angle gets screwed up and upsets the steering. Wedges will also give you less ground clearance. Those dropped pitman arms will also screw up the front steering. That is my opinion.

 

[Lumpy Grits]

The shims are used to return the steering geometry to the correct(pre-lift) spec. It does mess with U-joint angles some, and that's the trade-off we 'pay' for the lift.
I have had steel shims in my front axle spring pads for close to 30 years now. Don't see how a 5/16" to 3/8" think shim will have any affect on GC in the 'real world' of Jeep'n.
LG

 

[jafo]

Steel shims are the way to go. Aluminum degrades rapidly. Also stwel shims are made to be a part of the leaf pack unlike aluminum shims I have used. Steel shims, at least the Warrior brand ones, require taking the the leaf pack bolt out. You want to make sure you have a long enough bolt after installing the shim also. If not you'll need a longer bolt. The job is not as hard as it sounds. Just a couple of C-clamps to hold the leaf pack in place, take out the bolt, put the shim in, reinstall the bolt then put the U-bolts back in place and torque to spec.

Also, if you shim front and rear, they are different widths I think. Can't remember.

 

[Torxhead]

Add the lowering of the skid plate also. I think it usually comes to about a 1" or so drop.

 

[Lumpy Grits]

Never lowered my skid plate and I run 33" tires with no issues.
BTW: The OEM skid plate is a joke! I custom made one from .125 X 1 1/4" DOM tubing and 3/16" flat plate.
LG

 

[Posi]

^^^ this
Never understood lowering the skid plate = less clearance.
I'm always looking for more belly clearance not less.

 

[Torxhead]

^^^ this
Never understood lowering the skid plate = less clearance.
I'm always looking for more belly clearance not less.

As I recall, per lift kit instructions, like on a 4" lift, there was a skid plate lowering involved to decrease the driveline angle from the Transfer Case . An alternative was using a cv style u-joint and increasing the rear pinion angle to match the driveshaft angle.

 

[007]

As I recall, per lift kit instructions, like on a 4" lift, there was a skid plate lowering involved to decrease the driveline angle from the Transfer Case . An alternative was using a cv style u-joint and increasing the rear pinion angle to match the driveshaft angle.

So explain this to me...because I don't get it...

Does a skid plate lowering kit just tilt the whole engine/Transmission /Transfer Case down? Wouldn't that raise the fan? I have a AMC 304 /400/QT - there's no flex point there... How does it not correspondingly increase the front output angle?

 

[Lumpy Grits]

The t'case drop will bring the bottom of the engine fan much closer to the radiator.
I'm still run'n the single U-joint deal on each end of both custom made DS's. The Ford 9" does use a special U-joint to match the Ford yoke(larger OD bearing caps)to the std Jeep CJ size.
LG

 

[Posi]

As I recall, per lift kit instructions, like on a 4" lift, there was a skid plate lowering involved to decrease the driveline angle from the Transfer Case . An alternative was using a cv style u-joint and increasing the rear pinion angle to match the driveshaft angle.

I understand the reason why they want you to lower the Transfer Case .
Unless you bought a Jeep with a 4” lift, what I don't understand is why folks would want a 4” lift springs.
It's like riding on a big “U”.
A 4” lift doesn't ride as good or flex as good a 2.5” yj springs, or soa.
There are other options as well, soa, trimming sheetmetal, CV, among others.
I know a lot of folks run them, and their probably happy with them, but as you can tell I'm not a fan of the 4” CJ lift springs.

 

[Torxhead]

I run a 4" lift so I can go where Lumpy goes. I agree that a 4" lift is miserable.

 

[Posi]

So I have to get LG to go to Ouray so you can follow him!!
I have two extra rooms booked for you guys!
For real!

 

[Lumpy Grits]

Thank you Posi for that VERY kind offer.
Believe me, I would love to see Silverton again.
With my CHF(Class3)and my wife's very recent Thyroid surgery. There's just no way we could make it.
I'm looking forward to the trip reports and pictures.
Let me ask this-Has there been any thoughts on setting the 2018 dates for this run?
LG

 

[jafo]

Add the lowering of the skid plate also. I think it usually comes to about a 1" or so drop.

The Trail Master 4" lift kit of mine came with the skid plate lowering kit. Basically 1 inch composite bushing type spacers. Instead of puting in the lowering kit, I looked at my drive line angles and decided to go with shimming the front and rear. I really didn't want to put my drive train into any binding. Wanted to stay as close to stock alignment as possible. If you think about it, the skid plate is flat and fits the angle of the engine. I found that my Transmission mount was shot and was causing some issues with Transmission / engine alignment. As soon as I installed the new mount, I immediatly felt the difference. It also raised the Transmission off the skid plate a goos 1/4 of an inch. Put everything back into alignment. I'm glad I didn't put the lowering kit in.

My drive line angles are ok. Not great, but good enough. No vibrations. I did take the aluminum shims out of the rear to match the angles at both ends of the drive shaft. For some reason, the front is not at as a severe angle as the rear. But it works. I do plan on having a couple drive shafts made when I finally get my other Transmission /Transfer Case combo finally together and installed.