what degree shims should I order?

[RCP Phx]

I got an angle finder today and this is what I came up with. My driveshaft angle is 17 degrees and the pinion angle is 8 degrees. I have been told by several people that the pinion angle should be 2 degrees below the angle of the driveshaft, is that true? If it is do I order a 6 degree or an 8 degree shim? One garage told me that I should be ok with a 1 degree shim. I'm so "F"ing confused and at this point I'm not sure what to do. Can you guys please help me out. I have a 2001 Cherokee with an Auto trans, 4.0L, 8.25 rear, a RE 3.5 superflex, an SYE, and a Tom Wood's shaft. So as you can see I'm trying to build this thing with the right stuff, just this one has me confused.

Did you miss this?SYE's are about reducing u-joint angles,just because you dont have any vibes doesn't make it right.Also rotating the pinion up gains clearance at the yoke!

 

[Semper Fi]

ok I just ordered the 4*shims from RE. While I had the guy on the phone I asked if RE used the 3/8" center pin. He told me that was true but there is a catch. All of their shims are sold with the smaller 5/16" holes because they feel it would get to confusing to have shims with both sizes drilled in them. So that means that I will have to drill the shim to fit the 3/8" center pin in. Again I hope I ordered the right degree shim for what I need.
One thing that I have noticed is that the vibes I have, have slowly gotten less. When I first took the T-case drop off the vibes were bad. The more I drove the Jeep the less the vibes were. Now they aren't to bad but I still want the driveline angles to be right, so I'm ordering (ordered) the 4* shims. With the T-case drop on, my front driveshaft was totally collapsed and the vibes were BAD. By taking the T-case drop off the front driveshaft now has more than an inch of travel. Is this problem with the front driveshaft and a t-case drop normal? And if so why does everyone tell you to put t-case drops on, sometimes even with the SYE kits?

 

[Semper Fi]

I put the shims in today, and what a pain in the ass. I wasn't sure whether I should put the thick end or the thin end to the front. So I called a local garage and asked them. They told me to put the thick end forward, so I did. I put everything together and when I looked at what I had done, I started taking it back apart, stupid. (the thin end goes forward) Anyway, I got it together and I think it is close to where it should be. I'll have to have it measured to know for sure.

When I was putting everything back together for the second time, I massed the threads on one of the center pins. I called NAPA to get a new one. They told me that they didn't carry anything like that, so I went to ACE Hardware and bought a bolt and made my own. I had to round the head of the bolt with a file but it wasn't to bad. I'll try and post some pics tomorrow.

 

[steel58ers]

did the vibrations go away ?

 

[Semper Fi]

they seem to have gone away for now, but last time I said that was when I took the T-case drop off and the following day they were back. So for now, Yes they are gone! and I might add that it is a nice ride without the vibes!!

 

[Semper Fi]

I have had the Jeep up to 65 today and no vibes, I hope it stays that way. I forgot how nice it rides without the vibes. I still have yet to measure it and take a pic. I will try to get them tomorrow, but it's supposed to rain like hell here the rest of the day today and tomorrow.

 

[Semper Fi]

ok you guys are prolly getting tired of reading this thread but, I'm getting vibes again. Could they be coming from the front driveshaft?? I feel the vibes in the steering wheel that is why I ask. I was wondering if the u-joints in the front could be bad? They are the same ones that I had in there with my old lift and they are also the same ones that were in there when the driveshaft was completely colapsed by the T-case drop. I was thinking about taking the front driveshaft off and seeing if the vibes disappeared or not. If they do that would give me a starting point.

 

[Yucca-Man]

You already know the next step - take the front shaft off and see if that helps. Wheel balance, bearings, or axle u-joints can also contribute to what you're feeling, depending on the severity and timing.

 

[Semper Fi]

ok Yucca-Man, I took the front driveshaft off and I have very little vibes all the way out to 100mph. I drove home and put the front driveshaft back on and drove the same roads again. The vibes started at about 55 or 60, and got a little worse around 75, then stayed the same all the way out to 100mph. The vibes weren't real real bad, but they were there. What do you think I should start with ? the U-joints? I alos so have one other question. When your Jeep is level, how much space does your front driveshaft have in it to play? Not sure if you understand what I mean so I'll take a pic and show you what I'm talking about. IN this pic you see the shiny part? Is that all the room it needs to slide back and forth?

Just in case you were wondering what my back driveshaft looks like, angle wise

I think this is good but I have to measure it yet

 

[cal]

When I was putting everything back together for the second time, I massed the threads on one of the center pins. I called NAPA to get a new one. They told me that they didn't carry anything like that, so I went to ACE Hardware and bought a bolt and made my own. I had to round the head of the bolt with a file but it wasn't to bad. I'll try and post some pics tomorrow.

ACE sells allan head bolts that are a dead match for the center pins. They are $.99. I carry one for a trail spare..

-C

 

[Semper Fi]

hey yucca-man you out there? or anyone that can look at these pics and give me an answer? please!?

 

[cal]

Take the shaft to a driveline shop to be checked out and rebuild. It could just be u-joints, but it could be the splines in the slipjoint that are shot or the double cardan, and you won't be able to fix that in the driveway.

-C

 

[Semper Fi]

thanks cal, I give it a try

 

[mrfixit19]

i have about 2 1/2 inches and put 2 degree shims in but still have vibes to about 40 mph then it smoths out. i put the up country leafs with about one inch exta under my main leaf with about 1 inch in the shacles and spacers in front, put 31's on looks great and can handel the weight i put in the back now . o ya this is on an 88 two door.

bernie

 

[old_man]

Depending on your suspension, actually the length of your front control arms, the change in driveshaft length from stuffed to drooped can vary considerably. If your control arms are the same lenght as your driveshaft, it changes very little.

If you have bumpstops, the compression amount is reduced.