Parkian

I recently raised my 2000 XJ 3” in the back and got some pretty serious vibes. I installed 3* shims and they definitely help but I’m still getting some vibes. I don’t have an SYE for now and I really don’t want to do a transfer case drop.

I have the 231 TC and 8.25 axle.

Could someone who has/had a 97+ with a 3” lift, without a SYE or TC drop let me know if they were able to use 5* or 6* shims to correct the pinion angle????? My pinion is pointing up about 2* right now.

Will this pull my yoke out too much????? potentially causing more vibes????

fallenknight308

If you still have the stock DS in there, then shimming is not the way to go.
With a stock DS the pinion should be on a horizontal plane. (facing straight forward)
You only need to point it upwards when you install a "double-cardan"
type shaft, after a hack 'n tap or SYE install.

http://www.4xshaft.com/index.html
http://www.jeepforum.com/forum/f12/s...13/index2.html
Some info

Your vibes could also be from worn U-joints
But with 3" of lift I would go with a SYE.
That way, if you want to go higher in the future,
your covered in this area.
Search this forum, and google, this subject has been talked about for days
They should put one big sticky on it here!

BuckB91XJ

At this point having already installed 2-3 degree shims, you have 2 choices to get rid of the vibes. TC drop or SYE. That is it.

TrekkerJmm

X2... a 1 inch T-case drop fixed my vibes with a 3 inch lift...Tj

fallenknight308

If your not concerned with clearance the tc drop is fine.
I just installed my SYE and am happy with it

muddeprived

I have a 2001. I lifted it 2" and got vibes....bad vibes. I tried shimming it but that didn't work. Then I tried dropping the t-case 1" and that didn't work. I ended up going with a sye and front driveshaft.


Try the drop first and if that fails get the sye. Sorry but that's just how it is.

Parkian

Just to be clear.....

My pinion was pointing up after the lift was installed (bad vibes), I shimmed it 3* to bring it down by installing the shims at the front of the pack (fat end = front, narrow end = rear) (not so bad vibes). The pinion is still pointing about 2* upwards after the shims were installed. I'm asking if I can install a 5* or 6* shim in place of the 3* shim I have now to bring my pinon angle down so it is in line with the TC output.

I'm not trying to question anyones expertise (I know nothing) but a lot of people keep telling me either....

1. You don't shim unless you have a SYE.

2. Why are you trying to point your pinion up?? You should be doing the opposite, you should be pointing your pinion down, in line with the output from the transfer case.

1. Yes you can shim without an SYE (this is a fact because I did it and it worked)

2. I understand the concept of aligning the pinion angle with transfer case output angle. I’m trying to point my pinion down.

I know these two things already……

I’m asking, can I just shim my the axle downwards without pulling out my yoke or just causing vibrations from more extreme angles on my u-joints???

Once again not questioning anybodies XJ expertise here, I just wanted to clarify my situation.

If there is indeed nothing I can do about my yoke being pulled out too far, u-joint angles or just general vibes then I will concede that I need a TC drop and do it. I’m just trying to avoid doing the TC drop because I don’t have a garage right now to work in and it’s starting to get cold up here in the great white north.

Regardless, I appreciate all of your responses/help.

muddeprived

You are doing it right but I feel that it's the angles of the u-joints that are giving you vibes. You can align the pinion to match the ouput shaft but those u-joints can only take so much of an angle before they bind and vibe.

trapper

great thread!

mike albo

I have the OME 2inch springs it comes with a TC drop in the kit,I thought about not useing it I did put it in.I don't have any vibes at all,my pinion is flat also.

Parkian

Thanks everyone.

"You are doing it right but I feel that it's the angles of the u-joints that are giving you vibes. You can align the pinion to match the ouput shaft but those u-joints can only take so much of an angle before they bind and vibe."

Muddeprived: Special thanks, that is what I thought, and was the kind of answer I was looking for....specific. Not a knock to everyone else, but he's got the advantage of being blessed with a vibration prone 97+ XJ......lol.

Well it looks like I'm going to start looking at TC drop writeups. Hopefully a TC drop in combination with 3* shims will help takes care of things.

I hear there's something fun about removing studs..........

fallenknight308

Here's things as I have learned/ understand them:
1. If you have lifted your XJ more than 2" or more, you can have vibes.
2. At this point, it does not matter where you place the pinion angle
why? because you have thrown the stock DS off its proper axis anyway.
3. The common solution is to use a double cardan/joint driveshaft,
otherwise known as a CV driveshaft. Why? I'm not going into the complete physics of it,
but basically a CV has 3 points of "pivoting" movement, where stock has only 2
4. Jeep did not make this vehicle with lifts in mind, hence the after-market demand for this kind of thing.
5. A T-case drop is a quick fix for this problem. Not a permanent solution.
6. Here's another link
http://www.lunghd.com/Tech_Articles/...liminators.htm

If you do not want to ever lift this vehicle higher, then you might be fine with T-case drop/shimming.

There's two pennies. (technically six pennies)
Good Luck!!

Oh yeah, to the mods: why has this topic not been put to a "sticky" yet?

muddeprived

Nothing to it really. Heat them up real good till they are hot as hell and then use a pipe wrench to twist em off. They are held on by locktite so the will loosen it.

Parkian

Good explanation fallenknight.

So the extra axis of movement the double carden provides allows the drive shaft to rotate/play in a slight elliptical motion if necessary???? rather than the stock driveshaft just rotating in a circular motion but fighting to rotate elliptically causing binding??? Let me know if I’m way off base here???

I’m going to do the TC drop for now but there’s a new sense of urgency to get the SYE done based on that I’ve heard.

I have an album with a few pics of the lift process, feel free to take a look.

Thanks for the tip on getting the studs out mud.

Here’s a pic of my differential, as you can see I’m not far off level which is why I was trying to get away with a little more shim, oh well. I'm thinking a TC drop will at least line up the pinion properly.

4.3L XJ

I can understand your frustration with these responses. There are some things we do in this forum that will just about guarantee driveshaft vibrations. One is using an extended shackle. This tips the pinion angle up and changes the dynamics of the drive line.

There are two and only two ways to properly set up a driveline:

1. When using a single U joint at both ends, the pinion angle must be close to the tcase output angel. The Jeep manual says within 2 degrees. Six States Distributing, drive line specialists say 6 degrees. My personal experience is that 5 degrees I can begin to feel small vibrations. So, whatever you have done, you must correct the angles so they are as close as possible. If you cannot do it visually, buy an angle finder and use that. They cost about $20. Good ones have a magnetic strip on them.

2. If using a double cardan (CV) joint on the transfer case output, then tip the pinion up so that it is as much in alignment as possible with the driveline at the pinion. In other words, the pinion joint should not be bending much as all.

Instead of buying shims and throwing stuff at it, take some measurements first and do it right the first time.