Are 6* shimms, on '89 with 4.2" lift a good choise ??

Have the 3.5 RE rear leafs in together with the rest of the RE Super ride and OME's.

A-Measured with old sagged springs from center cap to bottom flare:
-15.75"
B-Factory should be
-17.00"
C- After lifting it is
- 21.26" ( so that's a 4.3"lift out of the RE 3.5" leafs, full gastank and spare in the back)

With some maths (neigbour knows how to operate his scientific calculatur)
we calculated that the angle from the pinion has risen 7* upwards compared to what it should be at stock heigt (B).

Compared to old sagged situation it's up 9*. (so it was 2* to low anyway and that may explain litlle vibes doing 65 mph.)

And yes very very bad vibes right now all the way up to 45 mph, after 65 and to much noise to have me worried enough not driving it untill it's solved.

Nice Neighbour made me 6* shimms today, for only $10 apair, going to fit them in this weekend.

Now you wonder what's the question, well I wondered if someone else calculated it this way with out measuring the angles under the vehicle.

The reason I didn.t was that it was dark, we did not have the angle finder, it was cold, late etc. And if I wanted them ready for the weekend he had to know what angle to make the shimms.



Red al the posts on shimms, SEY, Hack'nTap etc. so I know no two XJ's are the same just need some opinions on my 6* choise.
Thanx.

First time on , also posted on JU. Let's see where the knowlrdge is

Truly, the best cure for this is to get a SYE. Then it is very easy to match up the angles by pointing the pinion straight at the output shaft of T-case.

However, In order to get rid of vibes with the stock slip yoke, the pinion angle should be at the same angle as the output shaft. I actually had my old pinion point 1 or 1.5* down in order to take up for some axle wrap on the road. You should be able to get pretty close with a magnetic angle finder. Shims usually come in 2* increment, so if the 6 doesn't work, then try the 4*. It really hinges on your ability to accurately measure the angle of your pinion shaft (D35, I'll assume) and your output shaft. Once you know those two, you can do the math to figure the shim. Remember you want your pinion to be a degree or so pointing towards the ground rather a degree too much pointing up if you are, say 5* off and you only have 4* or 6*.

XJs have driveline vibes, buy better speakers.

So I did put in those 6* shimms, now only rough vibes around 37/mph (gone after that and a "moaning" from 60 and higher.
(thick part towards TC so pinion came down)

Measured the angles as good as I could with a old rotten angle finder ( need to get that protractor) and pinion and output shaft are not that much different.

1- When taking a speed bump or letting of the gas I can hear it rumble in the rear.

2- My yoke came out another 3/4 of a inch more so that will be about 1.8" from where it was before the lift.






3-But........................ I noticed alot of play on the yoke from the TC ........... I can move it up and down approx. 0.01"

4- It could be one of the tools "tinkling"in the boot, but I'm pretty sjure the sound came from the drive line, it's like someone taps my drive shaft with a table spoon. Not often, at very low speed and there is no ritme in it. U-joints just 5000 mls.

1- binding? and what is that exactly?
2- What's the limit?
3-The FSM is talking about "yoke runout specifications" how much play is acceptable?
4- Sounds familiar?

D**n, I want a SYE&CV, but no $$ untill after new year.

You dont have enough spline engagement.The question now is what to do about it.I definately recommend a SYE kit over trying to do it by having you driveshaft lengthened.If you are serious about your Jeep I would say go with the HD kits,they're only about $100 more but provide much more in benifits!

I'm way over here in the Netherlands and Jeeps aren't that common as in the USA so "just lenghtening a shaft" and things like that is mucho $$.

For that $ I could have 1/2 a SYE and new shaft sent over from Tom Woods for example.

How about a longer yoke? RE has one 5/8 longer but that's not enough, even when I drop my TC.

And what's that HD kit for 100$ ?


Hey, just a thought maybe my front drive shaft will fit........... turn around my shimms so the pinion is pointing directly to the TC............sounds to easy ther must be something that needs lots of adjusting.

RCP Phx said:

You dont have enough spline engagement.The question now is what to do about it.I definately recommend a SYE kit over trying to do it by having you driveshaft lengthened.If you are serious about your Jeep I would say go with the HD kits,they're only about $100 more but provide much more in benifits!

Click to expand...

It looks like youve lost alot more length that the longer yoke would make up for!I also noticed you have a 242 so your choices are very limited.BTW:the 231 HD kitsare $100 "more" than the other kits!The front driveshaft might fit if the length was right and you had a SYE kit(cv shaft output).

It costs me about $75 to lengthen at driveshaft here. All they are doing is cutting off the old tubing from the shaft parts and welding a new piece of 3/16 or 1/4" thick tubing and balancing it. Driveshafts are not jeep specific, even Volvos and Mercedes need driveshaft work, search your local machine shops for help.

Warning: Prior to me buying the SYE kit and shaft from Tom WOods, I had the same problem. I installed some new shims and was taking it for a test drive. As I was braking to a stop at the light before the freeway, the shaft separated and toasted the u joint and straps on the pinion. Loud as hell and scared the fawk out of me. If it happened at freeway speed it could have been worse. YOU HAVE A SERIOUS SAFETY CONCERN BECAUSE YOU DON"T HAVE ENOUGH SPLINE ENGAGEMENT. Welcome to the world of modifying your heep, now pay up sucka.

By chance do you have a TC drop? I know I am going to get slammed since it is a band aid but it my get you by till you get a SYE and DS. HTH Doug

Your drive line angle is way off, it appears to be a 0* and not anywhere near 6*. Do you have any closeup pics of your shims installed?

Like i said earlier, whe calculated the difference in angles according to what the axle dropped down.
We did hot had any tool to measure the real angles.

Thought we needed 6* shimms because the difference in height gave us a 6* difference on the pinion/driveshaft angle.

But when rethinking it should had been 1/2 of 6* because pinion up 3* makes the TC/drive shaft angle also 3* less............... right??

Well here the pics.

Left:







Rougly I could measure 17* pininion/driveshaft angle and a 13* TC shaft/driveshaft angle.

So I'll have to put those two in line, correct me if I'm wrong but that means I have to put the pinion up for 2* (1/2 the difference from 17* and 13*) and add another 1* for compensating the axle wrap.

Did not do the TC drop yet, because surprisely there are not four bolts but two bolts and two threads with a nut that holds my crossmember. So I hve to deal with that first and get some 1"nuts to go over the threads so I can put in a bolt that holds the crossmember.

But if I do the TC drop that will change angles by approx. 2* on the pinion and 1* at the TC so the differnce will be only 3*.
Right?

Hope my way of thinking is right, did a setup on my work bench with exact the same lengt from the driveshaft etc, So I could see what happens when you drop the TC, lower the pinion etc.

No protractor for sale in my neighbourhood, need one

End of the story so far, appricite your help.

Dazz said:

Your drive line angle is way off, it appears to be a 0* and not anywhere near 6*. Do you have any closeup pics of your shims installed?

Click to expand...

Hold On!!

GrimGrimDutch said:

(thick part towards TC so pinion came down)

Click to expand...

You need to tilt the pinion up, you made the angle worse! The thin part should go forward.

Re: Hold On!!

I know, but before I put in the shims the pinion was pointing more upwards then the TC was pointing downwards.


So I made it go down, the result now it is way to much down.
I think I more likely need 3* shimms in stead of 6*.
Like I said i NEED that protractor so I can measure right after the TC drop.

Thanks, I'll let you know how thingds work out

CW. said:

You need to tilt the pinion up, you made the angle worse! The thin part should go forward.

Click to expand...

With a stock driveshaft the fat end on the shim usually goes toward the front of the vehicle!

yeah, but if he turns the shim around and points the pinion up, it will help the angle of the u-joint and push the slip yolk farther into the t-case. Doing that with a 3 or 4* shim and a t-case drop would most likely eliminate all vibes. I ran 6.5" of lift with that setup and had no vibes at all, and with the stock drive shaft.

GrimGrimDutch said:

Like i said earlier, whe calculated the difference in angles

Thought we needed 6* shimms because the difference in height gave us a 6* difference on the pinion/driveshaft angle.

But when rethinking it should had been 1/2 of 6* because pinion up 3* makes the TC/drive shaft angle also 3* less............... right??

Rougly I could measure 17* pininion/driveshaft angle and a 13* TC shaft/driveshaft angle.

So I'll have to put those two in line, correct me if I'm wrong but that means I have to put the pinion up for 2* (1/2 the difference from 17* and 13*) and add another 1* for compensating the axle wrap.

But if I do the TC drop that will change angles by approx. 2* on the pinion and 1* at the TC so the differnce will be only 3*.
Right?

Hope my way of thinking is right, did a setup on my work bench with exact the same lengt from the driveshaft etc, So I could see what happens when you drop the TC, lower the pinion etc.

Click to expand...

Man, that's enough to get anyones head spinning. You are making this much more complicated that it needs to be. Ignore the driveshaft. Just put an angle finder on top of your valve cover and measure the angle.

* If you don't have an angle finder, use a carpenters level (bubble) and calculate the angle off horizontal. *

Do the same for the pinion. You may have to use the circles cast in the back of the differential housing and compare to vertical.

The valve cover is parallel to the transfer case output shaft. Once you know this angle, and the pinion, set the pinion to be roughly one degree less than the valve cover angle. You should never have to measure your driveshaft angle or the included u-joint angles.

You made my day , I knew there had to be an easier way.
Going to get things sorted out this wednesday.

Drop the TC and measure the easy way, grinding of my "beatifull machined 6* shimms will be the most work.

sweet jesus!!!

Rougly I could measure 17* pininion/driveshaft angle and a 13* TC shaft/driveshaft angle.

Click to expand...

The problem no one has mentioned yet. You cannot exceed 15 degrees (and that is extreme) with a single cardan driveshaft.
You need the slip yoke elimination and a double cardan driveshaft.

The rest of your calculations are commendable, but the fact remains....you've outgrown your current driveshaft configuration.

Well...

Nope

Re: Well...

bgcntry72 said:

Nope

Click to expand...

I can get by very well with understanding the english language.

But your "Nope"doesn't ring a bell.

This is what an TC drop and shimms did for the yoke on the TC drive shaft.



I grinded of 2* from the 6* shimms, took me about 5 hours of grinding.................... to get them done.

If I knew my neighbour sold me that good quality steel I just had him made new ones for $12.
only a little vibe at 38 mph..
Even the old before lifting vibes at 65 mph are gone. I think these where from the old sagged leaf packs.
Hve to measure and check the angles again as soon as it stops raining.
Think I grinded of 1/2* to much..............

.............O well I'm happy for the time being, now Im going to find out how to put in a front drive shaft into the back because if I order one from the USA the approx. $250 and shipping $50 (weight) will cost a bundle. And customs will throw some tax on that $300.
So all together the new CV will cost me almost $ 400.

Only ordering the SYE when times and $$ comes will be a better idear money wise.

Angles DV and U-joints are now about 10*, mmmmm can live with that for a while.

STRYKER said:

sweet jesus!!!




The problem no one has mentioned yet. You cannot exceed 15 degrees (and that is extreme) with a single cardan driveshaft.
You need the slip yoke elimination and a double cardan driveshaft.

.

Click to expand...