Installed 8.8, axle offcenter, vibes...

[D_JEEPER]

As the title hints, i installed my new 8.8 axle yesterday, but even with the raise in the MORE brackets for the rear track bar mount, my axle is about 2" shoved to the passanger side.

I am running the 3.5" RE Superflex kit and I have the CV rear shaft and SYE. Im getting some really good low speed vibrations all around, would it make sence to think that the axle being way off centered now is causing this? The vibes are so bad that i dont want to drive the jeep at the moment.

I am looking to get the black diamond rear track bar for 0-4" lift since i have the extra correction through the track bar bracket we welded on.


anyone else have anything similar to this??? Shoot me any input...

[Little Jeep]

Originally Posted by D_JEEPER

As the title hints, i installed my new 8.8 axle yesterday, but even with the raise in the MORE brackets for the rear track bar mount, my axle is about 2" shoved to the passanger side.

I am running the 3.5" RE Superflex kit and I have the CV rear shaft and SYE. Im getting some really good low speed vibrations all around, would it make sence to think that the axle being way off centered now is causing this? The vibes are so bad that i dont want to drive the jeep at the moment.

I am looking to get the black diamond rear track bar for 0-4" lift since i have the extra correction through the track bar bracket we welded on.


anyone else have anything similar to this??? Shoot me any input...

Are you saying that one tire sticks out 2 inches more than the tire on the other side? OR are you saying that your driveshaft is off center, but the axle itself is centered under the Jeep?

Define low speed? (Vibes)

Install in TJ or YJ?

[D_JEEPER]

The axle is actually over to the passanger side about 2" i would say.

on the drivers side, i can barely get my finger between the tire and the coil bucket whereas i can stick my whole fist sideways between the coil bucket and tire on the passanger side. thats how it is offcenter, heh.

The vibrations are like a rumble that shakes the whole jeep in proportion to the speed. all the driveshaft bolts are good and tight and the adapter flange is correct.

i just didnt think a CV shaft would vibrate so much as it isnt maxed out.

in a TJ btw...

[SHARPMACHINE]

Not much help for you, but I am planning on an 8.8 soon and have the same concerns. I have heard of people installing a wheel spacer on one side at install to reduce the offset???? Are youre universals new? Let us know how this works out.

[atblis]

What exactly did you do? Center the axle under the vehicle, or did you try and center the pinion?

Pinion angle?

Not familiar with installing an 8.8 in a TJ, but it sounds like who ever welded your brackets on screwed up.
________
LIVE SEXY CAMS

[Ixer]

how did you measure the bracket placement? i believe that the pumpkin is offset about 2-3in to teh pass side...

[D_JEEPER]

well, in order to center the axle with the upper and lower control arms, we had to take the measurements off of the axle, which remember, is shorter by about 2 inches. this i believe contributed to the loss of track bar. everything else measured up pretty well.... the pinion angle is the same as the d35...


also, we set up the bracket placement with a jig made from a D35. we then centered them on the axle by measuring from the back for the caliper on each side until it was level.

[The Black Sheep]

Im at a loss as to how it got 2" offcenter if you measured from the wheels/calipers etc and not the pinion. Best advice i can say is center the axle correctly first and fore most then tell us if it is still having vibes. Find out where the 2" difference came from, or what happened, start taking measurements from your old axle and see where things need to go on the new one.

Something is not adding up here, or theres something you are not telling us.....

[D_JEEPER]

i dont know, im going to order a black diamond track bar and go from there. since the pinion is already offset to the passanger side more than a D35 and then the axle is all the way over, i think that has something to do with it....

[Bubba_Jeep]

Obviously, you need to center the axle under your Jeep. As you know, the track bar does that. So, if the axle is offset, either move or mod the axle mount, or buy an adjustable track bar.
I would imagine too much pinion offset, with respect to the transfer case output shaft would result in vibration, the same as vibration is caused when the pinion is too high or low, with respect to the transfer case. It may even be a bigger problem when running a double carded joint at the transfer case. Remember, the u-joint at the axle should, theoretically, be set to "0" angle with respect to the pinion and drive shaft. Since you can't rotate the rear axle to be in line with the transfer case, you may need to move the whole engine/trans/transfer case assembly to one side.
I'd suspect the combination of the 8.8's pinion being offset with respect to the D35's pinion, and your track bar position adding to the total pinion offset is just a "bridge too far", with regard to u-joint alignment.
Get your axle centered, like it should be, and your pinion angle corrected, as needed, and I'll bet your vibration will be acceptable.

[rockrknockr]

^ X100

center the fawkin axle

and then when the pinion is still offset a bit from center, not to worry. the CV joint/u-joints will take care of that HORIZONTAL angle just as they take care of the VERTICAL angle.

[Wild Hare]

Originally Posted by SHARPMACHINE

Not much help for you, but I am planning on an 8.8 soon and have the same concerns. I have heard of people installing a wheel spacer on one side at install to reduce the offset???? Are youre universals new? Let us know how this works out.

thats crazy talk. an offset diff does nothing. a ford 8.8 diff is 2.5 offset to the passenger side netting a 5" difference passenger to driver side axle lengths. the posters mis alignment of the rear axle may or may not lead to vibes. if the axle is set farther to one side than the other but still parallel to the front axle no vibes should occur however the vehicle will dog track. however, if the rear axle is not parallel with the front then a vibe could occur.
first and foremost, the 8.8 has to be centered and aligned correctly.

[D_JEEPER]

uhm yeah the jeep tracks just fine, i think its just the 5" offset that is throwing the vibes.

Are driveline vibes more violent under accelleration?? my vibes seem to magnify under accelleration.

[Little Jeep]

I have an 8.8 in a TJ. The axle should be centered under the Jeep. The pumpkin will be off center, but that is a non issue. The 8.8 is only less than 2 inches narrower than a stock axle. This has proven to also be a non issue (no need for wheel spacers). The pinion angle with approximately 3.5 to 4 inches of lift should be about 14 degrees. This is probably much greater than your stock D35.

[rockrknockr]

Originally Posted by Wild Hare

thats crazy talk. an offset diff does nothing. a ford 8.8 diff is 2.5 offset to the passenger side netting a 5" difference passenger to driver side axle lengths. the posters mis alignment of the rear axle may or may not lead to vibes. if the axle is set farther to one side than the other but still parallel to the front axle no vibes should occur however the vehicle will dog track. however, if the rear axle is not parallel with the front then a vibe could occur.
first and foremost, the 8.8 has to be centered and aligned correctly.

are you pretty sure the axle shaft lengths vary by 5"? just checking here, that sounds like quite a bit. i tried looking this up and came up with only this so far:


ord Truck Style Rear Axle Shaft 91-94 EXPLORER, NAVAJO (30 5/8)
$89.95
MG1725
8.8" assembly. 1991-94 EXPLORER, NAVAJO STYLE. 30 5/8” Long, 2/4WD, 5 Lug, LH, 31 Spline




Ford Truck Style Rear Axle Shaft 91-94 EXPLORER, NAVAJO 27 3/4
$89.95
MG1724
8.8" assembly. 1991-94 EXPLORER, NAVAJO STYLE. 27 3/4” Long, 2/4WD, 5 Lug, RH, 31 Spline



30 5/8
-27 3/4
--------
2 7/8" difference

[D_JEEPER]

no, we were talking about the diff being 2.5" offset to the passanger side. then, as my axle is pushed to the passanger side 2 more inches by my fumbling track bar that is too short, it totals about 5" offset total.

[The Black Sheep]

Again i could be wrong but don't TJs have a basic 4-link setup that doesn't require a Track bar in the rear? Maybe its just my limited knowledge on the subject but i swear ive seen guys with 4-linked rears that axe the trackbar alltogether because the links center the axle. I think you should take some pictures....

[DevinB]

Originally Posted by The Black Sheep

Again i could be wrong but don't TJs have a basic 4-link setup that doesn't require a Track bar in the rear? Maybe its just my limited knowledge on the subject but i swear ive seen guys with 4-linked rears that axe the trackbar alltogether because the links center the axle. I think you should take some pictures....

If you triangulate the links, you negate the need for a track bar, which is what you've seen. If you have a standard four link like a TJ, the links only control the up/down movement of the axle, the track bar locates the axle left/right.

Triangulated:



Notice the upper links aren't parallel to the lowers? That keeps the axle from moving side to side as well as rotate up/down, so you don't need a track bar.

[Little Jeep]

Originally Posted by The Black Sheep

Again i could be wrong but don't TJs have a basic 4-link setup that doesn't require a Track bar in the rear? Maybe its just my limited knowledge on the subject but i swear ive seen guys with 4-linked rears that axe the trackbar alltogether because the links center the axle. I think you should take some pictures....

If he is using a stock like setup with upper and lower control arms in near stock postions, a TJ WILL require a trackbar to center and hold axle centered under Jeep. If he had a YJ, the trackbar would not be such an important issue.

[Totalled]

First, center the axle under your rig. Second, with the CV rear shaft, is the pinion pointed inline with the shaft? Is needs to be with a dual cardan shaft.

[Wild Hare]

Originally Posted by D_JEEPER

no, we were talking about the diff being 2.5" offset to the passanger side. then, as my axle is pushed to the passanger side 2 more inches by my fumbling track bar that is too short, it totals about 5" offset total.

i misrepresented my quote. the axles are not 5" different, but the diff is offset 2.5 inches making it 5 inches difference from backing plate to center of flange one side to the other...
and, as was said above. a tj 4link only controls up and down and still needs a track bar to center the diff

[ChrisTX]

I responded on JU, but your UCA and TB mount look like they're too far over. You have way more room between the bracket and the diff than I do. I had to rock my junction block back just to get enough room to run my brake lines. When I set up my brackets, I found center of the D35, then measured out to the center of the spring pad (I think it was 19.5" on both sides). Then from there, I measured from the center of the spring pad to the bolt hole of each mount. If you measure to the edge of the bracket, it's not accurate because the brackets are bigger. Go to the 8.8 and do the same; find center and measure out to the spring pad, then from there to each bolt hole. See what you come up with on that track bar mount.

[D_JEEPER]

you know im not using the same spot for the junction block? my junction block is right damn next to the track bar bracket. i welded on an upside down bolt to the housing to hold the block. look closer, you will see it.

I think thats what you are talking about

[ABQ-TJ]

Did you use the measurements from Stu's site? They are dead-on.

[D_JEEPER]

i found some of the vibrations last night in my driveshaft... the metal/rubber dust seal for the ball in the double cardon joint had come off and was being mashed in the driveshaft works. i removed it and that took care of a good portion of the vibes... but im still getting them at around 10-30 mph. i have not had my jeep up faster than that for fear of detonating u-joints.

still waiting on the track bar....