Vibes from hell!

[thisfirstlove]

So before i left for school this year i finished swapping in an 8.8 rear out of a 98 exploder. I got back and went to drive the jeep today and ive got bad bad bad vibes. At the time i put the new rear in i swapped to 4.88's front and rear. I havnt gotten the jeep aligned yet, since i took the axles out of the jeep to swap the gears, but i didnt think would give me vibes that bad. Can poor instilation of gears give you vibes? Or maybe it is just the alignment i dunno...i guess my question is, Am i getting vibes from my gears?

 

[AZ XJ]

how long was it sitting? was it on the tires? just a shot in the dark but if it's for a long period of time they could possibly be flat spotted enough to cause vibes.

 

[MaXJohnson]

two things;

the pinion angle on the new 8.8 in the rear may be off

and

you've increased your driveshaft speed from 20% to 40%, depending on the original gear ratio before the change.

Increasing the u-joint speed or angle will increase the likelyhood of vibrations.

 

[thisfirstlove]

Yea, it has been sitting for a while and it is freezing here, im in NH so that could be it. But it was vibing so bad i didnt even want to drive it more then down the street and back. The pinion angle looks ok, is there any fix for the speed thing?

 

[thisfirstlove]

Also, could the vibes be coming from a poor gear setup? this was my first attempt at re-gearing so im sure its not anywhere near ideal

 

[DaffyXJ]

IMO the gears will create vibrations if the pinion isn't tightened. Other than that the backlash and carrier preload will make noise or heat but not vibes. Did you crush the crush sleeves and set the pinion preload?
Most likely it is bad operating angle on the rear drive shaft.
Could be a flat spot in the tires too if it's been sitting along time.
Just my opinion.

 

[RCP Phx]

Also theres no mention of having a SYE kit.Check "ALL" the angles carefully,since the 8.8 has an offset pinion you have to deal with "compound" angles.

 

[thisfirstlove]

Ya i got a SYE installed, the rear pinion might be a little loose, i tightend it down as tight as i could, even brought it to the shop and had them put the gun on it

 

[XJ_ranger]

the rear pinion might be a little loose, i tightend it down as tight as i could, even brought it to the shop and had them put the gun on it

yikes!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

 

[thisfirstlove]

like i said, i havnt been there since the end of june...i just got back to miami. The jeep is gettin an alignment on monday so well see if that is the root of my problems. Ill have them tighten that pinoin nut down more too