xj to yj slip yoke after dana 44 install

i just recently got the rear driveshaft lengthened 1" and the yj slip yoke(i know it was a waste of money by the way, i shoulda done a sye) with new u joints, anyway, i noticed after swapping in the xj dana 44 last week i got vibes back at 60+ under acceleration, well i looked tonight and it looks like the slip yoke is pushed all the way into the t case now, like right up against the output cone. im wondering with the new yj yoke and under maybe a little axle wrap under the accelaration that the driveshaft could push into the t case too far and cause probs? shouldnt it be sticking out a little bit anyway, maybe by 1/2" or so? so im thinking i need to get it retubed and shortened by an 1" and maybe under axle wrap the vibes wont be there if it cant push into the t case anymore. by the way before i retubed i had no vibes, so im thinking the shaft is too long, any thoughts, im heading to the lost coast tomorrow...

Dana 44 drive shaft is about 1" shorter than a dana 35 driveshaft when it stock. The pinion sticks farther out on the axle.

X2 on the exrta inch from 44. Well you could try just try putting a stock yoke back on and see if it helps, should free your slip back up by 5/8". Try that first before paying to retube.

yah, sorry i just assumed that the 1" longer pinion was common knowledge so i didnt mention that, but could the longer shaft be causing vibes, no one really answered that question. i wanna keep the yj yoke for the clearancing around the ears for better angles...local driveline guys said no...

How is your pinion angle? Are you using shims or anything to correct it or is it stock? This is because you mention that the vibes came back, which means your had vibes before. Right?

Sounds to me like the driveshaft being too long is one problem, and (I'm only guessing on this...) your pinion angle is a little off enough to cause another problem. It's only a guess since there aren't any pictures or stats on your lift or anything.

4LowandGo said:

How is your pinion angle? Are you using shims or anything to correct it or is it stock? This is because you mention that the vibes came back, which means your had vibes before. Right?

Sounds to me like the driveshaft being too long is one problem, and (I'm only guessing on this...) your pinion angle is a little off enough to cause another problem. It's only a guess since there aren't any pictures or stats on your lift or anything.

Click to expand...

It's in his sig, his stats that is...
89 xj, 3.5", 30/44 ,both open(lockright waiting for the 30), 31's, zj tie rod, power steering cooler, 3 tranny coolers, bushwackers, confer rack, factory tow hooks, all skids(diffs, t case, front end, gas tank, rocker protection,a beefy xmember skid in the works too) longer dakota rear brake line, and 4.5" lift shocks, jks discos, lebaron vents, mean green alternator, longer bumpstops, brushguard,stupid rustys air tube thing with cone filter with a homemade snorkel on the way



With only 3.5" lift your getting vibes? For one I wouldn't think you needed to retube. But when you had it retube did you measure it or did they? When the shop told me to measure for retube they told me to push the yoke all the way in then pull out a half an inch, then measure from yoke ears to center of Differental. Sound right on what was done on yours? The yeah, my next guess whould be what is your pinion angle?
But either way your slip needs some play, during uptravel that yoke will slam into your tcase and can kill your t case. So I would mess with that no matter what. But also double check pionion angle.

uh, yah, just a minor update but i took it to west sac driveline today and the 1" they reccamended in jan is being cut off.... the driveshaft was so far into the output shaft i had to jack up the rear with the high lift almost a foot or so.... yah, after swapping in that 44 last week along with new rear soft and hard brakelines from the valve back and all the other stuff i installed like zj drag link and diff skids i never once looked at the slip yoke i guess, even after fabbing up a square tubing t case drop to replace the aluminum cylinder thingys, i cant believe it. it kindsa ate that rubber seal around it. im really hoping i didnt total my t case, although a new t cae means sye and 4:1 if i wait around for a good deal i guess....anyway im thinking that major binding could have been causing vibes under heavy acceleration, liuke maybe some axle wrap was pushing the shaft too far into the t case and screwing things up, binding and causing vibes?