Rear driveshaft - how much compression travel needed?

[DanB98TJ]

Well, Fred and I got the rear D44 installed and the front D30 housing bolted in. Still need to bolt on the knuckles, slide the front axle shafts in, hook up the steering linkage, install and bleed the brakes. We'll finish things off tomorrow, barring any major problems. Thanks for the help, Fred!

The rear driveshaft was really close to bottoming out when we cycled the suspension - had about 1/4" of travel left. We also lengthened the uppers about 3 turns after we cycled the suspension to get the pinion angle in spec, and dropped the bumpstops about 3/8" to compensate for the different shocks.

I'm definitely okay on the street - no way I'll max the suspension cycle there, but I'm not sure about getting it twisted up. Anyone mind measuring their rear shaft and see how much it compresses as the suspension cycles? Fred had a nice "witness" mark on his, but with the J-arms and tri-link it probably won't move the same amount as a regular short arm lift. I'm hoping to avoid having the rear shaft shortened - once Fred gets the front J-arms installed I'll pick up the other two Currie lowers, and that will allow me to add a little length compared to the stock lowers - I had to use the pair I already have in the front (the XJ axle doesn't have any provision for cam bolts). I'm also planning a high clearance skid, so that will pull the shaft out a little from where it is now.

The front shaft is definitely a problem - it bottomed hard when we were cycling the axle. Hopefully Fred's old shaft will do the trick, otherwise I'll have to have it cut.

[karstman]

As long as you cycled it from the center so that both sides were fully stuffed and had compressed the bumpstops, I'd call it good. I would probably disconnect it from the pinion yoke and see if you can push if forward that full 1/4" just to be sure the travel is really there and nothing inside the DS binds up in that last bit of stroke. Don't need to do that when it's on stands and all, just make sure that 1/4 of travel is really there and nothing binds.

[DanB98TJ]

Just for S&Gs, we pulled the springs and disco'd the rear sway bar, then cycled the suspension again. At full right stuff/left droop, the shaft is bottomed out. I doubt I'd ever get that much flex with the sway bar connected...but I'm not willing to chance it. I'll pull the shaft next week and have it shortened by 1/2". Sucks to have to mess with it for that small amount, but I'd rather do that than shove the driveshaft through the transfer case....

Fred's old front driveshaft worked out perfectly - it was about 1 1/2" shorter than mine, so that was easily solved. Thanks, Fred!

We have the Jeep all back together and got to take it for a short ride.....the 4.88s are sweet! Besides the driveshaft issue, I have to figure out what to do with the rear track bar - the axle is about an inch to the left, but the RE track bar is as short as it will go.

[karstman]

I should have read your initial post more carefully and I assumed you had removed the springs the first time you cycled everything. Good catch with the bind.

FWIW - my RE bar is short too. I'm using the RE angled bracket and about 4-5" of lift from the springs, and I have the RE bar as short as it goes to get close to center with the axle. Could always cut it, sleeve it, and weld it back. I may cut the end off and replace the bushing with a rod end anyway, and I can adjsut the length a bit then.

later,
mark

[DanB98TJ]

We didn't cycle the suspension with the springs out after adjusting the pinion angle and bumpstops. I had a little - very little - travel left when we checked it when we installed the axle. Guess tilting the pinion up more took care of that....glad we pulled the springs and checked it again.

At least I'm not the only one having fits with the RE bar. It was fine on Fred's Jeep, and I think he even had a little adjustment left in it, but when I put it on mine we had to screw the heim all the way in. With the OME bracket on the D35 it was almost perfectly centered, but with the angled RE bracket on the D44 it isn't. I'm thinking about doing the heim on the frame end, too, so that will take care of it.

Besides the track bar and driveshaft issues, I have an axle seal leaking on the D44. I can't even drive enough it to break the gears in until I get that fixed. I did drive it a bit last night, and I love the 4.88s.

Sure wish Murphy would leave me the hell alone....

[Darrell C]

Originally posted by DanB98TJ
...At least I'm not the only one having fits with the RE bar. It was fine on Fred's Jeep, and I think he even had a little adjustment left in it, but when I put it on mine we had to screw the heim all the way in. With the OME bracket on the D35 it was almost perfectly centered, but with the angled RE bracket on the D44 it isn't. I'm thinking about doing the heim on the frame end, too, so that will take care of it.

Dan,

My rear RE trackbar seemed too long also, so I redrilled the frame bracket. The factory hole is far enough out on the bracket that sufficient room existed to redrill another hole closer to the frame. Think I came in about 7/8" IIRC, and then backed the heim out about 1 turn.

Might want to have a look at it...

[DanB98TJ]

Fred and I were discussing that option as well. Do you have any problem with the track bar hitting the "lip" on the inner edge of the frame mount when it's fully stuffed? Sitting level there isn't much room on mine.

I'm still trying to decide which route I want to take. I'd really like the heim on the other end, and may still do that, but for the time being I may just redrill the hole.

[Darrell C]

We test cycled the suspension in the garage and didn't notice any contact. However, to be honest, I haven't checked in quite a while...and I've gone on a couple trips where I packed pretty heavy in the rear for overnighters. I'll look under it tonight when I get home and check. I'll let you know how things are holding up.

Edit: If it does contact, it wouldn't be a big deal to take a small angle head with a cut-off wheel and shorten that bracket up.

[DanB98TJ]

Thanks - I'll probably just redrill it for now unless you find something weird. I didn't crawl under and look to see how much space there was, just checked it by the braille method, but it felt pretty close. While the bar is out I'll clearance the bracket a little...just to make sure.

[Darrell C]

Dan,

Sorry for the delayed response...life's been a pain lately

I checked today and found nothing weird. The bracket and track bar are fine. Let me know how things work out.

[DanB98TJ]

Darrell - No problem, and thanks for checking. I was busy dealing with the driveshaft and axle seal today, but got the Jeep together and got to drive it to work. I'll probably drill a new hole for the track bar this weekend, but will go ahead and start collecting the parts so I can swap it over to a heim when I have more time to deal with it.

[Blackjack]

I would go a little over a half inch shorter. There is not that much slip movement on a four link so going a little extra will not hurt. Just a little insurance that it will never have the chance to bottom out.

[DanB98TJ]

I actually ended up having 3/4" taken out. Any future changes I make (high clearance skid, etc) will allow more room on the slip yoke, and as it is now I'll have right at 3/4" of "space." The shaft was just reaching the end of it's travel as the suspension did.

I was pretty shocked that the shop only charged $30 to shorten the shaft, and had it done in a couple hours. I've had good luck with them in the past and they didn't disappoint me this time, either.

[Blackjack]

$30 is a good deal. The going rate in AK is $65 for a shorten and balance.