urethane bushings, yay or nay???

[volaredon]

I have an 01 XJ with 162K on it, that has a few little "nuisance" problems that we've had to just "live with", for a while; but now I have it in the garage, "down for maintenance" to take care of some of them;
one of these, has been what I can only describe as a "mini death wobble" because it only does it between 50-55; we've had it since 94K and it has ALWAYS been there; but while the speed range has not increased, the intensity has; 3 sets of tires between 2 sets of wheels (the set that was there when I bought it + 2 replacement sets) tell me that it is NOT tires/wheels/balance;

I pulled the front diff today, so I could replace the front 4-link bushings; (there are 2 that go directly in the diff housing, these 2 were both very weak on the right upper one, the bushing sleeve was loose in the diff housing, even, pushed irt out of the diff with my fingers!
I had bought some urethane bushings like eons ago, to put into this thing; finally got around to it today. I burned the old ones out with a propane "bottle torch" (why do urethane ones, NEVER come with the outer sleeves?) and bead blasted the shells to get rid of the last little bit of old bushings left over; then I tack welded the shells to the control arms, to be sure they don't move; the rt. top one I tacked to the housing, the left top one, I put a couple globs of weld (since the housing is cast iron there) on the shell to retain it; all done with an oxyacetylene setup the "old" way; got all the new bushings in, ready to put the diff back into place tomorrow;
Any opinions here on urethane bushings??? (vs replacing them with OE type rubber) I have no lift kit on this Jeep; I have 235/75-15 highway tread tires on, this thing don't see 4WD except in the winter (we live in the country) more for the wife's "piece of mind (it's her ride) I went with the urethane since the "death wobble" is basically the result of the front diff shimmying side to side within the chassis; so I figured the stiffer bushings might alleviate that. I also have a new track bar going back in as well; just because of the mileage issue. as long as the body holds up I plan on running the wheels off this Jeep; no plans to sell/trade in the forseeable future. this is my 1st time using urethane, but I've heard all the complaints from the hot rod and classic muscle car world.

 

[Bounty__Hunter]

You may notice a little more road noise and/or bumps transmitted into the chassis, but the rubber bushings at the other end of the UCA's should help negate this. As long as they fit in the axle tight, there shouldn't be a problem with using them.

 

[SteelHeadz]

Urethane bushings are better lasting than the oem rubber bushings but stiffer. There is actually a Technical Service Bulletin for this issue that requires replacement of the four control arms,2 upper and 2 lower. This also includes all the bushings. Check the steering damper for leaks and look at it's tube diameter. If it's half the size diameter compared to the shock absorber, that's the old design. Chrysler has since revised this damper with a larger one to take a bit more beating or replace it with an aftermarket one.

 

[pinebushman]

Rubber! Not worth the vibrations. If it aint broke dont fix it! my 2 cents

 

[volaredon]

Urethane bushings are better lasting than the oem rubber bushings but stiffer. There is actually a Technical Service Bulletin for this issue that requires replacement of the four control arms,2 upper and 2 lower. This also includes all the bushings. Check the steering damper for leaks and look at it's tube diameter. If it's half the size diameter compared to the shock absorber, that's the old design. Chrysler has since revised this damper with a larger one to take a bit more beating or replace it with an aftermarket one.

But, that's because the dealer dont service bushings seperately, the only way that you can get them from Mopar would be the control arm "assembly"; right? I mean my cont arms will be fine with the new aftermarket bushings. (like to get a balljoint on a Dak or a durango you also gotta get a whole control arm, stupid!!!)

Steering damper is new about 4 months ago and beefy. 2nd one replaced on this Jeep since I've owned it. I think I put Rancho dampers on there, both times.
On "rubber; dont fix what ain't broke", a couple of the originals were found to be bad so definitely had to be changed; and (1) since I bought a "kit" that included all 8 bushings and (2) the amount of wok involved (I have the front diff sitting on 2 floor jacks completely out of the chassis) I don't usually do all that work w/o doing the whole job; so, no, I'm not leaving the orig bushings in one end and urethane in the other! I never was a fan of "1/2-a$$ing" a job because that usually means re do's, one of my pet peeves.

 

[SteelHeadz]

But, that's because the dealer dont service bushings seperately, the only way that you can get them from Mopar would be the control arm "assembly"; right? I mean my cont arms will be fine with the new aftermarket bushings. (like to get a balljoint on a Dak or a durango you also gotta get a whole control arm, stupid!!!)

Steering damper is new about 4 months ago and beefy. 2nd one replaced on this Jeep since I've owned it. I think I put Rancho dampers on there, both times.
On "rubber; dont fix what ain't broke", a couple of the originals were found to be bad so definitely had to be changed; and (1) since I bought a "kit" that included all 8 bushings and (2) the amount of wok involved (I have the front diff sitting on 2 floor jacks completely out of the chassis) I don't usually do all that work w/o doing the whole job; so, no, I'm not leaving the orig bushings in one end and urethane in the other! I never was a fan of "1/2-a$$ing" a job because that usually means re do's, one of my pet peeves.

Yes you can service the bushings separate from the control arms and they are available from mopar. The next thing you probbably need to get checked is the alignment.

 

[Bounty__Hunter]

Well you had only mentioned the bushings on the axle end being bad. You will get considerably more road noise by replacing both ends with urethane bushings.

I personally would have pressed out the old bushing sleeves from the front axle, only removing the rubber is, in my book and in your words, "1/2-a$$ing" a job. Are the urethane bushings designed for this OEM application?

 

[volaredon]

Yeah I think they are; I mean, when I called the place, I got them I asked some pointed questions and it came out that these particular ones are made specifically for an XJ. They dont look like generic "one size fitz-all"; Ive done front end work for a living for 18 years but in the shop basically we just sold out of the Moog catalog; didn't get into much "custom" stuff.
but whether youre talking an old mopar muscle car, Mustang, Firebird, any time youre talking urethane bushings you gotta re use the old outer sleeves; I set the control arms out in the driveway (gravel) and set a lit propane torch near them til the rubber was gone; I then bead blasted the shells, and tack welded them in as a couple were loose when I started pulling them apart; which coulda been part of my problem in the 1st place; I try to do what I can to make anything I tear apart "better than it ever was" when I put it back together.

 

[volaredon]

well so far so good; "mini" death wobble GONE, more stable on the road; seems to have more steering "control" and road feel. even the wife commented on the difference! Now to hit up my teacher buddy this coming week; (teaches auto shop at the local career center; once school lets out for the summer that means no more access to an alignment machine for me til fall!) Whenever I run into a need to align something he has me do it as a sort of "guest speaker" thing and put on a "demo" for part of his class! (Helps I was an alignmeny guy for a living for 18 years, about 12 of which right next to this now-teacher, when we both worked at Sears Auto Center)

 

[heminut]

Basically only the toe can be set and as far as wobble,on mine ,I used the urthane bushings and like them.Having done what you did,I bet the alinment will be close or right on.These things are pretty straight forward.Are the axel u-joints free?I just had one get rusty needles after just 6Kmiles and it was NAPAS best.Try using the greaseable "Precision" ones.

 

[volaredon]

yuh; I know about the "toe and go" alignments on these; I made my living as an alignment guy, for 18 years; before switching to industrial maint in a steel mill and now on disability. Other than the tie rod adjusting sleeve liking to freeze up and twist apart like a toilet paper roll (it is made out of "too thin" of metal for its length) XJs are easy alignments!
On the U joints, they seemed all right (I have checked them recently; I bought my 83 Dodge P/U via Ebay last fall; and since I could not drive 2 vehicles simultaneously I tow-dolleyed the Cherokee home and pulled the rear shaft for the ride home; and I checked the front ones for binding when I put these urethane bushings in) though this Jeep has all the ones it left the factory with, except the front "wheel-joints", with 162K miles! though I may replace them anyway, before winter "just because", since I plan on driving the wheels off this thing unless the body goes totally to Hell.
Now I have another issue; I have what sounds like noisey front pinion bearings that started right after putting the new bushings in; I thought it might be a wheel hub bearing, but I swapped them out (I had spares laying around) and still there; it is definitely a bad bearing noise, definitely out of the front diff; at least I have;(1) an extra vehicle that I can send my wife to work in,(2) can do this work myself (3) still have my parts store contacts, meaning that I can still get my parts wholesale, (4) not on anyone else's "clock" any more, so I don't have to care about flat rate no more; if a couple hour job takes me a couple days, SO WHAT! Gonna have to get it up on stands and run it in 4WD, and see if I get any "vibration" out of the pumpkin, like a bad bearing will throw off.
But still glad I decided on urethane vs OE-type rubber, for the new front bushings!

 

[knudsen]

I put them on my J-10 leaf springs and they were a hell of a lot better than metal to metal I had b4! Couldn't get rubber. Had to burn the old bushing out with a propane torch, that was stinky. I made my own for my 58 willys leafs. I would use them without hesitation on leafs, but proceed with caution if you have a linked suspension and want flex.

 

[volaredon]

yeah burning out the old ones was a stinky mess; I just laid a propane torch in the driveway (gravel) and stacked like 3 of the control arms at a time and had a big ol' black smokey-"marshmallow" roast!