Full suspension bushing kit available?

[Jlindsey86]

Is anyone aware if a full kit of rubber bushings for the MJ suspension exists? Trying to piece together all the bushings I need to do a full replacement.

[ghetdjc320]

There are some XJ kits that cover most items. Changing the bushings in the leaf springs and control arms is quite a challenge. I’d recommend just replacing the arms since they are cheap. You’ll likely need an air hammer for the leaf springs. 

[watchamakalit]

 

Sometimes leaf spring bushings are best removed with a blue wrench.

[cruiser54]

When I replaced the bushings in my Alfa Romeo blue wrench style. 

[howeitsdone]

8 hours ago, cruiser54 said:

 

I bet that smelled like freedom

[AZJeff]

Yeah, taking bushings out of ANYTHING can be fun if you don't have a large arbor press and, more importantly, the right size bushings to press on the sleeve of the rubber bushing assembly.

 

On an MJ/XJ, unless you have a lifted vehicle, I recommend replacement control arms.  They can be had pretty inexpensively (under $20 each), and beat the hell out of burning out the rubber as Cruiser was demonstrating in the photo above.

 

The only area where you will have to use brute force is the upper control arm FOREWARD bushing, which is pressed into the axle housing, and is not part of the control arm (unfortunately).   If you have access to an air chisel, that job isn't too bad.  Otherwise, a hand chisel, a pair of Vice-Grips to hold the chisel, and a machinist's mallet are the next best approach.  (I am not real fond of burning out those bushings in the axle under the car, because of the proximity to things that don't like flames.)

 

As far as the leaf spring bushings go, you need to make sure that your springs are original Jeep parts, first.   On my MJ, some previous owner had switched them out for some aftermarket springs, and none of the OEM replacement bushings had the correct outside diameter to press into the spring properly.   I ordered bushings from several sources, all of which would not fit right, until I gave up.

 

I wound up taking the spring apart, and taking the main leaf to a truck spring shop where they matched up and installed some bushings using their press.  Then I put in new centering pins and new inter-leaf plastic anti-friction pads and reassembled the spring packs.

 

If your springs are OEM, it would still be easier for you to find someone with a large arbor press to remove/install the new bushings rather than burn and beat the old ones out (and beat the new  ones in.)

[pizzaman09]

The harbor freight 13 or 20 ton hydraulic press is surprisingly affordable and does a s excellent job on removing rubber bushings.  If you have liquid nitrogen, it makes breaking the rubber apart quite easy, that's how we salvage rubber aerospace parts where I work.

[AZJeff]

3 hours ago, pizzaman09 said:

The harbor freight 13 or 20 ton hydraulic press is surprisingly affordable and does a s excellent job on removing rubber bushings.  If you have liquid nitrogen, it makes breaking the rubber apart quite easy, that's how we salvage rubber aerospace parts where I work.

In additon to the hydraulic arbor press, the OP will need some sleeves to press against the outside edge of the currently installed bushings.  Pressing against rubber doesn't do very much, even at 13+ tons of pressure.  It MUST be exerted on the outside sleeve of the old (and then the new) bushing.

[ghetdjc320]

All the ones I’ve had I drilled several large holes on the rubber then hit the shell with an air hammer to collapse it inward. There is a bit of access to the shell where the spring eye wrap comes together. The bolts also tend to completely seize within the inner sleeve and offer require cutting. 

[AZJeff]

9 hours ago, ghetdjc320 said:

All the ones I’ve had I drilled several large holes on the rubber then hit the shell with an air hammer to collapse it inward. There is a bit of access to the shell where the spring eye wrap comes together. The bolts also tend to completely seize within the inner sleeve and offer require cutting. 

Yep, that drill and chisel method is what I use as well.  And air hammer (air chisel, in this case) are a Godsend for this kind of stuff.

[Jlindsey86]

Thanks for all the feedback. My plan is to purchase the bushings and have a shop replace them for me. 

 

It seems as polyethylene bushing kits are available but not so much full kits for rubber bushings. 

 

Are polyethylene that much better? My truck will retain its stock ride height.

[AZJeff]

20 minutes ago, Jlindsey86 said:

Thanks for all the feedback. My plan is to purchase the bushings and have a shop replace them for me. 

 

It seems as polyethylene bushing kits are available but not so much full kits for rubber bushings. 

 

Are polyethylene that much better? My truck will retain its stock ride height.

What you are talking about are "polyurethane" bushings.  Polyurethane is much stiffer than regular rubber, when used in bushings.  Its commonly used on applications where precision handling is needed (like on race cars or the like.)   It is not used on "regular" street vehicles because the polyurethane transmits much more shock and vibration back into the chassis, and can make ride quality quite harsh.

 

Unless you are running the baja in your MJ, I would steer clear of polyurethane.

[Pete M]

installing new arms is way easier than new bushings if you think you can tackle that.    I'd just skip that one upper bushing in the diff as you aren't likely to notice it.  lower arms are by far the biggest impact on handling. 

[Big_Mark]

Steer clear of the "red" polyurethane bushings, they are very durable as advertised, but as AZ-Jeff said, the ride quality is harsh. Also, the bushings are so hard the components they are installed in can become the flex point instead of the bushing, causing cracks at the mounts/frame/wherever the bushings are located.

I learned the hard way on my Scrambler. I used the poly body mounts and ended up with cracks in the body everywhere the mounts were located. Also cracks around the frame where the sway bar connected. No bueno

Stick with OEM if possible. You gotta figure if it took 20+ years for them to go bad, your replacements should last just as long