Greasable Spring Bushings
Ever since I installed rear (and originally, front) add-a-leaves on my '95 YJ, I've had to suffer the rough ride that they caused. It isn't so bad when I'm heavily loaded. In fact, when I'm loaded for bear on a wheeling trip, the ride is downright cushy (I installed the extra leaves to help support all that weight off-road). However, when I'm unloaded and topless around town in the summer, my Jeep rides like an empty grain truck. After a couple years, it seemed to be getting worse. It felt like I was feeling every crack in the road, which just isn't right.
After looking at my springs, I realized that my old, rubber spring bushings (especially the main eye bushings) had seen better days, and were most likely binding up. This binding prevents the leaves from rotating smoothly around the bolt in the spring hanger, which in turn passes road vibrations from the axle assembly right through the bushings and up to the frame & body where you can feel them. The logical solution seemed to be to install greaseable spring bushings, like those from Daystar. These polyurethane bushings are fluted to keep the grease between them and the inner bolt sleeve. The bolts are rifle drilled and have a zerk in the head for injecting new grease. Poly bushings don't flex as well as rubber ones, but they last much longer, provide tigher handling, and (most importantly to me) the greaseable models should soften my ride a bit.
After spending way too many months talking myself into it, I shelled out the $55 (including shipping) and got a set of greaseable main eye bushings from 4 Wheel Drive Hardware. I chose main eye bushings instead of shackle bushings because I knew my stock main eye bushings were in much worse shape than my stock shackle bushings. I figured if the main eye bushings seemed to help, I could add shackle bushings later on.
The bushings arrived a few days before the annual Flatlanders 4x4 Fest. Despite the constant rainy weather and my full garage (forcing me to work out on the driveway), I decided to install them two days before the trip. It just wouldn't be a proper wheeling trip if I didn't have my Jeep torn apart just before leaving, would it?
Most of the trouble comes trying to remove the old bushings. Numerous problems removing the first bushing prevented me from installing even one new bushing that night. I did, however, manage to make it past the point of no return by destroying part of the old rubber bushing. I ended up taking the next day (Friday) off work so I could at least get her rolling again ("My baby is sick; I can't come in today"). Despite the rain and my need for power tools to complete the job, I did manage to get one new bushing installed so I could leave town that night for the 4x4 Fest. I'll save you the story of my tribulations, and instead describe the proper way to replace these bushings, complete with all the tricks I learned the hard way.
First, a list of tools that I wouldn't do this again without:
- Pneumatic impact wrench. Sure, you could use a large, hand-operated wratchet, but I've gotten spoiled by technology. Things go so much faster with air tools.
- 13/16" and 7/8" wrenches and sockets.
- A sawzall, aka reciprocating saw, with a 6" metal-cutting blade. A hand hack saw would work, but it would take days instead of minutes to do the job. The blades of a saber saw just aren't long enough.
- A fine-tip torch. Mine uses oxygen and propane (or mapp gas) and has a 24" flexible hose for ease of use. I'm normally not wild about it, but it was perfect for this application. A normal, non-oxygen torch would work, but use mapp gas rather than propane because it burns hotter.
- A 3-lb hammer. What can't you do with a BFH?
- A short (18") pry bar. Good for both prying and banging.
- A large, flathead screwdriver with a 1/4-3/8" blade. I prefer Craftsman, because you'll be using this for banging and prying, and you're likely to make use of their lifetime warranty.
- Largish vice grips, intended for securely grabbing 1" round tubes.
- Needle-nose vice grips. Needle-nose pliers would also work if you've got strong hands.
- A grease gun with lithium grease (duh). GC-LB chassis grease works fine. I also used tub of grease that I could apply with my fingers so things installed easier, but it's not mandatory.
- Two large washers that work with the stock 9/16" main eye bolt.
- A hydraulic jack for raising & lowering the axle. The stock scissor jack would be fine.
- One jack stand.
- If any of your bolts are frozen to the bushing sleeves, you'll want a pneumatic cut-off wheel to free them. The sawzall would work, but would be much slower. I pity the poor fool who decides to do this with a hand hacksaw.
- I used a hand-operated come-along at one point to pull the spring forward so I could align the bolt holes on one of the bushings. This really shouldn't have been necessary.
Now, here's how the job should be done if you knew what you were doing (which you all now should):
- Jack up the Jeep. Support the corner you're working on with a jack stand. Remove the tire. Only do one corner at a time.
- Place a jack under the axle/spring and adjust it so that it's touching the axle, but not supporting much (if any) weight.
- Remove the bolt through the main eye bushing. The nut is 7/8",
but the bolt head is 13/16" (or maybe I have that backwards).
If all goes well, you should be able to pound the bolt out
of the hole using your BFH. Once the head is out a ways,
use vice grips or pliers to pull the bolt through.
If the bolt won't come out no matter how hard you pound, it's probably frozen (rusted) to the metal sleeve inside the rubber bushing. The older your Jeep is, the more likely this is to occur. In this case, you'll need your cutoff wheel to cut the bolt off. On the head side, make your cut as close to the spring as possible (between the spring and the hanger). On the thread side, make your cut on the outside of the hanger (the inside of the Jeep, away from the spring), but as close to the hanger as possible. This will make it harder to remove the spring from the hanger, but the 1/8" of bolt that remains will give you something to grab onto with your vice grips later on. To remove the spring once both ends are cut, twist the head end downward as far as possible, pry the hanger sides apart (if possible, but don't damage them), and beat on what's left of the thread end of the bolt with your large screwdriver (or punch) and BFH.
Once the bolt is out, lower the jack and possibly use your prybar to get the newly-freed bushing as far below the frame as possible.
- Now you need to remove the metal sleeve from the rubber bushing.
- If your sleeve is empty (without a cut off bolt stuck inside it): Light your torch and point it inside the metal sleeve so as to heat the inside of the sleeve. Point it as close to the middle of the sleeve as possible. If you've got a large torch, you may want to alternately point it in both ends of the sleeve to evenly distribute the heat. Remember that your fuel lines run along the inside of your frame, just a few inches above where you're probably heating. You shouldn't need to worry, just be mindful of where your torch flame goes when it shoots out the back side of the sleeve. If you can, rotate your torch around so that the top, sides, and bottom of the sleeve are all headed evenly. While doing this, it's possible that your rubber bushing will catch fire. If that happens, pull the torch away, blow out the flames, wait a few seconds for the rubber to cool, and resume heating the sleeve. Did I mention you should be doing this in a well-ventilated area (like your driveway)? Eventually, the rubber around the sleeve will start to bubble and sizzle as it literally melts. When this happens, use your BFH and the end of your prybar (or a large punch, or the head of a large bolt, etc) to pound the sleeve out of the rubber bushing. If the rubber is really melted and you hit the sleeve really hard, it'll shoot out the other side with just a couple good whacks.
- If your sleeve contains the remainder of your bolt, so you can't get at the inside of it: Attempt the technique describe above, but you'll only be able to heat each end of the metal mass rather than the inside surface of the sleeve. You've also got a much larger metal mass to heat, so it'll be harder to make the rubber bushing sizzle without first incinerating the end of the bushing with your torch. Just heat it up as best you can. When you think it's hot enough, try beating on what used to be the head end of the bolt with your BFH. If that doesn't budge the bolt/sleeve, use your vice grips to grab what's left of the bolt on the other side (this is why we didn't cut off the bolt inside the spring hanger) and try twisting the bolt inside the rubber bushing. If it won't twist, it's not hot enough. If it does twist, try pulling it outward as you twist it. Keep working it back and forth while you pull out. You may need to apply more heat periodically. Eventually you should be able to work it out of the rubber bushing.
- Now you need to remove the rubber bushing from the leaf spring. Let it cool a few minutes after you boiled it in the previous step. You'll probably need to rest your back at this point, anyway. Pound your screwdriver in between the rubber and the spring. Pry the rubber away from the spring, then insert your needle nose pliers and pull the bushing out of the spring. You'll probably need to do this several times, working your way around the edge of the bushing. Try not to pull so hard that your sharp, needle-hose pliers tear the rubber. Once it's out 3/8" or so, use your big vice grips to get a good grip on a large portion of it. you should now be able to pull the bushing free of the spring.
- You now need to remove that thin metal sleeve from inside the spring. The new poly bushing is too big to fit inside that sleeve, I'm afraid. This is the part that took me forever on my first bushing. The best way to do this is to use your sawzall to cut through the side of the sleeve. I recommend doing this right where the loop in the spring comes round to meet itself. Try to keep the blade flat against the sleeve so the blade doesn't bind up in the slot that you've cut. Once you've cut completely through the entire width of the sleeve, pound your screwdriver in between the sleeve and the spring (right next to your cut) and pry one end of the sleeve inward. Don't even try to pry one end up until you've cut completely through the entire sleeve. If the sleeve is bent, it'll be much harder to finish cutting through it. Now, grab the pried-up end of the sleeve with your big vice grips and twist it inward while pulling the sleeve out toward you. It should come out easily now that it's no longer press-fit into the spring.
- Congratulations! You've finished the hard part. Enjoy a refreshing beverage and rest your aching back for a minute or two.
- Time to insert the poly bushings into the spring. This is easier to do if you slather both the inside & outside of the bushing with grease. This doesn't have to be the same grease as what's in your grease gun, but it should use the same base (ie, both lithium-based). Try to fill the flutes inside the bushing with grease. Don't put the sleeve in the bushing just yet. Push the two halves of the bushing in from each side as far as you can. Bang on them with BFH if necessary. Once you've gotten them to within 1/4" or so on each side, you can squeeze them into place using a bolt and two large washers. Make sure the end caps of the bushing are flush against the side of the spring, otherwise you won't be able to get it back up inside the spring hanger.
- Insert the metal sleeve into the bushing. Orient the sleeve so that the grease hole points directly away from the gap where the spring loops around to meet itself. This will force new grease to travel through the entire bushing before it squirts out this gap. Smear some grease around inside the sleeve for good measure.
- Raise the jack to position the spring eye back into the spring hanger. You may need to pry or beat on the spring eye to position it correctly. On one spring, I even had to use a come-along to pull the spring forward a bit because the whole spring had worked its way backward and wouldn't line up horizontally with the hole. I also found that the spring was twisted a bit, so that I had to insert one end of the bolt and then realign the other side of the bushing before I could push the bolt all the way through.
- When you insert the bolt, make sure the grease hole in the side of it is oriented directly toward the gap where the spring loops around to meet itself. This forces new grease to travel all the way around the bolt before it comes out the hole in the sleeve. Be careful to keep the bolt stationary and only turn the nut when you're tightening everything down. Only torque the nut down tight enough to keep it in place. If you crank it to 80 ft-lbs (or whatever the factory spec is for the old bolt), it won't be able to rotate like it should. The nylon lock ring in the nut should keep it from rotating loose, and you can check it periodically just to be sure.
- Reinstall your tire and repeat the process for the other three corners.
Although the above instructions describe the installation of new main eye bushings, the process is very similar for shackle bushings. For something that sounds so simple to install, this can sure be a real bugger of a project if you don't know the little tricks.
It took a few days to really break in the bushings, but I can feel a small improvement in ride quality, even with the stock shackle bushings. I think I'm gonna install some greaseable shackle bushings -- at least in the rear -- and see if they make an even bigger difference. I don't have ready access to an RTI ramp, so I can't say for sure what effect they have on my axle articulation. After a couple trips to my favorite wheeling spot, I should have a good feel for whether the affect is really noticeable.
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last updated 23 May 2001 Obi-Wan (firstname.lastname@example.org)