Learn me: bushing replacement

So the time has come, the last wear/maintenance item I need to do is bushings on the miata. I've picked out a urethane set, knowing you get what you pay for, but it's the most budget friendly option. That's beside the point of this post though.

Old bushings are a total pain to remove, and from what I understand, new bushings going in isn't exactly a cakewalk either. What kind of tips and tricks has the hive come up with for replacing old bushings?

Fire? Chemicals? A BFH and a chisel? I'm open to suggestions.

Not sure if linking to other forums is kosher, but:

http://www.miataturbo.net/suspension-brakes-drivetrain-49/bushing-swap-$5-tool-no-fire-needed-56160/

I've heard here and elsewhere that Poly isn't a great idea on a Miata.

In reply to calteg:

That looks awesome, but some of the important pics are broken. I can't believe I hadn't stumbled across that before.

And in reply to Stefan: I've seen it here and other places. I've also seen people very happy using poly everywhere but the upper control arms. But every bushing thread I've come across turns into a debate, so this time I'm letting my wallet decide. $250 for a full set of ES poly bushings, cheapest rubber I've seen starts at $400. And if I come to regret it, it's my own fault, and I'll have to deal with it then.

calteg wrote: Not sure if linking to other forums is kosher, but: http://www.miataturbo.net/suspension-brakes-drivetrain-49/bushing-swap-$5-tool-no-fire-needed-56160/

why don't these linkys work anymore

gotta C&P, never did that before

things were better before all the improvements

Fire is for bushings that are bonded to the arms. The Miata ones are not, they are pressed in, so the right answer is to press them out. 20 ton HF press is one option, another is the big beefy c-clamp tool they sell. You can use threaded rod and washers, but it involves a lot of tedious hand wrenching to get the nuts all the way on and off. Try to avoid the temptation to run the threaded rod through both holes on the inboard side like the guy is doing in that photo, this will bend the A-arm.

Installing poly bushings is actually pretty simple, if you've got the tools to press the rubber ones out then putting the poly ones in with the same tools is trivial

The downside to poly bushings is that they require lube, and even if you get the sticky silicone poly bushing lube it still doesn't stay in place all that long. You can put in zerk fittings and re-grease periodically, but it makes a huge mess and will often only come out one side.

There aren't really any great off-the-shelf alternatives right now. Delrin will self-lube, but you can't use it in the bushings for the alignment cams because they will bind. The Mazdaspeed rubber bushings are similarly low-maintenance to the factory ones, but they're expensive and not all that much stiffer.

I am very interested in this, after my shifter rebuild comes in I was going to do bushings next. So what exactly is the down side of having the entire car have poly bushings?

In reply to Blitzed306:

Wait for keith to come in but binding causing spring rates to go up comes to mind

It's not just that binding makes the spring rates go up, it's that it's an inconsistent, non-linear increase in effective spring rate. Binding makes the car unpredictable and much more difficult to drive.

Poly bushings work fine when they're properly lubed (to avoid binding), but keeping them properly lubed is labor-intensive.

I did an energy suspension set a long time ago and it was a nightmare, did a superpro set recently and it was cake. You Do get what you pay for.

As long as they have a metal sleeve, a big sledge has driven out every bushing Ive ever replaced. I even drove them all back in like that on the Z28.

Shouldnt be bad with a press, ,ball joint press, or big hammer.

Having recently done this twice, the easiest method by far is the press. If you don't have/ don't want to buy a press (really you should though I've used it SO MANY TIMES since I got it) the C clamp works well. I did the threaded rod last time and it worked well with ratcheting box ends but I also ended up stripping my piece of allthread, so I had to use the clamp for a few. With either the C clamp or allthread methods you want something sturdy on the other side of the piece of pipe you're pressing them into - I used one of the adapters from a wheel bearing tool set I had.

If you're using the clamp or allthread, get some pressure on the bushing then use a torch on the outside of the suspension piece you're pressing them out of to get them moving. The point is not to melt or burn the rubber, just soften it up so it will slide out. Again, you don't need to heat the thing until it's red hot and smoke is pouring out. Just a little will do.

As for pressing in the poly bushings, they should just slide right in. I actually did a little writeup in my build thread for this recently, including drilling for grease zerks (a new one for me but hopefully it helps).

Yellow Miata

For the nuclear option, there's a guy on MT selling a kit to retrofit a bronze bearing to poly bushing kits. It's not cheap but he posted dimensions and materials if you're an intrepid DIYer

EDIT I see now that all the pictures related to this are broken. Awesome. Working on fixing that now.

Did them last winter in my Miata. Energy Suspensions says to use heat and that you shouldn't have to set them on fire, but after 25 years, they required setting on fire. No other way even attempted to move them. I had someone heat on the arm while I pushed on the side with a large punch and they would usually catch fire before starting to move. The new bushings, once lubed, slid right into the arms by hand or with a little persuasion from a C-clamp.

fasted58 wrote:

calteg wrote: Not sure if linking to other forums is kosher, but: http://www.miataturbo.net/suspension-brakes-drivetrain-49/bushing-swap-$5-tool-no-fire-needed-56160/

why don't these linkys work anymore

I'm not sure what changed - probably a setting the admins changed in the forum software to keep spam links from working, but to get links to work now you have to use the "insert" button while posting. The one that looks like a chain link above the smilie:

http://www.miataturbo.net/suspension-brakes-drivetrain-49/bushing-swap-$5-tool-no-fire-needed-56160/

It's not a big deal to go back and edit your post if you forget.

I've come to the conclusion I wouldn't do anything to a Miata/MX-5 without consulting Keith/Flying Miata first.

This is the set I'm buying.

Cmc: I actually have read your build before, I don't know why it slipped my mind. Thank you.

I put this post together for tips and techniques, and I think I'll be able to do the job, thank you all for pointing it out. Now whether I can talk myself into buying a press to do it or going with another method, well I guess time will tell. Press on sale at hf is only 150, but I really don't know how much I'd use it after this project. I've only done 3 wheel bearings over all the cars I've owned, and this is a first for bushings, it's a hard sell for premium garage real estate.

In my opinion, poly or delrin are not suitable bushing materials for any suspension member that needs to articulate in more than one plane. Suspension bushings that move in 2 dimensions need to be rubber or spherical.

Not saying they don't work on Miatas, just do your homework. Just because someone offers an upgrade part doesn't make it an upgrade.

Tyler H wrote: In my opinion, poly or delrin are not suitable bushing materials for any suspension member that needs to articulate in more than one plane. Suspension bushings that move in 2 dimensions need to be rubber or spherical. Not saying they don't work on Miatas, just do your homework. Just because someone offers an upgrade part doesn't make it an upgrade.

Agreed.

IME, poly is fine for 2 plane movement, delrin definitely is not.

My problem with poly bushings in the Miata application is that they behave like bearings, but bearings that depend on lubrication to work and are really difficult to lubricate effectively. I think the bonded Polybush parts might work well as they function like rubber, but in 99% of Miatas the cheap US poly is the wrong choice. It's worth noting that not a single car in the FM fleet runs on poly bushings, although I do have a full set of control arms in my garage with a set installed. After the first time they seized up, they went away.

The good news is that if you decide the poly units were a bad idea, they're really easy to remove

Presses are great for the job, but there are a couple of bushings you can't easily get with one due to the geometry of the control arms. If I was doing it at home, I'd grab the HF "ball joint" kit. This also lets you swap out the one on the rear upright without removing it from the car. I think we use a combination of those tools when we're doing bushings at FM, and we never use heat.

If you do get a set of Energy Suspension bushings, do a complete inventory before you do anything else. Every single sleeve, washer and poly piece. There's a packing slip in the box. The guys at Energy are good at making inexpensive parts, but they suck at packing. You do not want to be that guy who discovers the missing/incorrect part when he's on a deadline. Like Zach. We used to sell Energy, we stopped because we had to inventory every single box.

Keith Tanner wrote: Presses are great for the job, but there are a couple of bushings you can't easily get with one due to the geometry of the control arms. If I was doing it at home, I'd grab the HF "ball joint" kit. This also lets you swap out the one on the rear upright without removing it from the car. I think we use a combination of those tools when we're doing bushings at FM, and we never use heat.

Just to be clear, is that what you are referring to:
http://www.harborfreight.com/ball-joint-service-kit-for-2wd-and-4wd-vehicles-60827.html

Thanks.

That looks about right.

Keith Tanner wrote: If you do get a set of Energy Suspension bushings, do a complete inventory before you do anything else. Every single sleeve, washer and poly piece. There's a packing slip in the box. The guys at Energy are good at making inexpensive parts, but they suck at packing.

This is 100% true, and a pain to resolve. I eventually got all the bushings installed in my Miata.

So poly for control arms seems like a bad idea. Rear differential bushings seem like a good place for poly. Are their any companies that offer complete bushing kits that are rubber? Or high quality poly?

I did all the bushings in my Miata with hand tools. I made a sleeve from a chunk of tubing and used threaded rod, nuts,bolts and washers. An electric impact made the wrenching part easier. While the bushing aren't bonded to the A-arms they will be well stuck. Just hit the steel with a Harbor Freight heat gun while the bushing is under some tension and it will pop out. I used the rubber bushings from FM, not urethane. I also removed all the rust and painted the suspension parts. With a fresh coat of Rustoleum inside the bushing area the new bushings slip in really easy with a little dish soap.

In reply to Blitzed306:

Mazdasport competition and IL Motorsports both offer 30-40% stiffer than stock rubber. I'm presently hunting for OEM replacement rubber, and so far the only place that sells it that I've found won't let me check the price because I don't have an event timesheet or racing organization membership card. I have tracked down OEM part numbers though, so I'll get around to checking the dealership this week.

Which leads to a new question because I'm not this car inclined: Would the rear control arms do better with rubber or poly? Without steering, I'm guessing that means they only function on one plane so the risk of binding isn't as high as with the front?

From what I'm taking away, front/rear sway bar bushings and differential bushings would be fine in poly, control arms in rubber?

If money wasn't a problem for me right now, this would be over and done with with a order to FM for rubber bushings and frame rails, but I'm still reeling from my tax hit this year and trying to save my pennies for the ecotek swap.