Full suspension and polybush change, progress log

Technical Area Steering & Suspension
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  1. My model of MX-5 is: NC 3.5
  2. I’m based near: Bristol

Hi MX5ers

It’s been nearly a year in waiting, but hopefully I’ll be able to start work on this tomorrow.

I’ve accepted that this won’t be a rolling project and she’ll be off the road until done.

I’ve got the following:

A full set of Bilstein dampers and springs, with new top mounts and gaiters.

A full set of Strongflex red poly bushes for both front and rear.

Toolwise, in addition to the usual hand tools I’ve got the following:

A beefy DeWalt half inch dugga dugga and impact sockets and extensions.

A set of pullers

Some threaded rods with nuts, washers and square plates.

A jigsaw and blades

A reciprocating saw with metal blades, and a fancy expensive metal blade too.

A vice fitted to my workbench.

Thanks to everyone who has posted about their experiences, taking on this job, it’s been really helpful with my preparation.

I’m going to post updates on my progress in the hope that it might help others, and if course I’d appreciate some helpful advice along the way.

Wish me luck!

9 Likes
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I’ve got a full set a superpro bushes and waiting to buy some TEIN coilovers. I have an actual hydraulic press. I also bought a full set of rear trail arm links, painted, polybushed and with new boots all round. Good luck with our project.

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Best of luck , please share your progress

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Day 1.

Hours spent today: 9 hours

It took me all day, but I’ve removed everything from the front right corner.

It’s a steep learning curve. Other than changing shocks on a hatchback and doing little jobs like ARB links, this is the biggest suspension job I’ve taken on.

I knew the suspension strut needed to come out, so using my Haynes manual book of lies, I started with that, but then realised that it would be easier to crack all the bolts on everything so I knew where the problem areas were.

I got all the bolts cracked except the caster adjustment nut and bolt, which was seized solid.

I knew one of the castor bolts was seized because my alignment guy told me. He tried a bit of heat and an impact wrench at the time, but it was solid. Luckily the seized castor bolt position was pretty good, so we agreed to leave it.

Until now.

So, I removed everything else to help with access of the lower wishbone.

Using heat I got the castor adjustment nut off, but the bolt was seized solid. As a flexed the arm through its axis I could see a small gap appearing under the adjustment washer, so I knew it was the shaft of the bolt itself seized to the inner bush.

Lots of penetrating fluid and heat failed to budge it.

I resorted to cutting it off, and it took me literally hours. At the top I had to cut through the inner bush and the bolt. Thankfully once that was off I had a bit of wriggle room with a gap to get the saw blade directly on the lower part of the bolt.

I wish I’d bought a mains powered reciprocating saw rather than a cordless, It took several battery swaps to get both cuts done.

I’ve already bought 2 front castor adjustment bolt kits because I knew at least one was seized, and luckily so far it’s the only one I’ve needed to cut off.

I’m tempted to have a break from being on my hands and knees and spend the day tomorrow in the garage at the vice making a start on removing some of the bushes, but it’s forecast to be nice again so I guess I’d better get out there and remove the other side.

I’ll hopefully work more quickly tomorrow. It’s fresh in my mind what tools work best where, and I’ll be delighted if the other castor bolt isn’t seized. Today I was pausing to take pics at each stage in case I got confused about what goes where upon reassembly, but it’s quite straightforward and I won’t bother tomorrow. The arms are marked left and right, and the direction that the ball joint spindle points dictates which way round they go.

So, looking forward to a more straightforward day tomorrow, and hopefully I’ll get everything off the front left corner with minimal cutting.

Thanks for reading and any comments are welcome.

5 Likes
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Are you going to renew all the ball joints?

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Day 2

Hours spent today: 5

Today I got everything off the front left side and things went much more quickly.

The front left castor bolt was also seized, so had to be cut off.

None of the control arms or wishbones look bent out of shape, and all the ball joints are free of splits and work smoothly.

Both of the spindles with split pins needed the pins drilling out on this side of the car.

So that’s everything off the front and plenty of work to do changing the bushes!

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Not now I’ve I’ve inspected them, they all move smoothly and have no splits.

I think a read somewhere that the whole arm needs replacing if a ball joint needs doing.

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That’s interesting, I thought this also would be a replaceable part.

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Did you need a specific tool to free the ball joints from hub ? Or was it just a case of removing nuts and persuading / knocking out ?

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I just struck the top of the spindle with the nut a few mm further down to stop it flying off.

I do have a chisel type ball joint splitter, but I didn’t want to damage the rubber boots by forcing in.

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Day 3

Hours spent today: 2 hours

I squeezed in a couple of hours after work and managed to remove the first of many OEM bushes

@stevegilkes The jigsaw method does indeed jump about, but I couldn’t find a more effective way of doing this, so thanks for sharing in your thread.

Once I got the middle bit out, I chiselled away the shell in pieces but then realised that the shell has an inner and outer section and I’d only done the inner bit. Once I’d sawn through the steel outer shell and curled up one of the sawn ends, it popped out.

The new poly bush fits very nicely, but I’m going to get all the OEM bushes off this arm and will then look at installing the new ones with the supplied grease and… PTFE tape.

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Day 4

Hours spent today: 2 hours

Another couple of hours at the bench after work and that’s all 3 bushes off the lower right arm.

The rear polybush is a one piece unit with big lips. A press would be handy, but I’ll see how it goes with some threaded rod and some grease.

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Try a G clamp with a larger socket on back of arm , G clamp pushing on bush ?

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I’ve just took delivery of second hand front top arms , that’s the route I’m gonna try.
Pleased to find ball joints appear sound.

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Have you tried the threaded rod and socket method for removing and installing the bushings? It works well unless the liner is completely seized in, in which case you can resort back to cutting the bush and liner out. Works especially well when reinstalling tight fitting bushes.

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I’ve literally just taken delivery of arms ,
time off in August when I intend on cracking on with a fair few jobs on her.

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I found that the Polybush units went in without tools, with soapy water, and sometimes a boot against plywood on the ground.

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The g clamp is handy for inserting the steel inner bush which is that tiny bit wider than spec because it’s wrapped in ptfe tape.

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The threaded rod technique had to be used to install the big one piece bushes at the rear of the lower arms.

I didn’t have a socket big enough but used a hole saw with the teeth cut off. Again, thanks to @stevegilkes for describing this.

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You got to love those hole saws😂

1 Like