Full suspension and polybush change, progress log

Technical Area Steering & Suspension
21

Day 5

Hours spent today: 3

On Friday evening I had another three hours at the bench and, having some experience of doing the left lower control arm, changed over all 3 rubber OEM bushes to polybushes. So that’s the front lower control arms done.

Day 6

Hours spent today: 4

Front upper control arms.

These OEM bushes have a thick metal washer attached to the inner sleeve
on the outside edge of each bushing (the same as the lower arm front bushing). So I cut these off with an angle grinder first. This allows the drill to go right through the rubber between the inner and outer sleeve and get the inner sleeve out.

Things went well with the upper arms and I had them all swapped over in two hours.

Here’s a pic of the new polybushes waiting to be wrapped in ptfe tape

And the bushes wrapped and ready to be greased up and inserted.

Time will tell if it actually stops them squeaking. PTFE tape is only 30p per roll, so it’s worth a go :slight_smile:

So that’s the front end bushes replaced.

Next job is to build the new suspension struts for the front and get everything installed.

5 Likes
22

Looking good , any plans on coating arms , paint , plastic coat etc ?

1 Like
23

For bare aluminium arms etc I’ve always found a good rub up and spray with a bright zinc galvanising spray makes them look like brand new if you can get a good product with a decent sheen, many now just look like grey primer. Even better if you know someone that has access to a blasting cabinet, gaffer tape up any ball joints and bushes and a light going over they look great.

1 Like
24

Good call , a garage local to me used to advertise a soda blast unit

2 Likes
25

I wish I paid that much attention to the aesthetics :slight_smile:

Believe it or not, after removal I did give the arms a quick scrub in soapy water to get the worst of the oil off to enable me to handle them without getting oily.

I really should make more effort in this regard but they’re going back on like this :slight_smile:

1 Like
26

Nothing wrong with that. I’m just fussy.

1 Like
27

:rofl:eer sometimes when I pull stuff apart I can get a bit OCD putting it back together

2 Likes
28

Day 7

Hours spent today: 4

Time to tackle the rusty old struts.

After getting the spring compressed and the top nut off, I laid out all the top mounts bits to avoid getting mixed up with the order.

In addition to new dampers and springs, I’d also bought new top mount kits and gaiters. The old top mounts looked in excellent condition and the only difference I could see between old and new was that the two rubber doughnuts were a few mm higher on the new kit.

Maybe the old doughnuts became compressed?

The old bumpstops were fine, so I reused them.

The old springs were the same height as the new ones when uncompressed.

When building the new struts, even though I was careful, I still managed to scratch some of the flexible coating off the new springs with my budget spring compressor :frowning:

Anyway I got them assembled and fingers crossed the top mounts are fixed in the correct orientation in relation to the lower damper mounts.

Day 8

Hours spent today: 3

To tidy up the annoying scratches on the springs, I had a root around my paint cans and opted to use some black Bilthamber two pack epoxy mastic as it has some flex to it. The guidance says that the product has a two year shelf life once opened. These tins (part A and B) were over five years old, but after a good stir it was fine. While I had a bit mixed up I decided to put two coats on the bottom section of the dampers, the bits that got really rusty on the originals.

I also did a few other bits of prep:

Wire brushed the areas around the suspension mounting points which had surface rust, treated with rust converter and then waxoyled the areas.

Same as above for the ends of the anti roll bar, but painted with black hammerite rather that waxoyl. Also removed the ARB polybushes I’d fitted a few years ago to enable me to wrap in ptfe tape and regrease.

Cleaned up the threads on the suspension bolts with a copper bristled brush as they’re all being reused (apart from the castor bolts which had to be cut off).

I also had a bit of a sort out of all the bits and bobs and separated them into two boxes, one for the left side and one for the right to make reassembly easier.

So that’s pretty much everything prepared for reassembly, hopefully on the weekend.

7 Likes
29

Day 9

Hours spent today: 3

Reassembly was very straightforward, and it’s great having everything fit into place with no sawing or drilling.

The insides of the steel bush liners were coated with copper grease.

The positioning marks on the alignment bolts that I’d previously made with a white paint pen were long gone, what with cleaning and wire brushing (and replacing the castor bolts). So, when tightening the alignment bolts down I used the precision technique of positioning them all ‘in the middle’ :slight_smile:

Once one side was assembled the other side flew in.

A test drive round the block confirmed everything is working well. Phew!

Onto the rear suspension!

6 Likes
30

I’m a milwaukee man myself :stuck_out_tongue_winking_eye:

Nice progress. :+1:

1 Like
31

Ingersoll Rand for me

32

Day 10

Hours spent today: 5

Rear suspension

Today started well, but then I ran into some problems and would appreciate some advice on moving forward.

The ABS sensors in both the rear hub carriers are stuck in there. After removing to 10mm retaining bolt I got a tiny bit of rotation by levering on the end of the egg shaped washer which the sensor is mounted to, but even after working it back and forth and using penetrating fluid, they’re stuck.

I decided to work around them, which is annoying. Any advice on safely removing these would be appreciated.

I slackened the suspension bolts in situ. All the ball joints came loose apart from the bottom one with the pinch bolt (I think it’s called rear toe control). The steel pinch bolt was stuck solid in the alloy hub carrier on both sides.

I decided to drill out the bolts, and I messed up :frowning:

Using an angle grinder I carefully cut off the threaded end of the bolts, and then cut the bolt heads off.

I then made mistake number one.

I decided to also cut the bolt at the split in the pinch part of the hub carrier, to reduce the amount of drilling. As I started the cut I realized the rubber boot must be close underneath, but it was too late, I’d nicked it and grease oozed out :frowning:

I’ve found the part number for a replacement boot: f151-28-4a3. I can’t find them in stock in the UK anywhere.

I have seen several places selling a rubber boot listed as “upper control arm / toe control”. Is the rubber boot on the front upper control arm the same size as the tie control boot in the rear?

I can’t get a front wheel off to check properly at the moment because the back of the car is up in the air.

Also, any advice on how to fit these and if any special tools are required would be appreciated.

I then made mistake number 2.

Using a centrepunch I marked the centre of the bolt (or so I thought) and drilled out the bolts, but I was about 1-2mm off centre on both bolts. I’m kicking myself :frowning: I think when marking the centre point with the punch I didn’t take into account the fact that the circle I was looking at was the edge to the thread on one side and the edge of the actual bolt shaft on the other side.

Or I just didn’t mark it very well :frowning:

Anyway, there’s a bit of thread and bolt left in place and the ball joints are still solidly in there. The only remedy I can think of is to use a round file to remove the remains of the bolt, and then fit oversized bolts and nuts.

Please can anyone offer some guidance to help me out if this hole I’ve dug?

33

I think I did the same with the pinch bolt drill through. More metal working. You don’t have to go oversize on the bolt, only ensure the washers are wide enough, which they almost certainly will be.

I also found some generic boots that were would have done the job, and bought some case, but I got away with it.

I will have a look at my notes.

1 Like
34

Any chance you could helicoil it back to standard bolt size ?

1 Like
35

It seems that I was able to knock the pinch bolts through after the drilling, have you tried?

You should be able to get a generic boot to fit with correct size and shape.

36

I haven’t tried doing this but I will, thanks.

There’s only a couple of mm of bolt left in place, so I’m not sure if I can get a purchase on the edge but to try knocking it through.

37

Great thread @bainbridge , thanks for the detail and info and pics.

I come from the motorbike world so all these random shaped lumps of metal, connected in weird and wonderful ways, baffle me completely.
I understand linkages, but ■■■??
My previous Mk2 had been polybushed and handled superbly, I now have a Mk2.5 asnd was going to have a go at this but I think I’ll just put up with what I have! :sweat_smile: :sweat_smile:
Anyway, I’m impressed with your efforts, and who doesn’t like a good techie read late at night? :wink:
Good luck with the rest of the job :sunglasses:

2 Likes
38

@AdamB Thanks for wishing me luck and you’re welcome for the bedtime reading :slight_smile:

I too read about fixing cars at bedtime!

@stevegilkes has posted a great report on how he went about poly bushing his mx5, which is very helpful:

Do check it out if you’re burning any more midnight oil :slight_smile:

1 Like
39

Day 11

Hours spent today: 1

Only an hour spent on the MX5 today, but thankfully I was able to knock out the remnants of the two toe control arm pinch bolts on the rear hub carriers.

At least now I can go ahead and get all of the control arms removed from the car and start work on removing the bushings.

3 Likes
40

Hi guys, just realized that I did a booboo when changing the front dampers and springs.

I forgot to replace the damper top nuts with new nuts, even though I bought replacements in readiness.

Now that the struts are fitted and the front suspension springs are compressed with the weight of the car, am I right in saying I can safely remove and replace the top nuts in situ?

I can remove the struts and compress the springs again to relieve pressure on the top mount if needed, but is this necessary?

Thanks