Suspension rebuild/upgrades (updated 03/07/07)
Posted: Sat Jun 30, 2007 1:13 am
Okay guys. I've been busy under the car for a while now, so though I should let you know what I've been up to.
It all started with the need for a new fuel tank, and the desire to fit my larger Z1 rear discs. As usual (with me), it sort of spiralled out of control, and ended up with a complete rebuild and a long list of other tweaks and upgrades.
To avoid having to take the car off the road for too long, I bought a complete used rear end from Simon13 (Take a bow Simon
).
This was then stripped down so I could start the upgrades.
I was planning on using some uprated ARBs (H&R), so decided it would be good to reinforce the mounting points on the trailing arms. These are a known weak point with thicker bars.
The front subframe is also known to break as well, so this was also beefed up around the ARB mounting point.
and the engine mounting 'ears'.
I then turned my attention to the subframe. As you may know, the rear end is not adjustable for camber or toe as standard. Not an issue on a standard car, but fit lowering springs, and the geometry all goes to pot. This leads to uneven rear tyre wear and reduced grip (the lower you go, the worse it gets).
You can get eccentric bushes to adjust some of this out, but they're a pain to setup correctly, and don't offer all that much adjustment. For a while now, you have been able to get (from the US) an adjustment kit that uses eccentric bolts from the back end of the E39 5 series, and some slotted plates that are welded to the subframe. These allow the camber and toe to be adjusted independently of each other, and without removing the trailing arms (as you have to with eccentric bushes). Fitting the slotted plates is a big old job because you have to remove the subframe to do it, but once on the bench, it's not all that hard to fit.
This picture shows one of the tabs being aligned prior to the subframe being slotted to match the plate.
Once they are slotted, they need to be welded on. I'd like to say that I did the welding, but it would be a big lie. I am however lucky to have a specialist welding company not too far away, so I let them do it
After it was all welded, it was sent away (along with the trailing arms and front subframe) to be blasted and powder coated before reassembly.
When it came back from powder coating, it was time to put things back together. This started with the rear subframe bushes. Not having the proper BMW tool for this, I made my own tool from a piece of threaded bar and a couple of heavy duty PVC pipe caps. A bit of lube on the bush, and a quick tighten of the nuts had the bush sliding into place.
I then turned my attentions to the trailing arms. These needed to have new bearings pressed in...
...so out came my trusty threaded bar again.
Once pressed in, it just needed to be secured by it's circlip.
Once the bearings were in, it was time to fit the trailing arm bushes. I've read a fair bit of negative press regarding Powerflex bushes, so I opted for the Superflex variety. They get good reviews, and are also about 50% cheaper.
This was another job for Mr threaded bar. First the poly bush is fitted
Followed by the stainless centre sleeve.
And there we have it.
Next job was the brake backing plates.
rear hubs.
and brake pipes.
It was then time to bolt it all back together.
After finishing the rear end, it was time to start fitting parts on the car. I didn't take all that many photos on the front, but this shows the improved ARB mounting clamps. As standard, it only secures with a single bolt, and is just hooked in on the other end. This new clamp picks up on one of the subframe securing bolts and is much stronger (and easier to fit )
The rear ARB also suffers from weak single ended clamps, so these shiny billet aluminium mounts are much better.
No pics, but the front also got new control arms, control arm bushes & ARB links. I also fitted a 330ci Clubsport steering rack which is quicker than the E36 rack I had on there previously.
While I was rebuilding things, the E30 M3 rear calipers (required when using the Z1 rear discs) got a good seeing to as well.
I didn't take any pictures of the strip and rust dip, but this left me with totally bare caliper castings that were back to clean bare metal. I was obviously going to paint them, but to help stop the rust, I had the calipers copper plated. I chose copper, as it goes on a lot thinner than some other plating materials, and I didn't want a large buildup in the piston bores.
Here's one after plating and ready for a squirt of paint.
and after.
Even the pistons had some work.
After this, they were rebuilt with new seals etc, and are ready to go back on the car.
I think that's about it for now. I have got some of it back on the car, so updates to follow.
Enjoy,
Ian.
It all started with the need for a new fuel tank, and the desire to fit my larger Z1 rear discs. As usual (with me), it sort of spiralled out of control, and ended up with a complete rebuild and a long list of other tweaks and upgrades.
To avoid having to take the car off the road for too long, I bought a complete used rear end from Simon13 (Take a bow Simon
).This was then stripped down so I could start the upgrades.
I was planning on using some uprated ARBs (H&R), so decided it would be good to reinforce the mounting points on the trailing arms. These are a known weak point with thicker bars.
The front subframe is also known to break as well, so this was also beefed up around the ARB mounting point.
and the engine mounting 'ears'.
I then turned my attention to the subframe. As you may know, the rear end is not adjustable for camber or toe as standard. Not an issue on a standard car, but fit lowering springs, and the geometry all goes to pot. This leads to uneven rear tyre wear and reduced grip (the lower you go, the worse it gets).
You can get eccentric bushes to adjust some of this out, but they're a pain to setup correctly, and don't offer all that much adjustment. For a while now, you have been able to get (from the US) an adjustment kit that uses eccentric bolts from the back end of the E39 5 series, and some slotted plates that are welded to the subframe. These allow the camber and toe to be adjusted independently of each other, and without removing the trailing arms (as you have to with eccentric bushes). Fitting the slotted plates is a big old job because you have to remove the subframe to do it, but once on the bench, it's not all that hard to fit.
This picture shows one of the tabs being aligned prior to the subframe being slotted to match the plate.
Once they are slotted, they need to be welded on. I'd like to say that I did the welding, but it would be a big lie. I am however lucky to have a specialist welding company not too far away, so I let them do it
After it was all welded, it was sent away (along with the trailing arms and front subframe) to be blasted and powder coated before reassembly.
When it came back from powder coating, it was time to put things back together. This started with the rear subframe bushes. Not having the proper BMW tool for this, I made my own tool from a piece of threaded bar and a couple of heavy duty PVC pipe caps. A bit of lube on the bush, and a quick tighten of the nuts had the bush sliding into place.
I then turned my attentions to the trailing arms. These needed to have new bearings pressed in...
...so out came my trusty threaded bar again.
Once pressed in, it just needed to be secured by it's circlip.
Once the bearings were in, it was time to fit the trailing arm bushes. I've read a fair bit of negative press regarding Powerflex bushes, so I opted for the Superflex variety. They get good reviews, and are also about 50% cheaper.
This was another job for Mr threaded bar. First the poly bush is fitted
Followed by the stainless centre sleeve.
And there we have it.
Next job was the brake backing plates.
rear hubs.
and brake pipes.
It was then time to bolt it all back together.
After finishing the rear end, it was time to start fitting parts on the car. I didn't take all that many photos on the front, but this shows the improved ARB mounting clamps. As standard, it only secures with a single bolt, and is just hooked in on the other end. This new clamp picks up on one of the subframe securing bolts and is much stronger (and easier to fit
)The rear ARB also suffers from weak single ended clamps, so these shiny billet aluminium mounts are much better.
No pics, but the front also got new control arms, control arm bushes & ARB links. I also fitted a 330ci Clubsport steering rack which is quicker than the E36 rack I had on there previously.
While I was rebuilding things, the E30 M3 rear calipers (required when using the Z1 rear discs) got a good seeing to as well.
I didn't take any pictures of the strip and rust dip, but this left me with totally bare caliper castings that were back to clean bare metal. I was obviously going to paint them, but to help stop the rust, I had the calipers copper plated. I chose copper, as it goes on a lot thinner than some other plating materials, and I didn't want a large buildup in the piston bores.
Here's one after plating and ready for a squirt of paint.
and after.
Even the pistons had some work.
After this, they were rebuilt with new seals etc, and are ready to go back on the car.
I think that's about it for now. I have got some of it back on the car, so updates to follow.
Enjoy,
Ian.
).
