I’ve been searching for sometime to find a way to change the rear beam bushes on my Z3 without having to do a full strip down, exhaust, driveshaft etc, etc and came across a Youtube video by an Australian guy called Samuel Vella which caught my interest. His video shows how to remove the old bushes from his E34 saloon using the weight of the car, gravity and a little heat, then replacing with new Powerflex bushes. I wondered if his technique could be adapted for the Z3, main difference being the threaded bolt on the E34 can be removed through the rear passenger compartment and the Z3 can only be removed from underneath, which means removing the bush or subframe to get at it, so kind of defeats the purpose. So I came up with a solution that worked well for me and thought I’d share it with the Z community.
View: https://youtu.be/-HGUVzokpjM
I bought an 1 1/4” female to female malleable iron pipe fitting to use as a spacer because of it’s rather robust nature and it’s about 2” long, then cut it vertically in half. My idea was to use this in a clamshell kind of way, putting either side round the threaded bolt then securing with ducting tape. In addition I got a large washer which would cover most of the bushing and cut a slot in it so it would fit round the bolt. So now it’s time to bite the bullet and give it a go. What follows is a basic step by step guide but it’s worth watching the video as it gives you a more 3 dimensional overview even though it’s not a Z3.
First jack up the rear of the car and support on axle stands, chocking the front wheels, taking any suitable precautions, remove the wheels and the arch liners. At this point I used WD40 on all the bolts I was removing and let it soak in for a while. It’s useful to have a second set of axle stands to support the subframe during the procedure but blocks of wood can also be used, I also used wooden wedges to take up any space. I positioned the axle stand on either side of the subframe but nearer the centre so I had room to use the trolley jack as close to the bushes as possible.
The bolts can all now be removed but taking care that your hex bit is fully sunk home on the 2 hex bolts…..tap with a hammer, if you round off these bolts you’re entering a world of pain!!!! The large 22mm bolt may require a deep socket as the thread protrudes quite far and you want to make sure you’re on firmly….a breaker bar may be useful at this point.
Having removed all the bolts it’s time to decide which side you want to do first. I started on the left and removed a couple of the exhaust support brackets as the subframe will push down onto it and I felt this gave a little more flexibility. Position the trolley jack as close to the bush as possible then remove the axle stand supporting the subframe on the left. Gradually lower the jack and the subframe should slide down the bolt, mine came down about 2”. Then take a piece of wood to use as a lever, 2”x 2” or equivalent and push the subframe down……you only need about 3” so don’t go mad. Now slide in the slotted washer and the “clamshell” pipe fitting, wrapping it with tape to keep it rigid, then gradually jack the frame back up making sure the pipe fitting and washer are centred well, keep jacking up gently till the car raises of the lefthand axle stand by around 2”.
Now we have to apply the heat. In the video he uses a heat gun but this didn’t work for me so I then used a propane torch. I had a bucket of water, a watering can and a fire extinguisher to hand, just incase. I also packed a fire blanket behind the area I was working on, this is especially important on the right side as the fuel tank is fairly close and I also used a large ceramic tile to deflect any heat away from the tank. Work the heat round the bushing area for around 5 min and the weight of the car should push the old bush out, jack the subframe up a little more if necessary so the bush comes right out. There is a smell of burning rubber and a little smoke during the process but there shouldn’t be any fire…….if there is I would stop, you’re just heating the metal. I removed the old bushes from both sides before installing the new bushes but not sure if it matters.
Wait till things cool down then remove the threaded bolt, again you may need a breaker bar on this. The bolt will come out along with the large washer. Now place the top part of the Powerflex bush onto the subframe and place the washer on top. Pass the bolt back up through the subframe, the bush and the washer then tighten back in place, jack up the subframe so the bush is against the washer then slide in the lower part of the bush….I found pushing in about halfway then sliding in the metal liner worked best. You may find using the trolley jack useful in pushing the bush and liner home, I also used the “clamshell” pipe fitting to allow the bolt to slide through the bush as it sticks out about an 1”.
Now it’s time to put back the metal plate and secure the bolts, Powerflex suggest 140Nm on the main bolt and 30Nm on the hex ones now repeat the process on the other side. Once your done don’t forget to re-attach the exhaust mounts if you removed them, then the arch liners and wheels, lower to the ground and job done. I re-checked the torque on the main bolt once it was on the ground just to be sure. I think the whole job could be done in an afternoon, I spent a bit more time as I wanted to clean up and repaint some of the parts.
This worked well for me so I thought I’d share my experience but I take no responsibility if you decide to try this technique yourself, all I would say is, think things through, work safely and take all necessary safety precautions when working on your car…..and most of all, enjoy!!
I bought an 1 1/4” female to female malleable iron pipe fitting to use as a spacer because of it’s rather robust nature and it’s about 2” long, then cut it vertically in half. My idea was to use this in a clamshell kind of way, putting either side round the threaded bolt then securing with ducting tape. In addition I got a large washer which would cover most of the bushing and cut a slot in it so it would fit round the bolt. So now it’s time to bite the bullet and give it a go. What follows is a basic step by step guide but it’s worth watching the video as it gives you a more 3 dimensional overview even though it’s not a Z3.
First jack up the rear of the car and support on axle stands, chocking the front wheels, taking any suitable precautions, remove the wheels and the arch liners. At this point I used WD40 on all the bolts I was removing and let it soak in for a while. It’s useful to have a second set of axle stands to support the subframe during the procedure but blocks of wood can also be used, I also used wooden wedges to take up any space. I positioned the axle stand on either side of the subframe but nearer the centre so I had room to use the trolley jack as close to the bushes as possible.
The bolts can all now be removed but taking care that your hex bit is fully sunk home on the 2 hex bolts…..tap with a hammer, if you round off these bolts you’re entering a world of pain!!!! The large 22mm bolt may require a deep socket as the thread protrudes quite far and you want to make sure you’re on firmly….a breaker bar may be useful at this point.
Having removed all the bolts it’s time to decide which side you want to do first. I started on the left and removed a couple of the exhaust support brackets as the subframe will push down onto it and I felt this gave a little more flexibility. Position the trolley jack as close to the bush as possible then remove the axle stand supporting the subframe on the left. Gradually lower the jack and the subframe should slide down the bolt, mine came down about 2”. Then take a piece of wood to use as a lever, 2”x 2” or equivalent and push the subframe down……you only need about 3” so don’t go mad. Now slide in the slotted washer and the “clamshell” pipe fitting, wrapping it with tape to keep it rigid, then gradually jack the frame back up making sure the pipe fitting and washer are centred well, keep jacking up gently till the car raises of the lefthand axle stand by around 2”.
Now we have to apply the heat. In the video he uses a heat gun but this didn’t work for me so I then used a propane torch. I had a bucket of water, a watering can and a fire extinguisher to hand, just incase. I also packed a fire blanket behind the area I was working on, this is especially important on the right side as the fuel tank is fairly close and I also used a large ceramic tile to deflect any heat away from the tank. Work the heat round the bushing area for around 5 min and the weight of the car should push the old bush out, jack the subframe up a little more if necessary so the bush comes right out. There is a smell of burning rubber and a little smoke during the process but there shouldn’t be any fire…….if there is I would stop, you’re just heating the metal. I removed the old bushes from both sides before installing the new bushes but not sure if it matters.
Wait till things cool down then remove the threaded bolt, again you may need a breaker bar on this. The bolt will come out along with the large washer. Now place the top part of the Powerflex bush onto the subframe and place the washer on top. Pass the bolt back up through the subframe, the bush and the washer then tighten back in place, jack up the subframe so the bush is against the washer then slide in the lower part of the bush….I found pushing in about halfway then sliding in the metal liner worked best. You may find using the trolley jack useful in pushing the bush and liner home, I also used the “clamshell” pipe fitting to allow the bolt to slide through the bush as it sticks out about an 1”.
Now it’s time to put back the metal plate and secure the bolts, Powerflex suggest 140Nm on the main bolt and 30Nm on the hex ones now repeat the process on the other side. Once your done don’t forget to re-attach the exhaust mounts if you removed them, then the arch liners and wheels, lower to the ground and job done. I re-checked the torque on the main bolt once it was on the ground just to be sure. I think the whole job could be done in an afternoon, I spent a bit more time as I wanted to clean up and repaint some of the parts.
This worked well for me so I thought I’d share my experience but I take no responsibility if you decide to try this technique yourself, all I would say is, think things through, work safely and take all necessary safety precautions when working on your car…..and most of all, enjoy!!
