New Zed Shed project kicked off today, with the arrival of @Low Rider's 2.2i Sport! 
I've been chatting with Steve by PM/email for the last month or so because he mentioned that his Zed wasn't particularly happy. The biggest issue was that the traction control was being over protective to the point at which he couldn't drive with it turned on. There are some other things he would like looked at, but for now the critical thing to investigate is the handling. His slot in the Zed Shed came up this weekend, so on to the progress today.
When we popped out for the obligatory breakfast I took Steve so he could get a sense for how a Z3 should handle - and that traction control shouldn't be as invasive as he is experiencing. The roads were saturated with water, so perfect for showing how far you can push a Z3 before the TC should step in. To be fair, I took it steadier than if I was on my own and I know Rosie could have handled a lot more aggro before the TC would kick in. I think Steve was a little surprised at how well they handle, even in the wet! Or he was scared. With my driving it could well be either
Initial inspection:
First off the drivers rear is showing some excessive camber, so much that it's visibly obvious. Steve says that the drivers rear swing arm had already been replaced, and this had actually reduced the camber. We popped her up on to axle stands, whipped off the arch liners and had a visual inspection.
Exhaust:
So with the inspection over it's pretty clear that the sub frame needs to come out. *sighs*. 2.2i exhausts suck.
Exactly the same issue as Rosie had where the nuts had corroded to the point that we couldn't shift them. Quick phone around and the local National garage said they would have a look. Quick drive out to pop it on the ramp, and the diagnosis was that removing the nuts and studs wouldn't leave much in the way of flange to be able to bolt it back up again. However what was suggested was a good idea, although they didn't have the parts to carry it out... Basically suggested cutting the pipe and then using a sleeve to rejoin it again. This would allow the rear section to be removed without compromising the original joint. The alternative would basically be a new exhaust system, so we didn't really want to go that route.
Back to the Zed Shed, and back up on the stands again and out with the angle grinder. Right pain in the seating area, due to the angle grinder disc not being quite big enough to cut through in one. 45 minutes of messing and the rear section is out leaving enough room for us to work.
Sub-frame Removal
This seems to be the bread and butter of the Zed Shed, and the process is identical each time. I won't go in to the same detail again, but if anyone wants more information read back through this post.
We did have an interesting deviation from the process which we've not encountered. When undoing the 22mm nut underneath the passenger side beam bush, the main stud started unscrewing from the chassis. To counteract this we had to hold a "ruddy big spanner" on the stud, while removing the nut. What a pig to remove the nut, not worked so hard on one of these before.
Eventually, this happened! End of play for today as Lee needed to drop Steve off at the train station so he could get home.
The rear beam, or something else...?
This rear beam is going to get some extra attention to make sure nothing is badly wrong with it, possibly being the cause of the increased camber. Once it's up on the bench it will be stripped as usual, but Lee will be giving it a thorough look over and checking measurements.
Our current suspicion is that the drivers rear had a heavy sidewards impact at some stage in it's history. There is some evidence on the rear wing of it being blown over with paint. Obviously there was some reason why Steve had to have new swing arm fitted (which improved the geometry to an extent).
There will be plenty of pictures and data once we decide which night this week we will be continuing.
For reference:
When I'm prattling on about components have a look at the thread below which has some useful graphics on what the rear subframe comprises of. should help you to understand the process a little better.
https://zroadster.org/threads/bmw-z3-rear-subframe-bushes.6736/
I've been chatting with Steve by PM/email for the last month or so because he mentioned that his Zed wasn't particularly happy. The biggest issue was that the traction control was being over protective to the point at which he couldn't drive with it turned on. There are some other things he would like looked at, but for now the critical thing to investigate is the handling. His slot in the Zed Shed came up this weekend, so on to the progress today.
When we popped out for the obligatory breakfast I took Steve so he could get a sense for how a Z3 should handle - and that traction control shouldn't be as invasive as he is experiencing. The roads were saturated with water, so perfect for showing how far you can push a Z3 before the TC should step in. To be fair, I took it steadier than if I was on my own and I know Rosie could have handled a lot more aggro before the TC would kick in. I think Steve was a little surprised at how well they handle, even in the wet! Or he was scared. With my driving it could well be either
Initial inspection:
First off the drivers rear is showing some excessive camber, so much that it's visibly obvious. Steve says that the drivers rear swing arm had already been replaced, and this had actually reduced the camber. We popped her up on to axle stands, whipped off the arch liners and had a visual inspection.
- Rear beam bushes, ARBs and drop links all perished and needing replacing.
- Differential bush has failed completely. Rubber has started to de-laminate from the metal outer ring - and it collapsed completely with the slightest of twist from a screwdriver.
- Shock absorbers. Yet again a set of factory original shocks, and can be compressed easily and do not rebound out again. Replacements required.
Exhaust:
So with the inspection over it's pretty clear that the sub frame needs to come out. *sighs*. 2.2i exhausts suck.
Exactly the same issue as Rosie had where the nuts had corroded to the point that we couldn't shift them. Quick phone around and the local National garage said they would have a look. Quick drive out to pop it on the ramp, and the diagnosis was that removing the nuts and studs wouldn't leave much in the way of flange to be able to bolt it back up again. However what was suggested was a good idea, although they didn't have the parts to carry it out... Basically suggested cutting the pipe and then using a sleeve to rejoin it again. This would allow the rear section to be removed without compromising the original joint. The alternative would basically be a new exhaust system, so we didn't really want to go that route.
Back to the Zed Shed, and back up on the stands again and out with the angle grinder. Right pain in the seating area, due to the angle grinder disc not being quite big enough to cut through in one. 45 minutes of messing and the rear section is out leaving enough room for us to work.
Sub-frame Removal
This seems to be the bread and butter of the Zed Shed, and the process is identical each time. I won't go in to the same detail again, but if anyone wants more information read back through this post.
We did have an interesting deviation from the process which we've not encountered. When undoing the 22mm nut underneath the passenger side beam bush, the main stud started unscrewing from the chassis. To counteract this we had to hold a "ruddy big spanner" on the stud, while removing the nut. What a pig to remove the nut, not worked so hard on one of these before.
Eventually, this happened! End of play for today as Lee needed to drop Steve off at the train station so he could get home.
The rear beam, or something else...?
This rear beam is going to get some extra attention to make sure nothing is badly wrong with it, possibly being the cause of the increased camber. Once it's up on the bench it will be stripped as usual, but Lee will be giving it a thorough look over and checking measurements.
Our current suspicion is that the drivers rear had a heavy sidewards impact at some stage in it's history. There is some evidence on the rear wing of it being blown over with paint. Obviously there was some reason why Steve had to have new swing arm fitted (which improved the geometry to an extent).
There will be plenty of pictures and data once we decide which night this week we will be continuing.
For reference:
When I'm prattling on about components have a look at the thread below which has some useful graphics on what the rear subframe comprises of. should help you to understand the process a little better.
https://zroadster.org/threads/bmw-z3-rear-subframe-bushes.6736/
