Bush problems and angle of attack
Discussion
Does anyone have experience of the rear hub carrier? I put the wheels on the 350 at the weekend but looking at the rear end i'm not particularily happy with it because....
1) The OS rear wheel has more camber that the NS even though I've matched up the spacers as per the old setup (although only going by the labelled up parts as the car was bought in bits)
2) The A frames have poly bushes. On the OS one of the bolts that hold the hub carrier in place looked like it was trying to pull through the flange of the bush. So i have stripped it down again and fit a large washer, the same diameter as the flange on the outside of each bush. I have no washer between the hub carrier and the front bush but I have managed to fit one between the shock absorber and the rear bush. I've had to do this because the bottom bush in the shock absorber protrudes out of each side of the shocker and was trying to push the sleeve out of the rear bush and push into the flange. It now looks better but where I have no washer between the hub carrier and the bush, the hub carrier is really tight against the bush, so much so its deforming the flange. Is this normal? Problem is I dont think I'll have enough room to do this on the NS.
3) The rear shocks are Koni (from TVR car parts)and they look different at the bottom against an old set I have. The old ones have flush bushes where as the new ones the bush protrudes out of each side. Is it worth gringing the bush back and fit a washer?
4) How tight should the Hub Carrier bolts be? BFT or loose enough to allow free movement?
Thanks in adavance for any guidance
Cheers Shaun
1) The OS rear wheel has more camber that the NS even though I've matched up the spacers as per the old setup (although only going by the labelled up parts as the car was bought in bits)
2) The A frames have poly bushes. On the OS one of the bolts that hold the hub carrier in place looked like it was trying to pull through the flange of the bush. So i have stripped it down again and fit a large washer, the same diameter as the flange on the outside of each bush. I have no washer between the hub carrier and the front bush but I have managed to fit one between the shock absorber and the rear bush. I've had to do this because the bottom bush in the shock absorber protrudes out of each side of the shocker and was trying to push the sleeve out of the rear bush and push into the flange. It now looks better but where I have no washer between the hub carrier and the bush, the hub carrier is really tight against the bush, so much so its deforming the flange. Is this normal? Problem is I dont think I'll have enough room to do this on the NS.
3) The rear shocks are Koni (from TVR car parts)and they look different at the bottom against an old set I have. The old ones have flush bushes where as the new ones the bush protrudes out of each side. Is it worth gringing the bush back and fit a washer?
4) How tight should the Hub Carrier bolts be? BFT or loose enough to allow free movement?
Thanks in adavance for any guidance
Cheers Shaun
Can't really help with 2,3 & 4 as I don't have an 'A' Frame Wedge but I would probably sort these out before looking at 1.
The camber is adjusted by the shimms on the back and there are 2 sorts of shimms...ones that go between the diff and the brake disk and adjust the position of the caliper so it sits centrally over the brake disk. The second type of shimm fits between the drive shaft and the disk and adjusts the camber. Obviously altering either shimm will effect the camber but the idea is to get the calipers central first, then adjust the outer shimms to get the camber correct. I wouldn't worry too much about what was on before as these get taken off/altered/forgotten over time and once the backend is rebuilt it may alter anyway. Cheers Steve.
The camber is adjusted by the shimms on the back and there are 2 sorts of shimms...ones that go between the diff and the brake disk and adjust the position of the caliper so it sits centrally over the brake disk. The second type of shimm fits between the drive shaft and the disk and adjusts the camber. Obviously altering either shimm will effect the camber but the idea is to get the calipers central first, then adjust the outer shimms to get the camber correct. I wouldn't worry too much about what was on before as these get taken off/altered/forgotten over time and once the backend is rebuilt it may alter anyway. Cheers Steve.
)Shaun,
think Steve has nearly answered your question, here's my input...
I assume you had the rear brake disks replaced with new ones or you've just had it in bits...
Steve is spot on suggesting that the shims on the diff side of the brake disk just set up the brake disk in the middle of the caliper. Can I suggest that you don't reuse old shims unless they are perfectly clean and corrosion free, also make sure that all surfaces are spotless clean before you assemble everything, this ensures you don't get mystery vibrations from the back end.
The shims between the driveshaft and the brake disk affect the wheel camber, unless you are going to have all four wheels aligned by one of the specialists, who will add/remove shims and generally adjust the setup to the factory settings.
A DIY method of getting somewhere near is as follows, with everything tight up to the torque settings and the car rolled back and forward a few times, using a spirit level (I am assuming garage floor is level) measure how much the wheel rim at the top is in (or out) compared to the bottom, now remove the road wheel and the link running forward to the outrigger. Next the four bolts on the inner end of the driveshaft. This allows enough room (if the hub carrier bolts are slackened) for shims to be added or removed. If the top of the wheel in by 10mm pop in a 20 thou shim, put everything back again tighten and measure the camber (spirit level again!) By looking how much you have changed the setup you should be able to guess how many shims to put in to get the wheels looking right and measuring right...
What is the right measurement?
I remember calculating this using algebra and ending up with something like 3mm IN at the top of the wheel, please calculate your own value!
I'm sure the suspension settings have been published on here before.
Result, the car looks right, drives right and because there is minimum strain on the UJ's they last longer as well.
My method of measuring, is the only real difference in doing the job yourself or getting a specialist to set up for you.. There is no easy way of getting shims in or out.
Regards,
Brian (and a Red 350i)
PS If you're coming to Chatsworth, look me up, I'll be wearing a TVRCC tabard most of the day, ask anyone with a tabard and walkie talkie.
PPS all bolts in the suspension should be tight, I'm sure torque values have been published somewhere AND with the car on the road (MOT ramp ideal chance to check) recheck afte a couple of weeks.
think Steve has nearly answered your question, here's my input...
I assume you had the rear brake disks replaced with new ones or you've just had it in bits...
Steve is spot on suggesting that the shims on the diff side of the brake disk just set up the brake disk in the middle of the caliper. Can I suggest that you don't reuse old shims unless they are perfectly clean and corrosion free, also make sure that all surfaces are spotless clean before you assemble everything, this ensures you don't get mystery vibrations from the back end.
The shims between the driveshaft and the brake disk affect the wheel camber, unless you are going to have all four wheels aligned by one of the specialists, who will add/remove shims and generally adjust the setup to the factory settings.
A DIY method of getting somewhere near is as follows, with everything tight up to the torque settings and the car rolled back and forward a few times, using a spirit level (I am assuming garage floor is level) measure how much the wheel rim at the top is in (or out) compared to the bottom, now remove the road wheel and the link running forward to the outrigger. Next the four bolts on the inner end of the driveshaft. This allows enough room (if the hub carrier bolts are slackened) for shims to be added or removed. If the top of the wheel in by 10mm pop in a 20 thou shim, put everything back again tighten and measure the camber (spirit level again!) By looking how much you have changed the setup you should be able to guess how many shims to put in to get the wheels looking right and measuring right...
What is the right measurement?
I remember calculating this using algebra and ending up with something like 3mm IN at the top of the wheel, please calculate your own value!
I'm sure the suspension settings have been published on here before.
Result, the car looks right, drives right and because there is minimum strain on the UJ's they last longer as well.
My method of measuring, is the only real difference in doing the job yourself or getting a specialist to set up for you.. There is no easy way of getting shims in or out.
Regards,
Brian (and a Red 350i)
PS If you're coming to Chatsworth, look me up, I'll be wearing a TVRCC tabard most of the day, ask anyone with a tabard and walkie talkie.
PPS all bolts in the suspension should be tight, I'm sure torque values have been published somewhere AND with the car on the road (MOT ramp ideal chance to check) recheck afte a couple of weeks.
Thanks guys for your help.
As I bought the car in bits the shims were measured of the old ones which the previous owner had marked up. I have set the new discs in the centre of the calipers so thats all ok. I guess when I come to have it all aligned it will need additional shims on the outside of the caliper on the OS.
I think I have solved the other "problem" I was having - namely what appeared to be the bottom of the shocker and the hub carrier pushing into the bushes. The A frames have new poly bushes fitted which are flanged - I think the standard ones are not flanged and are flush with the inside of the A frame and so you have more space and flatter surfaces in the A-frame - hub carrier - shocker sandwich. Does anyone know if this is true? My solution has been quite radical by taking an angle grinder the the protuding bushes on the shocker's and fitting washers between the shocker and the bush one one side and between the hub carrier and bush on the other. This stops either pushing into the bush flange.
Has anyone else experience this problem with poly bushes?
As I bought the car in bits the shims were measured of the old ones which the previous owner had marked up. I have set the new discs in the centre of the calipers so thats all ok. I guess when I come to have it all aligned it will need additional shims on the outside of the caliper on the OS.
I think I have solved the other "problem" I was having - namely what appeared to be the bottom of the shocker and the hub carrier pushing into the bushes. The A frames have new poly bushes fitted which are flanged - I think the standard ones are not flanged and are flush with the inside of the A frame and so you have more space and flatter surfaces in the A-frame - hub carrier - shocker sandwich. Does anyone know if this is true? My solution has been quite radical by taking an angle grinder the the protuding bushes on the shocker's and fitting washers between the shocker and the bush one one side and between the hub carrier and bush on the other. This stops either pushing into the bush flange.
Has anyone else experience this problem with poly bushes?
This is my problem. I think that the original bushes were flush on the inside where as the poly have a flange. The shock was "digging" into the flange on one side and the hub carrier digging in on the other. I've now added washers into the arrangement to stop this but at the expense of loosing some of the bush on the koni. Has anyone else come across this?
Cheers Shaun
Cheers Shaun
Hi Shaun,
Sounds very likely as the standard bushes hardly protrude from the suspension arms at all as they have the steel outer to hold them in, Poly bushes need the additional shoulder to keep em in so will need to be quite a bit wider.
Had a similar problem when I upgraded a MK2 Escort to Poly bushes, had hell of a job getting the polybushed TCA back into a space that was designed for a metalastic type bush....
P.S. Your Chassis looks great !!!
Wish my replacement shock bushes would turn up...
Sounds very likely as the standard bushes hardly protrude from the suspension arms at all as they have the steel outer to hold them in, Poly bushes need the additional shoulder to keep em in so will need to be quite a bit wider.
Had a similar problem when I upgraded a MK2 Escort to Poly bushes, had hell of a job getting the polybushed TCA back into a space that was designed for a metalastic type bush....
P.S. Your Chassis looks great !!!
Wish my replacement shock bushes would turn up...
CarbonWedge said:
Just finished fitting my poly bushes and had the same problem, managed to get them in without cutting, just a lot of hammering, big pry bar and swearing. Then touching up all the newly painted parts I damaged 
Thats about the same method I usd to get mine in a couple of weeks ago Surprised you managed to get a washer between the shock and bushes
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