The Harvester
Kickback or Overtake
- Joined
- May 11, 2008
- Messages
- 38
- Reaction score
- 3
- Points
- 0
- Location
- Melbourne
- Members Ride
- VR HSV Senator 215i
A while back I was flicking through the forum to find out if VT rear brakes could be fitted to VR and VS IRS trailing arms but unfortunately couldn’t find any info. I went to numerous suspension shops to ask if it could be done but I got the same answer everywhere, can’t be done. I already knew that the problem with upgrading to VT rear brakes is with the handbrake shoes. The VS handbrake shoes are about 1 ½ inches too small in diameter and do not grab the inside of the VT rotor even with full adjustment they would not come even close. The major problem is that the VS and VT handbrake shoes are connected to the dust plates and they will not interchange no matter what.
I was not getting the answer that I wanted to hear so I decided that I would find out for myself. A mate has a wrecking yard for late model Commodores who let me do some VS and VT trailing arm measuring. First I was thinking that the complete VT trailing arm might bolt straight in place of the VS item but the VT trailing arm is 20mm wider each side. The VT trailing arm could physically bolt up to the VS diff cradle but the wheels would protrude through the guard 20mm on each side plus the sway bar and shocker mounts are in different locations so that was definitely a no goer.
I was just about to leave it at that thinking it can’t be done but perseverance stepped in and I got thinking because I have the parts in front of me and I have spent so much time on the internet and asking around if it could be done so why not try the last possible thing. So I ended up measuring all the areas of the VS and VT brake setups like the brake caliper mount height from the centre of the hubs, how far the hubs protruded from the caliper mounts, the dust plate mounting hole distances, brake cable catch to make sure the VS brake cable would fit onto the VT handbrake catch plus there were other numerous areas to check and by the end of it I was quietly confident that the VT handbrake and disc and caliper setup will bolt straight onto the VS trailing arm without any fuss.
There is still one more huge problem to overcome, the dust plates on both the VS and VT will not bolt off the trailing arm because they can’t fit over the hub. The hub needs to come off first before the dust shield will come off with the brake shoes and all the other mechanical parts needed. Damn it. I did some thinking to see if it was worth doing because when you press out the hubs the bearings get destroyed in the process and therefore adding more labour leading to more $$$’s. Curiosity got the better of me plus I had to know if it would work.
My plan was to keep the car on the road as it’s my daily driver so I bought a VT SS SI diff disc to disc complete with the LSD centre from ebay (You can use any trailing arm from VT to VZ because your only using the brakes not the trailing arms or cradle) so I could get the handbrake setup and rotors and calipers (plus I’ll use the LSD centre for another project later on). Then I bought a VS IRS diff off ebay using only the trailing arms and junking the brakes as they were not needed. By doing it this way the brake swap can be done without the car off the road and I didn’t know if it would actually work. I took both pairs of trailing arms to Pedders in Thomastown and asked them to swap bits over from here to there and pressing bits out and pressing bits in etc. Still I was told “ it ain’t gonna work” so I just said to them give it a go I’m paying for this and they were more than happy to give it go.
Pedders called me back the next day and said it was a perfect swap over but there may be a problem with the handbrake cable fitting but I told them that the cable should fit straight on and would probably just have to be adjusted. The next thing was to bolt the modified trailing arms to the car so I booked my Caprice in to have it lowered all round with a few other suspension upgrades while it was there. Now is a perfect time to have the camber kit fitted to the rear as the trailing arms have got to come off regardless.
The next day it was ready to pickup from Pedders workshop and they said it fitted just like a factory unit and the only adjustment was to back off the handbrake cable only. All the brake lines fitted perfect and the calipers and rotors fitted perfect and to look at it with the wheels off you would think it was all factory fitted. Now I can still use factory parts for easy servicing plus I still retain the original wheel track offset and I don’t have to chase any foreign aftermarket parts what-so-ever. I got to have my cake and eat it too.
Thanks to the boys at Pedders in Thomastown (on Settlement Rd. Contact Glenn or Gary Laird (03) 9464 4994) I was very happy with the work done and it was money well worth spending.
Pedders in Thomastown fitted new Sportsryder struts, strut bearings and Pedders bearing plates, Pedders heavy duty front end link pin kit, Pedders shock tower brace, Pedders Sportsryder front and rear lowered springs, Pedders inner and outer rear camber kit but more importantly they modified my VS trailing arms and fitted the VT rear brakes. Awesome.
How to fit - just follow the steps below.
1. Have your VT dust plate and brake shoes ready to be bolted onto your VS trailing arms. NOTE if your going for bigger than standard VT rear discs make sure that the outer lip on the dust plate is ground off before fitting them onto the VS trailing arm otherwise the bigger discs will not fit and trust me it is better time spent doing it now than when they are fitted. Also have 2 new hub bearings ready to fit the VS trailing arms.
2. Take out your VS trailing arms and press the hubs out this can only be done by a specialist as they have the proper required tools.
3. Bolt off the VS dust plate together with the handbrake shoes and other handbrake mechanical bits.
3. Bolt in the VT dust plate with the handbrake shoes and mechanical bits as a complete unit. No modifications required.
4. Press in the new hub bearings.
5. Your new trailing arms are ready to bolt back in.
6. Back off the adjustment on your handbrake cable by roughly 10-20mm at the handbrake lever end under the car. The other ends of the handbrake cable simply slip onto the VT handbrake arm which pops out the back of the dust plate, no modifications required.
7. Fit your VT rotors and do another check on the adjustment of your handbrake.
8. Connect your brake hoses and bolt up the VT brake calipers. Bleed the brakes do any final adjustments and checks that everything is where it’s supposed to be and that all bolts are tight etc.
My brakes have been fitted for nearly 2 months without a problem and I feel my car does brake a bit better even though they are just rear brakes. I've got a near new full set of VY HSV Clubsport 2 spotters with 330 and 315 curve slotted rotors to fit on which is why I did the VT rear brake job so that the rear HSV brakes could match up with the front HSV brakes. The rear HSV discs are 315mm in diameter and when Pedders tried to fit them they found that the lip on the VT handbrake dust plate has to be ground down flat because the HSV disc is bigger than a standard VT disc so I got them to fit the standard rear VT discs and calipers for now. Grinding the dust shield lip can be done when fitted to the car but would be much easier to do when off the car.
Does anyone know if VP VQ IRS rear brakes are the same as VR and VS IRS because this mod should work for them as well? May even work on solid/live axle units also if the handbrake dust shield mount holes line up but don’t quote me as I haven’t measured them up and I’m not about to do it either.
I was not getting the answer that I wanted to hear so I decided that I would find out for myself. A mate has a wrecking yard for late model Commodores who let me do some VS and VT trailing arm measuring. First I was thinking that the complete VT trailing arm might bolt straight in place of the VS item but the VT trailing arm is 20mm wider each side. The VT trailing arm could physically bolt up to the VS diff cradle but the wheels would protrude through the guard 20mm on each side plus the sway bar and shocker mounts are in different locations so that was definitely a no goer.
I was just about to leave it at that thinking it can’t be done but perseverance stepped in and I got thinking because I have the parts in front of me and I have spent so much time on the internet and asking around if it could be done so why not try the last possible thing. So I ended up measuring all the areas of the VS and VT brake setups like the brake caliper mount height from the centre of the hubs, how far the hubs protruded from the caliper mounts, the dust plate mounting hole distances, brake cable catch to make sure the VS brake cable would fit onto the VT handbrake catch plus there were other numerous areas to check and by the end of it I was quietly confident that the VT handbrake and disc and caliper setup will bolt straight onto the VS trailing arm without any fuss.
There is still one more huge problem to overcome, the dust plates on both the VS and VT will not bolt off the trailing arm because they can’t fit over the hub. The hub needs to come off first before the dust shield will come off with the brake shoes and all the other mechanical parts needed. Damn it. I did some thinking to see if it was worth doing because when you press out the hubs the bearings get destroyed in the process and therefore adding more labour leading to more $$$’s. Curiosity got the better of me plus I had to know if it would work.
My plan was to keep the car on the road as it’s my daily driver so I bought a VT SS SI diff disc to disc complete with the LSD centre from ebay (You can use any trailing arm from VT to VZ because your only using the brakes not the trailing arms or cradle) so I could get the handbrake setup and rotors and calipers (plus I’ll use the LSD centre for another project later on). Then I bought a VS IRS diff off ebay using only the trailing arms and junking the brakes as they were not needed. By doing it this way the brake swap can be done without the car off the road and I didn’t know if it would actually work. I took both pairs of trailing arms to Pedders in Thomastown and asked them to swap bits over from here to there and pressing bits out and pressing bits in etc. Still I was told “ it ain’t gonna work” so I just said to them give it a go I’m paying for this and they were more than happy to give it go.
Pedders called me back the next day and said it was a perfect swap over but there may be a problem with the handbrake cable fitting but I told them that the cable should fit straight on and would probably just have to be adjusted. The next thing was to bolt the modified trailing arms to the car so I booked my Caprice in to have it lowered all round with a few other suspension upgrades while it was there. Now is a perfect time to have the camber kit fitted to the rear as the trailing arms have got to come off regardless.
The next day it was ready to pickup from Pedders workshop and they said it fitted just like a factory unit and the only adjustment was to back off the handbrake cable only. All the brake lines fitted perfect and the calipers and rotors fitted perfect and to look at it with the wheels off you would think it was all factory fitted. Now I can still use factory parts for easy servicing plus I still retain the original wheel track offset and I don’t have to chase any foreign aftermarket parts what-so-ever. I got to have my cake and eat it too.
Thanks to the boys at Pedders in Thomastown (on Settlement Rd. Contact Glenn or Gary Laird (03) 9464 4994) I was very happy with the work done and it was money well worth spending.
Pedders in Thomastown fitted new Sportsryder struts, strut bearings and Pedders bearing plates, Pedders heavy duty front end link pin kit, Pedders shock tower brace, Pedders Sportsryder front and rear lowered springs, Pedders inner and outer rear camber kit but more importantly they modified my VS trailing arms and fitted the VT rear brakes. Awesome.
How to fit - just follow the steps below.
1. Have your VT dust plate and brake shoes ready to be bolted onto your VS trailing arms. NOTE if your going for bigger than standard VT rear discs make sure that the outer lip on the dust plate is ground off before fitting them onto the VS trailing arm otherwise the bigger discs will not fit and trust me it is better time spent doing it now than when they are fitted. Also have 2 new hub bearings ready to fit the VS trailing arms.
2. Take out your VS trailing arms and press the hubs out this can only be done by a specialist as they have the proper required tools.
3. Bolt off the VS dust plate together with the handbrake shoes and other handbrake mechanical bits.
3. Bolt in the VT dust plate with the handbrake shoes and mechanical bits as a complete unit. No modifications required.
4. Press in the new hub bearings.
5. Your new trailing arms are ready to bolt back in.
6. Back off the adjustment on your handbrake cable by roughly 10-20mm at the handbrake lever end under the car. The other ends of the handbrake cable simply slip onto the VT handbrake arm which pops out the back of the dust plate, no modifications required.
7. Fit your VT rotors and do another check on the adjustment of your handbrake.
8. Connect your brake hoses and bolt up the VT brake calipers. Bleed the brakes do any final adjustments and checks that everything is where it’s supposed to be and that all bolts are tight etc.
My brakes have been fitted for nearly 2 months without a problem and I feel my car does brake a bit better even though they are just rear brakes. I've got a near new full set of VY HSV Clubsport 2 spotters with 330 and 315 curve slotted rotors to fit on which is why I did the VT rear brake job so that the rear HSV brakes could match up with the front HSV brakes. The rear HSV discs are 315mm in diameter and when Pedders tried to fit them they found that the lip on the VT handbrake dust plate has to be ground down flat because the HSV disc is bigger than a standard VT disc so I got them to fit the standard rear VT discs and calipers for now. Grinding the dust shield lip can be done when fitted to the car but would be much easier to do when off the car.
Does anyone know if VP VQ IRS rear brakes are the same as VR and VS IRS because this mod should work for them as well? May even work on solid/live axle units also if the handbrake dust shield mount holes line up but don’t quote me as I haven’t measured them up and I’m not about to do it either.
Last edited:
