The Great Pumpkin - '71 Duster
So all the recent work I've put in to this car has finally paid off and it's driving great. At this point I have just about everything sorted out. The brakes work, the vibration is gone, it's aligned, registered and inspected. The tuning is close but not quite there but that can only be nailed down by driving it. Other than that, it's good to go!
So the one major obstacle I had were the brakes and they are finally working right. I think the pads and shoes needed to be bedded in or something since they seem to stop a little better the more I drive it. Honestly they're likely never going to be like the brakes on my Mazdaspeed but they stop the car fine. The improvement over the worn out 10" drum brakes that were on the car when I got it is pretty significant so mission accomplished on that front. The Roll Control is working now as well where before it was not holding because of the low pressure in the front circuit. The combination of the 15/16 master cylinder and the disc brake metering valve seemed to solve the issue. Next time I will probably go with another caliper setup, something with a little more piston area. I definitely learned a lot about brakes.
The driveline vibration is gone now too. The cause was too much negative pinion angle. I ended up taking the rear apart several times trying to narrow down the cause. When I changed to the Calvert stuff from S/S springs I left out the pinion shims the P.O. installed since the rear of the car was sitting lower. I won't bore you with all the measurements and such but there was a lot of head scratching for a bit. After staring at it for a while it finally dawned on me that I should change the spring mounting point and put the shims back in. The front spring hangers I got from Cass/Dr. Diff have two holes for the spring eye bolts. Initially they were in the lower hole so I tried them in the top hole and took it for a ride. The vibration was still present on deceleration but not as violent so I knew I was on the right track. Since I had 2 degree pinion shims installed, I was hoping 4 would do the trick. The main thing I was concerned about was having to re-weld the spring perches to correct the angle. Went down to SK Speed and picked up a set of 4 degree shims and some new perches just in case the vibration was still there. I lucked out though because the 4 degree shims did the trick. Nice and smooth now on and off the gas.
The car is now aligned and driving straight. My driveway alignment was close enough for horseshoes and hand grenades but in reality it was pretty far out. I knew that though which is why I took it to a shop that had an alignment rack. The place I went to deals with a lot of older vehicles. They had the factory specs in their alignment machine so I went with those, even if the OE specs were for 14" bias ply tires all around and a different ride height. The right side caster was toughest to get in line but once that came in, everything else fell in right away. Steering wheel is straight, no wander or pull. When I first got it the steering wheel was off because the entire front end was shot, including the steering box which had a ton of play in it. The one that's in there now is nice and tight. The car responds well and actually drives OK with the large rear and skinny front tires. The suspension is a little harsh but I don't mind.
So as all this was being finished up, I was psyched to clean a year and a half worth of dust off the car. Took it out on Sunday afternoon and had my kids help me wash it. (bad idea) I stocked up on detailing supplies and have been doing some buffing/shining when I had free time this week. Car has a ton of imperfections but I love it the way it is. It shines up nice.
Here's a few pics.
This is a shot of the 4 degree pinion shim installed. I had a bad driveline vibration on deceleration at lower speeds caused by too much negative pinion angle. The shims help to point the pinion upwards (or down if needed) to get it more parallel in relation to the transmission output shaft.
http://i273.photobucket.com/albums/jj214/rmchrgr/IMG_01812_zps485e5d6b.jpg
Here's the car being aligned. They didn't seem to mind me hanging out while they did their thing. I gave a nice tip.
http://i273.photobucket.com/albums/jj214/rmchrgr/IMG_01802_zps53d05f03.jpg
The rear is square with negligible thrust angle. I was stoked to see that.
http://i273.photobucket.com/albums/jj214/rmchrgr/IMG_01792_zps503fa207.jpg
All shined up, ready to roll.
http://i273.photobucket.com/albums/jj214/rmchrgr/IMG_01903_zps02c659ad.jpg
More to come.
So all the recent work I've put in to this car has finally paid off and it's driving great. At this point I have just about everything sorted out. The brakes work, the vibration is gone, it's aligned, registered and inspected. The tuning is close but not quite there but that can only be nailed down by driving it. Other than that, it's good to go!
So the one major obstacle I had were the brakes and they are finally working right. I think the pads and shoes needed to be bedded in or something since they seem to stop a little better the more I drive it. Honestly they're likely never going to be like the brakes on my Mazdaspeed but they stop the car fine. The improvement over the worn out 10" drum brakes that were on the car when I got it is pretty significant so mission accomplished on that front. The Roll Control is working now as well where before it was not holding because of the low pressure in the front circuit. The combination of the 15/16 master cylinder and the disc brake metering valve seemed to solve the issue. Next time I will probably go with another caliper setup, something with a little more piston area. I definitely learned a lot about brakes.
The driveline vibration is gone now too. The cause was too much negative pinion angle. I ended up taking the rear apart several times trying to narrow down the cause. When I changed to the Calvert stuff from S/S springs I left out the pinion shims the P.O. installed since the rear of the car was sitting lower. I won't bore you with all the measurements and such but there was a lot of head scratching for a bit. After staring at it for a while it finally dawned on me that I should change the spring mounting point and put the shims back in. The front spring hangers I got from Cass/Dr. Diff have two holes for the spring eye bolts. Initially they were in the lower hole so I tried them in the top hole and took it for a ride. The vibration was still present on deceleration but not as violent so I knew I was on the right track. Since I had 2 degree pinion shims installed, I was hoping 4 would do the trick. The main thing I was concerned about was having to re-weld the spring perches to correct the angle. Went down to SK Speed and picked up a set of 4 degree shims and some new perches just in case the vibration was still there. I lucked out though because the 4 degree shims did the trick. Nice and smooth now on and off the gas.
The car is now aligned and driving straight. My driveway alignment was close enough for horseshoes and hand grenades but in reality it was pretty far out. I knew that though which is why I took it to a shop that had an alignment rack. The place I went to deals with a lot of older vehicles. They had the factory specs in their alignment machine so I went with those, even if the OE specs were for 14" bias ply tires all around and a different ride height. The right side caster was toughest to get in line but once that came in, everything else fell in right away. Steering wheel is straight, no wander or pull. When I first got it the steering wheel was off because the entire front end was shot, including the steering box which had a ton of play in it. The one that's in there now is nice and tight. The car responds well and actually drives OK with the large rear and skinny front tires. The suspension is a little harsh but I don't mind.
So as all this was being finished up, I was psyched to clean a year and a half worth of dust off the car. Took it out on Sunday afternoon and had my kids help me wash it. (bad idea) I stocked up on detailing supplies and have been doing some buffing/shining when I had free time this week. Car has a ton of imperfections but I love it the way it is. It shines up nice.
Here's a few pics.
This is a shot of the 4 degree pinion shim installed. I had a bad driveline vibration on deceleration at lower speeds caused by too much negative pinion angle. The shims help to point the pinion upwards (or down if needed) to get it more parallel in relation to the transmission output shaft.
http://i273.photobucket.com/albums/jj214/rmchrgr/IMG_01812_zps485e5d6b.jpg
Here's the car being aligned. They didn't seem to mind me hanging out while they did their thing. I gave a nice tip.
http://i273.photobucket.com/albums/jj214/rmchrgr/IMG_01802_zps53d05f03.jpg
The rear is square with negligible thrust angle. I was stoked to see that.
http://i273.photobucket.com/albums/jj214/rmchrgr/IMG_01792_zps503fa207.jpg
All shined up, ready to roll.
http://i273.photobucket.com/albums/jj214/rmchrgr/IMG_01903_zps02c659ad.jpg
More to come.