JimShelly
Member
It is time to bring everyone who is interested up to speed on my lovely project. I’ll confess, I wondered if we would ever get this right, BUT in the end I have a car again. With an overdrive. I’ve put on less than 200 miles and I still have tweeking to do, but the overdrive works well. Gearvendors says don’t engage the unit under 30mph as there won’t be enough pump pressure, and by 30mph this car is definitely in 3rd, so in effect I now have a 4th gear. It does change the character of the car.
By the end of 2021 I’d solved all the engineering issues and driven the car on the road, but with horrible vibrations. This is what we did in January and February: We left the tranny and clutch alone, but pulled the rear end out of the car and unbolted the overdrive unit from the middle of the torque tube. The front part of the torque tube and the internal driveshaft from the OD to the torque ball comes apart easily. However, the rear shaft from the pinion gear was another matter.
I couldn’t imagine getting the torque tube itself out of the rear end after 81 years. We cut an access hole in the top of the tube, then measured where the pin lived and drilled a half inch hole on either side of the tube so we were able to punch the pin out of the driveshaft. We had an advantage in that we’d cut the tube itself to put in the OD unit, but I suppose this would work on an intact torque tube as well. It was not a tapered pin.
The driveshaft was stuck fast and we had to heat it up thru our access hole, then drove it off the pinion gear shaft with an air chisel. We then took both shafts to Long Island Driveshaft where they promised to reweld the ends and make them true (proving that vendors will lie to you on purpose.) The professionally straightened rear shaft still had 12 thou run out over a 10-inch length, so we took it off and tried again. No luck.
By this time the rear driveshaft end was pretty beat so I sourced a used driveshaft from Dave Tacheny in Minnesota, had it shipped, and went to Nassau Driveshaft in Merrick. They did quite a good job of cutting that shaft to length and welding on both the Buick ends and the splined adaptors for the overdrive. My dial indicator setup now indicated about 4-5 thousandths runout on both shafts. We reassembled with these driveshafts and shimmed the mounting flanges we’d welded onto the torque tube to get everything as straight as possible. I set up the Torque ball shims so the front driveshaft fell slowly to the floor when released and ever since reassembly, I’ve been playing with the Torque assembly mounts to center the driveshaft.
This whole process had taken a month during which time the car had been sitting in the corner of the shop. Rather than put dollies under the rear end and maneuver it over to a lift, we left it jacked up and installed the rear end as it sat. That made for a day of crawling around on the floor which really tired me out, but the job was done. I started up, checked my brakes, eased out of the shop and set off down the road. This photo at the bay is 5 miles into my test drive.
The vibration is lots less and I think I can work on centering the driveshaft so I feel less. As above, I now have a 4 speed car. I put on some 100 miles and shipped the car home to NJ. When I went for a brief drive around Robbinsville I heard the “scary noise”. It was hard to identify and I returned to Florida not knowing what was really going on. Nervous.
But, thinking about it, I’ve replaced the transmission input shaft pilot bearing with a pilot bushing, and my press fit was too tight. That is wearing in. I’ve put in a new pressure plate and flywheel from a 94 Jeep Cherokee. I’ve added the overdrive with all the alignment troubles that made, and I had the rear diff apart trying to find the pin fastening the rear axle to the pinion bearing, so I’ve reset the gear lash back there. I’ve pulled the flywheel, heated the ring gear until it dropped off, turned it around and dropped it back on the flywheel so the worn teeth would not slip on the starter Bendix drive. I’ve put in rebuilt rear lever arm shocks, and re-gasketed the exhaust manifold and downpipe. There were lots of things we’d done which might make noises.
On my next trip north I drove the car as much as I could, heard the noise several times, convinced myself it was coming from the transmission / clutch area and that some wearing in was going on. I also must continue aligning the whole drivetrain with the torque ball mounts. However, the worst is behind me and I’ll start some of the other projects I’d like to do before June when Great Race sets off from Warwick RI heading for Fargo ND for another 2500 mile drive. It ought to be a little cooler than last summer in Texas.
Reply
Report Edit Delete
By the end of 2021 I’d solved all the engineering issues and driven the car on the road, but with horrible vibrations. This is what we did in January and February: We left the tranny and clutch alone, but pulled the rear end out of the car and unbolted the overdrive unit from the middle of the torque tube. The front part of the torque tube and the internal driveshaft from the OD to the torque ball comes apart easily. However, the rear shaft from the pinion gear was another matter.
I couldn’t imagine getting the torque tube itself out of the rear end after 81 years. We cut an access hole in the top of the tube, then measured where the pin lived and drilled a half inch hole on either side of the tube so we were able to punch the pin out of the driveshaft. We had an advantage in that we’d cut the tube itself to put in the OD unit, but I suppose this would work on an intact torque tube as well. It was not a tapered pin.
The driveshaft was stuck fast and we had to heat it up thru our access hole, then drove it off the pinion gear shaft with an air chisel. We then took both shafts to Long Island Driveshaft where they promised to reweld the ends and make them true (proving that vendors will lie to you on purpose.) The professionally straightened rear shaft still had 12 thou run out over a 10-inch length, so we took it off and tried again. No luck.
By this time the rear driveshaft end was pretty beat so I sourced a used driveshaft from Dave Tacheny in Minnesota, had it shipped, and went to Nassau Driveshaft in Merrick. They did quite a good job of cutting that shaft to length and welding on both the Buick ends and the splined adaptors for the overdrive. My dial indicator setup now indicated about 4-5 thousandths runout on both shafts. We reassembled with these driveshafts and shimmed the mounting flanges we’d welded onto the torque tube to get everything as straight as possible. I set up the Torque ball shims so the front driveshaft fell slowly to the floor when released and ever since reassembly, I’ve been playing with the Torque assembly mounts to center the driveshaft.
This whole process had taken a month during which time the car had been sitting in the corner of the shop. Rather than put dollies under the rear end and maneuver it over to a lift, we left it jacked up and installed the rear end as it sat. That made for a day of crawling around on the floor which really tired me out, but the job was done. I started up, checked my brakes, eased out of the shop and set off down the road. This photo at the bay is 5 miles into my test drive.
The vibration is lots less and I think I can work on centering the driveshaft so I feel less. As above, I now have a 4 speed car. I put on some 100 miles and shipped the car home to NJ. When I went for a brief drive around Robbinsville I heard the “scary noise”. It was hard to identify and I returned to Florida not knowing what was really going on. Nervous.
But, thinking about it, I’ve replaced the transmission input shaft pilot bearing with a pilot bushing, and my press fit was too tight. That is wearing in. I’ve put in a new pressure plate and flywheel from a 94 Jeep Cherokee. I’ve added the overdrive with all the alignment troubles that made, and I had the rear diff apart trying to find the pin fastening the rear axle to the pinion bearing, so I’ve reset the gear lash back there. I’ve pulled the flywheel, heated the ring gear until it dropped off, turned it around and dropped it back on the flywheel so the worn teeth would not slip on the starter Bendix drive. I’ve put in rebuilt rear lever arm shocks, and re-gasketed the exhaust manifold and downpipe. There were lots of things we’d done which might make noises.
On my next trip north I drove the car as much as I could, heard the noise several times, convinced myself it was coming from the transmission / clutch area and that some wearing in was going on. I also must continue aligning the whole drivetrain with the torque ball mounts. However, the worst is behind me and I’ll start some of the other projects I’d like to do before June when Great Race sets off from Warwick RI heading for Fargo ND for another 2500 mile drive. It ought to be a little cooler than last summer in Texas.
Reply
Report Edit Delete