[C1] OEM fiber tach gear versus plastic aftermarket
03-08-2017, 01:59 PM
#1
Racer
Thread Starter
OEM fiber tach gear versus plastic aftermarket
Hi All:
I am starting my project to get my OEM tach working in my '60. Years ago, I was sitting at a light when I heard the worst sound ever -- like two cats fighting under my hood. I also noticed the tach gauge needle was jumping around all over. I disconnected the tach cable from the back of the generator and obviously the sound stopped as well as my tach. I ended up removing the tach cable and storing it inside a plastic bag all these years.
During my Rt 66 trip last year, I noticed the generator needed to be oiled more frequently since I checked it every time I gassed up. When I put oil in the rear lube port it began to drip out of the weep hole so as a precaution, I pulled the generator while parked at a Walmart in Albuquerque and discovered the fiber tach gear was completely missing all the teeth and it was spinning freely.
Plus, all the fiber gear teeth had become a pile of black paste that had settled along the bottom of the rear housing and weep hole. I guess with all the added miles of driving and me adding oil to keep the rear bearings wet, the slurry of the oil and fiber material gave way and created a small leak which made its way tot he weep hole. After I realized I could only add a small amount of oil up to the weep hole opening.
Flash forward to now, I would like to replace the worn tach gear and see if I can get the tach working again. I searched on Ebay and found an OEM fiber tach gear replacement and an aftermarket plastic tach gear from Corvette Central available. Since I don't ever plan on opening the rear housing of the generator to expose the gear, has anyone ever installed on of these plastic gears and had any issues? The teeth appear the same and presumably it is the exact same diameter. I'm just wondering if there would be any lubrication issues using plastic. I don't want to spend 3 to 4 times the amount on a fiber gear only to have it deteriorate quicker or worse, break some teeth because it is now brittle after spending more than 55 years on the shelf in a can.
Any advice would be great.
Thanks!!
Ted
I am starting my project to get my OEM tach working in my '60. Years ago, I was sitting at a light when I heard the worst sound ever -- like two cats fighting under my hood. I also noticed the tach gauge needle was jumping around all over. I disconnected the tach cable from the back of the generator and obviously the sound stopped as well as my tach. I ended up removing the tach cable and storing it inside a plastic bag all these years.
During my Rt 66 trip last year, I noticed the generator needed to be oiled more frequently since I checked it every time I gassed up. When I put oil in the rear lube port it began to drip out of the weep hole so as a precaution, I pulled the generator while parked at a Walmart in Albuquerque and discovered the fiber tach gear was completely missing all the teeth and it was spinning freely.
Plus, all the fiber gear teeth had become a pile of black paste that had settled along the bottom of the rear housing and weep hole. I guess with all the added miles of driving and me adding oil to keep the rear bearings wet, the slurry of the oil and fiber material gave way and created a small leak which made its way tot he weep hole. After I realized I could only add a small amount of oil up to the weep hole opening.
Flash forward to now, I would like to replace the worn tach gear and see if I can get the tach working again. I searched on Ebay and found an OEM fiber tach gear replacement and an aftermarket plastic tach gear from Corvette Central available. Since I don't ever plan on opening the rear housing of the generator to expose the gear, has anyone ever installed on of these plastic gears and had any issues? The teeth appear the same and presumably it is the exact same diameter. I'm just wondering if there would be any lubrication issues using plastic. I don't want to spend 3 to 4 times the amount on a fiber gear only to have it deteriorate quicker or worse, break some teeth because it is now brittle after spending more than 55 years on the shelf in a can.
Any advice would be great.
Thanks!!
Ted
04-25-2017, 01:55 PM
#2
Racer
Thread Starter
Update.
Well, I decided to purchase the plastic tach gear from Corvette Central for $17 and replace the worn out gear. After removing the rear housing on the generator, the gear comes out with it. Remove the gear and you will see a slotted nut that if I recall is 7/16". Be careful upon removing the nut since it is reverse threaded so you have to turn the nut to the right to loosen it. Going to the left not only tightens the nut, but you could end up crushing it and rendering it useless upon installation.
Got the new gear on and reinstalled the rear housing on the generator. It has been a number of years since I removed the tach cable and placed it in a ziplock. One end has the squared end and the other has what appears to be a smooth plastic cover on it.
I tried to slide the cable end with the square from the generator back towards the tach, but when I tried to push the cable inside the cable housing far enough to screw the end of the cable into the rear housing on the generator, the cable sticks out too far. I removed the cable and turned it end to end and inserted the cable end with the plastic cap and after some effort I was able to push the cable into the housing and slide it all the way to the tach in the dash. Hooked the cable housing up to the generator and turned the engine on, but no tach movement.
I can see the cable turning with the generator as the engine is running and I carefully back off the cable housing from the generator so I know that part is fine. Is the other end of the cable also supposed to be squared off? Did something break off the rear of my tach which explains the plastic "cap" on the tach side of the cable. The only other thing I could try is to remove the cable from the housing, turn the cable end to end and insert the squared end to meet up with the rear of the tach and turn the cable with a drill counterclockwise to see of the tach moves.
Any suggestions?
Ted
Well, I decided to purchase the plastic tach gear from Corvette Central for $17 and replace the worn out gear. After removing the rear housing on the generator, the gear comes out with it. Remove the gear and you will see a slotted nut that if I recall is 7/16". Be careful upon removing the nut since it is reverse threaded so you have to turn the nut to the right to loosen it. Going to the left not only tightens the nut, but you could end up crushing it and rendering it useless upon installation.
Got the new gear on and reinstalled the rear housing on the generator. It has been a number of years since I removed the tach cable and placed it in a ziplock. One end has the squared end and the other has what appears to be a smooth plastic cover on it.
I tried to slide the cable end with the square from the generator back towards the tach, but when I tried to push the cable inside the cable housing far enough to screw the end of the cable into the rear housing on the generator, the cable sticks out too far. I removed the cable and turned it end to end and inserted the cable end with the plastic cap and after some effort I was able to push the cable into the housing and slide it all the way to the tach in the dash. Hooked the cable housing up to the generator and turned the engine on, but no tach movement.
I can see the cable turning with the generator as the engine is running and I carefully back off the cable housing from the generator so I know that part is fine. Is the other end of the cable also supposed to be squared off? Did something break off the rear of my tach which explains the plastic "cap" on the tach side of the cable. The only other thing I could try is to remove the cable from the housing, turn the cable end to end and insert the squared end to meet up with the rear of the tach and turn the cable with a drill counterclockwise to see of the tach moves.
Any suggestions?
Ted
04-25-2017, 06:56 PM
#3
Team Owner
Member Since: Oct 2000
Location: Washington Michigan
Posts: 38,899
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First thing I'd do is to rebuild the generator - pitch the bushings and replace them with sealed ball bearings (all of the usual vendors have generator rebuild kits with everything you need). Then put the oil can away and focus on the tach cable and the tach drive gearbox that drives it. Most 60-year-old generators have been rebuilt at least once, and replacing the bushings with sealed ball bearings was normally part of the rebuild. Takes about ten minutes to rebuild the tach drive gearbox - Corvette Central has the parts for that too.