Labor Day Putting down your wrenches or time for
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| | | | Joined: Jul 2007 Posts: 28 'Bolter | | 'Bolter Joined: Jul 2007 Posts: 28 | Hello fellow bolters,
I recently "finished" my 13 year restoration of my 1941 GMC 3/4T and took it for the first test ride. After hearing some grind/whine from the tranny I headed for the barn but before I got back I lost granny and 2nd gears. After removing the shifter/top plate from the 1953 Muncie 4 speed I saw the broken fork. It was frozen on the guide bar thus the grind/whine and ultimately breaking. Several on-line searches for a replacement produced no good results. Can anyone point me in the right direction for a replacement?
I guess it sat too long prior to using it. Hopefully replacement forks are available and I will be back on the road re-testing soon.
Thanks for any info.
John, | | | | | Joined: Sep 2009 Posts: 5,754 Gearhead, Stovebolt Tech and Parts Tracker, Mod for Swap Meet and GTT | | Gearhead, Stovebolt Tech and Parts Tracker, Mod for Swap Meet and GTT Joined: Sep 2009 Posts: 5,754 | John,
If I read your post correctly, it sounds like you have a’53 “SM420” currently installed. Yes/No/Maybe so??!
Lots of SM420’s to be had if you do some web searching.
It may be less money to pickup a complete trans for parts.
I am currently away from my resource books, but would be glad to look up specific part info and post that here tomorrow if you like.
Others will be along to offer more help as they can.
Have a great evening!
Dan
~ Dan 1951 Chevy 3 window 3100Follow this story in the DITY Gallery"My Grandpa Carl's Truck and How it Became Mine"1966 Chevelle (Wife's Hot Rod) | 2013 Chevy Silverado (Current daily driver) US Army MSG Retired (1977-1998) | Com Fac Maint Lead Tech Retired (1998-2021)
| | | | | Joined: Jul 2007 Posts: 28 'Bolter | | 'Bolter Joined: Jul 2007 Posts: 28 | Hi Dan,
Yes indeed it is the SM420. I was hoping to just pick up a fork, or a set of forks. I have seen several SM420's in searches but none with the shifter and forks. They seem to be the elusive piece. Your help is greatly appreciated!
Thanks Dan, | | | | | Joined: Aug 2017 Posts: 660 'Bolter | | 'Bolter Joined: Aug 2017 Posts: 660 |
Last edited by Shaffer's1950; 06/26/2023 3:49 AM.
1950 Chevy 3100
| | | | | Joined: Mar 2004 Posts: 6,212 'Bolter | | 'Bolter Joined: Mar 2004 Posts: 6,212 | Here's the part numbers for both Yokes (shifter forks) 4.303 Yoke, COMM/UTIL 4-speed....1st and 2nd speed.....591906 COMM/UTIL 4-speed....3rd and 4th speed.....591495 Plug those numbers into the BIG auction site and shop away! Mike B  | | | | | Joined: Jan 2022 Posts: 2,435 'Bolter | | 'Bolter Joined: Jan 2022 Posts: 2,435 | Here's the part numbers for both Yokes (shifter forks) 4.303 Yoke, COMM/UTIL 4-speed....1st and 2nd speed.....591906 COMM/UTIL 4-speed....3rd and 4th speed.....591495 Plug those numbers into the BIG auction site and shop away! Mike B Brand new 591906 on ePay for $10 + $11.94 shipping listed in February, but it is still there.
'57 GMC 102, Original 347 V8, HydraMatic, 3.08 rear gear, added A/C, disk front brakes, HEI, AFB carb, '98 Honda Black Currant paint. T-boned and totaled 10/12
'52 GMC 152 Stake Bed, Original 228, SM420, added A/C, HEI, disk front brakes, '67 Chev 3.55 rear gear. Gets used as a real truck.
| | | | | Joined: Sep 2009 Posts: 5,754 Gearhead, Stovebolt Tech and Parts Tracker, Mod for Swap Meet and GTT | | Gearhead, Stovebolt Tech and Parts Tracker, Mod for Swap Meet and GTT Joined: Sep 2009 Posts: 5,754 | John, Looks like several fellow Bolters stepped up to the plate and have found and provided what you need for information, not to mention a direct line to the part itself.  Let us know how the repair work progresses when you get the needed parts. Pictures to go along with the narrative would be great!  Dan
~ Dan 1951 Chevy 3 window 3100Follow this story in the DITY Gallery"My Grandpa Carl's Truck and How it Became Mine"1966 Chevelle (Wife's Hot Rod) | 2013 Chevy Silverado (Current daily driver) US Army MSG Retired (1977-1998) | Com Fac Maint Lead Tech Retired (1998-2021)
| | | | | Joined: Jul 2007 Posts: 28 'Bolter | | 'Bolter Joined: Jul 2007 Posts: 28 | All,
Thank you so much for the information. I will follow-up on these leads right after work today and let all know how it goes.
Regards, | | | | | Joined: Jul 2007 Posts: 28 'Bolter | | 'Bolter Joined: Jul 2007 Posts: 28 | All,
Update: Although I could not initially see any part numbers on the forks, your responses told me they are numbered so I took a closer look. With a high-powered flashlight at just the right angle I could barely see it. My transmission has two identical forks for 1-2, and 3-4 gears and that is part number 590514 which from the sources you led me to indicates it is an earlier transmission - most likely a '41 which came new with the truck. Comparing my part to the photos from the supplier confirmed it. The truck has a '53 motor in it and I assumed the transmission came with it but apparently not. I was reminded what they say about assumptions.
In any case, the replacement fork is on the way and I should be able to test-drive it again soon - right after polishing up the guide bar so the fork will move back and forth freely.
Thank you so much for the leads!
Now back to work work. | | |
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