Click on image for the lowdown. 
====
| | | Forums66 Topics128,161 Posts1,056,957 Members48,458 | | Most Online14,466
Apr 26th, 2026 | | AD Chevy Trucks  Over 6,000 pictures Brad Allen has an awesome collection of Chevrolet factory pictures that he has set up from film strips. Check them out!
Lots of work on Brad's part ... pure enjoyment (and references) for you!
| | THANKS!
For helping keep this great
old truck web site
on the Internet for over 30 years! and not clogged down
with Ads!  Again, thanks!
| | | | Joined: Oct 2016 Posts: 37 'Bolter | | 'Bolter Joined: Oct 2016 Posts: 37 | The 4 speed transmission shift arm is sloppy on my 1955 Chevrolet first series 3100 pickup. This has caused me to grind the gears from third to fourth. I have a spare transmission that seems to be tighter. There are eight bolts holding the cover on. Can I just switch the arms and top plate without it turning into a major project. If I remove the pin that looks as though it is holding the arm, will the arm come out? Will that make it easier? The shop manual says be careful of springs,pins, levers, etc. On a previous thread someone made it sound fairly simple. I am a backyard putz. Am I missing something, or can someone give me some advice, or should I find a professional, which might be like finding a needle in a haystack!! Thank you. | | | | | Joined: Jan 2013 Posts: 1,518 'Bolter | | 'Bolter Joined: Jan 2013 Posts: 1,518 | Assuming you have the sm420 with granny low transmission. Two things could be the culprit. First the end of the shift arm could be worn and second, the three-four shifter yoke could be worn too.
You can remove the top of the spare trans by removing the 8 bolts, make sure both transmissions are in neutral. then replace the entire assembly to the transmission you are using. Just align the sliders on the main shaft with the yokes of the top loader and it will slip right in.You possibly might need to slide the reverse/first gear a bit forward or backward to fit it all in nicely. Easy/peasy
Last edited by sstock; 06/20/2018 11:56 AM.
1953 Chevrolet 3100261 cu inch, sm420, 3.55 rear, torque tube still,omaha orange, still 6 volt, RPO green glass, side carrier spare, all done In the DITY GalleryVideo of the 261 running1964 GMC 1000305 Big Block V6, sm420, the next cab off restoration
| | | | | Joined: Oct 2012 Posts: 130 'Bolter | | 'Bolter Joined: Oct 2012 Posts: 130 | I had a the same problem -sloppy shifter - with my 49-3100 with a 4 speed SM420. I put a new shifter, spring and fulcrom pins and there is no more sloppy shifting. Got all parts from Novak Transmission. | | | | | Joined: Oct 2016 Posts: 37 'Bolter | | 'Bolter Joined: Oct 2016 Posts: 37 | Thanks for the information. I always have the fear of messing things up! Is Novak Transmission in your area, or can you tell me how to get in touch with them? Thank you.
| | | | | Joined: Oct 2016 Posts: 37 'Bolter | | 'Bolter Joined: Oct 2016 Posts: 37 | Thank you for your reply. How can I tell if I have the SM420 transmission? I do have the granny gear. | | | | | Joined: Jan 2013 Posts: 1,518 'Bolter | | 'Bolter Joined: Jan 2013 Posts: 1,518 | Google sm420 and look at the pictures. Keep in mind depending on the year of the truck the rear bearing and yoke will be different for the torque tube type driveshaft then say an open drive line. Some heavy trucks might have a ebrake assembly off the rear yoke as well.
You can always post a picture of your top cover too.
Last edited by sstock; 07/10/2018 8:28 AM.
1953 Chevrolet 3100261 cu inch, sm420, 3.55 rear, torque tube still,omaha orange, still 6 volt, RPO green glass, side carrier spare, all done In the DITY GalleryVideo of the 261 running1964 GMC 1000305 Big Block V6, sm420, the next cab off restoration
| | | | | Joined: Jun 2011 Posts: 5,096 Crusing in the Passing Lane | | Crusing in the Passing Lane Joined: Jun 2011 Posts: 5,096 | Novak is in Salt Lake City, or suburbs.
Ed
'37 GMC T-18 w/ DD 4-53T, RTO-610, 6231 aux., '95 GMC running gear, full disc brakes, power steering, 22.5 wheels and tires.
'47 GMC 1 ton w/ 302, NP-540, 4wd, full width Blazer front axle.
'54 GMC 630 w/ 503 gasser, 5 speed, ex fire truck, shortened WB 4', install 8' bed.
'55 GMC 370 w/270, 420 4 speed, grain, dump bed truck from ND. Works OK.
| | | | | Joined: Jun 2004 Posts: 8,597 Riding in the Passing Lane | | Riding in the Passing Lane Joined: Jun 2004 Posts: 8,597 | You do not have to remove the pins to remove the shifter lever. . Take a pair of vise grip pliers. Press down on the coller on top of the trans. & turn it about 25 degrees CCW. The lever should lift
out.
Last edited by Wrenchbender Ret.; 07/10/2018 6:10 PM.
They say money can't buy happiness. It can buy old Chevy trucks though. Same thing. 1972 Chevy c10 Cheyenne SuperIn the Gallery Forum | | |
|
|
