I've had my '52 truck for just a few days now (since Monday). My aunt and uncle had the truck fully restored a few years ago. I've driven it a few times with no issues. However on my way back home from running an errand this morning, I couldn't get it to stay in third gear. I would shift into third, apply the gas, and within a few seconds it would pop into neutral (no problem with R, 1, or 2). I've done some Googling and the only similar thread I came across was on the stovebolt forums. Some people said it was syncrhos and others said it was merely an alignment problem. I was hoping someone here would be able to provide a little insight. Thank you in advance!!
Too much end play in top train … a shim between 2nd gear thrust washer & the rear bearing is one way to fix it, or a shim between clutch gear & front bearing also works.
I'd check the linkage for slop/adjustment, doesn't cost anything and you don't have to pull the trans. Assuming it's a 3 speed.
Look closely at engine mounts, for a recent 'change'. (they're vulcanized rubber) Also, of course, shift linkage, as @Terrible 80 suggested. Most likely excessive end play in main drive...@302 GMC.
Thanks a bunch for the suggestions, 302GMC, Terrible80, and Atwater Mike. Trucks of this vintage are completely new to me so I'm definitely not ashamed to admit my ignorance. I will research the linkage adjustments, motor mounts, and shims and hopefully will be able to fix this myself. I can do the labor; just need to be pointed in the right direction. Thank you again.
I think I'm wearing Google out trying to research this shifter/transmission. I noticed that the bushing for the R/1 shift lever is missing (circled in attached photo). Does anybody have a lead on where to find these bushings? I think I've found bushings for just about every GM column shift ever made, but I'm not sure which one is correct for my '52 truck. Thanks in advance for the help and thanks for bearing with a newb!
I've found a lot of workable substitutes at a local hardware store like an ACE or a True Value. Repaired a couple of antique radio tuners, found bushings to repair and reengineer my O/T late 60's Pontiac's brake pedal to remove the slack and add a power brake booster not to mention a lot of other things I have forgotten over the years.
...had the same problem with a 52,..pull off the trans side cover, flip the "u" shaped sliders on the inside of the side cover 180 degrees (just turn them, do not take anything apart) put it back together, ...shifted like new after that, one side of the "u"'s get worn...
Its a common problem. sometimes the engagement on the inpuit shaft gear and the syncro becomes worn. worn pilot bushing in the crank. linkage sloppy and not adjusted properly so its not going fully into gear. Your trans is a early version of the 55 open drive line 318 Muncie trans. I simply don't like the closed drive line. I changed the rear end and installed a open drive rear end. usually one from a chevelle or other mid sized GM car. that way I got tall rear end gears. then changed to 54 & older 5 lug passenger hubs & drums on the front. that way I could run a wide choice of wheels & a modern GM open drive trans, I always liked a SM 420 granny low 4 speed in a truck. that way I could run really tall rear gears and still have it pull a load.
Thanks, Old wolf. I think I found rubber bushings for the shift levers at Chev's of the 40's. I would rather have a nylon busing like the one installed in the 2/3 shift lever. I think over the weekend I will pull that busing and see if I can find a match at the parts store or hardware store. I also noticed that the shifter seems to need alignment (this could be due to the missing R/1 shift lever bushing). When in the neutral gate, I feel like I should be able to pull the lever towards me (as if about to shift into R/1) and then push it away from me (as if about to shift into 2/3) with more or less no hitches. Right now, if I pull it towards me in neutral and then go to push the shifter away from me, I have to raise it slightly instead of being able to smoothly go back and forth (hope that makes sense). Is there a procedure to align the shift levers (I found one for later, mid-60's three speeds, but the levers are completely different)? I guess I'm just hoping (I know..."hope" is not a strategy) that this is a relatively easy fix given so few miles on the transmission (and the fact that I've only been able to drive this beautiful truck three times since getting it) vs. having to pull it out and tear it apart (which, given my unfamiliarity with this vehicle would be a daunting task). Thank you again to everyone for all of your help and suggestions.
I havent adjusted shift linkage on a truck like yours, but generally you want both shift levers on the column so they are perfectly aligned with each other in neutral. Then make sure both levers on the transmission are in the center of their travel while in neutral. Sometimes if there is a lot of wear you have to fiddle with the adjustment to find the sweet spot, where you can go through the gears smoothly in a nice H pattern without binding. Usually it only takes 10-15 minutes to adjust. Before driving the truck run through the gears and make sure both levers on the transmission fully engage into each gear.Dont forget to lubricate everything too, it can make a huge difference. Sent from my SM-G950W using The H.A.M.B. mobile app
I had a 65 Ford short box pick up years ago with really rusty floors and cab mounts it would act up with the three on the tree shift linkage. Your truck sounds like it doesn’t have rust issues but any sloppy cab movement,bad motor mounts or bad trans mounts really plays havoc on three on the tree type shifting.
I had a similar problem with my son's 46 Chev sedan g/box, and looking at an exploded view, they look the same.. Heres what I found when removing the side cover.. 1. The selector lever (item 53 and 54) that went thru the housing to the selector inside the box, had flogged out the riveted end (where it is secured in the shift assy), and was not allowing full travel of the gear being engaged (I set it halfway thru the wear, and welded it).. 2. On similar designed gearboxes, (GM Aussie Holden had the same set up) I ground slightly more of a recess in the items 57 and 58 detent/interlock, just to give it more of a grip on the selector shaft.. 3. If you didn't want to modify the groove, you could fit a heavier spring 55 to apply more detent pressure.... Hope this helps..
The exploded view pictured is not your trans. your trans has a 4 bolt side cover. You could swap the bushing from the 1st and reverse over to the second and third to see if that helps? with the fixed shaft steering collum and your shifter securely attached to it. you will not have a problem even if the cab is flopping around. a shade tree fix for the old 318.s junping high gear. was you remove the impuit shaft and take about 20 thousands off the part that engages the syncro. remove the front pilot shaft bearing and place a .030 shim between the bearing and the gear. that moves the impuit shaft rear ward and allows the (.o20) non worn rear part to go a bit farther into the syncro assembly. .
Thank you, 66gmc, Tri-power37, inthweedz, and Old wolf. I went to Home Depot and Lowe's today and found some nylon spacers that fit the bushing hole in the shift levers perfectly and also fit the clevis pins on the ends of the shift rods that insert into the levers. They are too tall, though, so I am going to shorten them. Once the bushings are in place, I'm going to work on the linkage alignment. Since the levers appear to be the same, I'm going to lay a narrow, thick, short piece of wood flat stock across the top of the levers and another piece across the bottom and then c-clamp them in place. This should ensure that the levers are perfectly aligned in neutral. I'll then loosen and adjust the rods so that when secured to the levers, they are both in the center of their travel between R/1 and 2/3. After that I'm going to try checking the fluid level in the trans and maybe even just drain and refill with new 80w90 lube. Then I'll go for a drive and see if the problem persists. Thanks again to everyone who's chimed in. I'm learning new things with every reply!
Well the problem seems to be fixed! I redid the bushings where the shift levers connect to the shift rods (attached pic) and I can now shift into third and it stays in third. I made all the bushings out of nylon pieces I got at Home Depot and Lowe's. I had to make some modifications, but it helped and took slop out of the shifter. As best I can figure (that is to say it makes sense in my head not being completely familiar with trucks of this vintage), with no bushing in the R/1 shift lever, the 3/8" OD clevis pin on the end of the shift rod was riding freely in a 1/2" OD hole in the shift lever which is 1/16" of unnecessary play in either direction. That 1/16" could've translated to an even larger number by the time you get down to the gear box. So sliding the shifter up from 1st to 2nd with that much slop means that the R/1 shift rod wasn't being lifted as high as it should've been when going from 1st to 2nd (and later to 3rd). As I said above, it makes sense in my head, but I'm still learning about these old trucks. Thanks so much for all the replies and help, everyone!!
UPDATE: Made it back home. Of course, after about a mile of holding it in third, it started working again with no trouble. So my issue has once again reared its ugly head. Of course it happened on the way to a get together. The shifter isn't going completely into third gear. I can hold it there, but it pops into neutral when I let go of the shifter. I've pulled over. Gonna let it cool down a bit and see what happens.
Adjust your shifter so it barely goes into second and reverse. Then you can be 100% certain its going all the way into third gear. Probably your syncro and the teeth on the rear of the pilot shaft are worn out. The best cheap reliable fix is a SM 420 granny 4 speed and a tall geared open driveline rear end. My 66 GMC has that trans and a 336 ratio Dana 44 rear. Its a 6 hole rear. Could easily be installed an a AD truck.
Old Jimmy Waterworth had a 64 chevy truck that popped out of high gear. He beat a drepression in the dash above the speedometer to the right side. Cut a forked stick and jammed that in there to hold it into gear. Worked until the collar on the syncro that the shift pawl fits on wore out and broke off.
...did you remove the side cover and turn the U's 180 degrees as I previously suggested, did this on mine and it shifted like new.
Hey @rusty1 , no I have not yet tried that since the issue went away after replacing the (non-existent) bushings in the linkage. I will give that a shot and report back. Thank you!
@rusty1 When you say "turn the U's 180°" are you talking about the large and small U's on the inner shift levers (circled in the crappy attached pic)?
As much as you have looked at it I'm sure you would have noticed if the trans was not tight to the bellhouseing.
Have you had someone shift it into third gear while you lay under the truck and listen/feel if you get that notchy sound/feel when it goes into third. (engine off of course) To make the adjustment: 1. Put the gear shift lever in 3rd. 2. Loosen the adjuster. 3. Move the lever on the side of the transmission as far into 3rd as it will comfortably go. Should give that notchy feel. (no forcing) 4. Tighten adjuster and confirm that trans is still all the way in 3rd. 5. Adjust 1/R for correct neutral gate. Also you could put a witness mark on the shift rod after you adjust it to see if the adjuster is slipping on the rod.
EDIT: @rusty1 I didn't remove the side cover today because I didn't have a replacement gasket. So today I followed the procedure outlined by @X-cpe (thank you again!). I put the gear shift in 3rd, loosened the adjuster on the 2/3 shift rod, and then got under the truck and moved the 2/3 shift lever back to neutral and then moved it into third. I got one positive feeling movement, but I knew it hadn't completely engaged. I pushed a little harder (being extremely careful not to force it) and got a nice positive click fully into third gear (the adjustment was definitely off). I tightened the adjuster on the 2/3 shift rod at this point. I moved the shifter back into neutral and noticed that it was now sitting completely horizontal as stated in the shop manual (before in neutral, it was at about 2:30 to 2:45 as hour hand goes). I then removed the top of the shift box on the column so I could see the shift gate easily to adjust the R/1 neutral gate; after aligning the 2/3 rod, the R/1 gate was maybe an 1/8" to 3/16" out of alignment. After getting it aligned, I went for a test drive and had nice, positive shifts into all gears with no signs of trouble. I then came home and changed the fluid (which I was happy to find out could not have been easier) and went for another test drive. It seems to be shifting well. I've been very focused on my shifting to ensure that I make slow, deliberate movements with the shifter, too. So, I'm going to make a few more test drives (close to home, haha) over the next week or so and see how it goes. Hopefully this takes care of the issue for good. Sorry for rambling on! Thank you again to everyone who chimed in with advice, opinions, and other help!! Really great group of folks on the H.A.M.B.!
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