The Stovebolt Site Forums The Parking Lot Big Bolts Sm465 transmission stuck in 2nd gear(L•1•2•3)

Hello my truck has been working pretty hard last few days and today I had an issue. Thankfully after I dumped a load of rock and on my way home I got stuck in 5th/6th gear when pulling out on the highway and going up a hill so was shifting kinda fast and once I peaked the hill I couldn't upshift and had to drive home at 20ish mph a good 15 miles. Wow was that frustrating. And I was trying my damndest to get it out of gear the entire slow ride home. Any pointers on how to unjam it? And everything I found online about fixing what caused it requires it to be in partial reverse to disconnect upper cap. How do I get past this snag?

Thanks mike

[quote=DIY.MechanicMike stuck in 5th/6th gear

Thanks mike[/quote]


Clear as mud, 4 forward gears on SM465.
What year / model rig you got.
Common for the 3rd gear countershaft snap ring to break allowing gear to move forward on countershaft.
The late design & service repair got rid of that snap ring & installed a spacer between it & countershaft input gear.

I have a 1972 chevy c50 with high/low rear end. And if this 3rd gear counter shaft snap ring is broke causing the jam-up, how do I get i side to get the broke snap ring out? Do I take the pto cover off the one side or do I need to remove the cover and my pto assembly for dump to get in there to find this snap ring? Cuz it's obvious I'm not going in threw the top until I get it un jammed so I can put it halfway in reverse like they say to get the top cap off. I'm lost Haha.

Don't know how that snap ring that could be installed w/o trans disassemble.
I'd try to find info on updated design parts Monday. Either way transmission will need to come out & disassemble to repair. Was as pretty common failure back in the day.

I've had similar issues with worn out older transmissions .
Try removing the shifter from the trans. so you can see where the shifter enters to move the forks . sometimes the knob on the shifter comes out of the groove where it selects gears , a large screwdriver should line up the groove the knob slides in . If this works remember to follow the H pattern as best you can when shifting

Ok I already have shifter out and I cannot get the grooves to line up. Like I said this booger is jammed in there. I dont wanna drop trans yet til I get it unjammed/out of gear, cuz its held in a great position for that as is. If I had it on the floor I'd have to worry about balancing it while trying to get it outta gear. I was wondering if I drained fluid and took the pto cover plate off I could use a screw driver to wiggle gears around and try un jamming it from the bottom end since the top cap cant come off u less you have it halfway in reverse. But I'm not familiar with jimmying around in there to unjam gears, or if that's even the way I should go about getting it unjammed. I just dont know how to get past this snag.... seems like the shift fork is really caught up in there.

This is where I'm at and cant get the middle section to go up and line up with the two outer linkages for that neutral position.

PTO covers of, should be able to work 3rd speed counter gear rearward. Look for part of snap ring jammed between shaft & gear if won't move with moderate pressure. Correct on the mid way position of the reverse lever for cover removal.
Special tool for removal of main shaft & rear counter shaft bearings that goes into the snap ring groove in bearing race. May be a trans shop that would pull the brgs for you.

BTW, I've got 2 of the sleeves for the updated repair. If you want one send me a p.m..
BC

Ok I'll get to draining fluid and removing cover and see if I cant unjam things. Now the updated repair your saying, what exactly is this?

I'm not experienced in rebuilding stuff but I do a good job of following directions to rebuild things. I did have the engine in pieces when I changed the clutch after 6months of owning it. And I have USED the truck for 5 years since that clutch repair and resealed the whole engine cuz it ha a minor oil leaks everywhere haha. So I obviously did a great job on that part. But my unskilled self should have rebuilt trans at that exact time or I wouldnt be here. But, I'm a firm believer in " if it ain't broke dont fix it". And I did get 5 years of alot of heavy duty usage before this. But once I finish this itll be good to go for a while.

But I have found a few different rebuild kits online. How do I know if they come with this update? I know mine is the old cast iron trans and not newer alum top version. Also do the rebuild kits come with the shift tower kits included or is that separate? Lots of different kits it seems for this trans.

Ok so fluid was changed when I had trans off during clutch replacement. It was still pretty clean and no chunks of anything. So that seems like a good sign, I was expecting some metal pieces. But here is a pic of the inside of driver side pto passage. There seems to be two main shafts in there, an upper and a lower. The upper shaft looks like it has the slider that the shift fork hooks to. And toward the engine is a yellow/gold toothed ring that turns just a lil each way and then a metal toothed ring slightly wider then the gold one. I'm just referancing these parts cuz they seem to be part of the shifting gears. But not 100% what I should be looking for or what to giggle around on while I have my dad trying to shift it back to neutral with a lever?.?.?

As per above photo: Top L.H. : input shaft, 4th syncro ring, 3 - 4 shift collar (is in 3rd gear position so 3rd syncro not visible), 3rd driven gear & second driven gear. The counter shaft is the lower, all gears are attached solid to counter shaft. The middle gear in photo is 3rd, the snap ring is still in place so that's not the issue. Get the other PTO cover off try to pry on ether side of 3 -4 shift collar to move it forward.

Ok so I dumbied it down for myself cuz I dont know which is what in there Haha. So I color coded most of the main parts in there I believe. So if you could explain it using the color coding I'll better understand what parts your talking about. But I guess I'll take the pto off the other side if you think I need both sides open to giggle stuff around to get it to come out of gear.

Orange: input shaft Yellow: 4th syncro blocker ring Green: 3 -4 shift collar (in 3rd gear position, 3rd syncro ring hidden by shift collar) white: 3rd speed main gear Grey: 2nd speed main gear

Red: counter shaft Purple: 3 speed counter gear Pink: 2nd speed counter gear (all gears splined on counter shaft)

With both PTO covers off & 2 prybars try moving blue towards green. A helper on the top would be helpful.

Ok thank you so much for breaking that down for me and anyone else that may see this. I know I took that down to kindergarten level explanation but sometimes that makes complicated things easier. Haha. Cuz there are alot of different parts in there. But I'll go take that other side off and try moving the blue one towards the green while my dad trys moving the upper end.

Thanks,
Mike

If you disconnect the driveline & have a helper depress the clutch so you can rotate shafts it might help.

Ok thanks for that last tip, I was just coming back to say well I tried prying and my dad on upper end prying as well and it didnt come out. But I'll try disconnecting drive line and rotate shaft while doing it. Hopefully that helps.

If not idk what to do. I guess I'm just gonna have to drop it and take it in somewhere and get charged a fortune cuz I've already exhausted the whole weekend trying with what I got. What's the worst thing that can happen if I drop it and try removing the upper cap without being halfway in reverse? Cuz I'm already thinking I'm gonna need to replace parts so if that's the only way to get in there I guess I'm gonna have to break something else to fix the original broken/jammed up part. Cuz she isnt wanting to come outta gear.

Ok with more frustrating efforts I failed again at getting it out of gear!! However I laid under there with a flashlight just looking at everything I could like a crime scene or something, and i found some metal on metal action in there. It appears that the 3rd speed main gear has rubbed the shift fork(like the shift fork dropped/lowered) just barely grinded into it but its shiny so that's how I seen it. The gear itself appears fine tho.

So back to my other question what will happen if I try opening the top cap of transmission without having the shifter halfway in reverse? Cuz I HAVE to get inside this thing so I can FIX IT!!! I dont care if I break something that's already bent or whatever cuz its obviously causing this and only any to fix it is to get inside. So something's gotta give or break haha. I would prefer to know what I'm gonna break tho before I do it so I can break it the right way lol.

Thanks,
Mike

You usually can get it off that way. raise it up & move it around. Most guys take them apart that way as they don't realize you need it to be halfway in reverse. You cannot put it back though unless you have it just right.
George

Ok so I got the transmission dropped and top cover opened up after alot of wrestling, and there is some minor issues inside. There is a tad bit of metal flakes in the bottom of trans "pan" I think there is something magnetic there. Anyway the reason it wouldnt come out of third is cuz the gold "gear"ring for third is ate up pretty good on the edges and the slide was caught up on a metal bur. All the gears seem fine in there but obviously I have it out so I'm gonna a just rebuild it. So where are some good sources to get a complete rebuild for this transmission? Napa can only get a rear seal for it so they are no help. Gonna have to be a online order.

Get a good book & follow directions to disasemble it. You cannot remove the upper shafts with out dropping the cluster (counter shaft) gears down to the bottom of the case. Used trans. like this are easy to find used. I would get a used one & use it or disasemble it for parts. The seals & brgs. are available at any parts store. The ones in light duty trucks are the same except some variations in the rear output shaft & some had the emerg. brake on the back. The ones in the light duty trucks are usually in good shape as they are not worked as hard as the ones in the medium duty trucks.
George

Ok well where is a good resource for a book on this transmission? And source for a complete rebuild kit? I really would like to get it ordered today since its Monday and maybe I'll have it by end of week for the weekend.

My transmission has the emergency brake on the back.

I also know a great bone yard to get a used trans from if I needed one. But I would rather stick to the medium duty transmissions cuz I dont wanna deal with any differance they may have. And not to mention dropping the trans in the medium duty trucks, you dont even have to lift the truck up or anything. Slide some mining belt under there and get you a floor jack positioned on bottom of trans, and pop off bottom bell housing "trap door", remove lower bolts from trans to bell housing, then position a ratchet strap under the tail end of trans to hold it up level once you remove the upper bolts, then you and possibly a partner can roll floor jack toward the rear to pull it outta the bell housing then lower it. There will be lots of finagling with the strap while pulling back and lowering. But much easier removal then a light duty truck cuz of the ground clearance issues, and possible unlevel ground of boneyards Haha cuz I havnt been to many that have flat ground for "safe" lifting of vehicles for big removals like a trans.

See if Novak has the kit for the SM465.

Mike B

I did come across Novak but they are out of stock. Lucky me lol. I found some others online around the 200 dollar range does that seem right? I also found some closer to 120 dollar range as well on ebay but not 100% on quality there. The 200 dollar one is at least made in Japan by skf so that seems to be more of a quality kit.

For that kind of money you could buy a complete good used trans and not bother with the rebuild.

Mike B

Would be worth looking into since your going to have to pay someone to fix it.

I'm not paying anyone to rebuild it. I'm rebuilding it myself. I have a guy that can assist with pressing parts on and off. And if I bought a used trans it would just be a ticking time bomb for this same thing to happen to it. Resulting in me in the same place but with two transmissions needing rebuilt and me not driving truck. So rebuilding this one will assure me that I'll have a good 20years at least before it needs anymore love. Engine just got alot of love 5 years ago and I just put a "new" used twospeed rear end in it and it just got fluid changed and about to replace the seal where driveshaft connects cuz it started leaking about 6months ago. So rebuilding the transmission is the way I'm going so I dont have to worry about this truck for a while besides little stuff. Cuz I plan to keep this truck on the road for at least another 10years if I can. Or unless I can afford to get a bigger truck for road use and just keep this one for farm work. Either way I want it running and operating until the frame breaks in half Haha.

Sounds good. If you want one of these spacers (from early post) you can have it for the postage.
Replaces the 2 snap rings on the counter shaft, was used in production later on.
I Broke the 3rd gear counter shaft snap ring on my bosses' "77 K20 , just out of warranty. Drove the trip back w/ load of tires & no 3rd gear.

Tough job with a load!

Ed

It was a 350 with 4.56:1 axles, just a few weeks in service. Wound out well, would run past 100 mph with ease. Did I mention I wasn't quite 17 at the time?

I used to go into the PTO outlet & weld the gear to the shaft when that snap ring broke.
George

I've seen that, good a fix as any for the issue at hand. I think the only reason for the snap ring was it was cheaper to build the countershaft that way rather than 1 piece. Seems as the spacer between the gears come out in mid "80 production of the 465.

Hey I had a question about the speedo gear in that removable housing portion and the "gear/bushing" that drives it for accurate speed at the dash, I swapped a two speed rear into my truck about a year ago and havnt had accurate speed since. Cant go over 55-60mph so not a huge issue, but if I can get a replacement gear to match my new ratio that would be awesome, I just dont know where to look for info on this particular issue... but I'm sure the ratio and gear tooth count have to do with matching everything up for accurate speed at the dash. If anyone has any info on a chart or sourcing these gears for the correct ratio that would be great if you gave me a push in the right direction.

Thanks,
Mike