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Old 04-19-2017, 11:57 PM   #1
El Dorado Jim
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sm 465 popping out of gear

Hi, just thought I would share this, I just installed a new crate engine in my truck, then went down and registered it,,,now for it's maiden voyage with the new engine, runs great!!!! but the 4 spd was popping out of third gear, I hadnt driven the truck since I put this sm465/205 in it, except down the road at my house but never getting on it......looked online and found Anaheim Gear has replacement third gears upgraded from the old,I guess this is a common problem with sm465's never had the problem with my other trucks ...got the gear and slider, ordered a bearing /synchro kit and gasket set and there is a sleeve that replaces some lock rings on the intermediate shaft....anyway, I got it all back together and in the truck and SUCCESS!!!!!!! shifts perfect and stays in all gears like it should....I have a press and made a couple specialty tools from pieces of pipe and made my own socket to tighten the rear main shaft nut and used a bearing remover with a gear puller to remove the bearings ,it was a big job but worth it....there is a great youtube video of a guy tearing apart his sm465 from a 4 wheel drive like mine, was helpful
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Old 04-20-2017, 12:55 AM   #2
'68OrangeSunshine
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Re: sm 465 popping out of gear

I have had the same problem on my SM465 in a '68 C/10 [292 L6, 3.73 posi rear.]
I keep my hand on the shift knob if it starts to happen.

Don't get that gripe on my '71 GMC Jimmy [350,SM465,NP205,3.73 posi].

Wonder what causes it?
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Old 04-20-2017, 07:45 AM   #3
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Re: sm 465 popping out of gear

I have not heard of this problem before, and don't have it with mine, but I am curious as to what you find out.
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Old 04-20-2017, 11:32 AM   #4
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Re: sm 465 popping out of gear

I have heard of this before, seen some info online on how to fix, glad you were able to have success. I have this transmission in my truck but seeing as I have yet to drive it there hasn't been any problems.
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Old 04-20-2017, 02:28 PM   #5
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Re: sm 465 popping out of gear

I have had this problem on nearly every truck with a 4 speed in it. It's because the gearing is such that the truck spends most of it's life in 3rd gear. Towing, starting, stopping, etc is mostly in 3rd. Most folks only downshift from 4th to 3rd, and rarely to 2nd due to the granny low.

It has to do with bearing and gear wear and there is just enough that it allows misalignment.

I am fearing this EXACT same scenario on my son's 70 GMC K2500 that we're doing. Dropping in a crate engine to a worn transmission/transfer case.

I hope that's not the case, but if I was a betting man.........
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Old 04-20-2017, 03:19 PM   #6
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Re: sm 465 popping out of gear

This is a common problem. The transmission shop I use tells me its because people usually rest their hand on the shifter and are slightly pulling on it before upshifting. Time for a rebuild.
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Old 04-20-2017, 10:13 PM   #7
'68OrangeSunshine
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Re: sm 465 popping out of gear

Mine started slipping even after a rebuild.
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Old 04-21-2017, 12:00 AM   #8
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Re: sm 465 popping out of gear

I have not had this problem with the other sm465's in my other trucks...I probably have over 200,000 miles on the one in my 74 K20 and never a problem,,,Bilt4me, they are not hard to rebuild, just a pain in the a#s to pull and put back in....especially mine with the transfer case behind it....don't be afraid to rebuild it yourself if you have a press.....
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Old 04-21-2017, 06:50 AM   #9
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Re: sm 465 popping out of gear

Jim-
Wow, you're quick. You got that engine in and running, then pulled and redid the tranny in a heartbeat. Nice work!

I hope to get my "crate" installed this weekend. Got any tips for wrestling in the SM465 back in when the time comes?
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Old 04-21-2017, 08:09 AM   #10
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Re: sm 465 popping out of gear

You start typing "SM465 pops" and Google shows top searches which finishes up "out of 3rd gear". One common suggestions is:

"There are two snaprings, they retain the input countergear and the third gear countergear. They wear and allow the two to walk, which causes the transmission to jump out of gear. These are replaced with a spacer bushing (p/n 14020811 from Anaheim Gear, essentially tubing as far as I can tell) like this.

But visit the Google and you will find a dozen threads addressing this.
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Old 04-21-2017, 10:56 AM   #11
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Re: sm 465 popping out of gear

Quote:
Originally Posted by Mike C View Post
You start typing "SM465 pops" and Google shows top searches which finishes up "out of 3rd gear". One common suggestions is:

"There are two snaprings, they retain the input countergear and the third gear countergear. They wear and allow the two to walk, which causes the transmission to jump out of gear. These are replaced with a spacer bushing (p/n 14020811 from Anaheim Gear, essentially tubing as far as I can tell) like this.

But visit the Google and you will find a dozen threads addressing this.
Great info Mike! Thanks!

What do y'all think: We currently have the engine out of the truck. Driveshafts are off. Transmission and transfer case are still in the truck.

Should we drop the transmission and TCase NOW and go through them for seals, the 3rd gear issue, seals and bearing? We have no idea if the trans /Case leak, make noise, are worn, or anything.

Should we pull them out and go through them or finish dropping in the engine and DS, get it up and going and see how it goes from there?

The SM465 and NP205 are the only pieces of the driveline that have NOT been rebuilt at this time. Rear axle had spiders blown out and center pin welded in, front axle had totally shot front knuckles and pinion leaks. Rebuilt both.

What say Y'all?
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Old 04-21-2017, 09:38 PM   #12
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Re: sm 465 popping out of gear

Pay the man now or pay the man later... I would do it now. While you are still working on it and not down the road when all is finished and you want to drive.
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Old 04-21-2017, 10:50 PM   #13
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Re: sm 465 popping out of gear

My SM420 had the same problem, I bought some NOS parts and had it rebuilt... Not cheap.
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Old 04-22-2017, 12:24 AM   #14
El Dorado Jim
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Re: sm 465 popping out of gear

Quote:
Originally Posted by Mike C View Post
You start typing "SM465 pops" and Google shows top searches which finishes up "out of 3rd gear". One common suggestions is:

"There are two snaprings, they retain the input countergear and the third gear countergear. They wear and allow the two to walk, which causes the transmission to jump out of gear. These are replaced with a spacer bushing (p/n 14020811 from Anaheim Gear, essentially tubing as far as I can tell) like this.

But visit the Google and you will find a dozen threads addressing this.
I installed the spacer also on mine, even though my snap rings were still in good shape,no instructions came with the spacer, I looked it up online, you remove the two snap rings and a spacer on the intermediate shaft and install the spacer, figured I may as well fix it right, but the third gear and slider should be replaced as well, it is an upgraded gear ,I talked to a guy at Anaheim gear and ordered the gear and spacer over the phone....was about $160.00 for the parts, he also sent replacement springs for the shift forks...but I didnt replace mine, the detents were really tight ...I ordered a bearing and synchro/gasket kit off of Amazon for about $100.00...I did the work myself and pretty cheap vs. taking it to a trans shop...

Last edited by El Dorado Jim; 04-22-2017 at 12:32 AM.
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Old 04-22-2017, 12:30 AM   #15
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Re: sm 465 popping out of gear

Quote:
Originally Posted by saxart View Post
Jim-
Wow, you're quick. You got that engine in and running, then pulled and redid the tranny in a heartbeat. Nice work!

I hope to get my "crate" installed this weekend. Got any tips for wrestling in the SM465 back in when the time comes?
yeah buddy, it helps that I'm retired.....have time now!...pulling the trans/transcase was fairly easy, I have a transmission jack...pulled them as a unit, I installed the 465 by itself then the 205 w/adapter after that ...and ended up having my son help me align the transcase/crossmember ,just couldnt get it by myself...just wish I knew trans was bad when I had the engine out!!!let us know when you get yours running!!!my engine runs great, real happy with it..have less than 50 miles on it so far though..
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Old 04-22-2017, 12:33 AM   #16
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Re: sm 465 popping out of gear

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Originally Posted by nds1968 View Post
My SM420 had the same problem, I bought some NOS parts and had it rebuilt... Not cheap.
my brother in law has a sm420 in his jeep, it is popping out of second gear occasionally, any ideas? bad second gear?
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Old 04-22-2017, 12:41 AM   #17
El Dorado Jim
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Re: sm 465 popping out of gear

Quote:
Originally Posted by BILT4ME View Post
Great info Mike! Thanks!

What do y'all think: We currently have the engine out of the truck. Driveshafts are off. Transmission and transfer case are still in the truck.

Should we drop the transmission and TCase NOW and go through them for seals, the 3rd gear issue, seals and bearing? We have no idea if the trans /Case leak, make noise, are worn, or anything.

Should we pull them out and go through them or finish dropping in the engine and DS, get it up and going and see how it goes from there?

The SM465 and NP205 are the only pieces of the driveline that have NOT been rebuilt at this time. Rear axle had spiders blown out and center pin welded in, front axle had totally shot front knuckles and pinion leaks. Rebuilt both.

What say Y'all?
I think I would try and run them like they are, chances are they are fine....but if you can afford it , go ahead and rebuild the trans...atleast
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Old 04-22-2017, 02:37 PM   #18
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Re: sm 465 popping out of gear

Quote:
Originally Posted by El Dorado Jim View Post
my brother in law has a sm420 in his jeep, it is popping out of second gear occasionally, any ideas? bad second gear?
Call this guy, he knows everything there is to know about all these transmissions. He has an add on CL but he has an actual shop packed full of parts https://pittsburgh.craigslist.org/pts/6099317167.html You can also contact Novaks https://www.novak-adapt.com/catalog/...s/sm420-parts/ but they couldn't help me, they said the parts I needed are impossible to find but that guy on CL had them but he knew what he had... Nate
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Old 04-22-2017, 09:56 PM   #19
El Dorado Jim
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Re: sm 465 popping out of gear

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Originally Posted by nds1968 View Post
Call this guy, he knows everything there is to know about all these transmissions. He has an add on CL but he has an actual shop packed full of parts https://pittsburgh.craigslist.org/pts/6099317167.html You can also contact Novaks https://www.novak-adapt.com/catalog/...s/sm420-parts/ but they couldn't help me, they said the parts I needed are impossible to find but that guy on CL had them but he knew what he had... Nate
thanks a bunch!
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