SM465 shifter dentent balls/springs - The 1947 - Present Chevrolet & GMC Truck Message Board Network

dyno · 01-27-2010, 11:20 AM

My 4 speed likes to fall out of 3rd gear. I suspect it's worn detent balls and springs in the cover. How hard are they to change? The manual I have is not very clear...any tutorials out there on how to do it?

Thanks

**old Rusty C10** · 01-27-2010, 01:40 PM

im not a mechanic who can rebuild a transmission by any means but mine did that and it was the synchros and bearings in the transmission ( or so i was told by the rebuilder)

dyno · 01-27-2010, 08:35 PM

I had a guy rebuild it years ago and he didn't do the balls and springs, so I figured that was it.

MR .T · 01-27-2010, 08:40 PM

Ive taken apart 4 speed saganaws and they are very easy to change the balls.

James McClure · 01-28-2010, 10:58 AM

Dyno. I'm an OLD Chevy mechanic. Do yourslf a favor, don't tangle with a 465 without a GOOD manual #1. Next your problem isn't detent balls or springs. They would have to be missing to be a problem, they work like a combination lock. The problem is the 3-4 shift hub OR excessive play between the input shaft and the output shaft (they come togther in a bearing at the front of the output shaft) Also check drive shaft length. If the yoke bottoms out on the output shaft it could knock the trans out of gear if bearings are worn or output bearing snap rings are broken or missing. Also check the shifter itself for excessive looseness. If the stick rattles around to much it could bounce just right on decel and pop it out of gear. Do you shift with or without the clutch? No clutch shifts are ok BUT, if not done correctly they wear both shift hubs and blocker rings (syncro's) jim

dyno · 01-28-2010, 11:14 AM

Hi James,

Thanks for your input. I had the tranny rebuilt a few years ago and he said he went through the whole thing. Maybe he lied. Anyway, the driveline does not bottom out. The shifter is fairly loose. Maybe I'll try another shifter and spring. It does it when I'm on a washboard road and de-cellerate.

MR .T · 01-28-2010, 11:49 AM

the shifters on those are prone to cracking below the pivot.

dyno · 01-28-2010, 11:57 PM

I carefully felt each gear position. 1 and 2 position, I can feel the detent click into place. 3 and 4 gear just slides loose. I'm sure it's the balls/springs.

01-27-2010, 01:40 PM	#2
old Rusty C10 Robert Olson Transport Join Date: Oct 2002 Location: recent transplant to NC USA Posts: 20,287	Re: SM465 shifter dentent balls/springs im not a mechanic who can rebuild a transmission by any means but mine did that and it was the synchros and bearings in the transmission ( or so i was told by the rebuilder) __________________ Bob 1951 International running on a squarebody chassis "If a man's worth is judged by the people he associates himself with, then i am the richest man in the world knowing some of the fine people of this board" http://67-72chevytrucks.com/vboard/a...t.php?f=25&a=9 (you can review the site rules here!) PM Me for your vehicle/parts hauling needs in the North East US or see my Facebook page Robert Olson Transport Live each day to the fullest.. you never know when fate is going to pull the rug out from under you... I hate cancer!!

01-27-2010, 08:35 PM	#3
dyno Registered User Join Date: Sep 2008 Location: Middleton, Idaho Posts: 352	Re: SM465 shifter dentent balls/springs I had a guy rebuild it years ago and he didn't do the balls and springs, so I figured that was it. __________________ "Built- not bought" 1958 GMC 150 4x4 in progress 1980 K20- Restored 1985 K3500 Flatbed 58 GMC 4x4 build thread: http://http://67-72chevytrucks.com/vboard/showthread.php?t=557675

01-27-2010, 08:40 PM	#4
MR .T Registered User Join Date: Jan 2010 Location: Kitchener, Ontario, Canada Posts: 94	Re: SM465 shifter dentent balls/springs Ive taken apart 4 speed saganaws and they are very easy to change the balls.

01-28-2010, 10:58 AM	#5
James McClure One shot, one kill. Join Date: Dec 2007 Location: Saratoga Springs NY Posts: 859	Re: SM465 shifter dentent balls/springs Dyno. I'm an OLD Chevy mechanic. Do yourslf a favor, don't tangle with a 465 without a GOOD manual #1. Next your problem isn't detent balls or springs. They would have to be missing to be a problem, they work like a combination lock. The problem is the 3-4 shift hub OR excessive play between the input shaft and the output shaft (they come togther in a bearing at the front of the output shaft) Also check drive shaft length. If the yoke bottoms out on the output shaft it could knock the trans out of gear if bearings are worn or output bearing snap rings are broken or missing. Also check the shifter itself for excessive looseness. If the stick rattles around to much it could bounce just right on decel and pop it out of gear. Do you shift with or without the clutch? No clutch shifts are ok BUT, if not done correctly they wear both shift hubs and blocker rings (syncro's) jim __________________ 1984 K20 350M engine with 465,000 miles. Well, it's finally done!! Almost 2 years of work, but it was really worth the effort. Little stuff left to do is mount winch, wet sand & buff out and build belly pan\running boards. Body work takes lots and LOTS of beer!!!! God, Guts and Guns made America and God, Guts and Guns will preserve it! The worst thing you could do is get into my sights, but that don't matter, you'll never know it, cause you'll never hear the shotJim or Paladin whichever you choose.

01-28-2010, 11:14 AM	#6
dyno Registered User Join Date: Sep 2008 Location: Middleton, Idaho Posts: 352	Re: SM465 shifter dentent balls/springs Hi James, Thanks for your input. I had the tranny rebuilt a few years ago and he said he went through the whole thing. Maybe he lied. Anyway, the driveline does not bottom out. The shifter is fairly loose. Maybe I'll try another shifter and spring. It does it when I'm on a washboard road and de-cellerate. __________________ "Built- not bought" 1958 GMC 150 4x4 in progress 1980 K20- Restored 1985 K3500 Flatbed 58 GMC 4x4 build thread: http://http://67-72chevytrucks.com/vboard/showthread.php?t=557675

01-27-2010, 11:20 AM	#1
dyno Registered User Join Date: Sep 2008 Location: Middleton, Idaho Posts: 352	SM465 shifter dentent balls/springs My 4 speed likes to fall out of 3rd gear. I suspect it's worn detent balls and springs in the cover. How hard are they to change? The manual I have is not very clear...any tutorials out there on how to do it? Thanks __________________ "Built- not bought" 1958 GMC 150 4x4 in progress 1980 K20- Restored 1985 K3500 Flatbed 58 GMC 4x4 build thread: http://http://67-72chevytrucks.com/vboard/showthread.php?t=557675

01-28-2010, 11:49 AM	#7
MR .T Registered User Join Date: Jan 2010 Location: Kitchener, Ontario, Canada Posts: 94	Re: SM465 shifter dentent balls/springs the shifters on those are prone to cracking below the pivot.

01-28-2010, 11:57 PM	#8
dyno Registered User Join Date: Sep 2008 Location: Middleton, Idaho Posts: 352	Re: SM465 shifter dentent balls/springs I carefully felt each gear position. 1 and 2 position, I can feel the detent click into place. 3 and 4 gear just slides loose. I'm sure it's the balls/springs. __________________ "Built- not bought" 1958 GMC 150 4x4 in progress 1980 K20- Restored 1985 K3500 Flatbed 58 GMC 4x4 build thread: http://http://67-72chevytrucks.com/vboard/showthread.php?t=557675



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