Thinking about picking up an SM465

[MtnClimber]

It's a 10 spline, all gears shift and rotate easily. Seems to be a great deal but I know little about them. Any issues with the 10 spline SM465? I've heard a read about adapters from AA. Would it be better to have a 3 speed transfer bolted to the SM, or keep my 4sp transfer? I won't be going any bigger than Q78 (36"s)

 

[orangefj45]

465s are great transmissions. extremely strong and durable although they're a little on the heavy and bulky side. they do work out great in 40s, 45s and 55s.
t-case choice really depends on what gearing you're looking for. in general, the 3spd case will offer slightly lower gearing but the cases are weaker than the 4spd counterparts.
figure out how the cruiser will be driven/wheled and build accordingly. you can always dump the 3spd gear set into the 4spd case for the best of both worlds scenario. do a search on here for that "conversion'. it's not a big deal.

hth

georg @ valley hybrids

 

[MtnClimber]

I'll look into swapping 3sp gears in my 4sp case...

As for the worn shaft splines, would that or has that cause and catastrophic damages? I've never had to deal with that.

To add, I did end up picking it up. It came with the top half bell housing, a nose cone, and a starter all for $75. I figured If I decided not to use it, I could at least clean it up, replace a couple of things on it and make a profit.

 

[MtnClimber]

The splines are pretty square and the edges seem nice and sharp

 

[batcon]

I'll look into swapping 3sp gears in my 4sp case...

As for the worn shaft splines, would that or has that cause and catastrophic damages? I've never had to deal with that.

To add, I did end up picking it up. It came with the top half bell housing, a nose cone, and a starter all for $75. I figured If I decided not to use it, I could at least clean it up, replace a couple of things on it and make a profit.

Can't go wrong with that!

 

[dargreg]

On all 465,s I,ve done the needle bearings on the input shaft should be replaced if there is any considerable miles on the unit.Other than that they are tough.

 

[Cdaniel]

Check that aluminum bell housing closely for cracks after you clean it up. They can have some weakness sometimes.

Great trans in combo with the 3spd gears. Was perfect when I was running 33's. Switching to 35's left me wanting a little, but not bad.

An Orion 4:1 is probably my next step.

 

[MtnClimber]

Check that aluminum bell housing closely for cracks after you clean it up. They can have some weakness sometimes.
Great trans in combo with the 3spd gears. Was perfect when I was running 33's. Switching to 35's left me wanting a little, but not bad.
An Orion 4:1 is probably my next step.

The bell housing is Iron

I thought about the Orion, but don't want to shell out the $1,700. I emailed AA and asked if it were possible to buy just Iron case and swap stock innards into the Iron casing, but got no reply. I don't really want to go too low in the gearing, but I would like to have the Iron housing.

 

[Cdaniel]

My bad. I'm always too quick to reply. A closer look at your pic, yes you've got the good bellhousing. Did you happen to get the cast clutch fork too? A good find all around. Though the fine spline output is stronger.

I did the the unthinkable in old Chevry truck resto circles. I cut off the starter mounting part of that iron bellhousing so I could mount the later model (and more available) starter.

I believe the Orion gear ratios cause the distance between the input and output shafts to change, so they couldn't retro fit into a Toyota case. Or not?

The bell housing is Iron

I thought about the Orion, but don't want to shell out the $1,700. I emailed AA and asked if it were possible to buy just Iron case and swap stock innards into the Iron casing, but got no reply. I don't really want to go too low in the gearing, but I would like to have the Iron housing.

 

[MtnClimber]

I did get the cast clutch fork, though I may upgrade to a steel unit.

I don't know the configuration of either the Orion or stock TCs, but changing the distances between shafts isn't necessary only unless there is a clearance issue with either of the gears and the housing or something else.

I was reading on the NOVACK site that there really isn't a strength issue between spline counts, but only in shaft diameter. The 10 spline and the 32 spline is almost identical in strength.

Spline Misunderstandings Clarified

"More splines are stronger"

Not necessarily. Larger shaft diameters are stronger, and larger shaft diameters usually require a higher quantity of splines. However, the automotive powertrain industries migrated to more splines on shafts due to their ease (speed, cost, etc.) of manufacture - smaller splines being able to be roll forged instead of the larger splines having to be machine cut.

A 32 spline output shaft vs. a 10 spline spline output shaft is probably only minutely stronger, and a decision of use here should be driven more by compatibility than perceived strength.

 

[Cdaniel]

Not sure the stamped steel fork is an upgrade. The folklore at the time I installed mine said go with the cast one. I don't remember the reasoning though.

From the AA Orion webpage:
"This case replacement has the same external width, eliminating driveline modifications. The casting contours that outline the low speed output gear will position the drain plug approximately .500” lower on average. The new low ratio gear set supplied replaces existing gear sets except for the PTO gear or PTO spacer sleeve"

That statement might lead you to believe its possible to put new gears into an old case. But the change in the idler shaft diameter probably prevents it? I guess the .500 lower part got me thinking something changed to move the center line. Maybe it's just clearance and strength built back into the housing.

In spite of Novak's assertions I believe fine vs coarse spline strength is all in the shaft diameter. The root diameter of the fine spline is larger than a coarse one. Harder to twist/break a fine spline. Is the issue between the two on a 465 the wear on the actual splines?

I'm curious if anyone has broken a 465 output shaft, or spun the spline off of one.

I did get the cast clutch fork, though I may upgrade to a steel unit.

I don't know the configuration of either the Orion or stock TCs, but changing the distances between shafts isn't necessary only unless there is a clearance issue with either of the gears and the housing or something else.

I was reading on the NOVACK site that there really isn't a strength issue between spline counts, but only in shaft diameter. The 10 spline and the 32 spline is almost identical in strength.

 

[MtnClimber]

I was actually thinking of having a fork made, but we'll see.

All that Orion jibber jabber doesn't really say weather or not if stock gears and internal could be used in JUST the Iron housing. That's why I tried to see if it would work and if they would sell JUST the housing.

I spoke with a guy that knows a lot about the SM465 and the 420s among others, and I was told that I should not ever have to worry about breaking that shaft. Other components in the driveline will break far before the input and output shafts will break, and the clutch will slip before that shaft will ever break a sweat. Sounds like he holds high confidence in these transmissions. lol

 

[orangefj45]

i'll try to help clear a few things up here......

1) the cast iron clutch fork is the way to go. look around in your local wrecking yards or hit up the transmission shops. just make sure that if you guy a good used fork, the "pads" where it makes contact with the throw-out bearing need to be round and smooth. also, check for the spring that holds the fork onto the pivot ball. if it's broken or missing, find another fork.
if you clean up a good used fork, leave the spring in place and clean the area with brake clean or solvent, then blow it out with an air blower. removing the spring can and will cause it to break unless you know how to do it. use anti-seize on the splring and pivot ball.

2) the spline wear lil'john was talking about is on the main shaft, not the input shaft. it's the one that sticks out of the back of the trans and he's certainly got a valid point.....put some grease on the splines before mating it to the spud shaft IF you're using an AA adapter. if not, then the tc input gear will slide right onto those splines.....

3) orion cast case. the dimensions and distances between the gears and shafts are the same. BUT, it won't work. the orion uses a much larger idler shaft and bearings and your early idler won't work. the orions are a bit larger because of the heavier casting and need for more room for the larger diameter low speed output gear. that's why they hand down an additional 3/8" or so.....

hth

georg @ valley hybrids

 

[MtnClimber]

Thanks for the info. The iron fork I have IIRC had a hole where the pivot ball goes into and it was quite greasy, but I didn't see a spring anywhere.

 

[orangefj45]

it'd better have one. more of a retaining clip........

 

[Gotta40]

you can get in on the group buy for a adapter here,
https://forum.ih8mud.com/40-55-series-tech/428058-sm465-plate-adaptors.html
to run your 3spd case behind it.

 

[landcrusher909]

you can get in on the group buy for a adapter here,
https://forum.ih8mud.com/40-55-series-tech/428058-sm465-plate-adaptors.html
to run your 3spd case behind it.

Same plate I am running and it works Great ! I am going to upgrade to a 4 speed clutch and pressure plate, Just got back my T case from Georg ( Awsome rebuild ) You wont regret the SM465 upgrade. Picks were taken a few weeks ago when I pulled it back out doing a motor swap and power steering upgrade

 

[Cdaniel]

So how are the shafts mated with a plate adapter?

 

[MtnClimber]

I'm guessing custom shafts?

 

[Pin_Head]

A weak link on 465s is the snap rings that retain the gears on the counter shaft. Wear on this allows the gears to move on the shaft and it will pop out of 3rd gear. GM made an updated countershaft spacer to replace the snap rings and prevent this problem. It is a $10 part. Pull the top cover and see if it is installed. You may want to rebuild it and add the updated spacer if it has not been done yet.