New/Old SM465

[C&D Crew Cab]

I've just bought an '88 V30, my dream truck, and I'd like to start collecting parts and pieces as spares and also maybe "Freshen up" a few things and swap them out. One of the things I'd like to do is buy an SM465 and an NP205, put in new seals as well as new syncros in the tranny and change them out. Under the heading of "I don't get out much" I've just learned (I think) that somewhere around '87 they got away from the 10 spline output/input shafts and went to a finer spline. So does my '88 have the finer spline? Is finer spline stronger?

Also, I see people refering to "round bolt pattern" or "race track pattern." Do the finer spline and round bolt pattern go hand in hand? Does anyone have a pic of this bolt pattern or have some other way of identifying the later model unit if it's still bolted to the trans?

Sorry for all the newby questions guys. Thanks for your help. What a great site - - - tremendous knowledge base.

Dave

 

[tRustyK5]

81 was when the SM465 went to 32 spline. Everything before that was 10 spline.

I'm not 100%, but I'm pretty sure that when they went 32 spline they also went to the generic 6 bolt round pattern. Your '88 is 32 spline, and the round pattern already.

The other pattern is easy to identify as it looks like a figure 8 (or a racetrack) where the T-case mounts to the adaptor.

The 10 spline units used a female coupler that was prone to wear and eventually failure. The 32 spline is a direct connection into the T-case input gear. Fine spline is always stronger...

i'd freshen up what you have if you're having problems with it. If it still works fine then leave it alone. Common issues for the SM465 include the shifter mechanism becoming very sloppy, popping out of 3rd gear and that's about it. The shifter is reasonably easy to fix, the 3rd gear problem means pulling and disassembling the tranny.

Rene

 

[C&D Crew Cab]

81 was when the SM465 went to 32 spline. Everything before that was 10 spline.

I'm not 100%, but I'm pretty sure that when they went 32 spline they also went to the generic 6 bolt round pattern. Your '88 is 32 spline, and the round pattern already.

The other pattern is easy to identify as it looks like a figure 8 (or a racetrack) where the T-case mounts to the adaptor.

The 10 spline units used a female coupler that was prone to wear and eventually failure. The 32 spline is a direct connection into the T-case input gear. Fine spline is always stronger...

i'd freshen up what you have if you're having problems with it. If it still works fine then leave it alone. Common issues for the SM465 include the shifter mechanism becoming very sloppy, popping out of 3rd gear and that's about it. The shifter is reasonably easy to fix, the 3rd gear problem means pulling and disassembling the tranny.

Rene

I'd like to tighten up the shifter. You say that's an easy fix?

 

[tRustyK5]

http://www.pirate4x4.com/tech/billavista/sm465/index.html

Should help you out.

Rene

 

[Snoozer]

Call the guys over at Novak Conversions. They will help you out with getting parts you need. I learned about a fix for that "3rd gear jump-out".

I have a 465 in my garage waiting for a rebuild this summer. But mine needs a few things other than new synchros and seals. It will be a "new" trans when I'm done with it.

Keep us posted.

 

[nvrenuf]

There was a change to 32 spline in '81 but only for the 208 equipped 4spd's (round pattern). The 205 combos remained 10 spline through '84 (figure 8 pattern), '85 marked the change to 32 spline and round pattern 4spd/205 combos.

 

[C&D Crew Cab]

There was a change to 32 spline in '81 but only for the 208 equipped 4spd's (round pattern). The 205 combos remained 10 spline through '84 (figure 8 pattern), '85 marked the change to 32 spline and round pattern 4spd/205 combos.

Good info. You guys are a wealth, thanks!

Dave

 

[82355]

81 was when the SM465 went to 32 spline. Everything before that was 10 spline.

Not on K30's. They retained the 10 spline until 1984 or 85. I can't remember for sure. My 1982 K30 has a 10 spline SM465/NP205 combo. By 1988 though, he should definitely have the 32 spline SM465/NP205.

popping out of 3rd gear and that's about it . . . the 3rd gear problem means pulling and disassembling the tranny.

Also, by 1988, wasn't GM installing the spacer on the counter shaft from the factory to prevent the SM465 from popping out of second?

Martin

 

[5280k5]

Also, by 1988, wasn't GM installing the spacer on the counter shaft from the factory to prevent the SM465 from popping out of second?

Martin

Yes, they should have. I had looked up the spacer for a '85 when I worked at the dealer and it showed it in the exploded view. When I wound up doing a full rebuild on my 465 the kit I used actually came with a redesigned third gear & synchro as well as the spacer. My tranny had the spacer in it after all but was still jumping out of third gear. If anyone needs a good rebuild kit give these guys a call, talk to George he knows his stuff.

http://maps.google.com/maps?sourcei...1&gl=us&view=text&latlng=16955597225989443456

 

[nvrenuf]

Not on K30's. They retained the 10 spline until 1984 or 85. I can't remember for sure. My 1982 K30 has a 10 spline SM465/NP205 combo. By 1988 though, he should definitely have the 32 spline SM465/NP205.

Refer to post #6

 

[82355]

Refer to post #6

Haha, yeah you beat me to the punch.

Martin