SM465 Transmission Question

[Swims350]

ok so you want to convert the 2wd one you have to a 4wd one to work with the frame?

 

[davbell22602]

ok so you want to convert the 2wd one you have to a 4wd one to work with the frame?

Yes or what other 4wd L123R trany will work also?

 

[Swims350]

not sure I know the 88-98 trucks had a 4 spoeed stick shift but I forget what it is maybe sm420? or something.

Yea if you want to convert the 2wd to make it 4wd you just need the t-case adapter which may end up better off with the t-case too, this is where you would run into problems.

Most old t-cases are ps drop and these newer trucks are ds drop. Now they do have a np241 ps drop in the squarebody burbs and such, if you find that then that's what you need.

if you find a sm465 t-case adapter it may only fit the old 208,205, or 203 t-case. if so then the drivehsfat and the ps drop is a problem.

I'm sure advance adapters has something but they aint cheap.

for the trans itself you'd need the rear shaft, and then the adapter, which could lead to what I said above lol.

 

[davbell22602]

not sure I know the 88-98 trucks had a 4 spoeed stick shift but I forget what it is maybe sm420? or something.

Yea if you want to convert the 2wd to make it 4wd you just need the t-case adapter which may end up better off with the t-case too, this is where you would run into problems.

Most old t-cases are ps drop and these newer trucks are ds drop. Now they do have a np241 ps drop in the squarebody burbs and such, if you find that then that's what you need.

if you find a sm465 t-case adapter it may only fit the old 208,205, or 203 t-case. if so then the drivehsfat and the ps drop is a problem.

I'm sure advance adapters has something but they aint cheap.



for the trans itself you'd need the rear shaft, and then the adapter, which could lead to what I said above lol.

Ok, My 90 2wd C2500 has the sm465.

 

[HotRodPC]

I do beleive the only difference is the output shaft. I assume that is what Imann is reffering to when he says main shaft.

 

[Irishman999]

I do beleive the only difference is the output shaft. I assume that is what Imann is reffering to when he says main shaft.

It looks like all one main shaft. front to back.

 

[HotRodPC]

It looks like all one main shaft. front to back.

But its not. You have input shaft, countershaft, then output shaft. IF it was all one main shaft throughout, then you'd only have a 1 to 1 ratio throughout and no gears to shift.

 

[davbell22602]

I was recommended that it maybe easier just to 2wd to 4wd on what I got now with solid axle conversion kit.

http://offroaddirect.3dcartstores.com/

Someone said too much work transferring everything over plus hole for 4wd shift.

 

[nvrenuf]

SM465 4spd info:

1) All 2wd SM465 trans has a short 35 spline tailshaft

2) Up to '84 all SM465's originally mated to a NP205 had a short 10 spline tailshaft

3) '81 to '84 all SM465's originally mated to a NP208 had a long 32 spline tailshaft

4) From '85 on all SM465's regardless of t-case had a long 32 spline tailshaft

5) '85 on SM465's used a hydraulic clutch with an external slave cylinder on the drivers side

6) NBS truck SM465's used a hydraulic clutch with an internal slave cylinder on the passenger side




Also, in the transition to the new body style trucks the shifter tower placement on the top cover moved. This was ONLY for the NBS trucks, all square body truck SM465's are centered. I can't remember if it was moved forward or rearward on NBS trucks.

This thread is confusing for me.

*IF* you are trying to convert your 2wd 90 NBS truck to 4wd, why not use the 4wd trans you have in the K2500 frame with it's mating t-case? To do this you would just need to swap the top covers and be done.

I'm going to reread this thread again...

 

[89Suburban]

SM465 4spd info:

1) All 2wd SM465 trans has a short 35 spline tailshaft

2) Up to '84 all SM465's originally mated to a NP205 had a short 10 spline tailshaft

3) '81 to '84 all SM465's originally mated to a NP208 had a long 32 spline tailshaft

4) From '85 on all SM465's regardless of t-case had a long 32 spline tailshaft

5) '85 on SM465's used a hydraulic clutch with an external slave cylinder on the drivers side

6) NBS truck SM465's used a hydraulic clutch with an internal slave cylinder on the passenger side




Also, in the transition to the new body style trucks the shifter tower placement on the top cover moved. This was ONLY for the NBS trucks, all square body truck SM465's are centered. I can't remember if it was moved forward or rearward on NBS trucks.

This thread is confusing for me.

*IF* you are trying to convert your 2wd 90 NBS truck to 4wd, why not use the 4wd trans you have in the K2500 frame with it's mating t-case? To do this you would just need to swap the top covers and be done.

I'm going to reread this thread again...

Holy ****, how do you know this stuff, lol.

 

[nvrenuf]

Holy ****, how do you know this stuff, lol.

I got my first square body in 87 and been tinkering, mod'ing and trial & error ever since. It's too bad I was never able to make a living with the Chevy trivia in my head.

 

[89Suburban]

I got my first square body in 87 and been tinkering, mod'ing and trial & error ever since. It's too bad I was never able to make a living with the Chevy trivia in my head.

 

[HotRodPC]

Good info. I'll likely copy and paste that info to a SM465 thread at some time.

 

[nvrenuf]

Good info. I'll likely copy and paste that info to a SM465 thread at some time.

That's cool, I may try t put together a t-case list too.

 

[HotRodPC]

That's cool, I may try t put together a t-case list too.

That'd be cool too. We've got categories for those kinds of info now too.

And as far as the hole location for the shift stick, I am fairly certain it moved back in the NBS. Reason being the NV4500 shifter is more to the rear of the trans where the SM465 its centered on top or a short box.