sm 465 question

[brett37]

I am currently swapping a turbo 400 out to a 4spd in my 4x4 one ton chevy. I have been told by two people that the sm465 came in a heavy duty version. By means of bigger bearings

Has anyone heard of this and which configuration did Chevy build them. I need to know so I can identify them when purchasing them.

In addition I see also differences in the 205 big/small bearing on the input shaft, holes drilled for case support/ not drilled which ones had what?
Thanks


Brett

 

[badger red]

I remember reading about another sm465 several years ago, in Petersen's 4Wheel Offroad magazine. I think the main difference was the input shaft was bigger, like 1-1/2 inches in diameter instead of the standard 1-1/8 diameter, and that the bigger shaft was used in 1-1/2 ton and up trucks. Also needed a bigger bellhousing, like an S.A.E. #3, if I remember right.

Not sure on the bolt holes for the 205 case support...I think older configurations that used the small mount that tied into the frame would of course have them, and all automatics that would have used the support rod from the back of the bellhousing. Hopefully someone else will chime in on this.

Hope this helps.

Jeff

 

[dyeager535]

No differentiation made for '85-88 C/K/R/V10-30 465 input bearings, so if it did exist, it probably was in the larger trucks, as mentioned.

Not sure why you'd need it, as many people run these things, behind all sorts of motors, if there was a weakness, it would be pretty commonly heard about.

 

[brett37]

My friend purchased a junkyard trans called a local tranny shop ordered bearings picked them up at the counter with his old bearings to match and the guy said you have the bigger bearings.

His sm465 bolted up and into his 1972 3/4 ton 4x4.

Another friend bought a new 87 Chevy Diesel 6.2 with a sm 465. He had to special order the truck. When he ordered it he got the option of the heavy duty trans. What that entails I do not know. Anyway we will keep on talking about it. My local chevy dealer is tops they will spend time looking up the old stuff. Maybe they I can find some specific info.

Thanks for the tips guys i will use it in my search for the answer.

Brett

 

[badger red]

It is possible there are some variations in bearing sizes, depending on the year of the tranny. You have to remember that the sm465 was offered in light trucks from 1968-1992, so there could have been some variations in internal parts over the years.

The fact that your friend checked off the "heavy duty trans" option on the order sheet could have been what Chevy called the sm465 in their literature, and nothing more--just a thought.

The article I mentioned about 1-1/2 inch input shaft said don't bother with it--too much trouble for the little extra strength you will get.

Jeff

 

[dyeager535]

If your buddy still has the truck, check the RPO tag. It will tell. My suspicion is that the heavy duty option WAS the 465 itself. RPO M20 as I recall.

 

[brett37]

Thanks for the info unfortunately my friends truck was sold years ago I should have kept it he bought it new 4x4 with 6.2 diesel with a gear vender.

I found some info on 4wheeloffroad.com/brandpages/chevy/131_0208_sm465...

they say the 88 and up had thicker input bearing and the clusters and cases have different diameters and will not interchange with one another.

4 wheel offroad got their info from Anaheim Gear here in souther cal which my workplace has done business with them before.

 

[90_K5 Blazer]

If I am correct, there are 2 different possible spline counts on input shafts, one being stronger than the other...