GM tranny ID help & applications??

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I will try to post up a picture but I have a GM 4 speed that mates to a 205, I am trying to figure out which one it is, 465/ 420? I am not familiar with this stuff.. Any links to reference the #'s?
Secondly I have a 2WD tranny I might be unloading and was curious if it is usable for the granny-low conversions. TIA, Kief.
 
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Go to the technical links on this site there is a list of the casting # for the sm465.

Also do search I found all kinds of info on the 465 here including how to mount it up to the 3sp transfer.
 
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SM420 never mated to anything. Any 4x4 setup from back then that might have had a 420 in it was a divorced transfer case approach.

If it's GM and mated to a 205 then AFAIK, SM465 is the only option.


Mark...
 
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kachow!

I will check the links but I will attach a pic. OK, next question, I am gonna pop the covers and see what kind of shape they are in. I figure look for corrosion bad sounding bearings and play from input to out put. Any tips?

SM420 never mated to anything. Any 4x4 setup from back then that might have had a 420 in it was a divorced transfer case approach.

If it's GM and mated to a 205 then AFAIK, SM465 is the only option.


Mark...
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SM465


Mark...
 
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I will check the links but I will attach a pic. OK, next question, I am gonna pop the covers and see what kind of shape they are in. I figure look for corrosion bad sounding bearings and play from input to out put. Any tips?



Separate the trans and T/C. Check the output shaft/input gear splines. These 10 spline units are notorious for wearing out.


Mark...
 
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SM420 never mated to anything. Any 4x4 setup from back then that might have had a 420 in it was a divorced transfer case approach.

Mark...

Mark--- are you sure of this? I am not saying you are wrong because I don't really know what I had, just curious. Back in the days-----somewhere in the early to mid 70's, I bought a 1967 Chev 3/4 ton 4X4 P.U. It was a 4sp (non-syncro granny) w/rockwell TC ( not divorced ). I kept having troubles with the TC so I got a used TC (my memory tells me it was a 205) but it wouldn't bolt up to my tranny so I got a tranny that it would bolt to ( had inspection cover on both sides ). The shift patterns were different. One had R on the left and the other had R on the right side of the pattern, but don't remember which was which. I put a 10k PTO winch on it after swapping tranny's so I do remember the dual inspection covers. What a workhorse P.U. it was!
 
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Don't know what tranny you had, but both the SM420 and the SM464 have reverse back and on the left


Mark...
 

Mace

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Most likely t18 hand..

I was under the impression that all 4wd sm465's were 28 to 30 something spline..

10 spline was only 2wd..
 
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Nope. 10 spline was 4wd only. 2wd were fine spline and IIRC the later 4wd also. 205s (and 203s) behind Sm465 are 10 spline.


Mark...
 
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It could have been a NP435. Gm used some NP435 transmissions during that time. I know because I got one from a guy that was putting an automatic in his 66 GMC. I thought that I was getting a SM420 and was surprised when I saw that it didn't match with the photos of a SM420. I checked the gear ratios to find out what it was.
 

Mace

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How bizarre..


sm465_mainshaft_tails_closeup_array.jpg
 

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