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How strong is a SM465?

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by kickinasphalt383, Mar 4, 2002.

  1. kickinasphalt383

    kickinasphalt383 1/2 ton status

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    I know they are really strong, but how strong?

    Is it stronger than a NV4500? How much power can one handle?

    Thanks
     
  2. BowtieBlazer

    BowtieBlazer 1/2 ton status

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    Sm465's are stronger than stone! You can grind em' into gear, jam em' into gear, baby them some, and just all out tear them up and they will still work fine. Mine was O.E.M. on my 84 and through 5 owners and to the day has never been rebuilt. Its gone from Wyoming - TX - FL - to Louisiana (me). I really prefer the SM for ease on drivetrain. I can baby my axles or I can slam them. The common caveman or mechanical clutch on them can be a pain in the knee at times.

    I don't have acess to nor have I driven a NV4500 but one day I hope to slap one in place of my sm465. I will be keeping the SM because I think it will work forever. From what I hear though the NV's are about as strong. However, I believe the gears in the SM465 are a bit thicker and therefor a stronger tranny internals wise. I'd love the OD one day though. If you can't afford a NV the sm465 is by far nothing to spit at many people here can vouch for dogging there's as well with little back talk from the tranny.
     
  3. 84_Chevy_K10

    84_Chevy_K10 Banned

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    I've never seen one fail. I've got one in the garage that is going in my truck when I put it back together.
     
  4. Chris Demartini

    Chris Demartini 1/2 ton status

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    <font color=blue>The only broken one I've heard of was mine, and thats because it was full of mud for a few months and I didnt know it
     
  5. RedDwarf

    RedDwarf 1/2 ton status

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    Yes, they are stronger than an NV 4500.

    It is really a 1 ton to 1.5 ton transmission. They can hanlde the torque of a big block with no problems.

    Only problem is a tendency to fall out of 2nd gear when they get worn, but as long as you stay on the gas, it will stay in.
     
  6. m j

    m j 1/2 ton status

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    dodge guys dont like the nv4500, cant remember what it was that breaks, 5 th gear comes apart or something?
     
  7. SCOOBYDANNN

    SCOOBYDANNN 1/2 ton status

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    I thought it was 3rd or last gear that it fell out of. and there is an easy fix for that too.
     
  8. mike reeh

    mike reeh 1/2 ton status

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    the one i drove popped out of 2nd gear, but it was when you WERE on the gas....

    mike
     
  9. morphed86k10

    morphed86k10 1/2 ton status

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    are you guys sure you aren't talking about the same gear? Its common for some (not pointing any fingers here ....:) to say the SM465 has an L gear, 1,2,3. I just call it gears 1-4, and I start in second usually. My tranny has popped out of third (1.7 to 1 ratio gear) in some real nasty stuff. Now its just automatic for me to hold the shifter from bouncing around when driving hard.
     
  10. ArrowheadK5

    ArrowheadK5 1/2 ton status

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    I think the stock transmission on my k20 is a SM465? It pops out of 2nd gear (L-1-2-3) when at low RPM and if I try I can force it out of 3rd gear at low rpm. It does not have any effect on my driving, so I don't consider it a problem.
     
  11. TX Mudder

    TX Mudder 1/2 ton status

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    The 465 should survive with no problem even in a built big block application.
    I would guess input max to be in the 800 hp range.
    They do like to fall out of second gear when the synchros are worn, and I think they about come from the factory with the synchros worn, so who cares.
    BTW, if you look at a stock SM465 shifter, it is labeled L 1 2 3 not 1 2 3 4.
    -- Mike
     
  12. kickinasphalt383

    kickinasphalt383 1/2 ton status

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    i was thinking of swapping a cummins into my truck(so loads of torque). but if a NV4500 can hold the cummins then a SM465 should no problem... i also hope they make a super strong clutch kit for it to!!
     
  13. RedDwarf

    RedDwarf 1/2 ton status

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    Exactly. I always use the L-1-2-3 designations. "Granny Gear" isn't used for regular driving. Makes sense to me to start off in "first" instead of always using "second".
     
  14. RedDwarf

    RedDwarf 1/2 ton status

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    BTW, 2nd gear is 1.57 in the 465, not 1.7
    It was 1.7 in the SM 420
     
  15. Blazer1970

    Blazer1970 1/2 ton status

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    The shift knob on my '72 465 is labeled 1,2,3,4, as god intended. They just went to that L,1,2,3, labeling when less intelligent people couldn't figure out that you have to start in second gear.
     
  16. thatK30guy

    thatK30guy 1 ton status Premium Member

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    I have always gone by the 1-2-3-4 pattern.

    I have also experienced the '3' gear popping out of gear while accelerating. Got that repaired easily, too.
     
  17. tRustyK5

    tRustyK5 Big meanie Staff Member Super Moderator GMOTM Winner Author

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    I've seen both ratio's claimed for SM 465's...if I'm not mistaken MJ did a tooth count to confirm and found it to be 1.7:1

    Rene
     
  18. TX Mudder

    TX Mudder 1/2 ton status

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    I believe 2nd to be 1.57, not 1.7.
    Hmm, I didn't know the early 465s were labeled 1 - 4, not L - 3.
    When I got my truck, it had a crappy 8-ball shifter knob that I chunked as soon as I found an original 465 knob. But mine is the L - 3 style.
    Do you know of any source for a 1 - 2 - 3 - 4 knob? I've never seen one and kinda like the idea of that one.
    -- Mike
     
  19. arveetek

    arveetek 1/2 ton status

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    The '70 Chevy C-10 I owned at one time had the 465 with the 1-4 shift pattern knob. I had to replace that transmission with another used 465 after it crapped out, and it also had the 1-4 shift knob. I'm not sure what year that tranny was.

    My '86 has the L-3 shift knob.
     
  20. m j

    m j 1/2 ton status

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    input gear is 17 teeth it drives a 40 tooth counter gear
    3rd- 36 tooth counter drives 26 tooth speed
    2nd- 23 tooth counter drives 35 tooth speed
    1st- 14 tooth counter drives 39 tooth speed

    1st = 6.554
    2nd = 3.5805
    3rd = 1.699
    4th = 1
     

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