k5warwagon
1/2 ton status
Looking at a 82 gmc that came original with a v6. It now has a 350 and the owner is telling me the 4 speed (with granny gear) is original. Is this a 465 or some other trans?
Thanks,
Thanks,
CK5
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Are all granny gear 4 speeds SM465s?
- Thread starter k5warwagon
- Start date
np435 is the dodge/ford version of the same thing...
Are you sure it's a granny 4spd? Iirc, there was an o/d 4spd used for a little while in the 80's.
That said, if it's original and a granny it'll be a SM465. Any idea what t-case is in it? I ask because I doubt you'll find a swapped in 4spd mated to the original np208.
KansasTwister
1/2 ton status
http://kansascity.craigslist.org/pts/1484649230.html
+1. I would assume with a granny gear its a sm465. why would anyone wanna fabricate and put something else behind a v6?
COCHEV
1/2 ton status
my buddy bought an 84 gmc pickup last year that originally had a 4.3 liter and a 4 speed (thats what the build sheet showed) it had sense had a 350 stuck in there, but the 4 speed was the sm465 and it had a 208 behind it...
Wasn't there also a SM420 or was that a 2WD trans only?
Here's the Novak conversions information: Since it's including military applicaitons it must mate to something.
The Novak Guide to the
GM Muncie SM420 Transmission
The SM420 is an impressive, heavy-duty truck transmission designed for and used in ½, 3/4, 1 and 2 ton trucks. The SM420 was made by General Motors from 1947 to 1967. Military specification versions were made through the early 1980s. The SM420 is found in GM trucks, busses, heavy equipment and various military applications.
The "SM" in the transmission's designation stands for Syncrho-Mesh, in the tradition of other GM gearboxes, though we have heard that it may refer to Stewart - Muncie, a merged transmission division of GM.
Features
The SM420 is a top loaded, top shifting truck style transmission. It enjoys the lowest compound gear of all the common truck transmissions at 7.05:1 and as such it is a popular choice for those wanting a very low crawling gear.
The SM420 features a power-take-off (PTO) port on the driver's side of the case.
The SM420 is fully synchronized in the second through fourth gears. All gears are helically cut except first and reverse, which are spur gears.
The Novak Guide to the
GM Muncie SM420 Transmission
The "SM" in the transmission's designation stands for Syncrho-Mesh, in the tradition of other GM gearboxes, though we have heard that it may refer to Stewart - Muncie, a merged transmission division of GM.
Features
The SM420 is a top loaded, top shifting truck style transmission. It enjoys the lowest compound gear of all the common truck transmissions at 7.05:1 and as such it is a popular choice for those wanting a very low crawling gear.
The SM420 features a power-take-off (PTO) port on the driver's side of the case.
The SM420 is fully synchronized in the second through fourth gears. All gears are helically cut except first and reverse, which are spur gears.
k5warwagon
1/2 ton status
I believe it's a 208 transfer case. runs good but it's got rot.
Burbdood 74
Giver of not a single damn...
I had an 86 K-10 with a 4.3, SM465 and an NP208 t-case from the factory. I used to get passed going uphill by infants in walkers. I had a goose pass me one day and he flipped me off. What a POS.
I bought a 1985 K10 from a junkyard that had an SM465/NP208 behind a 4.3 V6. I used the flywheel from the 4.3 on my 350, and swapped the tranny/transfer case into my 1988 V10 Suburban..
Martin
Martin
josh86k10
1/2 ton status
My uncle had an 86 or 87 K10 with the 4.3 and SM465/NP208 back in the day. I think it was fuel injected so it was probably an 87. It did fine - wasn't a tow rig or a sports car, but respectable for a work truck. It did get crappy fuel mileage though, worse than my grandpa's 86 C30 350 or my 86 K10 305 (at least when it was stock).
greengiant0311
1/2 ton status
Ok since we are on the topic. How can I tell which transmission and t-case I have? I've crawled around looking but can't find any noticeable numbers on either! It's an 80 Scottsdale
in 1980, there were 2 options, th350/np205, or sm465/205 really the only year where the 205 was the only t-case used and almost all were slip yoke rear driveshaft.
