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vern
09-02-2006, 10:48 PM
I have an 84ish chevy 1/2ton with a problematic 4 speed transmission (the 4 speed with a 1st gear that is only good for pulling trees out of the ground) The tranny has been replaced 2 times and the last one was repaired 3 times under warranty. It always pops out of 3rd gear.

I am thinking about replacing the standard with an automatic. I will be using this truck as a tow rig as it is only a 2 wheel drive. Anyone have any idea how hard it would be to replace the standard tranny with an auto? And would the auto have a lower gear ration as the truck seems to have a non stock posi rear end that is geared for highway.


p.s. anyone have problems like mine with their 4 speed? the guys at the trany shop said its a known issue with these things.

kootenaycat
09-02-2006, 11:57 PM
I haven't heard of Chevy 4 speeds with problematic 4 speeds, especially third. I'd say the rebuilder isn't doing his/her job! If it jumps out of gear, I'd inspect the mating gears/hub/synchros/shiftfork/indentsprings to see why it's doing it. If it jumped out of 4th, I'd say there's a engine/trans alignment problem, but 3rd is going through the countershaft.

As for swapping in an auto, get a steering column, pedal assembly, tranny cooler, and do eet! Not sure about the driveshaft length, probably going to need a different one.

m j
09-03-2006, 11:10 AM
get the shop that "repaired" it to replace the shift forks with new ones
they are pricey so no one likes to include them in a rebuild

ottoman
09-03-2006, 01:07 PM
i got a t400 and probly a colum to go with it

trailburban
09-03-2006, 03:06 PM
to put an auto in you need a floor shifter and a kick down cable and an auto tranny.

also if it's kicking out of 3rd check the linkages for a slight bend (causing them to be a little shorter in effective distance). if the link has an arc then the gears won't mesh properly and will cause it to pop out of gear.

if that tranny guy can fix a tranny then he shouldn't be in buisness.
theres not such think as a problematic tranny that is unfixable.

and if thats the tractor tranny i'm thinking of, then it's a fairly simple tranny to rebuild.

goto Quality Transmission in New West, they did an excellent job on my tranny and cheep too. (if you go out that way)
or try calling him up, he's very helpful

tenpack
09-03-2006, 03:47 PM
sounds like you got a sm465 with a granny low first gear, i beleive a 6.68.


http://www.pirate4x4.com/forum/showthread.php?t=379346


scroll down and read RG's post.

jeeper
09-03-2006, 03:59 PM
Have you done a body lift thats causin the body to contact the shifter ?

m j
09-03-2006, 05:45 PM
the sm465 shift forks have a plastic liner applied to them that wears off over time
once that is gone you cannot get full engagement of the gear

vern
09-03-2006, 05:49 PM
Kinda figured the tranny shop was full of bs. It has been a few years since it was in the shop, the warranty has expired. The standard tranny has to go, even if it wasnt a problem it would still be going (I miss driving an automatic). The plan is to find a turbo 350, a steering colum with tilt and shifter, get a new trany cooler and pray the conversion goes as easy as I think it will.

kootenaycat
09-03-2006, 08:43 PM
also if it's kicking out of 3rd check the linkages for a slight bend (causing them to be a little shorter in effective distance). if the link has an arc then the gears won't mesh properly and will cause it to pop out of gear.



If it's a Muncie, the gear shift will drop straight into the the top of the shift forks. The only linkage 4 speed I can think of are the old car ones, M21/22, Saginaw, BW T-10/ST-10. Not sure if the OD 4 speed in the diesel was linkage or direct.

u2slow
09-03-2006, 09:37 PM
Screw the auto idea.... unless you like less power and worse economy. [35]

Buy another $50 gearbox and give 'er a whirl.

I've had about 6 of them in different trucks over the years... only one of them did the 3rd gear popout. If you search you will find there are specific parts/kits to address that exact problem.

m j
09-03-2006, 11:53 PM
and those specific parts and kits are total BS in my opinion.
if it is in gear properly it isnt going to fall out.

vern
09-05-2006, 06:11 AM
Screw the auto idea.... unless you like less power and worse economy. [35]

Buy another $50 gearbox and give 'er a whirl.

I've had about 6 of them in different trucks over the years... only one of them did the 3rd gear popout. If you search you will find there are specific parts/kits to address that exact problem.


The 3 inch lift and 32inch supper swampers on my weekend driver also give me less power and worse economy.. should they go to?

This 1/2 ton will be my daily driver, and after working 12 hours straight I think I will enjoy turning on the engine and putting the tranny into drive.

tenpack
09-05-2006, 08:29 AM
why doesnt u2slow swap his auto out of his burban and vern can give him the sm465, that way everyones happy.

HEAVY METAL
09-05-2006, 09:58 AM
the sm465 shift forks have a plastic liner applied to them that wears off over time
once that is gone you cannot get full engagement of the gear


:D yup.. had the same problem... i had to hold mine in gear and with 350 hp ataround 4-5 grand was a bitch to hold it in [15] ..just go spend 50 bux for nother one...autos suck but that just my opinion....[cheers]

u2slow
09-05-2006, 08:27 PM
why doesnt u2slow swap his auto out of his burban and vern can give him the sm465, that way everyones happy.

The 465 is already installed. Oddly enough, nobody wanted the auto, so I had to junk it.

This 1/2 ton will be my daily driver, and after working 12 hours straight I think I will enjoy turning on the engine and putting the tranny into drive.

You don't need an automatic.... you need a chauffer. [f]