The Stovebolt Site Forums The Parking Lot Big Bolts Muncie sm420 transmission top shaft detent spring

I have a broken shift fork shaft detent spring on my first-second shifter fork. I've tried all the usual suppliers, novak, torque king etc. with no luck. Does anyone have a source for these springs? There 1 inch tall and 5/16 inch diameter. Will the springs from a sm465 fit?

If you measure the wire diameter of the spring, many hardware stores have a large selection of springs.

Ed

McMaster Carr will have it, large assortment of springs
Take compression measurements on your broken one to match the k value

I found many springs either usable directly, only needed to be cut down, or needed moderate but doable modification to work.
It’s my second place to look for springs

First place is my large assortment of springs from all the things I’ve taken apart over the years, I always break appliances down before recycling
Screws wire springs plastic shapes switches transformers are all kept in my garage stock for project tinkering
-s

LOL! I'm a packrat as well. I come from a long line of them.

I second the McMaster Carr suggestion.

There are hundreds of 5/16" OD springs on Ebay. Measure the diameter of the coil wire, pick one that's close, and cut it to length. "It ain't rocket surgery, ya know!"
Jerry

I prefer to use parts that are engineered to perform as intended. Just because a spring has been made out of a certain gauge wire doesn't mean it will have the same compression rate, different alloys produce different compression rates. The detent springs in the shifter top are engineered to be strong enough to position the shift fork properly while being soft enough to prevent premature wear. I was able to find the correct springs from Ampdistributing.com. one of the great things about the chevy big bolts is the sometimes frustrating availability of parts, new or used. So far I've been able to find everything I need for my 6400. It's more challenging on my truck because it's the 1955 first series which was only produced in 1954 - March of 1955 but a lot of the fun in restoring the old girl is searching for and locating the parts that I need. I have a 1968 chevy 1/2 ton and a 1968 gmc 1/2 ton that I can order most if not all the reproduction parts so it's just a matter of ordering what I need. With my 1955 6400 most parts aren't readily available. I've found parts trucks by driving thru the farmland near me,parts from eBay, off different forums and thru networking. The thrill of the chase. I'm still a few months from getting my girl on the road but she's coming together piece by piece and I'm already looking for a new project and it's going to be another old big bolt

Kilhansen YOU PACKRAT !I understand your pain,come from a packrat line myself,its even worse when you have friends that run the junkyard-they call it re-cycle to kind of clean it up.Have neighbors who run trucks till they croak ,then park em in the weeds ! GM too ! Well when they leave then you get your shot! I have to say its big fun to dismantle trucks that are free to you,and right in your range. Have learned how to store parts in the form of a rat rod to keep stuff alive,235,clutch,4-speed,brakes,drums,cooling,Its just a packrat life !!

"Good Grief, Charley Brown!"
Jerry