So thinking all bellhousings in chevy were the same, I assumed the new 3 spd from a 78 half ton would fit the bellhousing from my 63' with a SM420 muncie tranny. Bolt pattern does line up but the center cap on the input shaft is about 1/4" larger diameter on the newer transmission. Anybody run into this?
Yup. Ran into these issues with our dirt car. Ran a BH with the larger hole in a pinch, and it ended with the driver at the hospital getting flywheel removed from his legs. Not good.
There are a lot of different chevy bellhousings. Truck bellhousings got the bigger center hole starting around 67-68 when they switched from the SM420 to the SM465. The 3 speed transmissions also got a bigger bearing retainer to fit the bellhousings. Should be able to find a car trans to get a bearing retainer from, or if you have a lathe you can just turn it down.
Oh yeah, it's a Chevy...they're all the same...it's those Fords you gotta watch out for... I wish I had a nickel for everytime I heard that line of crap when I was the only one running Ford's as a teenager...what a line of sh!+ Yes there are difference's in trucks and cars...make sure you get it all to fit tightly or you'll definately have some issues...
I ran into the same thing on a 454.Wound up using a truck housing cause I had one and 11 inch bell housings aint cheap 621 s go for 150 bucks.Good friend made me a ring to fit the bearing cap on the muncie held with set screws with an OD of the truck housing
I took the cap off the input shaft on the muncie and put it on the saginaw, and low and behold it fit. However when exchanging and putting the cap on the muncie it did not, the bearing collars for the input shaft are also different sizes. Is this going to be an issue as well? As far as I can tell the collar on the saginaw is smaller so it fits inside the cap from the muncie, I just don't know how snug it would be in there. Can't turn the bellhousing down there isn't enough material on the rim, I need a good 1/4 - 3/8"....wait I get it turn down the retainer cap...that might just work.! WTF Flywheel to the legs might hurt a bit!!
The seal issue would make me want to use the correct retainer. Some transmissions have a seal (such as the Saginaw), others use a slinger nut (such as the Muncie)
I'll have to take a closer look now for that seal. I bolted it all back together with the muncie collar on and stuck it into the car just so I could get a location for the tranny mount bracket fabbed. Another issue I ran into is the muncie bolted to the bellhousing from both sides but I'm thinking of welding a nut to the inside of the bellhousing so I can bolt it from the outside. Saves me from pulling the whole belhousing off if I wreck this 3 spd. Thanks for the input though I figured there might be a thing or two to watch for.
I have a bellhousing pulled from a 63 Chevy pickup that had a 283/3 speed combo along with the bellhousing motor mounts. The input retainer pilot bore is right close to 4.650". I would think that there would be one within 30 miles of you if not closer. If you need what I have, I'll need help with how to send it from Arkansas to wherever in Canada. Not experienced with shipping stuff to Canada.
Thanks for the offer but you are likely right, I'm sure a local wrecker will have something its just a pain sometimes, certain something else like starter won't fit then...you know one thing leads to another.
Squirrel told you right, the simplest way is to change to the car retainer or turn it. The only truck bell housing you can use without a starter issue is the 68-72 cast iron. Those are not exactly all the same either, some have pads for rear engine mounts some do not.
Yah that was pretty much the new plan, that Squirrel fellow sounds as though he has been around the block a few times. My good man Pino at Pino's machine shop will get more of my hard earned...me an 'ol Pino have become quite close since I started this project, seems like there is always something that needs machineing.
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