Technical Advice needed!1964 bel air Inline 6 transmission upgrade/repair suggestions?

Hey guys basically I have a Chevy bel air 1964 3.8 230 inline six with a three speed trans that was originally coloum shift, I had it the best I could but was sloppy no matter what so I recently went to switch it out for a hurst floor shifter which seemed to go quite smoothly, however, upon driving it away it crunched upon putting it into gear. Long story short I’ve been on a nightmare mission to figure it out and ended up actually replacing the entire clutch from pivot ball to flywheel arp bolts the whole nine. Unfortunately when I went to drive away finally I shifted into gear with no crunch but the car didn’t move. I took it all apart and the transmission input shaft was sheered straight off. Snapped like perfectly which as you all are more than aware left me feeling all the bad feeling ever of disappointment and upset. My question is now do I just replace the shaft on what already is a pretty weak and not highly reccomended three speed trans- or should I go upgrade and get a Muncie 4 speed? Am I able to just swap a trans out ( with correct splines obvs) or they come different lengths and awhile new ball game like occurs with changing things out to make it fit? I’m super bummed and I just don’t know the best next move after reading all the posts about the box in it already, my faith in it isn’t exactly high, however maybe I’m wrong- the muncies look and sound promising, what’s your guys opinion of the next move. Any help is appreciated largely and I’m just trying to get her back moving so bad, thanks

 

That 3speed in good shape will live behind the small block Chevy.A lot of times that crunch going in to first is the result of the main input bearing going bad.If it was bad enough it didnt support the shaft,and that might have put enough strain on it to snap.Muncies are not cheap trans so figure on 1000 bucks at the least for one that doesnt need rebuilding.A Saginaw would be cheaper,and work fine.They run 300-450 bucks.A Camaro T5 might be fine too around 700. Match the first gear ratio to your rear gear as much as you can.

 

I've had a full syncro Saginaw 3 speed out of a Chevy pickup in my 48 since the early 90's . I horse traded or wangled it out of my buddy when I put my truck back together with the 250 in it. It's a bit fatter in girth an a lot heavier in weight than the 3 speed you have but it sure shifted nice in the 100K plus miles I used it in the 48. I'd hunt for one of those. On the other hand it isn't very hard to find an input shaft for your 3 speed and go again.
Back in 1974 I had a 57 Chevy Panel with a 327 that had Jahns 12.5 pistons, Engle solid lifter cam an 2.02 heads with a Corvette 2x4 intake on it. That bugger would pull the left front wheel on a hard launch and in a street race with a Mercedes Benz I blew my clutch taking the input shaft with it. My Boss's son saw me race the Mercedes and when he saw me blow the clutch he just went in and told the wrecker driver to go get me. I think I had to buy a new input shaft for that one and actually ended up putting it back together in the dealer's shop (Pontiac) that I worked in and charged and then paid for my own work. Meaning that they wrote out a work order, I did the work, and then got charged for the work I did along with parts and then got paid for that same work on my next check. Beat the tar out of working on it out in the parking lot on lunch hours for a week or more. It wasn't all that hard to swap input shafts outside of keeping track of the needle bearings.

 

Haha that’s awsome-Thanks for your input and suggestion it’s totally appreciated and will most definitely hunt for one- like right now. Cheers!





Sent from my iPhone using The H.A.M.B. mobile app

 

Thanks for your help, ratios noted, will the trans you suggested fit right in like a replacement or be the same size/ length? Thanks again man


Sent from my iPhone using The H.A.M.B. mobile app

 

Save the broken input shaft, you might be able to use it as a clutch alignment tool if you don't have one

 

The Saginaw came in Camaros in the 78-84-ish years.The input shaft has grooves,or rings. 3 rings is a 3.50 1st gear, 2 rings 3.11, 1 ring 2.54 no ring is 2.84. Your 3spd is 2.94 1st gear. The 3.11,or 2.84 should be good replacements.The tail shaft may be a fine spline so a new yoke would be needed.I think this is your easier swap.The late 60"s 3 spd is a nice trans too if you can turn one up.Camaro t5 transmissions can be made to work,but they bolt in at a angle since they use a different bellhousing,and that leaves the shifter at a funny angle.It can all be worked around,but it makes for a harder swap.

 

Side note : The color of that broken shaft end appears to indicate that it had already developed a crack & was just waiting to snap, so it already was "on borrowed time".

 

X2 on drtrcrV-8's message.

 

Had one of those in my 58 Impala with a 348. The only weak spot I ran into was second gear. If I was really on it and it hooked up in second, it would snap the collar off the second gear (I was 17 at the time and was always really on it). I got real good at rebuilding that trans. If driven normally, the trans held up fine. I'd just rebuilt what you have, they are pretty simple.

 

Had a 58 Chevrolet, 3/4 ton, Ex-Navy truck (still painted gray), that someone had put a 55, 4 barrel, 265 in. It was still a 3 speed column shift, and one day, leaving a stop sign "normally" (meaning not beating on it or anything), it just "boomed", and the engine free-wheeled. Got it home, checked it out, pulled the trans, and the exact thing happened to me, it snapped the input shaft in that "necked down" space". I had a passenger car 3 speed trans and replaced it with that, but had to use bolts/washers/nuts on the two lower trans bolts as truck trans those lower bolts go from the bell-housing into the lower, threaded ears of the trans. The passenger car trans was actually a little quieter to boot. You'll be much happier with the Saginaw 3 speed over the old Muncie 318 trans. Course you found out you needed a fine spline slip yoke, and some new floor shift parts? I had a 63 Biscayne, 4 door sedan with a 230 six and 3 speed with 53K original miles on it; came up from el Campo, Texas on the gulf and the hood had some rust through along the hood supports. Parted it out when I lost interest, but I still have the beautiful condition front seat.
I am Butch/56sedandelivery.

 

That’s rad, I appriciate your post and thanks for advice- I respect this site and all it does to help and be a place for real people and straight answers. You guys are amazing and thank you for reply’s, it genuinely goes a really long way for me- can’t wait to sort it in the next few days give or take but I’ll def keep y’all posted, the only way to learn how to build cars and hot rods is by doing it-and that Im learning and learned fast. After the second trans pull on the old gal it honestly isn’t quite as intimidating. I say that but... I love this car and you guys are going to help me back on the road-Cheers guys

 

steve thanks for your information it helps massively. I appriciate you sharing your time and knowledge. It’s noted and you kick ass.

 

that makes me actually feel a little better about it all haha, I appriciate you taking time to help my knowledge and understanding become greater, you kick ass thanks a lot. Ps I’m glad it didn’t go out somewhere other then my shop, a lucky unlucky person? Haha thank you all ur awsome..

 

Thank you all very much for taking time to help me

 

Not to be negative, but why did you hack up what appears to be a very solid floor?

 

You could make posters of that photo and sell 'em! I'd buy one!

 

what appears to be...perhaps..but don’t be fooled When I got the car there wasn’t any floors at all, they were rusted out flintstone style and I fabricated a new floor/floor pans for it so it’s not really a bother to me to re do it upon completion, the trans is very upsetting to me, floor fab is not...I’m going to re do it all anyways

 

haha let’s do it