Technical 3 Speed Gear Ratios

Butch
In the mid 70's a friend of mine had a bench seat 67 Malibu with a 327 and factory floor shifted 3 speed, only one I have seen.
Not sure which one, may have been a T85.
Also, IIRC the 65 Corvette had a 3 speed standard if the 4 speed wasn't ordered.

 

I have been looking and looking for casting numbers, relating to these Saginaw 3 speed transmissions.
No luck, thus far.
Does anyone have a "casting number list" for these Saginaw 3 speeds ?
It has been said that the first gear ratios are identified by "lines" or "grooves" on the input shaft.
Has anyone actually seen these lines or grooves?
Do these lines or grooves go around the input shaft or do they run parallel with the input shaft ?
Any pics or descriptions would be appreciated.
Thanks.

 

Yes they are easy to see. they go around the inpuit like they took a v file and notched every spline. Possibly tomorrow I can take a few pictures

 

The spline itself is notched ? Pics would be appreciated, Old Wolf.
Any thoughts on available casting numbers ?

 

CrankshaftCoalition.Com and select transmissions under categories to the left of the page.
I am Butch/56sedandelivery.

 

I followed your instructions, but didn't find anything giving me info on the Saginaw 3 speed.
I'm looking for a Saginaw 3 speed casting numbers list and a pic to show grooves (1, 2 or 3) on the input shaft.

 

The first gear ratios are the same for the Saginaw 3 and 4 speed transmissions relative to the grooves on the input shaft. Use the 4 speed chart to ID the first gear ratio by the grooves. I can't give you casting/part numbers for any of these transmissions; if they're out there, I can't find them either, so just go on the input shaft grooves to ID the trans/first gear ratio. The grooves themselves are cut around the cir***ference of the splined input shaft.
I am Butch/56sedandelivery.

 

This has some info on the input shaft grooves: http://www.dandltransmission.com/saginaw.html

 

If these are like the Muncie 4 speeds and the fact that historically they have had their internal parts replaced; they may or may not have the identification grooves.

 

from this photo i do not see any grooves.

 

It is also a MUNCIE 318 transmission, and NOT a Saginaw. Muncie, 4 bolt side cover, Saginaw, 7 bolt side cover (both 3 and 4 speed) There were only two different ratio ge****ts for those, p***enger car and Corvette (don't know what they were). However, that one seems to have the "full length spline" input shaft,; earlier ones had a "necked down" area just before the end of the throwout bearing collar. I snapped one of those leaving a stop sign driving "normally" in my 58 Chevrolet truck. I am Butch/56sedandelivery.

 

Thanks !

 

Good point, didn't think of that.

 

I have seen that chart in my search travels, but I was not clear as to what the grooves looked like, on the input shaft.
Butch has stated the grooves travel the cir***ference of the shaft, so, at least I have a mental pic of what those grooves may look like.

 

If the trans is out of the car, and it will be if you're counting grooves, just put it in gear and turn the input shaft and count the turns, until the output shaft makes 1 full turn. Only sure-fire way to know, 50 odd years later. If you'd been out picking up beer cans and Coke bottles the whole time you've been yacking about this, you could have bought a 3.70 gear and begged somebody to put it in.
Good Luck.

 

Ok here are pictures of a Saginaw 4 speed. it has 3 rings on the inpuit.

 

Ive destroyed so many of the old peanut 318 Muncie trans that I can ***emble one in a heart beat. the necked inpuit trans has a different gear ratio than the full length ones. I don't know why but it irritates me that some insist the 318 Muncie is a Saginaw?

 

thanks for the info. i will spin the motor and count the driveshaft turns in first gear to find the ratio

didn't mean to annoy you. i just did not know what i had, just learning.
Bob sorry to highjack your thread.

 

Rex A Lott,
The concern is wanting a smooth take off, without slipping the clutch.
The issue, for me, is whether to swap ******s or the rear pumpkin, based on cash out of wallet.
If I had picked up cans and bottles, maybe my cash flow would have been better.

 

Old Wolf, thanks for taking the time to post the "Saginaw groove pic".

 

No problem here. You didn't annoy me, we're learning together.

 

If it was me I would swap transmissions. The later Saginaw with two or three grooves will have a deeper first gear. its stronger and fully synchronized.

 

i have one with an od. my plan was to weld a tower on to replicate what i have. i need to find the top of a ****** with the same shift forks. the early ****** tower shifts different.

 

Either the 3:11 or the 3:50 first gear would make me happy.
Any one know what year the 3:50 first gear came out in the fully synchronized Saginaw ?
Late '60's or early '70's ?
Camaro and / or Nova ?

 

The Trans I pictured is a 350 geared 4 speed. It probably came out of a vega.

 

This thread on Chevytalk addresses gear ratios and 6 cyl vs V-8.
http://www.chevytalk.org/fusionbb/showtopic.php?tid/167700/


Just my 2c, but since you just recently figured out the OD, I would change the rear gear ratio. IMO an easier swap than the ******, plus you keep the OD.

 

Thanks,
I have looked at Camaro and Nova specs online, have only been able to find 3:11, and that's in a mid '70's Nova.

 

I understand about the money deal, but this is one place that you would be better off to save your money until you can buy what you need....a 4.11 gear for the rear end. If you spend your money and make a combo you dont like, you will hate it every time you drive it.
Changing the transmission to a standard w/ no overdrive and a tall 1st gear may help the car take off, but you are going to be stuck with the 3.50 for the highway, and its not going to be a great ride. I have a '55 with the 235 and a Powerglide and its got the 3.55 gear, totally stock. I usually avoid the interstate. It will go 60-65 with no trouble, but that's good way to get run over around here. It will run the 70-80 the traffic is flowing, but its turning hard and I dont like to do it.
I'm curious if you put a big cam in along with the dual carbs and maybe killed the bottom end torque, which is why you're hunting more gear now? What compression ratio are you running?
Good Luck

 

Thanks for the C.T. info.
Good stuff there.
My driveline is from a '59, except for 3rd member, which is the Ford.
'59 shows, in its specs, a 3:70 axle ratio for the O.D.
For me now, it's all a matter of money, as to which will cost me less to do ...... a Saginaw 3:50 , or a 3:70 chunk.
Doing the 3:70 or 3:89 chunk would be more straight forward, while the Saginaw may require some mods to the shifter linkage.

 

^^^
First change will be the shifter linkage as you suggest. The newer ****** will have shift levers attached to the side cover with bolts vs the '59 which I suspect has a "U" bolt. Finding the small pieces could be the biggest trouble as bolting up to the bellhousing will be the same pattern, but the input shaft spline could also be different.