The Stovebolt Site Forums The Shop Area Engine Shop Not all saginaws are created equal?

was about to pick me up a saginaw 3 speed i saw in the paper, when casually browsing through chevy asylums website, i came across his page dealing with a 3 speed saginaw and their differences. there are truck 3 speeds and car 3 speeds as well? heres the link: http://www.chevyasylum.com/63chevy2/63chevy213.html

can anyone teach me more on this?

bottom of this page shows ID for different gear ratio saginaws - 'lines' = groves on the input shaft - there were saginaw's used all over GM, especially in the muscle cars as well as trucks, 3spd and 4spd - whatever the trans you have an eye on is from [ask!] it will work, but you might have to fiddle the linkage, and you might not like the ratios - this page [half way down] will help ID the different brands

extra trannys are almost worth as much as extra cylinders, just can't be used on the CI!

Bill

Hi Murdoc. The page you referred to is on my website. That's the Saggy trans that's in my 63 Nova. It's a 4-speed. The three grooves or lines on the input shaft are used in the same way on a 4-speed as a three-speed.

Although I expected a super low 1st gear with the 3 rings on the shaft, it's not bad at all. There's only about a 1500 rpm drop between gears.

As Red58 sez, the tranny can probably be made to work, but the linkage could be interesting, especially if you want to use a column shift. I got a Hurst shifter with the trans in my Nova and it's adequate. Not the best, but it works.

hth,

Bill, thanks for the response and Ray, thanks for the awesome website, i have pulled all sorts of valuable information from it. okay, i see now that it was a 4 speed, my bad. but do you know of any tell tale signs to look for on the outside of the tranny that can indicate whether its a truck or a car three speed?

don't think there's any way to tell except if you have the correct part number for a sag trans in the truck, or if the person that has it knows what it came out of - I think the only difference was the ratios, and that's prolly what the part number will indicate - nothing else was specifically truck - I think the 'no groove' was the truck standard

Bill

I agree with Bill. I don't know of any way to differentiate between car and truck trannies other than the part number. And then that could take a buncha research. According to my Chevy By The Numbers book for 65-69, there were 23 versions of the 3-speed Saggy in 65, and only 4 in 66-70.

Incidentally, the 66-70 is supposed to have a synchronized 1st gear, something the earlier models didn't have.

The book also mentions that there was a Muncie heavy-duty 3-speed available from 69 to 72, but I've never seen one.

What that book doesn't provide is a list of casting or part numbers for the various transmissions. It's very lacking in that respect.

Sorry I couldn't be of more help.

some of the truck transmissions had a 5th mounting bolt on the top, and some had a rear mount on the top of the tailshaft housing, kinda hung from the frame.

Yeah, the bolt at the top is for the elusive heavy duty tranny.
I used to have piles of Saginaw 3 and 4 spd trannys around here,bought them when they were unwanted,then all the Muncies got expensive,sold all the Sags.Like the man above said,the trucks generally had the 2.85 first gear,the one with no marks on the input shaft.3 spd Malibu types with 6's usually had the 3.50 first gear 3pd.Some Vegas used the 3.50 first gear 4 spd,V-6 Buick and Olds Vega types,used the 3.11 first gear and the V-8's used the 2.85 and 2.54 fist gear.There were exceptions to this,options on ratios .All the Saginaws I ever saw were the same length ,21 inches,all the same input and out put splines.Minor non functional differences like back up light switches,high gear swiches for emmission controls and tailhousing bosses for torque beams and or counter weights can give you a clue to the trannys original application.
The front bearings in Saginaws can get sloppy with age and abuse,then the main shaft bearing surface will become worn where it fits into the needle bearing of the input shaft.The spring washer between the main case rear bearing and first gear can fail,causing the gear to bang around.
All Saginaws,3 and 4 spd,except for over drive models,have the same main shaft and within a particular ratio group ,the same gears except for the counter gear which is different from 3 and 4 spd.The 3spd cases look identical to the 4 spd case,but the boss retaining the reverse gear shaft is different.The gears themselves have no idea what engine is in front,no one model is stronger than another.
Just pick one that suits your needs.

yeah i just looked at one of the ones i have and it has the 5th mounting bolt up on the top. a plesent suprise i must admit. too bad chevy never really took very good record keeping on al this stuff, it really makes things difficult at times

I ordered a 1972 Chevy 1 ton van with a heavy duty transmission. It was a HUGE Saginaw 3 speed. I put over 240,000 miles on it and no problems with the trans. Very low first gear ratio and big rpm drop to 2nd and again to 3rd. The 350 engine had plenty of torque to pull a 6,800 # trailer and didn't hurt the trans. There must be a zillion different transmissions out there that we never hear of. I have never seen another like my '72.