Tuck's quandry into the possibilities of running a Saginaw four gear in his project got me to thinking about those poor neglected trannys and prompted me to refresh my memory on them a little. You can find them in almost any GM body style from the late 60s to the early 80s, and I seriously doubt that you will ever need to pay more than $100 for a useable one from a buddy, swap meet or boneyard. They are common, plentiful and cheap. They feature a cast iron case with all three shift levers on the side cover, to aid you in identifying them. Their external dimensions and mounting points are shared with the Muncie four speeds, allowing for that legendary GM parts interchangability. Some Saginaw trannys have provisions for a shifter mount on the tailshaft, and some don't. (Some car models featured a shifter bolted to the floor of the vehicle rather than the tranny.) You're better off to locate a trans with the shifter mounting holes on the tailhousing, but aftermarket sources DO offer brackets to allow the use of a 'conventional' shifter on the other tailhousing. The most common Saginaw four speed is the wide ratio variety equipped with a 2.85 first gear, 2.02 second gear, 1.35 third gear, and a 1:1 fourth. However, 1973-77 Chevy Vegas used a Saginaw tranny with a 3.11 first gear, 2.20 second gear, 1.47 third gear, and the usual 1:1 fourth. Don't be intimidated by the fact that the trans came out of a Vega...it's still the same design as those used behind the V8 engines, with lower ratios to help the 140 cube motors get the cars rolling! Alot of guys robbed Vega trannys in the 70s and 80s to gain the better ratios! Now, the Saginaw ain't a super heavy duty drag race tranny...but it IS more than strong enough to handle a stout mill in a light car with a semi-sensible driver! Using one in your 4000 pound big block Impala with slicks and nitrous might be asking for trouble...but they work fine as a low-buck alternative to the Muncie and T-10 in most lighter rods for street/strip duty! Just a few tips to save ya some money...and help lift the cloud of disrespect often bestowed upon the poor, humble Saginaw transmissions of the world!
There is huge pool of mis-information regarding ratios for these transmissions. My buddies always argued whether the vega style with 4 banger had a 3.40 or a 3.50 first gear. I honestly don't know but it was low enough to drive in traffic with a 2.29 rear gear ratio in a 3300 lb car. The 406 smallblock never whimpered leaving a stoplight, even on steep hills. The 4th gear was like other guy's overdrive. On the interstate, I'd cruise at 75 at about 2300 rpm... Super shops usta sell the Hurst linkage arm and lever kit for about a hunnert bucks. I used this kit on a yard sale $5 Hurst 3 speed shifter...new, still in the box! The 3 speed shifter controlled the 4 forward gears and I used a separate Hurst shifter handle, welded directly to the reverse lever. Worked very nicely and everybody asked about the 2 identical shifter handle and knobs sticking outa the floor. I used Toyota shift boots too.. I never broke my Saginaw but the reverse idler went to shit once, requiring a complete tear-down to change it. Gave me a chance to look over all the parts. The guy I sold it to was doing smokey burnouts for his buddies and when he slammed a 2nd gear powershift, the tranny finally exploded and he replaced it with a [gasp!] 350 turbo...yawn... The best news is the cost of these things. I bought mine out of a 1980 Pontiac sunbird at U-pull-it. Cost was $35 plus a $10 core chg. I later brought 'em a junk 3 speed tranny for my $10 core money.
I was a little leary of putting a Saginaw in my shoebox since it has a mild 350 and it weighs every bit of 3600 lbs if not more. But I haven't been dissapointed with it yet. I drive the living shit out of it everytime I get in it, and with the exception of a broken front bearing and the resulting broken input shaft collar/ retainer, it hasn't given me any trouble yet. The low gear ratios are an advantage, since you can run a higher rear gear than normal and still have plenty of low end pull. I've got the 3.11 first gear (2 groove) trans in it now and love it...2nd gear will just about jerk your eyeballs out of their sockets if shifted properly. I wouldn't have any problem with running one in a light car like a Model A. Saginaws don't get any respect, but for the price, they're hard to beat. I just picked up one of the 3.50 first gear (3 groove) variety at the last swap meet in excellent shape for $45. Muncies and BW T-10's break every now and then too. Here's a run down of gear ratios. You can identify which one you have by the number of grooves on the input shaft: SAGINAW 4-SPEEDS (CAST IRON) 0 LINE INPUT -2.84/2.01/1.35/1.00 1 LINE INPUT - 2.54/1.80/1.44/1.00 2 LINE INPUT - 3.11/2.20/1.47/1.00 3 LINE INPUT - 3.50/2.47/1.65/1.00
I've got two transmissions that I thought were four speeds sitting in the basement - but only two shift levers. So it's a 3 speed then?
GRIM your hoarding shit again... Cool info hack! thanks dude... so if i get the right tranny my 3:42 gears and the first gear are gonna ROCK the HOUSE in those a rails!!! sweet Tuck
I'll trade you for a motorized girl's bike with "gut coring" handlebars. In all seriousness, you can have one - I may make use of one of them eventually but I'll never need both. You wouldn't happen to actually have an old B&S or similar motor laying around would you?
I'm running a 3.42 rear gear in my shoebox. I think the 3.11 first gear (2 line) trans would be awesome in an A. I've also heard that the 2 line yields the least RPM drop between gears of all the Saginaws, so that'll help keep 'er hummin'.
Of course I'd prefer a 5 horse - yeah, I'm going to build a motorized bike of sorts. But not a mini bike. Think Whizzer with a little board track racer and a lot of farm town crazy kid thrown in. No hurry on anything - I actually need a car finished before I start monkeying with silly shit.
I'm so glad you guys brought this up. I have two 4-speed Sags and I was a little apprehensive about using them. One is going into the 60 El Camino behind a 283 and I figured it's safe in that car. But reading all this helps a LOT and the one on the floor in my garage is the 2-line input shaft. Travis
Fair enough. That trans. is yours anytime though. Don't know how you want to get it up there. It's HEAVY of course.
I have a Saginaw 4-spd in my GMC. Been running it behind the stepchild SBC (307) for 18 years with no problems. And I'm not gentle with it either. Neal
Fat- so is this a 3 or a 4 speed? How much of advantage is the aluminum Muncie? I found one w/shifter for 800buxx... seems steap. WHEN compared to the saginaw...
Tuck, according to the Hurst tranny ID guide that looks like a Muncie 4 speed to me. There should be a reverse lever on the tailshaft.
modernbeat!!! hows it going down there in TX im gonna hang with you guys this year at the roundup!!! COOL, im gonna buy this tranny from Orange52... just wanted to figure out what it was. Thanks Tuck
Tuck....that's the famous saginaw 4 speed tranny, right there. The two shifter shafts with levers on 'em are for the forward gears and the one with a bolt sticking outa it is for reverse. Iron = Saginaw. Aluminum = Muncie except in very rare cases..... Now, count the machined grooves in the input shaft sticking out the front of the case where the clutch goes and refer to the post above for ratio info.....
yeah rocky i PM'd orange52 to see if he could do that for me. Cant wait to find out the gear ratios! this KICKS ass... ill get the HEX second gear scratch and then some in the 29! Thanks~
Hmmmm...Better take another look at those trannies when I get home....One of them may be a four speed after all.
yep sag , let us not forget that there were cast iron case BW t-10 and super T10's as well, mostly 327/409 and early BBC(65), the sag is a good tranny IF you use it hte way it was meant- EASY + LIGHT duty,I use em cause I can get another at will-cheap, like 100 bucks-tough part is getting a shifter hurst does not make any anymore, and ebays are getting almost new prices,thet are great behind a 6 or small mild V8(like a flatty),but total junk behind anything w power,you will find this out the first time that smokey burn out grabs tire.$800 is WAY out of line ,someone is trying to give it to you in the shorts.hell I can get a BW T10 for that-use as is, w the shifter.
Tuck, if I understand what I'm looking for correctly, looking at the input shaft mine has two grooves that go around the input shaft. Thus, 2 LINE INPUT - 3.11/2.20/1.47/1.00 I can email you a pic if you'd like. Troy
I put a saginaw behind a 235 in Laura's nipple mobile and it worked great. I was glad to have the deep 3 groove tranny due to the 2.72 rear-end in that thing. It wouldn't set the world on fire as far a acceleration is concerned but it would damn near idle down the highway at 70 mph. Which if you've ever owned a shoe box chevy, you know that's a problem.
Guys- I'm glad to see the lowly Saginaw getting its due. Had one in a'66 Nova many years back. I drove it long and hard with no problems, then switched over to a close-ratio Muncie and the thing absolutely fell on its face - until I compensated with a deeper rear-end gear. I just picked up a Saginaw for my hot rod project for the very reason Fat Hack mentioned. My deal is ultra-low budget (although Saginaw 4-speeds seem to be more in the $150 - $200 price range around here - haven't seen any of those kiler $50 deals!), so I'm hoping - by taking advantage of the Saginaw's low first-gear ratio - to use my existing (stock) rear-end gear (and save money) while having a car that I can drive down the highway with. BTW - Anyone have a Hurst Competition Plus (has to be the CP version - no "Indy" or factory stuff) shifter assembly that fits a Saginaw? Also, how about a Hurst T-handle?
One final word on these things: The Saginaw was apparently the standard 4-speed that GM put behind the 275hp 327 in Camaros and this was counted as a "high-performance" package with performance equivalent to the 295hp SS-350! If it's good enough for GM, it's good enough for me! (Says the guy with the M21 Muncie behind his 327...)
When I broke the Muncie in my 350 powered daily driver (back in '77 or '78) I replaced it with a Saginaw because it was all I could find quick. I drove like a kid back then and never had any trouble with the Saginaw. In fact I kept the transmission when I sold the car, and only parted with that transmission in the last year or so.
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