What is it about the Saginaw four speed that makes it a weak transmission? From what I have gathered reading about them here (full disclosure - I have no experience with them), they are weak and not very durable. I know the highest horsepower Camaro they were installed in was the L30/M20 - could they handle the power level of the L30, or was it marginal in that application? Can one handle the power from a stock L30 driven on the street? Is there anything that can be done to strengthen them? More curious than anything else. Thanks!

I had a Saginaw 4spd with a built 350 when I first bought my 69'. It was a bit sloppy from age, but it worked just fine. After I installed my TKO I sold it...easily. One guy almost drove to ATL from TN, lol. But a local guy ended up buying it.

From what I had heard/read (and I had no experience with them at all), a Saginaw 4spd was really a Saginaw 3spd with very slight modification, and not necessarily a good one. And it was phrased that way as a rap against the the 4spd. That's all I know.

The Saginaw is heavy in weight, due to the case being made of cast iron.
The ratio spread is alittle wide.
I had no problems with one OE installed in a '68 327, seemed to handle those 4K rpm clutch dumps I gave it.

I have one in the '67, 300hp there about's. I've beat on it a bit, some nice burn outs, etc. I wouldn't go out and buy one but if you have one use it.

the gear ratio's are actually good, for a performance app., but the deep first lowers the torque rating( cant get around that). I think th biggest part of the bad rap they get is the shifter that comes from gm on them.....it is shiit!!!! it is probably responsible for more broken transmissions than the torque rating. that shifter is prone to hang up between 2 gears, or not fully engage the gear - resultig in carnage!!!! jmo

I had one that I installed in a 72 Camaro that had a freshly built 355 SB with about 375 HP and I was running a 4.11 12 bolt. I would launch that thing and bring a front tire off the ground slightly. never gave me problems. And to hoot I was 19 and stupid so it took a lot of punishment.

They take a lot more abuse than people give them credit for. I've had one for many years and beat on it pretty hard from time to time. It's a 2.54 first gear 4-speed though. The 3.50 first gear trannys would probably come apart if the car hooked up hard, due to the torque multiplication of the super low first gear. The low first gear is nice on the street though. Bottom line is, the 2.54 first gear ones will take more abuse.

Here's how to identify which one you have by looking at the input shaft. They have grooves, or lines, that run around the shaft at 90 degrees to the splines.

http://www.racersguide.com/trans_ratios.html

And yeah, they're heavy. Better eat your Wheaties before you try to bench press one and stab it in. ;)

Mark

Ditto Mark!

pdq67

My uncle has around a 390hp 350 with a saginaw and he beats the hell out of it and it still keeps ticking.

I blew one, make that three, with a 283.

I had one in my 67 L30/M20. I blew reverse out of it and bought a Muncie. Mine and a couple of others I drove didn't shift quick that well at all. They were balky shifting. Driving normally, they were fine. I was glad when mine blew and I had a good excuse to buy the Muncie. My dad wouldn't have let me just swap for a faster shifting trans. They are strong enough for a 327, but shifting them is something else. When I did get it to shift fast, with great effort, it made a grinding noise like I was tearing it up, so I tended to make easy shifts most of the time.
David

Thanks for all the input!

I think because Chevy never put them in high performance Camaros they wer pretty much written off. The heavier case also made them less attractive to racers. The wide ratios in some probably helped make low horsepower cars more driveable, like the L-6. I guess I will install mine and see what happens. It does have a Hurst shifter on it. Wish me luck!

What are the visual cues that define the Saginaw from the Muncie?

Saginaws have a cast iron case and the reverse lever is on the inspection cover. Muncies have an aluminum case and the reverse lever is on the tailshaft portion of the case.

http://www.nastyz28.com/chevy-manual-transmission-identification.php

Mark

I guess everyone gets a bad one now and then.
It's just like a lot of other debates like cubic inches are always better than smaller.
My "expert" neighbor told me that he didn't like them because they didn't shift fast enough... that does not make any sense what so ever and that would have to do with the linkage not the transmission it's self.
I have never seen one destroyed from abuse, and having a 40yr old saggy 3spd behind a 400hp+ 327 and nothing has happened, then they can't be THAT weak.

Since I first posted in this thread back in Feb. I've changed engines which went from 300 to around 400hp. I've also managed to put a hurtin' on the third gear syncro. It's drivable but I'm not sure if I'm going to fix it or move on to something else. Guess it could have happened to any trans, I was banging on it pretty good.

I would tend to agree with some that said you would blow it up if you really hooked up, slicks etc... We had one on street tires in a 73 LT with L-82 and it worked good.