Correct Saginaw Transmission -'73 Vega GT

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Correct Saginaw Transmission -'73 Vega GT

Postby ol55 » Mon Jan 18, 2016 2:19 pm

After the new clutch, the transmission still crunches into third gear on upshift and downshift. All others seem to work ok. My understanding from the PO is that this is the original Saginaw that came with the 4 cyl. Would like to rebuild another Saginaw to put in and have seen several posted for sale.

Questions:
Which (first) gear ratio should I buy?

How do I tell I have the right ratio?

Is the standard ratio the same for all Vega in '73?

Thanks,
Larry
'73 Vega GT Hatchback hot rod.
'76 Cosworth
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Re: Correct Saginaw Transmission -'73 Vega GT

Postby cjbiagi » Mon Jan 18, 2016 3:47 pm

Most of the 4 cylinders came with a 3.11 first gear. There are some Saginaws with a even lower 3.50 first gear but most likely you have 3.11.
Why do you want to get another trans rather than rebuilding the one you have? Most likely you just need a GOOD rebuild kit with syncros, bearings, gaskets, seals etc. I recently rebuilt my Saginaw and it's not too bad to do, the important thing is to get the correct snap ring pliers (which I did not have). Removing and reinstalling a couple of those is a real bitch without the correct pliers. There is also a excellent 45 minute video on the internet that you can rent for 2 days for a few bucks that is very detailed and worth the cost. The trans gear ratio is identified by looking at the input shaft, there are some grooves or rings on it that identify the ratio. If you need a high quality rebuild kit let me know, I can get one with the good forged syncro's, a heavy duty front "max" bearing and all the parts you need in one kit.

4 speed Saginaws
no lines= 2.84-2.01-1.34-1.00
1 line= 2.54-1.80-1.44-1.00 common
1 Line= 2.54-1.80-1.32-1.00 rare
2 Lines= 3.11-2.20-1.47-1.00
3 Lines= 3.50-2.46-1.65-1.00
Clyde.........75 Monza 2+2
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Re: Correct Saginaw Transmission -'73 Vega GT

Postby bugdewde » Mon Jan 18, 2016 11:38 pm

Here's some good info from the h-body.org F.A.Q. (Frequently Asked Questions)
Section 3: Transmissions and Rear Ends
http://h-body.org/library/hbodyfaq/index.html

There's a ton of good info in the other sections, too. See index on left of page.
Dwight

'73 Vega GT Hatchback, mostly stock....
'72 Vega GT Kammback, 215 V8
'73 Vega Wagon - Currently in Limbo....
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Re: Correct Saginaw Transmission -'73 Vega GT

Postby avewhtboy » Tue Jan 19, 2016 12:57 pm

Just an FYI, if you are putting an engine with any horsepower you might as well ditch the saginaw and go with a better transmission.
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Re: Correct Saginaw Transmission -'73 Vega GT

Postby cjbiagi » Tue Jan 19, 2016 4:41 pm

It seems for every story about how someone blew one of these up there is another about how well it survived behind a hi performance engine. Without a doubt they are not as strong as a Muncie or Super T10 but they will survive behind a mild 350 if not abused especially in a light weight car. If you do go with another trans be aware that you may have to fabricate a torque arm connection if you use one. My Saginaw has survived pretty well over the past 40 years, I recently did have to replace a broken 1-2 slider assembly and did a full rebuild on it, there is a complete thread on the rebuild about a year ago. Basically it comes down to what you already have and how much you want to spend.......

viewtopic.php?f=8&t=40581
Clyde.........75 Monza 2+2
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Re: Correct Saginaw Transmission -'73 Vega GT

Postby nutt » Tue Jan 19, 2016 4:55 pm

Yep, eliminate wheel hop, install a solid motor mount on the driver's side to eliminate the twisting which will bind the factory shifter and don't dead-hook....that little sag will surprise you.
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Re: Correct Saginaw Transmission -'73 Vega GT

Postby Smiley » Tue Jan 19, 2016 9:37 pm

For a 71-74 car with the 4 link I prefer a pre 71 Muncie 4 speed as a Saginaw replacement. they are lighter, stronger and use the same spline input output shafts.
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Re: Correct Saginaw Transmission -'73 Vega GT

Postby Monza Harry » Wed Jan 20, 2016 6:30 pm

cjbiagi wrote:It seems for every story about how someone blew one of these up there is another about how well it survived behind a hi performance engine. Without a doubt they are not as strong as a Muncie or Super T10 but they will survive behind a mild 350 if not abused especially in a light weight car. If you do go with another trans be aware that you may have to fabricate a torque arm connection if you use one. My Saginaw has survived pretty well over the past 40 years, I recently did have to replace a broken 1-2 slider assembly and did a full rebuild on it, there is a complete thread on the rebuild about a year ago. Basically it comes down to what you already have and how much you want to spend.......

viewtopic.php?f=8&t=40581

Clyde is right on here, but from my experience most of the ones we (my brothers and myself) broke, came from using the 4 banger trannies for the low first gear to get our boat anchors moving with the wrong diff gear( plus they were cheaper, did I mention we were kids?), the trannies would usually break 2nd gear with a crazy @$$ shift it should have never been exposed to! The tighter spread trannies survived much longer due in large part to the lower shock shift of the tighter ratio's of the 6, and 8 cyl. trannies. And we rarely ever had two tires worth of traction, (one wheel peelers) so I am sure that helped out too! Harry
I'm not a hoarder I'm a preservationist 78 Monza Spyder (Soon To Be 2+2 with Spoilers)
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