Muncie, Saginaw...lots of questions?

[shifty]

I'm tranny-ignorant. I'm shopping for a 4spd (floor shift) to drop in my truck right now.

I'm just wondering - Why the heck is a used Muncie 4spd five times as expensive as a used Saginaw 4spd? I've been looking at the M20/M21 Muncies and the 4spd Saginaws. Can someone fill me in on some history or at least give a brief overview? Is there really that much of a difference between the two?

Also - Aside from having an easier time shifting, what benefits will I see in swapping from 3spd on the column to 4spd on the floor? I mean, what will the extra tranny gear do for me in terms of gas mileage, top cruising speed, shifting points, ease of acceleration off the line, etc? I won't be changing my gear ratio in the ass-end, only the tranny. I don't know what my current gear ratio is either.

I always hear people say "sad old saginaw" over and over again here.

PS - not sure if this helps, but ... this is only going to be a temporary tranny until I can pay off the truck and drop an LT1 or LS1 + 6spd into it. Plan on doing this within 1-2 years.

[shifty]

A couple more PS's

I found this thread: http://67-72chevytrucks.com/vboard/s...00&postcount=8

It talks about some differences. I should also add it will be bolted to a 250 and I *do not* plan on doing any towing or pulling with my truck. I just want to get a nice driveable vehicle out of this deal.

I don't know much about Borg Warners either, but I guess the T10 will fit (I keep hearing people mention S-10 has a T10 and it will fit in my truck?).

My shaft with my 3spd saginaw is 10-spline. I just dropped a new 10" clutch and assembly into the truck, so I'm trying to stick with it (set me back ~$160).

When did they stop using the 10-spline shafts? If I get a newer tranny, is it hard to swap out to a different shaft with fewer splines, or does someone maybe sell an adapter?

For newer trannies, like something of an S-10, is the tranny a clean swap, or are driveshaft mods necessary?

[rodnok1]

Saginaws are a fairly weak trans, Muncie's were designed to handle alot more abuse. Check this link out http://www.nastyz28.com/transid.html
All of these have 1:1 final ratios so you don't gain any mileage from that in itself. General speaking trans with higher spline counts can handle more abuse, you have to check the trans to see what it is. You can get different first gears in some to help/change acceleration. If you are really only going to keep a year, get a saginaw. They are cheap. I use to get junk yard saginaw trannys for 75-100. They lasted about 3-4 months in my Trans-Am(I am hard on Trannys). A good munice/Borg Warner T-10 setup will cost quite a bit. Since you have a saginaw already, swapping a 4 speed in should be easy, with the same spline count. I do believe the driveshafts are same length between 3/4 speeds(don't quote me on this one).

[69 longhorn]

Originally Posted by rodnok1

Saginaws are a fairly weak trans, Muncie's were designed to handle alot more abuse. Check this link out http://www.nastyz28.com/transid.html
All of these have 1:1 final ratios so you don't gain any mileage from that in itself. General speaking trans with higher spline counts can handle more abuse, you have to check the trans to see what it is. You can get different first gears in some to help/change acceleration. If you are really only going to keep a year, get a saginaw. They are cheap. I use to get junk yard saginaw trannys for 75-100. They lasted about 3-4 months in my Trans-Am(I am hard on Trannys). A good munice/Borg Warner T-10 setup will cost quite a bit. Since you have a saginaw already, swapping a 4 speed in should be easy, with the same spline count. I do believe the driveshafts are same length between 3/4 speeds(don't quote me on this one).

Yes, a saginaw 3 or 4 spd is the same lenght as the M 20/21 muncie, & will have the proper spline, to fit the stock d shaft. there were some variations on the input shaft spline, but the general rule was M20/21 were 1 1/8" 10 spline. the M22 (the bad boy), had a larger tail shaft.....same as a 400 turbo. it also ran a 1 1/8" 26 spline input shaft. That M22 (rockcrusher), howled like a MOFO......about like the Richmond 6 spd box I am running. It was a load of bucks, but I got 2 more gears..........1 lower(sweet), & 1 overdrive (sweeter than he!!) you can get a new borg warner 4 spd .....its a Richmond now, but check the Summit or Jegs price before you drop a load of bucks on a rebuilt Muncie............69L

[70 shorty]

Hey Shifty thanks for asking what I'd also like to know, except I'd like to put a car 4 spd in mine as a permanant thing. I've got a buddy with a Muncie 4 spd in his Vette that he's going to replace with a Muncie M22 when he puts his 502 in it, so I'm going to try to talk him out of the one in the Vette now.

[JodysTransmissions]

Why spend the money for a 4 speed if you are planing a 6 speed in a year or two?

[shifty]

Originally Posted by JodysTransmissions

Why spend the money for a 4 speed if you are planing a 6 speed in a year or two?

For my driving sanity until then. I'd like to drive the truck to other places and be more comfortable driving it around town and doing so with a 3spd isn't cutting it - besides ... it's only like $200 to get one used...so why not?

[jhwkns]

I've had what I consider good luck with the saginaw in my truck. I bought it at a J/Y for a hundred bucks pulled the side cover off, and had a peek inside. Everything looked fine. I put 40k miles on the gearbox before it started to get a little noisy. I overhauled it, and have since driven it about another 40K. It works great. The question of strength. Sure.. they're not as strong as a M-22, but I wouldn't call them weak either. It's just as strong as the three speed trannys that came in these trucks. They're identical in design. They even use the same synchros, and bearings. I'm sure that there are plenty of board members out there driving around with a 35 year old saginaw three speed right now. You're probably one of them shifty. IMO that's a pretty tough gearbox. I drive mine about 1,500 miles a month, and it's got a pretty wicked 350 in it. So far so good. Another good point for the saginaw is that there is a linkage kit available for our trucks. There isn't for the Muncie, or BW.

[hobby67stepside]

Here's a link with lots of info http://www.gearzone.net/muncie.htm

[3 on the tree]

Any of you old timers like me remember the Vega GT? The 4 speed in the GTs was the same Saginaw 4 speed they put in the Camaros and Firebirds. I pulled my 3600 pound dirt track car with one inna 70 SWB Jimmie for 3 seasons, no problems at all, and it bolted in place of the 3 speed, though the Vega shifter was a little short.

[shifty]

Oh - someone mentioned "car tranny" above. So - let me get this straight - if it's a CAR tranny, the linkage is at the tail of the shaft? Whereas with a truck tranny it's in the front? I don't know if I'm understanding correctly.

[3 on the tree]

Originally Posted by shifty

Oh - someone mentioned "car tranny" above. So - let me get this straight - if it's a CAR tranny, the linkage is at the tail of the shaft? Whereas with a truck tranny it's in the front? I don't know if I'm understanding correctly.

Older truck 4 speeds have the shifter coming out of the top of the tranny, towards the front. 95% of the 3 speeds I have seen have the shift linkage on the side of the tranny with a shifter on the column. Compared to a truck 4 speed, your shifter on a car 4 speed will be to the right and back some. If you do this swap, just pull the tunnel cover off, then install the trans and shifter. Then measure and mark the tunnel cover, cut the hole and reinstall. Make sure you measure the full movement of the shifter, so the hole is big enough. You know where the side cover on your 3 speed is? Typically the car 4 speed shifters mount on that side of the trans and to the rear.

[shifty]

Cool, thanks.

I was at a wedding up in Orkney Springs, VA the past few days. The groom's father (a close friend) has a '71 Chevelle I've been wanting since I met them half my life ago. Found out he has a Saginaw 4spd and might be willing to part with it - it also has a Hurst shift kit and whatnot.

[jimfulco]

I put a '74 Vega Saginaw in my '72 Nova (350-4bbl) back in about 1978. It has the 3.11 low gear, vs the 2.54 that its original Saginaw had. I've had no problems with it other than a worn-out front bearing retainer. I use the stock 10.4" clutch & I don't sidestep the clutch pedal, but otherwise, I run the you-know-what out of it. The Sag has the same undeserved reputation as the 307 engine. It is NOT a bad transmission. They were used in 6-cyl & small V-8 applications starting in the mid-'60s, and were used throughout the '70s & maybe the early '80s. There were 4 different gear ratio sets available. ID & ratio info can be found at www.dandltransmission.com