[rockandroller1991]

I have a 1980 camaro Saginaw 4-speed and recently the 1st and 2nd went out and it wouldnt shift between the 2. I poped the the side shaft off and the cluster gear looks great and all the syncro's look good. but the first and second gear wont slide on the cluster gear. does anyone have any idea of what it might be?

[oldbogie]

Originally Posted by rockandroller1991

I have a 1980 camaro Saginaw 4-speed and recently the 1st and 2nd went out and it wouldnt shift between the 2. I poped the the side shaft off and the cluster gear looks great and all the syncro's look good. but the first and second gear wont slide on the cluster gear. does anyone have any idea of what it might be?

To start with this is a constant mesh transmission, which means the output gears are always engaged with their input counterparts on the cluster gear. Gear selection happens thru the synchro collar which when pushed by the shift yoke that rides on the collar, it will engage the synchro's blocker ring first with three dogs that press the blocker ring into a mating surface on the desired gear. When that gear and the speed of the output shaft match, the collar will slip over sets of external teeth on the blocker ring and the gear locking both the gear and synchro to the output shaft thru the collar.

A failure of the yoke to move the collar would indicate a failure or miss alignment of the linkage external to the Saginaw. If the side cover is removed, so the shift linkage is disconnected and the shift yoke still won't move then there is a problem with the yoke's internal linkage or it's bent. There is a detent in the side cover that can become damaged and hang up the yoke's hardware.

A failure of the collar to be moved when the yoke is not in contact would indicate a failure of a component inside/under the collar. There are serrations where the collar moves upon and is locked to the output shaft, they are matched within the collar, if damaged they can hang the collar up. There are three dogs that are evenly spaced around the shaft spline adapter under the collar, within, are two spring steel circular torsion springs that press the dogs outward against the collar. There is a groove inside the collar that catches the dogs and moves them toward three large reliefs in the blocker ring. If any of these parts are excessively worn, broken, or have come out of position; the collar will be jammed and become immovable.

To see what's under the collars the tail-shaft ( also called main-shaft or output-shaft) has to be removed, so it can be disassembled.

There is a needle bearing inside the input gear that the main-shaft engages. If these have failed the shaft will become misaligned and moving the synchro collars will become difficult if not impossible. There are similar bearings within the cluster gear that can have the same effect. The input shaft/gear rides on a ball bearing in the front of the case, a failure here will jam shifting up and take out the needle bearing the output shaft rides on. There are numerous thrust bearings that if failed will allow the cluster gear and or mainshaft to slip fore and aft during shifts which can let the innards of the syncho assembly all out of position. There is a bushing on the end of the output shaft inside the tail housing as well as another ball bearing forward of that on the mainshaft, failures here will present similar results from engaged gears randomly popping out after being selected or jamming the shift collars by allowing their internal guts to get out of position.

Bogie

[rockandroller1991]

Hey thanks for the great information. I was wondering if you knew of any books/manuals that are just for the saginaw or gm transmissions?

[oldbogie]

Originally Posted by rockandroller1991

Hey thanks for the great information. I was wondering if you knew of any books/manuals that are just for the saginaw or gm transmissions?

Books:

On line purchase http://carburetor-manual.com/saginaw...ook-p-260.html

http://www.amazon.com/Modify-High-Pe...ref=pd_sim_b_5

http://www.amazon.com/Rebuild-Modify.../dp/0760320470

The only other and perhaps best resource would be a Motor's manual or a specific GM vehicle manual in the period of 1961 thru 1985. The Saginaw 4 speed showed up in a lot of light to medium duty vehicles like Corvair, Tempest with a 4 or 6 cylinder engine, Vega and cousins after 1973, Monza and it's relatives as well as other models. The Corvair is a variation in that it doesn't use a tail shaft, and the input is thru an oddball concentric input shaft that comes off the clutch on the front of the engine, passes thru the differential, passes thru the transmission mainshaft to engage a short input shaft/gear. The guts inside the box are the same as others, but how power gets in and out of the box is different (pay no attention to the man behind the curtain kind of thing). My bet would be these guts even show up inside the tranny/diff housings of early FWD and rear engine models like the Citation and Fiero.

Parts other than at the GM store by you:
http://www.dandltransmission.com/saginaw.html


I suspect there's a lot of people out there that think they have a Muncie (turbo Buick guys), when in fact it's a Saginaw, unless you know your stuff, they're not always easy to tell apart and the Saginaw did see use in some smaller optioned V-8s including Corvette and some pickups. All in all it's a decent gear box as long as you keep the input under 250 hp and the vehicle not more than something around 3000/3300 pounds. But GM pushed this in some installations. They also showed up in some Fords.

Bogie

[mmerlinn]

Originally Posted by rockandroller1991

I have a 1980 camaro Saginaw 4-speed and recently the 1st and 2nd went out and it wouldnt shift between the 2. I poped the the side shaft off and the cluster gear looks great and all the syncro's look good. but the first and second gear wont slide on the cluster gear. does anyone have any idea of what it might be?

NONE of the gears in the Saginaw slide. In fact, the general rule is that no gear (except some reverse gears) slides in any transmission designed and built after the 60s. There are some exceptions, but they are few and far between.

The only moving (not rotating) parts in a Saginaw are the shifting mechanism and the synchronizer sliders, as well as a reverse gear.

So, your problem is somewhere in the 1st/2nd shifting mechanism and/or slider.