Muncie M22 Question

[Noel O.]

Kind of on odd question I guess. In a big block, side exhaust car (C2 or C3) how audible should the M22 gear whine be from inside the car versus car with an rear exit exhaust?

[Ronald L.]

Re: Muncie M22 Question

Noel, just depends upon how fast you are going and how old the side pipes are What year specifically?

[Warren F.]

Re: Muncie M22 Question

Noel,

My '71's with M22's howl pretty good in the first three gears at low speeds with rear exiting exhaust.

[G A.]

Re: Muncie M22 Question

Back in the early '80's I had a '67 435 convertible, side exhaust. You could hear 1-3 without any problem, anytime. M-22's are fabulous noise makers due to the straight cut gears. If it isn't making noise you ain't driving it!

Dan

[Duke W.]

Re: Muncie M22 Question

M-22s don't have "straight cut gears", correctly known as spur gears other than reverse. The M-22 gears are helical but have a lower helix angle on the first, second, and third meshing gears compared to other manual transmissions, which yields greater torque capacity, but at the expense of more noise.

The BW T-10 and I believe Muncies and the Super T-10 all use spur gears for reverse, which is why they have a distinctive whine in reverse.

Duke

[Jerry G.]

Re: Muncie M22 Question

M-22s don't have "straight cut gears", correctly known as spur gears other than reverse. The M-22 gears are helical but have a lower helix angle on the first, second, and third meshing gears compared to other manual transmissions, which yields greater torque capacity, but at the expense of more noise.

The BW T-10 and I believe Muncies and the Super T-10 all use spur gears for reverse, which is why they have a distinctive whine in reverse.

Duke

In a related question. We are using M-22s in road race cars and having a problem with it not staying in 4th gear. We think there is a clearance problem(too much) with the main shaft and the front case bearing. does anyone have clearance specs for the M-22? Machining drawings or dimensions for the main case would help. Jerry

[Domenic T.]

Re: Muncie M22 Question

Jerry,
Also check the dog houses on the input shaft and see if they are rounded.

You cant see the slider very well but they can make it pop out also.

I don't have the specs here but I think the play on the mainshaft thrust is about .010.

DOM

[Wayne M.]

Re: Muncie M22 Question

In a related question. We are using M-22s in road race cars and having a problem with it not staying in 4th gear. We think there is a clearance problem(too much) with the main shaft and the front case bearing. does anyone have clearance specs for the M-22? Machining drawings or dimensions for the main case would help. Jerry

Jerry -- I am far from being a Muncie expert, but I noticed that in two trannys I have, that there was a spacer inserted between the bearing and the front face of the input/clutch gear (pic below; M22 obviously on the left).

Notice the shim on the M22; it's etched 0.037 and measures such. The brass shim on the M21 shaft measures 0.048". IIRC, seems that rebuilders added this to move the input back towards the mainshaft, perhaps to improve meshing of the 3-to-4 clutch assembly. I'd have to dig a bit to find the article on the reason for such a mod.

[G A.]

Re: Muncie M22 Question

M-22s don't have "straight cut gears", correctly known as spur gears other than reverse. The M-22 gears are helical but have a lower helix angle on the first, second, and third meshing gears compared to other manual transmissions, which yields greater torque capacity, but at the expense of more noise.

The BW T-10 and I believe Muncies and the Super T-10 all use spur gears for reverse, which is why they have a distinctive whine in reverse.

Duke

OK. Right you are. Speaking from a pure technical, engineering and machinist perspective, they are not "straight cut gears".
As we all can see from Wayne's excellent photo above however, the M-22 gear appears straight in comparison, as you said, and thus in colloquial America we uneducated still refer to them as straight cut.

Dan

[Joe L.]

Re: Muncie M22 Question

Jerry -- I am far from being a Muncie expert, but I noticed that in two trannys I have, that there was a spacer inserted between the bearing and the front face of the input/clutch gear (pic below; M22 obviously on the left).

Notice the shim on the M22; it's etched 0.037 and measures such. The brass shim on the M21 shaft measures 0.048". IIRC, seems that rebuilders added this to move the input back towards the mainshaft, perhaps to improve meshing of the 3-to-4 clutch assembly. I'd have to dig a bit to find the article on the reason for such a mod.

Wayne-----


The shims must have been added. I don't think that Muncies were originally built with any sort of selective fit shim on the input gear.

Also, note that the M-22 gear still has the oil slinger installed.

[Domenic T.]

Re: Muncie M22 Question

Wayne-----


The shims must have been added. I don't think that Muncies were originally built with any sort of selective fit shim on the input gear.

Also, note that the M-22 gear still has the oil slinger installed.

Joe,
I think you are right.

I never got a shim in a kit but I do remember reading that there was a max limit (not to exceed) or you had to shim it.

With that there must be a part # for the shim?

DOM

[Joe L.]

Re: Muncie M22 Question

Joe,
I think you are right.

I never got a shim in a kit but I do remember reading that there was a max limit (not to exceed) or you had to shim it.

With that there must be a part # for the shim?

DOM

DOM------


Not from GM. I know of no such shim ever available from GM for a Muncie. There could have been such an aftermarket "fix", though.

[Chris H.]

Re: Muncie M22 Question

Noel, I had a 396 coupe with side pipes and an M22. I could easily hear the gear whine over the pipes especially in the lower gears.

I made an in car video driving one day and the whine is very pronounced. Man I miss that car......

[Jerry G.]

Re: Muncie M22 Question

Joe,
I think you are right.

I never got a shim in a kit but I do remember reading that there was a max limit (not to exceed) or you had to shim it.

With that there must be a part # for the shim?

DOM

Anybody know what the" not to exceed" is on these units

[Noel O.]

Re: Muncie M22 Question

Guys,

Thanks for all the replies. Very helpful