Rick,
Keep in mind that I copied this from a 1952 RESTRICTED Security
Information Department of the Airforce Technical Order TO 19-75CAJ-2.
So when it says to remove the second and high speed shifter shaft and
remove the low and reverse speed shifter, one can only assume it is to
thoroughly confuse the commies that at trying to get a disabled M-38
back across the Yalu.
I just copied the TO and it is apparently in error. Can you imagine the
wasted time in some motor pool while some poor soul tried to figure that
one out without asking sarg? He would just say "what the hell does the
manual say? NOW DO IT!!!"
Under disassembly:
Remove shifter fork pins from the second and high-speed shifter fork and the
low and reverse speed shifter fork. Remove the two 3/8-inch countersunk head
pipe plugs. Slide the second and high-speed gears shifter shaft from
gearshift control housing and remove low and reverse speed shifter fork. >
Did you mean to say, "Slide the second and high-speed gears shifter shaft
from gearshift control housing and remove second and high speed shifter fork"
I think probably so.
Remove gearshift rail hole expansion plugs. >
I have no idea what gearshift rail hole expansion plugs are. I can't find
them in my manual and I can't find anything on my shifter that looks like
this. Can you elaborate for me.
These are a little soft plug that goes in the aft ends of the shifter
rail holes to keep grease in and dirt and water out.
How about removal of the shift lever spring and shift lever. I assume that I
did it right when I removed it but it would be nice to know for sure.
The manual doesn't say, but it seems if you get all the other stuff out
of the tower case, then you just unscrew the cap and remove the shift
lever. I don't think it will come out unless you have one or maybe both
of the shifter shafts removed.
<Now clean and inspect.
Inspect the transmission case and gearshift control housing for cracks or
damage of any kind. Any cracked or otherwise damaged units must be replaced.
Replace the gearshift control housing if it is cracked or has stripped
threads. >
I'm thinking that if I had the expansion plugs, I would then have threads,
otherwise I can't find any threads on my gearshift control housing. Are
there other ones that I'm missing?
The only threads would be for the shift lever cap and for the plugs in
the front of the shifter shaft rail holes and there is a screw that
holds the interlock plunger in the case, I think.
<Replace the gearshift lever if it is excessively worn or bent. Replace the
gearshift control-housing cap if it is bent or has stripped threads. >
Above when you mentioned the Gearshift control housing were you speaking of
the entire assembly right?
Correct.
Now with the control housing cap are you speaking of just the housing
without the internals right?
Speaking of just the cap that holds the shift lever.
<Replace the 3/8-inch countersunk head pipe plugs if the threads are
stripped. >
Again I'm assuming we are talking about something I don't have.
These are in the front of the shifter shaft rail holes to keep out water
and dirt and keep grease in.
<Replace the gearshift lever support spring if it is cracked or distorted.
Replace the poppet balls and poppet ball springs if they are worn, broken, or
distorted.>
Good, but I like Reed's idea of replacing them any way because they are cheap.
I would totally agree on that one, especially if you were able to get a
good quality ball and spring.
<On to assembly of subassemblies:
Assemble Gearshift Control Housing. Install new gearshift rail hole
expansion plugs into shifter shaft holes in end of gearshift control housing.>
We've been through this one before.
I think right here would be a good time to reinstall the Shift Lever and the
shift lever spring. Please tell me there is an easier way than the way I did
it. I tried for about an hour and a half the first time I removed it to put
it in by screwing it in. I finally gave up on that approach and pressed the
spring back down over the keepers using two large screw drivers. Is there an
easy way to do this?
I am not aware of any keepers. I just have the shaft with a fulcrum
pivot ball held to the shaft with a pin, then a spring with a washer on
top, all held down by a metal cap that screws down on the threaded top
of the tower. There is also a gasket under the cap. We must have
something a little different here.
<Insert poppet ball springs and poppet balls into gearshift control housing
while housing is placed upside down. Depress poppet ball and poppet ball
spring, and insert the low and reverse speed gears shifter shaft into the
gearshift control housing. >
I found a blunt ended 1/4" shaft to work very well for this. I do not
recommend using something with a point on the end because it can slip off the
ball too easily.
Yessiree!!!!
<Depress the other poppet ball and poppet ball spring; install the second and
high-speed gears shifter shaft into the gearshift control housing. Install
the second and high-speed shifter fork onto the second and high speed gears
shifter shaft. Install the low and reverse speed shifter fork onto the low
and reverse speed gears shifter shaft. Secure both shifter forks onto the
shifter shafts with shifter fork pins. Flange the ends of the gearshift fork
pins with a center punch. Install 3/8-inch countersunk head pipe plugs in
ends of gearshift control housing.>
I noticed that these head pipe plugs are only installed in the front end of
the gear shifter control assembly. Yet there are two holes just like the
front ones in the back. All three shifters I have seen so far have been full
of dirt and grease in these back two holes with no covers installed. Would
it be possible to add two more plugs to the back to keep out the dirt or are
these used like a vent.
This was answered above.
Wonderful write-up Ron. We are all in your debt. Thanks for the help.
AW SHUCKS---Twas nothing. except my wrists are still sore. I really
need a scanner.
Glad to help,
Ron, IA
43GPW, 51M38
PS-you should have seen me building top loader 39 gearboxes for my 40
Ford with the 324 Olds in front and the Zeypher rear end. At least 3 a
month. Almost 40 years ago. There is a nineteen and a twenty-one tooth
deal that can stop you going off the jacks. Don't ask.
