Transmission enquiry....

Bob Carriere · #1 30-10-06, 03:08

Well it was a cold rainy/snowy day....so Grant and I stayed inside the barn with the furnace blasting away..... must be getting soft...

So we tackled taking the tranny shift tower apart.....

Now for my questions.....

why do cab 12.... and maybe cab 11 have a longer shift lever....

Measured from the first bend in the shifter to the threade part of the shift knob is approx 15 inches on the arlier model and ONLY 10 inches on the cab 13....??

See the picture..... the first tower came from my cab 11... it is short like a cab 13 and instead of being angled forward it is mounted backwards....... shifting still worked fine BUT they was no longer any lock for the reverse gear......

I will tranplant the longer shaft from the spare 12 into my cab 11.

Parts washed out nicely.

Was there any kind of leather boot or rubber boot to keep dirt from entering the tower and tranny???

Bob Carriere · #2 30-10-06, 03:09

Would the shorter shifter be easier to use with a shorter overall throw...????

cletrac (RIP) · #3 30-10-06, 03:30

My cab11 C8 has the long shifter that's bent ahead. It's about the same length as a civilian 2 ton.
The cab 11 and cab 12 would need this shift lever to make clearance around the battery box.

Phil Waterman · #4 30-10-06, 19:12

On one it is toward the driver and the other pointing toward the left. When I first installed the shift lever on the Pattern 12 I had it the wrong way around and had to reach behind to shift the lever. As the lever is easy to remove (sometimes) and will work either way around I suspect that the it from time to time may get installed the wrong way around. The length is more important and how bent the shift lever is. On my Pattern 12 with the lever pointed forwards in 3rd gear it is touching my knee and not far from the steering wheel. It would be interesting to see the different (NOS) shift levers side by side.

mike mckinley · #5 31-10-06, 04:28

hi bob

regarding shift lever boots.....there was a sheet metal peice that fits around the shift lever and is bolted to the floor. this piece runs from the rear of the dog house to near the back of the cab, so it would also have the battery box sitting on top of it. the part where the shift lever comes through, if i remember correctly, is a square hole and around this hole are small holes approx 1/8" dia, which if i were a betting man would be to fasten a shift boot to the piece. having said that, i havn't seen a pic of said boot, but given the design of the shift tower, i can't imagine a good, quality G.M. product not having one. do you have one of these sheet metal pieces in your collection? if not, please let me know as i could dig mine out and post a pic if required.

cheers!!
mike

cletrac (RIP) · #6 31-10-06, 06:23

Here's a picture showing a shift boot on a cab 11, even if it is just a Ford

Phil Waterman · #7 31-10-06, 14:38

On my Pattern 12 there is no evidence of a plate around the shift opening (see picture) there was the remains of a foam pad between the sheet metal cover and the top of the transmission case. There is a boot retainer plate around the brake lever.

Phil Waterman · #8 31-10-06, 14:44

Here is a picture of the lever layout as the Pattern 12 was found with the back of the cab removed.

Grant Bowker · #9 31-10-06, 17:42

In Phil's photo, the (Chev) reverse lockout release lever is on the right.
In David's photo, the (Ford) reverse lockout release lever is on the left.
Both levers are canted forward.
Perhaps someone dismantled their Chev shift tower and then looked at a Ford to see which side the lever should be on (after all, you and I looked at other transmissions for guidance) and because they thought that the lever had to be on the left, put it together incorrectly. (either that or they thought that they had found a magical way to get around the reverse lockout (they might have wanted to this if the mechanism had crudded up and the catch lever broken off short)).
On Phil's truck the lever looks like the longer version, seeming to confirm what the outside truck was showing us, that longer levers seem correct for earlier trucks.
Like all theories, more than one observation is needed for proof.

Phil Waterman · #10 31-10-06, 22:45

Grant, your hunch maybe in part correct- I know from experience that you can install the shift lever either way around. When installing the transmission and engine I always remove the lever and when I put the assembly into the Pattern 12 I installed it the wrong way around made shifting very interesting to say the least. You can also install the lever without the reverse lockout installed, though I don’t recommend it because it makes shifting rather noisy.

Pete Ashby · #11 31-10-06, 22:53

Below is a picture inside the cab of my C15A #12 .

I have never seen a #11 or #12 cab Chev with a shift tower gaiter but Phil notes there is a sponge rubber gasket that fits over the tower and under the cab plate to form a crude seal on the top of the gearbox. I bought mine from Brian Asbury NoS a few years ago now.

Pete

Max Hedges · #12 01-11-06, 08:32

photo of chev truck
Max

Grant Bowker · #13 02-11-06, 02:50

Found in Blueprint For Victory (pages 138-139) photos of Cab 11 Chevs being assembled. The shift lever leans forward, has the reverse lockout catch lever on the right and appears to have the proportions of the long rather than short lever style. Does anyone else have period photos to refer to (before the postwar bodgers got to work confusing us)? I should have thought to look earlier, but....
The only photo found of a Chev cab 13 also has the lever bent forward, catch pointing right.
Not really relevant to this thread about Chevs, but the Ford prototypes shown have the reverse catch lever pointing left.

Bob Carriere · #14 02-11-06, 03:24

So to recap......

Cab 11 and 12 have a longer shift lever and to have the reverse lock out work properly it should be located on the right side of the knob and pulled by the index.....

On close examination of my cab 11 which had the shift lever installed reversed....... Grant and I figgered out that the tranny would indeed shift even if the lever was mounted backward but the cast iron lock out tab in the tranny tower would be inoperative..... which may have been done on purpose when you consider the trcuk was used to plow snow whichimplies a lot of forward and reverse shifting.

Amazingly after cleaning up the tranny tower the locking mechanisms work flawlessly and the rod fell in just by gravity. Therefore it explains my desire to install a boot to keep future crude from falling in and gumming up the mechanism.

I might consider using some stiff black foam as a seal between the tranny tower and the sheet metal cover plate. In answer to Mike.... yes I do have the floor plate..... albeit rusty and will serve as a template to repro a good piece...... thanks for the offer.

Again thanks for all the advice and the very descriptive pictures.

Bob