2015 at the Hammond Barn

[Bob Carriere]

.... my patience with the box is hitting bottommmmmmm

[chris vickery]

Looking good Bob.
Your pics bring back memories of restoring my 12 cab...
I like how you made the bottom framework for the cab.
I made my pieces from flatstock cut out on the bandsaw to the correct radius and pieced into place by cutting out the bottom part of the angle and then wrapping the angle to match the flat radiused piece.
No fancy bending required and just a bit of welding. Of course I had made a template on a sheet of plywood just to be sure using the old frame.
At the end of the day whatever works.
Just wait until you have to re skin the back of the cab.
My windshield frame was custom built from 2 M37 window frames, cut and welded on a jig to original specs using the old refurbished hardware.

[Phil Waterman]

Hi Bob

First we are talking Chevy CMP?

Assuming yes then, as to which way you drive out the lower counter shaft I'm not sure which way it likes to be driven, put it is definitely one way. I believe the end toward the bell-housing is tapered so that it goes in from the rear and is driven out toward the rear.

Someone please confirm, because memory says that someone on MLU has BROKEN a case by driving the shaft the wrong way. (15 minutes later checked the manual and the lower idler shaft goes in from the rear and out toward the rear, my problem was what the different shafts are called.)

Strange you should be looking for transmission parts it is the Second Transmission Rebuild Question This Month I've read. Herman, in Belgium was in touch last week looking for help with getting parts to rebuild the lower cluster shaft bearings for his CMP. His problem was his e-mail would not work to get in touch with Obsolete Chevy in Georgia little e-mail relaying e-mails between the gal who knows what parts they have stashed away, and Herman and his parts are now on the way.

Obsolete Chevy http://www.obschevy.com/Pages/OurCatalogs.html parts is where I've been getting transmission parts for years. They are the ones who had a NOS transmission when I needed on two years ago. You can check on line to see if they have the part you need. But if they don't have it listed give them a call because they have a lot of parts not listed in online catalog because they have only one or two.



Cheers Phil

[Bob Carriere]

Hi Chris

Yes we discussed cutting and doing a curve piece as you mentioned but in the end did the pie cuts and welding.

We have now finished replacing the bottom angle iron. A jig is really needed when you start cutting out parts as the remainder becomes very floppy.

See photos of the semi finished back wall. It has to go back in the jig to finish the reinforcement ribs and tack weld them in the proper spot.

Cheers

[Bob Carriere]

...and it originated froman enquiry from Herman.

It seems that the front bearing.... Hyatt 1206 is no longer available but NTN as a substitute that does not fit.

The counter shaft is 38.mm the ID of the new substitute is 38.44 and loose/

I have ordered both the 1207 and the offending 1206 and await there arrival..... will go into town with the countershaft and try them there for size.

The reverse gear shaft MUST BE driven from the front towards the back or the case will crack for sure. the front end of the shaft is cut semicircle and fits into a beefed up section that effectively keeps the shaft from spinning. The reverse gear rotates on that shaft supported on two brass sleeves/bushings.

To remove the countershaft from the bottom of the case you need to hammer the visible end of the shaft at the rear towards the front..... that will push out the sheet metal cap that sit tight over the front 1206 bearing.

The 1206 from bearing has an insert or bearing race that needs to be removed to fit over the shaft. The shaft measures just under the original 38mm and the OD of the insert is 38.44mm making for a loose fit.

[Bob Carriere]

.....is not very helpful. One would need to call them for specifics on these two bearings.

Still determine to see if there IS a modern substitute that fits properly or start building up a reserve of these odd sizes.

Bob C

[rob love]

The original GM part number for the bearing of 142260 comes up on ebay a couple times.

As well, for cross reference purposes, here is a link to the NSN for subject bearing, along with other part numbers (and the code for the manufacturers) of the same bearing.
http://www.dlis.dla.mil/webflis/pub/...4596&newpage=1

Some examples are: EMERSON POWER TRANSMISSION CORPORATION
ROLLWAY BEARING pn UM1305B108

CNH INDUSTRIAL A18182

MERITOR 1228H268 or 2338N580

The NSN page also gives the GM part number of 7451442, which on ebay leads you to these: http://www.ebay.com/itm/GMC-roller-b...item1c4e05e032

The dimensions he gives are somewhat off, but they are a hyatt 1206, are in Quebec Canada, he has plenty, and they are $6 each.