cab spotweld sequence?

[aerotruk63]

In what order do you think the different pieces of cab were spotwelded together?
They would have had to leave openings for both tips of the spotwelder to make contact.

[Keith Seymore]

The build starts with the floor pan, adding internal structure which will be later used to attach the door rings and rocker outer panels. Front of dash is built up separately, then conveyed to the main line and added to the floor pan. Door rings and the cab back may have had some small details added and were then conveyed to the main line. The roof outer panel goes last. Squarebodies had a small strip of braze applied to fill the seam between the top of the A pillar panel and roof outer, which was then smoothed down by grinding.

Cabs can be diverted into a short repair area or sent directly to an accumulator, which banks parts prior to paint in order to allow the paint and trim lines to continue to run in the event of downtime in the cab shop. (Some assembly plants, Fremont in particular, did not have an accumulator but built straight through the process with no banking or re-sequencing of the build).

I know I've seen some pictures of 60-66 trucks in the cab shop but was not able to find them quickly. I looked in the restoration thread but they may have been Photophuck'd.

http://67-72chevytrucks.com/vboard/s...hlight=Fremont

http://67-72chevytrucks.com/vboard/s...sembly&page=10

I should add that the cab is "framed up" by hitting the critical spot welds and then later goes through a "re-spot" process where the (intentionally) missing gaps in spot welds are filled in.

By the time the squarebody came around the pickup cab build was fully automated. Workers fed the individual parts into the conveyers and a complete cab popped out the other end. Flint Line 1 was fully automated, but Flint Line 2 (Suburban and Blazer) was still a manual process until the end of the squarebody run.

http://www.73-87.com/7387info/Assembly%20Line.htm

In most cases the assembly plant uses existing openings to reach the back side and complete the weld. Different lengths and shapes of "pincers" are used in order to accomplish this. If there is an inaccessible area the plant objects to, and the several different assembly locations are in agreement, engineering will make a design change to the product to help facilitate access. It sounds easy but due to differences in process and personality it is hard to get seven or eight assembly plants to agree on anything.

It's pretty amazing. It's like smashing a bunch of Campbell's soup cans into small shapes and welding them together until you have a pickup cab.

K

[Keith Seymore]

In the picture above the small cart ("body truck") supports the cab floor and forms the basis of the mobile fixturing. Each cart is assigned a number for tracking purposes, maintenance and to assist in problem diagnosis.

For the plants that I am familiar with the body side "gate" (the white fixture shown) rides along side the vehicle until the door frame is secured, is removed and cycles back for reuse. There are several fixtures in use at a time; they are also numbered for the same reasons as mentioned above. This carousel technique is used in other areas of the plant, too (A/C evacuate and charge, for example) where the cycle time exceeds the amount of time the vehicle is in station.

In some plants (Pontiac Michigan, for example) the body side gate number is stamped on the cowl tag in order to document which fixture was used, as an aid in problem diagnosis.

K

[aerotruk63]

Thank you Mr. Seymore. Informative presentation..