Page 20 - Spring 2018 GMC Vintage RVing

Technical Corner MAINTENANCE, PARTS, TIPS, INNOVATIONS AND MOREMINI TECH SESSIONSThe Mini-Tech Sessions consist of a 15-20 minutetech/informational sessions that features one thing that the presenter wishes to share. What is that one thing that youmay wish to share? No formal powerpoint presentation or handout required. Email [email protected] for more info.>> GMC Curb Feelers and Gas Nozzle Adapters| John A. ChalfantHow do you protect your new alloy wheels when you get too close to a curb? John came up with an adaptation of an old 50s idea of curb feelers. These are made to fit the GMC and “warn” you when getting too close to a curb or other obstruction on the right side of the coach. These curb feelers make a huge amount of noise when hitting something. Fueling our coaches in California can be a challenge because of the vapor reclamation requirements for gas pumps. The nozzles are large and do not fit into our fuel fill area well enough to trigger the pump. John developed an adapter that fits into the gas fill tube and extends enough to allow the gas nozzle to function as designed.>> How to Repair the Broken Dash Sub-Structure| Richard HugginsThe sub-structure for the dash can deteriorate (especially on the ’77 and ’78) to the point of collapsing. Options are to replace with an expensive new dash, e.g., the Mac Dash or repair. During this session, John discussed his approach to repairing the sub-structure. There are 17 pieces making up the structure. John explained his approach showing pictures of the process. His technique involved welding the pieces back together. However, this is not the end product. The key is to epoxy the pieces after they have been reconstructed. Being good at jig-saw puzzles is an added benefit. To place the structure back into the dash, John used a mirror to see behind the dash. Working with a mirror was a challenge because everything is backwards. Working under these conditions with a soldering iron resulted in some burned hands according to John. Finally, back together with dash cap back in and stronger than ever.>> The GMCMH Curve and Window Treatments| Gary CoasterGary bought the Guske’s coach a few years ago. The Guske’s were a vendor providing blinds to the GMC Community. After they purchased the coach, Gary then took over the blind business and now offer blinds to the Community. Gary discussed the challenges associated with the unique curvature of the GMC Motorhome. He indicated that most of the industry provides day/night shades but most are gravity hung shades so do not conform to the curve of the GMC which is 51⁄2 inches from the window when measured in the center from where the blinds attach at the top and bottom. A good understanding of how to approach window blinds or curtains in the motorhome can result in a good installationand years of enjoyment.>> Tips and Tricks on Tackling the Interiorof your Coach | Forest CrowForest discussed things that one can do to make your coach more personalized. He discussed flooring and sources for materials.He explained how he approached replacing the headliner in hiscoach. His technique allows you to take the headliner down without removing the cabinets. When chasing leaks, Forest figured out howto piece the rear ceiling end cap that makes it much easier to remove. He also explained how he built valances for the windows to helphold the curtains/blinds against the wall. Forest talked about how he eliminated problems with vapor lock by putting a diesel fuel filter canister just prior to the mechanical fuel pump. The purpose is to keep a small reservoir of fuel available closer to the engine. Forest finished up by talking about how he converted the rear full size bed into twin beds without moving the bath module.>> GMC Unplugged – Solar SystemsAND Dry Camping | Carl Stouffer & Chris ChoffatIn this session, discussion centered on how to efficiently dry camp without the need to frequently run a noisy generator. Replacing all lights with LEDs greatly reduces the power demands. If the original Norcold refrigerator is still in use, then replacing this with an absorption fridge that runs on propane replaces the largest battery draw that original coaches have. An inverter helps power 120v accessories while dry camping. For serious dry camping, the addition of solar panels helps keep the batteries charged eliminating the need to runthe generator nearly as much. The second part of the session talked about components needed to install an efficient solar panel system and how these systems operate. Discussion centered on sizing the panels needed for your needs. A single large watt panel, multiple smaller watt panels, the type of charge controller, number of batteries (amp-hour requirements) are all factors in making decisions about what equipment is needed and how to install a solar system.>> Transmission Rebuilding | Manny TrovaoManny describes in detail how he rebuilds the 425 transmission used in the GMC Motorhome. Initially, the transmission must be disassembled and Manny talks about the process of removing the components and his decision to clean and re-use parts or discard and replace with new parts. He noted that replacement parts are becoming more and more difficult to locate. Manny removes all bearings and bushings, replacing them with new. He then explained some of the “special” things he does to make the transmission more durable. These include things like wider bands, using metal versus plastic parts, and modifications to allow for better lubrication. The case is cleaned and reassembly is started. Each component is installed with appropriate lube being applied. According to Manny, shift kits are not a good modification for our motorhomes. Governors for the 425 are getting hard to locate. Manny cleans and20 GMC VINTAGE RVING MAGAZINE | GMCMI.COM