There are only so many things you can do to certain trucks before the work and the parts needed surpass the intent of having the truck. Sure, many old trucks today get partially or fully updated with brakes, suspension, and drivetrain pieces that make that vehicle not only fun to look at and drive, but also competitive out on today's roads and the traffic that plagues them. However, not all classic trucks are meant or destined for such/much use, but you want to enjoy time behind the wheel as much as possible.
Driveline gearing is one area that can really help an otherwise stock truck be more fun to drive and actually safer out on the road. Most old trucks were geared to haul something from point A to point B with little regard to freeway cruising speed. More often than not, there is a numerically high ring-and-pinion ratio in truck rearends to help in the hauling department, with 4.11:1 being average. Later in the 1970s there were more 3.73:1 or equivalents to help in the driveability department, but if you have a closed-drive pre-'55 Chevy truck you are stuck with 4.11:1 or even 4.57:1, which makes that six cylinder spin pretty hard out on the open road.
Of course, many owners of these early Chevy trucks have ditched the closed driveline for a later (often S-10) rearend and an open-drive Saginaw transmission, but by swapping the stock ring-and-pinion with a 3.55:1 gear set from Chevs of the 40's, you can keep the underside of your Chevy basically stock and cruise easier-500 to 800 rpm easier at 65 mph depending on the ratio you start with.
We brought this clean, original '50 Chevy half-ton over to California Transmission Rebuild
Chevs of the 40's has brand-new 3.55:1 ring-and-pinion sets in stock, and a comprehensive installation kit is available too. The install kit has all-new bearings, seals, gaskets, and more to completely rebuild your rear differential. Of course, this is somewhat of an involved job and requires some specialized tools like a hydraulic press, bearing pullers, feeler gauges, and a magnetic-base dial indicator, but if you can borrow or buy them and follow detailed instructions, you'll be good to go.
One other area of concern is that these trucks have been on the road for 60-plus years and the rear differential is one of the hardest worked areas on the truck. One of the common parts that needs to be checked is the carrier housing that the ring gear bolts to. The carrier bearing races often have spun on the carrier housing rendering the carrier housing junk. Unfortunately the rearend needs to be disassembled to inspect these areas and new carrier housings aren't available at this time.
We were turned onto California Transmission Rebuilders in Torrance, California, by a few of their happy customers. Gilbert, the shop owner, has been working on vintage drivelines for many years, so we decided to watch the pros as they walked us through replacing the 4.11:1 ring-and-pinion in a '50 Chevy truck with the 3.55:1 gear set from Chevs of the 40's.
Before we get started, here is the heart of the parts being installed from Chevs of the 40
Along with the ring-and-pinion set, Chevs of the 40's has a complete installation kit that
With the truck in the air and the wheels off, the rear differential cover is removed and d
While the differential is draining, the retainer on the slip joint/yoke ball is loosened a
Next, the transmission needs to be supported so that the tranny mount and crossmember can
Back to the rear of the differential, the first thing that needs to come out is the differ