Clue: it was a nickname given to a venerable Studebaker sedan.
The answer is "Sweet Chariot" was the nickname given to unreliable vehicle used to transport "The Four Horseman" from camp to camp during the summers of 1927-1930. Together the four covered almost 7,000 miles in each of the four summers.
The Four included: Chauncey Shamberger, known as "Chief," who was the administrator, Dan West who was the discussion leader, Al Brightbill the music leader, and Perry Rohrer the recreation director. Joe Van Dyke joined the other four in the summer of 1929.
These men went from camp to camp, week after week, providing leadership to campers. Taking turns driving, they usually traveled on Sundays to get to the next camp, bouncing along graveled roads at an average of 35 miles per hour. On one occasion, by changing drivers frequently, they left a camp at New Windsor, Maryland, on Saturday morning and were signing in campers near Palmer Lake, Colorado, on Monday morning!
While traveling on Sunday they would frequently develop their own "Sunday service" as they sang all the songs and hymns they could remember. Al strummed his guitar in the crowded car filled with the five men. In the midst of the songfest Dan enjoyed telling about the black conscientious objector who stepped out of rank and sang a spiritual.
Camping for "The Four Horseman" as they became known to the church, was not a vacation but was a serious responsibility to make each camp meaningful for each young person. They were trained specialists and carried a heavier load in each camp than those who came as leaders from the local area for a given week. Traveling together from camp to camp was a time to joke and poke fun at each other, trying to relax as they eagerly looked forward to the next camp.
As so it was eighty years ago as the camping movement was beginning in the Church of the Brethren that "The Four Horsemen" spent four summers traveling across the country in an old Studebaker sedan that came to be known as "Sweet Chariot."
Source: Passing on the Gift: The Story of Dan West, Glee Yoder