RV and motorhome transmissions

A-1 Transmission works on RVs alongside cars, trucks and 4x4s. This page explains what is different about a motorhome drivetrain and what owners should have ready when they call.

At a glance

• RVs and motorhomes are on the shop's list of vehicles
• Automatic and standard transmissions and transfer cases are listed services
• Weight, heat and long idle periods are the main wear factors
• Call with the chassis make, year and engine

What is a motorhome drivetrain?

A motorhome is a living space built on a truck, van or purpose-built chassis. The transmission under it is often related to those used in pickups and commercial trucks, but it is asked to move far more weight, and it does that with a body that catches the wind and a long wheelbase. Wikipedia's article on motorhomes describes the main classes and how they are built, and the chassis maker's manual is the place to find the exact transmission and fluid for your coach.

Because the coach is a home as well as a vehicle, its weight changes with water, fuel, gear and passengers. The manufacturer's weight ratings in the manual set the limits, and exceeding them is hard on the drivetrain.

Grades, heat and the high desert

Reno's normal July high is 93.9 F and August is 92.1 F (NOAA 1991 to 2020), and a loaded coach climbing out of the Truckee Meadows on I-80, US 395 or US 50 can raise transmission temperature well above the air temperature. Heat breaks down fluid and wears clutch material. A transmission temperature gauge, where one is fitted, is worth watching, and the towing and heat guide covers what to do when it climbs.

Winter brings different risks. The Reno normals show 5.2 inches of snow in each of December, January and February, and coaches that travel to the Sierra pass through cold mornings when fluid is thick; the cold mornings guide explains why shifts feel slow.

Storage and seasonal use

Many RVs sit for months and then go out for a long trip. During storage, seals can dry, and fluid that has not circulated may behave differently when the coach is first driven. Check for drips under the coach before a trip and compare the fluid with what the owner's manual describes. A spot on a clean driveway or storage pad is an easy early warning.

Signs a motorhome transmission needs a look

• Slipping or a rise in engine speed without matching road speed on a grade
• Hard shifts, or shifts that hunt between gears
• A warning light or a transmission temperature reading that stays high
• A burning smell after a climb, see burning smell
• Red or brown fluid under the coach

If the coach slips or overheats, call before driving it far. If it will not move, see getting a vehicle that will not move to the shop.