Home Zephyr: Our 1961 GM 4106 Vintage Bus Conversion

Zephyr: Our 1961 GM 4106 Vintage Bus Conversion

GM PD-4106-446

Meet Zephyr – our full time home on wheels!

Our bus in service as a regional charter passenger coach in the early 1960s.

Our bus began life in September 1961 as a regional charter tour bus in Arizona for Citizen Auto Stage Co out of Nogales, AZ – and is serial # PD4106-446.

While our bus was never a “hound” – this model of bus was designed in cooperation between GM & Greyhound to be the heart of their fleet in the 1960s. It was designed to seat 41 passengers and carry all their luggage.  With its aluminum construction and beefier engine, the 4106 was considered the ‘sportscar of buses’ for its day.

Our bus was converted and titled to be Class-A motorhome in 1989, and had less than 20,000 motorhome miles on it when we found it in Yuma, AZ in June 2011.

She’s 35′ long, 96″ wide and weighs in at about 24,000 lbs.  She has a 2-stroke 8v71 Detroit Diesel engine, with Allison v730 automatic transmission.

We did extensive research on bus conversions starting in spring 2011 after deciding it was time to sell our prior home on wheels – a highly geeked out fiberglass 17′ Oliver Travel Trailer that we traveled in full time for 3 years.  We even bought an Amtrak Rail Pass to travel the country to look at buses and learn from other ‘busnuts’.

Our bus before and after her first bath.

We found our bus on Craigslist, and the ad was so simple and lacking in details that we almost didn’t go look at it. But we are so glad we did!  When we walked in, it held more promise to become our ideal technomadic home than any other bus we had looked at.

The interior was well designed (with solid wood cabinetry), the engine ran strong and the body straight & nearly rust free. She needed to be caught up on nearly 15 years of neglected maintenance – but she just begged to be given a chance to go out adventuring again!  We said YES!

We’ll be working on updating the bus and making her truly ours as we travel full time.  We’re doing some projects ourselves, some with help from friends we visit and hiring professionals with tasks well beyond our skills and available tools.

Our Dual Desk setup.

Our Dual Desk setup.

Kitchen Re-remodel with slide out counter extension.

The Living Room looking forward

The Living Room looking forward

The new bathroom countertop and vessel sink!

Our engine bay before and after our engine overhaul in summer 2013.

Our engine bay before and after our engine overhaul in summer 2013.


Our Fall 2014 Project - installing 800w of solar at AMSolar.com.

Our Fall 2014 Project – installing 800w of solar at AMSolar.com.

Thus far we have done:

  • 800w Solar Panel Installation at AMSolar
  • Massive interior updating (new floors, kitchen, bathroom, ripped out the dinette, installed a dual computer desk, put in cat doors, re-covered valences, etc).
  • Lots of gadgets that help keep us online
  • Built a cutting edge Lithium Ion battery & Victron MultiPlus inverter
  • Massive amounts of house systems revitalization (plumbing, electrical, etc.)
  • Replaced the fridge with a Vitrofrigo Danfross compressor model (12v/110 electric only)
  • Replaced one roof air with a Coleman Mach 8 (with heat pump and strip) when it went out, our remaining A/C is a 1980s Dometic Penguin DuoTherm that continues to chug along.
  • Converted to LED lighting
  • Replaced all of the dash gauges with custom designed gauges from SpeedHut.com.
  • Had a major out of frame engine & power system overhaul at Interstate Powersystems after our engine overheated.
  • New driver and passenger seats (by Flexsteel, installed at Bradd & Hall in Elkhart, IN).

Summer 2015 Upgrade Projects:

Zephyr is currently at Master Tech RV in Elkhart, IN getting some major renovation work done. On the task list includes:

  • All new windows – upgrading to dual pane.
  • Replacing our diesel generator with a smaller propane powered one.
  • Replacing our hot water heater with a Precision Temp propane hydronics system that will also be for engine pre-warming and furnace.
  • Repaint the exterior, body work and awning replacements

For a full list and details of the projects: Zephyr’s Summer 2015 Renovation Hit List


Our aim is to create a versatile coach for a variety of environments and camping situations – from boondocking off-grid for weeks at a time, drive-way surfing with friends & family, scenic public campgrounds to going pole-to-pole in urban RV Parks.  Our pace of travel varies quite often, and we want to be comfortable whether we’re just overnighting or pulling in for a few months. We like to mix it up.

Our 2009 MINI Cooper, named Pixel, is our ‘toad’.

We tow a 2009 MINI Cooper (manual transmission) behind the bus as our primary means of local transportation when we’re parked.  We also enjoy walking, using public transportation and intend to eventually add folding bicycles that fit in our bays.

More Information on our bus:

The Story of our Bus:
Why we sold our Oliver 
Why a Vintage Bus?
Our Search for a Vintage Bus
Buying our Bus
To Tow or Not To Tow (a vehicle behind)

Remodeling & Project Logs:
(July 2011) Interior Remodeling: Round 1
(October 2011) Interior Remodeling: Round 2 – Dual Desk
(August 2011) Our Lithium Iron Battery (LFP) Research, Cost Analysis and Installation
(January 2012) 7 Months in a Bus (Review of bus life, plus maintenance & remodeling costs so far)
(February 2012) Our Propane Free “Goal”
(March 2012) Kitchen & Bathroom Remodel
(March 2012) Project Dominoes – Simple Refrigerator Replacement sparks 33 other projects
(Updated continuously) Our Mobile Internet Gadgetry Setup
(June/July 2013) Our 8v71 Engine Rebuild
(May 2014) Shopping & Installing RV Seats in Elkhart, IN
(May 2014) The Master Tech Marathon (major electrical re-wiring project)
(June 2014) Three Years in a Vintage Bus (update on our maintenance & project costs, and thoughts on living in a bus conversion.)
(Oct 2014) 800 Watt RV Bus Roof Solar Install
June 2015) Zephyr’s Summer 2015 Renovation Hit List

Listing of the RV Gear we’ve selected or “Stuff in our Bus”

Further resources:

Bus Conversion Magazine: Considering a bus conversion yourself? There’s no better resource than this magazine. Subscribe immediately, order some back issues – you’ll learn a bunch. Their forums are full of fellow ‘bus nuts’ (you’ll soon understand.. owning a bus conversion takes a nut) who have far more expertise than we do. Ask your questions there, you’ll be tapping into a wealth of information.

US Coach: 888-262-2434 – If you own a bus conversion, this number should be on your speed dial. Luke stocks a lot of parts for these machines.

Take a Video Tour of our Bus:

 Our Bus Photo Album

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