Revcon Class A

Straight cut gears are stronger, but noisier. Feeling was that the torque multiplied by the low gears could break things. The VP of engineering at Revcon was very well known in Formula 1 racing - wrote the book on aerodynamic down force. (The T22 he designed had enough down force that at 100 mph, it could have run around the track upside down) But anyway, racers can break anything, so I think that drove the thought process of the design.

Dave, why the straight cut gears in 1st and 2nd?

The Dana 70 is chopped off on the ends. Axle half shafts use U-joints on the inners, and C-V joints on the outers. Photos on this page:
http://s213.photobucket.com/user/Daveinet/library/Engine?sort=3&page=1

tatest wrote:
I see more GMC motorhomes in actual use, not often restored to vintage condition, just in usable condition. I suspect as a project, the GMC is less expensive, and there were more of them made to serve today as a supply of cannibalized parts.

You kind of answered your own question. There were about 12,000 GMCs built, and only about 2000 Revcons built, which makes a Revcon much more rare. As far as cost to work on, the older Revcon that was based on the Toro drivetrain was considerably lighter than the GMC, which meant a lot less stress on the drivetrain. The newer drivetrain, most parts can be bought at NAPA, once you know what you are looking for. As a project, it really depends which part of the project. GMCs often get all the interior cabinetry replaced, where a Revcon, there would be little reason to. The shell and frame integrity is stronger as well in the Revcon.

Dave,
I enjoyed reading your drivetrain description. I am curious about something. Does the Dana 70 have u-joints or cv joints at the wheel ends? I would guess cv.

whem2fish wrote:
give dave time to check o he has the 502 fire breathing dragon

X2... oh oops that's me, aaa...OK.

The gritty: At that price, you want to know a few things. First, the front suspension should not have ANY signs of wear. Front end parts are expensive, he is asking top dollar, so one needs to know they will not be investing money in expensive repairs. For the price I would expect more than just "mechanically sound". He mentions the front windshield is cracked. The windshield its self is only around 500 bucks, but to replace it is around $2000.00. The reason is that to pull the windshield requires trimming off some of the fiberglass around the windshield and then repairing it, once the windshield is replaced. If you look closely at the fiberglass, you can see a seam where it is designed to be separated, so the windshield can be removed.

The Good:A Revcon in good condition is a wonderful coach. It is by far the best handling full size motorhome ever built. Aircraft aluminum stretchform shell is structural. Interior cabinets are Wilsonart lament formed over a solid wood frame, with honeycomb support inside - extremely light weight, but very strong. I can easily hang my full body weight from the upper cabinets. This design means the center of gravity is around 30 inches from the ground. Unless you hit something sliding sideways, this things is impossible to roll - and yes I have slid the front end in a hard swerve - swerved so hard I pulled a muscle in my back - yet no sway or loss of control. I have driven 70 down a 2 lane road, and when meeting a semi oncomming, let go of the steering wheel, until he was passed. The coach just stayed straight, with no movement from wind. I have been in a microburst, estimated 90 mph crosswind. The only problems I had was the wind hit the side of the coach and blew up the wall, pulling my window awning open. That and the window drain holes were spraying water straight into the coach. No problem driving in it, other than visibility. I did pull off at the nearest exit to secure the awnings.

more good: As mentioned, the cabinets are Wilsonart laminate. The laminate is very strong and durable. On a 30 year old coach, most interior cabinetry will look just like it did when it left the showroom. The upholstry will show wear, but the cabinets will look new. The interior walls are plastic coated aluminum, which provides a surface that is durable, cleanable, and does not rot. This is a low profile motorhome, so the underneath storage is shallow, however the interior storage is very good. Lots of usable space. About 10 years ago, someone posted they traded their 33 footer in for a 37 footer multislide with full size basement. They found they had difficulty fitting everything in from their old coach.

Things you should know:The Revcon is a very well built coach, with great handling. But FWD coaches, while they handle well, do require the front end to be in good condition. Not that the front end parts wear significantly faster than a rear wheel drive coach, but that when parts do wear, it aggravates the handling worse than a conventional drive train. The engine is a stock 454 truck engine with a Revcon specified trans - meaning Kevlar bands, straight cut gears in 1st and 2nd, and a Revcon built torque converter. They use a custom transfercase/chaincase and then run the drive shaft forward. The front differential is a Dana 70 run in reverse. Even though the Dana was specified for front drive, the diff does wear faster in that position than it would in the rear position. It is not a high pinion diff, or reverse cut gears. Crazy as it sounds, differentials twist under load - a lot. The carrier twists which causes wear on the sleeve where the bearing race presses on to wear. Eventually you loose mesh, and break teeth. The solution is to use a Tru-loc carrier, which is much tougher than stock. I also have girdles and a custom made cover to stabilize the bearings, so they do not move under load. I don't expect mine to ever break. OK, 600 ft-lbs of torque and a hard shift from 4th to 2nd at 50 mph may not have been fair to the stock diff. But I was doing over 85 by time coach plus toad got past the slow truck.

Lyle also posts here sometimes, he may be able to give another perspective. He is running a modern 8.1 in his coach. Not sure why, but it seems gear heads gravitate towards Revcons.

There is one on craigslist oregon Dayton, $8500 pretty cool and in very good condition.

Pogoil.

gi ve dave time to check o he has the 502 fire breathing dragon

GM started building the front-drive Olds in 1966, front-drive Cadillac in 1967, using the Olds-developed drivetrain package but with Cadillac engines instead of Olds engines. Cadillac has been making front-cars ever since, Olds was making them as long as Olds was making anything.

The Olds-powered drivetrain found its way into the GMC motorhome, 23 to 26 foot. Early models got the 455 Olds, then the 401 Olds when they stopped making the 455. GMC motorhome was discontinued before GM went to corporate engines replacing each division making their own.

Revcon (which has made a lot of things other than motorhomes) started building a front-drive aluminum shell motorhome in 1968 using the Olds Toronado drivetrain. They kept making front-drive vehicles using this package until it was no longer available with large enough engines, then built their own drivetrain for the next ten years. The one you direct us to is late enough vintage to have the Revcon drivetrain rather than the Olds. It still has a lot of GM parts, like the Chevy engine and a large TurboHydromatic transmission.

I've seen Revcons from this era parked in fields, as well as contemporary (but fundamentally different) FMCs. I don't see many in campgrounds or on the road, and I think people buy them as restoration projects and get discouraged. A restored, fully functioning Revcon has to be really worth something, like a classic limited production luxury car.

I see more GMC motorhomes in actual use, not often restored to vintage condition, just in usable condition. I suspect as a project, the GMC is less expensive, and there were more of them made to serve today as a supply of cannibalized parts.

Hi--try their website for Revcon owners--www.revconeers.com
Pretty cool, all aluminum. A little long in the tooth for today's world.

Air Force used to use them. Of course they were stripped out, no windows, and we had some very nice electronics in them. Had the transmission go out in one, the hill was too steep for the added weight and a rookie driver.