I thought I'd share a lesson I learned this week about my GearVendors Over/Underdrive on my 1984 Chevy P32 chassis.

I got it stuck in the mud in my drive. I was in reverse getting it out. I went to forward and then back to reverse and NO REVERSE. Mind you, I was not "rocking" the transmission from drive to reverse....just merely going from one to the other after stopping. I thought I had knocked out REVERSE in the 475 Turbohydramatic (yes, 475 not 400). So we took out the trans and GearVendors and took them to a rebuilder. Nothing was wrong with the trans but there was NO REVERSE in the GearVendors. I called GearVendors and talked to Mike. They were very helpful. Mike explained to me that the GearVendors has a very small reverse band...only about 1 inch wide. If you have a VERY HEAVY coach (mine is 34 feet or and I think 15,000 lbs), this can be a tremendous strain on that tiny 1 inch band. He told me that you had to be careful backing up with a GearVendors up inclines or things like backing up onto leveling blocks....you could easily burn out the reverse band. You should NEVER put your leveling blocks behind the wheels and back onto your blocks BUT in front of the wheels and DRIVE FORWARD ONTO THEM. After I hung up with him, I got to thinking and realized the people I bought the coach from, had a rather tall curb that you had to "jump" to back into the drive where they stored the Barth. More than likely, most of the damage was done before my driveway episode.

The final part of the story, is that if you have problems with your GearVendors, they will ship you a rebuilt unit with a one-year warranty for $850. I didn't think that was such a bad deal considering the unit is $2000 to $3000 new. My other option was to try to find a replacement driveshaft (Probably $200-$300) and miss the quietness of the overdrive and the gear splitting capabilities.

Thanks all of you all for the tremendous help you have been with all of your posts. I hope this helps someone else out before they do what I did!

K&E

The reverse clutch in the GV is the same size as the drive clutch. It is just that the reverse torque "pulls" the clutch off of the drum. The big killer is that if the GV is on in it's "Manual" mode, and you are reversing at more than 20 mph, which is easy to do with wheel spin, the unit will self-destruct. Make sure it is off. I have been selling and installing Gear Vendors since 1983 and every vehicle I had owned until the 2002 Chevy with Allison, had one. My rig tipped the scales at 29,960 lbs, the GV is rated for 30k. It is a fantastic unit.

Billy,

Could you explain more about the manual mode and the reverse situation? Thinking back, I was spinning the tires when this happened. What I had in the post was what Mike at GV explained or more like what I interpreted in a 5 minute phone call. Why does the GV have a reverse in it? I would have thought an overdive unit would have only have something to do with forward gears and I don't understand the reverse segment of the GV. Also, if the unit should be turned off in a reverse situation, what about installing a relay wired to the back-up lights that would kill the power to the GV when shifted into reverse? Would that keep something like this from happening again? Thanks, K&E