Any one have any experience with a Gear Vendor? Thinking about one for me 1976 Dodge 360 with TBI. I get 9.5-10 mpg now, hoping for more.

What are your thoughts?

Views: 195

Reply to This

Replies to This Discussion

Hi Jack! use the tine search box top right. there quite a few good article/discussions on gear vendor installations, including the need for some fabrication.  I wonder what your differential gearing is now and if just swapping to a "taller" gear ration would work and still pull the rig up 7% grades?  

I could change the rear end gears and get better fuel mileage.  With the Gear Vendor I can split gears and get about 20 % less rpm down the freeway.

I may have a problem with a taller rear end when I tow my car and go up some step grades so that is why I was thinking about the Gear Vendor.

There are several manufacturers of a Gear Vendor unit. They have several models that fit onto the Back of the tranny, eliminating a carrier if you have one,, and a unit which is old school that mounts on the input shaft of the rear differential. Basically adding an additional gear,(think over drive gear). My Dodge Diesel had a 2 speed rear end, and all it was,,was an installed extra gear on the differential input,, leaving the original 4;10 axle ratio. Was great on the straight away having that *extra gear,, and can flip a switch on the shifter to drop it out of the *overdrive,per say for a steady incline... With an average rating of a 20% increase in economy,, if you keep the rig for a couple years, it actually pays for itself and it helps you keep up with the flow of traffic.

Do you know the name of the manufacturer? has some specs of their products, with newer and more efficient units.

My gear vendor unit was built by DANA corp..

Hi jack!  yes, if you're towing a car changing out the rear end wouldn't be a very good option. Let us know what you wind up doing and how it works out.

Pat is right, if you change the gear ratio to a higher gear ratio, you will end up LOADING up the engine, putting to much demand on it with low RPM's, resulting in you having to drop down a gear to get back into the power band to have the torque to pull. The only efficient method is adding an additional gear for a steady flat highway speed with lower RPM' without dropping so low as to load up the engine. Motor homes a.k.a.  3/4 and 1 ton chassis vehicles use the 4:10 / 4:11 gear ratio's. With the idea being that these heavy duty trucks usually cruise at or around 55 mph. Max.

I know that changing the gear ratio is not a good idea, I was looking at the idea of a two speed rear end but I think that I will stay with the gear vendor.


Greetings Jack, A year or so ago I was in your position and was looking at adding an over drive unit to the Palace. I done some research but decided to leave well enough alone because of the cost and recovery; I didn't see it to be a good fit with my only using the Palace to travel around the state of Ohio and surrounding areas. I didn't think I could ever justify the cost.. Now for some one on the road a lot would be a different story. One option I found with Gear Vendors was a system that came in between transmission shifts.; tranny goes to first then GV comes on some where between first and second and so on. in essences making a four speed an eight speed. I didn't get way into this unit because it cost $2,700 or so according to the wright up I was reading. Then there is just the standard bolt on O.D. but you will still be paying out some green for that as well and for both you will have to replace the drive shaft. All the peripherals aren't cheep either. There is an other option you could toy with to some degree without re gearing or adding an OD unit and that is tire size. You can do this by comparing ratio's and doing the math without buying any thing. I know that when I went to my current tire ( 9.50 x 16.5) up from eight something. it made the Palace a lot better in ride quality and possibly even a little better on gas. I never have checked fuel millage on my Motor Home; if i did I would probably park it LOL. Any way you spin it, It's going to be expensive and you aren't really saving anything if you don't have a chance to recoup your investment. Your not saving anything if you don't at least do that.

Thanks Rich. That is the 64 thousand dollar question. How much will I use it to recoup my investment. Best laid plans of mice and man.

I do not believe that I would ever get my investment out of it but I may if I sell it. I have visions of keeping it for many years to come and I like to travel a lot.

I need to do a lot more thinking on the subject.

Thanks for your input. I value it greatly.


I had a 1977 Dodge Tioga with a 360 and 3 speed. We got about 9-10 mpg and from all the folks I talked to that is the best you're getting unless some major weight and/or drag reduction is happening. That's actually not bad for a Class C that's 40 years old. I think that messing with it now will only reduce your mileage or any reasonable payback. I spent time updating stuff like the electrical generation, swapped to LED's everywhere and was planning solar until the LH1 bombed out in Florida. Now we have LH2 (Tiffin Allegro 1987) and am planning some new trips this year. Best of Luck.

Thank you Daniel. The more that I think about it the less that I want to do it. I have all of the power that I need and the mileage is good. I believe that it was a thought in passing and a little bit of boredom on my part. I have always had a saying "it it is not broken, don't fix it."





  •         How To Links 

-Search Good Old RV's

-Start a New Group 

-Roof Repair Photos & Products

-Repair an RV Roof

-Pick Roof Sealer   

-Understanding RV Electrical Systems 

-Get RV Insurance   

-What to Look For When Buying a Used RV

-Jack Installs Fuel Injection in his Dodge 


 Paige's VintageTrailer Art  

 Paige's VintageTrailerFabric

 Artist Roads                                            Sandy's Stained Glass     



If you love classic and vintage RVs then come Join us. Come on in and have some fun. JOIN HERE NOW

Blog Posts


Posted by Linda Lee Toepfer on January 18, 2021 at 1:40pm

1982 Chevrolet Travel Mate Class A

Posted by Barb Stanley on December 17, 2020 at 9:15am

Looking for help identifying this camper

Posted by Jeff on October 7, 2020 at 12:57am — 1 Comment

Balboa owners

Posted by Bill on May 19, 2020 at 8:11am


Posted by Eddie Marquez on May 5, 2020 at 2:34pm


  • Add Videos
  • View All


If you love classic and vintage RVs then come Join us.

 Come on in and have some fun.         JOIN HERE NOW!

 Dedicated to a simpler, more rewarding and fun way of life in a Good Old RV... 

Vintage Travel Trailers, Vintage Campers, Camper Restoration, Bus Conversions, Vintage RV Forums, Old RVs, Tiny Homes, Boondocking


A work of art by member Paige Bridges

Get your Good Old RVs T-Shirt HERE


 Disclaimer - Please Read it

Enjoy this site and use it totally at your own risk.

By using or viewing this site YOU agree to Hold Harmless anyone associated with it including other members. Also, YOU agree that YOU are solely responsible for ANY and ALL actions, results or damages. Members "opinions" are just that and any repair or alteration comments or recommendations are by folks who are not licensed repair  or mechanical professionals. Any repairs or modifications you do totally at YOUR OWN RISK. Use licensed professionals for all work to avoid possible serious injury or damage. Use  banks for purchases.  Have fun!

Copywrite & Trade Mark Registered GoodOldRV© ,GoodOldRVs©,©,©,GoodOldRV.Com©

© 2021   Created by Russell E Johnson.   Powered by

Badges  |  Report an Issue  |  Terms of Service