Gear Vendors Under/Overdrive Transmission – Hot Rod Approved

Hot Rod Approved

The Gear Vendors unit is a supplemental planetary gearbox that adapts to the output shaft of your existing transmission to provide an extra gear of 0.78:1. The initial benefit is the addition of a 22-percent overdrive in high gear, but because the Gear Vendors can be engaged in any gear, it actually doubles the number of ratios available in any transmission. For example, your TH350 becomes a six-speed (First, First/Over, Second, Second/Over, Third, Third/Over). Likewise, a four-speed manual or automatic becomes an eight-speed, and a five-speed becomes a ten-speed.

Here’s why you care:
First, because most street cars will go quicker down the dragstrip if you can split the gears, since the engine stays closer to where it makes peak power. On the street, the Gear Vendors allows you to always find the right engine rpm for the conditions. Ever climb a hill with your 700-R4? In many cases, Overdrive is too high and Third is too low. With a Gear Vendors, choose Third/Over and you’ll hit the engine’s sweet spot. Finally, on the highway, your engine’s comfortable cruise rpm will result in a mph that’s 28 percent faster with the Gear Vendors engaged in top gear. For example, if you have a non-overdrive trans, 3.50 rear gears, and 27-inch-tall tires, you currently cruise 70 mph at 3,000 rpm. With the Gear Vendors, you can either drop your rpm at 70 to 2,400 or maintain the 3,000 rpm and hit nearly 90 mph.

The Gear Vendors unit is available for nearly any domestic trans, auto or manual, overdrive or not. If you really want to get fancy, you can even stack multiple Gear Vendors units behind the trans. They are also available to mate to most transfer cases for use in 4x4s. In any application, the GV can either be triggered by a simple on/off power button or controlled by the Autodrive computer, which makes the unit shift on its own just like an auto/overdrive transmission

Gear Vendors Under/Overdrive
Overall Ranking: 21 Points
Goes Faster N/A12345
Looks Better N/A12345
Saves Hassles N/A12345
Bolts Right Up N/A12345
Bang for the Buck N/A12345
Just Plain Cool N/A12345

HOT ROD Approved Official Rankings

Goes Faster — Rating: 5
The Gear Vendors can provide the best of all worlds depending on how you use it: It can either
improve acceleration, multiply your top speed, or improve your gas mileage. Therefore, it deserves our top honors in this category.

Looks Better — Rating: N/A
Sorry, but even those of us who check out a car on our hands and knees might not truly appreciate the beauty of the Gear Vendors. It’s just not an appearance item.

Saves Hassles — Rating: 3
It’s one of those things you’ll never miss if you’ve never experienced it, but once you drive a GV, you’ll always want one. More tangibly, the GV can save you money if you already invested in a beefy trans and now you want overdrive. Also, it’s the strongest way to have both a trans-brake automatic trans and overdrive.

Bolts Right Up — Rating: 4
For a component as seemingly complex as a supplemental transmission, you’d think it’d be a pain
to install. Not. You can physically bolt the GV to your trans in about 15 minutes. Getting the driveshaft shortened is also not a big deal. In some cases, the most hassles will be adding some floorboard clearance, as the GV is “about the size of a 3-pound coffee can” per the company’s literature. See the dimensions on the Web site.

Bang for the Buck — Rating: 5
Frankly, this isn’t cheap. By the time you’ve got the car running with a Gear Vendors, expect to pay about $2,500. But that’s less than the cost of an overdrive auto trans with similar beef, and we think the GV has greater benefits.

Just Plain Cool — Rating: 4
If you’re not really into driving your car, the GV won’t turn you on too much. But if you want to bark the tires five times in a row, or if you love playing with gears, this thing’s for you.

The Best Thing About It: Being able to split gears for speed and economy.

Things We’d Change: We’d like it a tad less expensive, but we’re not complaining.

Hot Rod

FROM: Wayne Creel
65 GTO

Hi Rick,

I bought my second G/Vendors. This one is for my 1965 GTO (see attached). Rays Trans. In Ft. Worth, Tx. Is doing the install. Supposed to be ready tomorrow.I looked thru the pages of your catalog and was really surprised to see my red AMX on page 13.

Thanks for a great product and I am sure this will not be my last g/v.

Thanks again,
Wayne Creel
Early, Texas

FROM: Mark Pichler
69 Camaro SS

Dear Rick Johnson,

I am extremely happy with your Gear Vendor overdrive. I have a street/strip 69 Camaro SS which has a 522 BBC with an 8-71 blower (see attached photos). The Camaro weighs 4,000 #s (with driver) and has run a best of 9.59 @ 141 mph.

69 Camaro SS

69 Camaro SS

I run a 4.10 gear and with the Gear Vendor overdrive it now acts like a 3.23 gear which is GREAT for the highways. I would recommend the Gear Vendor overdrive to anyone who has a high horsepower/high torque car and still wants to drive their vehicle on the street.

Also to note – Your customer service is 2nd to none.

Keep up the good work!! I hope to see you next year at Hot Rod Drag Week 2010.

Big Thx Again!!

Mark R. Pichler
Farmington Hills, MI

FROM: Ian Rainbow
50 Chevy

Heres a couple of photos of my car with the Gear Vendors. We took it to the drags the day after it was street legal. I was learning to drive on the track as I hadn’t raced for about 20 years, after 3 runs I remembered it had another gear so hit the over drive and it picked up 11 mph. We did 5 runs in total and ended up with a 10.91 at 129mph. Not bad on pump gas and a novice at the wheel.


Ian Rainbow
Key West Fabrication & Supplies Ltd
Henderson, Waitakere
New Zealand

1950 Chevy

FROM: Steve Walsh
87 Buick Grand National


I have an 87 Buick Grand National, I have gone through 2 transmissions {2004r’s} from differentvendors & had them rebuilt when they did not hold up.

87 Buick Grand National

87 Buick Grand National

I was getting very frustrated with this as it cost alot of money & my time. While searching for someone else to build a transmission for me a friend told me to phone the boys at Coan Transmission. I phoned them & they told me to put a TH350 & a Gear Vendors in it & you will never look back. WELL I did & to tell you, I think the Gear Vendors is the ONLY way to go.

The Gear Vendors was very easy to install and with very good instructions. With 28lbs of boost & clicking it into over drive the Gear Vendors has no problems & thats one less thing I have to worry about.

This is the best change that I have made to the car.

Many thanks again,

Steve Walsh
Calgary, Alberta

FROM: Richard Knowles
1984 Ford Ranger

Dear Sirs,

On 9/14/09 I ordered the GV as a final touch for my project 1984 Ford Ranger. It was promptly shipped on 9/22/09. UPS delivered it to me in Massachusetts on 9/29/09. First I was impressed with the neat, very nice job, your packing and shipping crew did. As I laid out all the parts on a table in my garage, and read through the install manual, it became clear to me that this was a high quality product, from a top notch company. The next morning I drained my tranny, removed my driveshaft and tailshaft housing. Just 4 hours passed before I had the adapter, GV unit, electrical components, and wiring harnesses installed. (the wiring harness connections were so well marked and color coded that “even a caveman could do it!!” ) The piggyback adapter for plugging my aftermarket electric speedometer sensor to the GV sensor was a real nice surprise, it made it so easy, and I later found that re-programming the speedo was not even needed. So off to my local driveshaft guy,(Mitchell Differential+Driveshaft, in Shrewsbury, Ma.) The next morning after picking up my new shorter driveshaft,(decided to keep original in case of any future changes) I installed it to find 5/8″ free play on slip yoke, Wow!! I must have measured right! Promptly I filled the GV with recommended synthetic gear oil… $$$!!! and filled my tranny fluid. Now, I did one last inspection of all my work, and prepared for the big road test!

84 Ford Ranger
84 Ford Ranger
84 Ford Ranger

As per the instructions, I drove a few miles with the overdrive off. Now my finger was shaking with anticipation just as it was about to depress the gv button……..(will all my time, and all that money be worth it?)……… click. YES!! It worked perfectly, just as described on your website. My 302 w/roush heads and all the other goodies seemed to come alive like never before, it seems to be in the peak powerband right up through all of my new-found 6 gears! The Performance Automatic Super Streeter C4 seems to be made for the GV. What a huge difference on the interstates at 70 mph the rpm is now down from just over 3000 to 2400, and it is quiet and relaxed. In just a little over 2 weeks of driving I’ve already noticed I’m not having to unsnap my tonneau cover and fill the fuel cell as often. This GV is on the top of my very long list of modifications and improvements.neau cover and fill the fuel cell as often. This GV is on the top of my very long list of modifications and improvements.

My wife often likes to remind me of all the money I’ve poured into my Ranger project, since I retired from my career as a truck driver, just over a year ago. She is right, no expense has been spared on the re-make of this fun little truck. The Gear Vendors is worth every penney and will eventually payback in fuel savings and less wear and tear.

So thanks to all who helped out in sales, and Mike in tech, for your assistance, and thank you all at Gear Vendors for such a fine product. Feel free to use my letter or pictures if you care to.


Richard Knowles
Brimfield, MA

FROM: Gary Rosenboom
65 Chevelle Pro Street/Gear Vendors

Hi Rick,

We have a 1965 Chevelle Malibu SS Pro Street. It has a 355 CI Blown engine with a Crane Roller Cam, 488 spooled rear end, four link suspension, B&M TH 400 Automatic.

65 Chevelle

65 Chevelle

We took interest in Gear Vendors when trying to figure out how to lower RPM in overdrive at highway speed. First consideration was to install a 700r4 with overdrive but didn’t want to loose the beefy TH 400. With the spooled 4:88 rear end and the 31×18.5-15 Mickey Thompson tires the Chevelle hooks up nicely and feels nothing but nasty. The only problem, at highway speed the RPM was not desirable. After receiving helpful information from Gear Vendors it wasn’t hard to make the decision on which way to go.

With the Gear Vendors under/overdrive, it has given a reduction of engine RPM at highway speed that we can live with. Considering the rear end gears the car has, it is a great improvement, plus the additional bonus of changing the 3 speed to a 6 speed. It makes the Pro Street even more exciting to drive.

Thanks for a great product.

Gary & Barbara Rosenboom
Rosenboom Frame & Body Inc.

FROM: Warren Freitas
1964 Nova – Oh So Nova


Thought it was time I let you know you how well the unit was holding up in my 64 Nova with a 454 engine . My car was featured in the March 2005 issue of Super Rod magazine shown on your web site. I drive the car every day and I don’t baby it . The overdrive unit has performed flawlessly. I have over 43,000 miles on the car and I shift it manually only. Can’t tell you enough how great it has been driving with a Gear Vendors overdrive.

Thank you many times over,
Warren Freitas

Oh So Nova - Nova 1964

FROM: Al Cravens
1967 Nova

Al Cravens, 1967 Nova

     Having over 700 horsepower and 650 ft pounds of torque made my decision to utilize the gearvendor overdrive very simple. I wanted a unit that would hold up to that kind of power, improve my gas mileage, reduce engine RPM at highway speeds, and survive aggressive driving long term. The gear vendor product has been bullet proof and is a welcome addition to my 67 Nova.

Al Cravens, 1967 Nova

All my research kept pointing to Gearvendors as the best solution to meet my needs. I have built a car that runs great at the track, is capable of cruising around town, and is very comfortable at sustained highway speeds. I just can’t imagine a car that can do all these things without a Gearvendor overdrive unit installed. Additionally, the electronic control unit allows me the flexibility to manually engage the overdrive unit or just let the computer do it for me!

Thanks Gearvendor
Thanks again,
Al Cravens

Al Scheib’s 57 Plymouth Fury Blown & Injected 480cid Hemi = 2500HP


      It was a pleasure meeting and talking with you at the Spring Fling car show in Van Nuys. I want to tell you how happy I am having a Gear Vendors overdrive unit in my 1957 Plymouth Fury. You guys produce an outstanding product. I first tried a competitors overdrive unit (I had not heard of Gear Vendors, yet) that could not handle one-third of the horsepower I have. I wish that I had one of your units back in the 50’s when I was a youngster.

1957 Plymouth Fury

      The engine in my Plymouth, which is a drive-in cruise car, not a trailer queen, is a Keith Black 480 cu. in. engine that was campaigned in the 70’s funny car of Parnelli Jones. It was a low six second ¼ mile car on nitromethane. It was dyno tested at 2500 h.p. back then and I have added another 500 h.p. with the addition of the Nitrous Oxide, bigger cam and a larger 871 B.D.S. blower. I still run the 45% overdrive on the supercharger that was run on the funny car. Upon occasion, I have called out at local drive-ins for a speed contest to prove its performance. No sweat there. They won’t let me run it at any of the nostalgia drag meets until I put in a roll cage but I can’t do that without losing my rear seat.

      The car weighs 4100 lbs., has 5:13 rear gears and tricked out 727 torque flight transmission that is still operated by the original push buttons. I had your Gear Vendors overdrive unit installed in the car over ten years ago and it has never failed me yet. I have had several races with the car and boy, do I enjoy stretching the race with that extra gear. I must admit that the first time I put the pedal to the metal, I was expecting breakage with all my horsepower but to my surprise it took the load very well. Next I took the car to the edge by engaging the overdrive while I hit the nitrous button. All I can say is WOW, it all hung together. Your unit is unbelievable.

1957 Plymouth Fury

      My car was selected by Matell toy Hot Wheels for one of their 40th anniversary series packages. The car has been in many magazines over the years and recently was entered into the encyclopedia world history of cars, the Hot Cars edition. In closing I just want to say “YOUR DA MAN”.

A Very, very happy customer,
Al Scheib
Earl Scheib, Inc.
Beverly Hills, CA


      Enclosed is a picture of my Bel-Air that I installed your overdrive in.It’s a blown, radical 427, TH 400, 9″ (4.11), the best of everything. I built the Nomad for my wife so she wouldn’t yell at me when I hit the gas. It’s a 502, dual quads, TH350, 9″ (3.00),with air, power everything ( even vent windows), cruise, etc. etc. They look good going down the road together!

Les LeClair autos

      The reason I’m even writing this is because I am very impressed with your product. Your salesman, John Struzik, was very helpful. Dealing with the tremendous number of manufacturers as I have since 1964, and putting up with inferior design, quality, and service,your product was a real pleasure to work with. It got so that if a manufacturer told me: It bolts right up, or It requires no tools, or you’ll have it in 2 weeks, I would not believe them!

      I followed the instructions to install the overdrive, they were right on, the wiring and actual installation was a breeze. The best thing is. It worked!!!! The first time, and every time. Thank you, thank you, for such a great product! I’m bragging to all my friends and car buddies about it and hopefully it will generate some sales for you. Have your customers call me, I’ll tell them.

      Again, I’m very happy with Gear Vendors.

Les LeClair”

Subj:  (no subject)
Date:  1/2/00 2:44:17 PM Pacific Standard Time
From: CaptsIrwin@aol.com
To:     info@gearvendors.com

Just pulled your web site up on my computer. Thought I would drop you a note and let you know about my GearVendors. I have it in a 250 diesel Ford Pickup, and it is just wonderful. I have driven this oufit all over the USA, Canada, and Nova Scotia. I live in Florida. We have been in every state in the union (not Hawaii cause our camper won’t float) every province
of Canada except Northwest Territory and New Foundland. We pull a 34 ft (tow behind) and what a wonderful invention the GearVendors is. Never have had a problem with it. Recommend it to everyone.

Dick Irwin,
Leesburg, FL

Subj:  Attn: Rick Johnson
Date:  5/1/00 11:36:25 AM Pacific Daylight Time
From: chesser@jps.net (Angel Inez Lamb Chesser)
To:     info@gearvendors.com

Sorry it took me so long to let you know how much I appreciated the good service and the way I was treated by your employees while I was there a couple of months ago. You installed the new electronics on my very very old gear vendor. It works great….thank you VERY MUCH! Also, I am amazed that my unit was in perfect condition and has been in use on my 1987 Ford since the truck was new. I am on my second engine and second transmission but I still am on my first gear vendor and it works great!

My other truck is a 2000 Dodge 3500 duely 4 X 4. It has an automatic transmission and I think the gearing is 373. I wish I had some additional gearing. I called already and your people are sending me some information now.

Thank you very much,
Ed Chesser

Subj:  Gear Vendors
Date:  5/9/00 5:07:15 PM Pacific Daylight Time
From: Johnsontwdd@aol.com
To:     info@gearvendors.com

I just returned form my first trip with my new gear vendors under/overdrive. The unit was installed by Chance transmission, one of your dealers here in Kansas. I am extremely pleased with the service and treatment I received from this shop. The unit was installed in my 27 foot, 1989 Jayco, class C motorhome. I have a 460 V/8 with a 3 speed C-6 transmission. I only have 30 K miles on it and have averaged between 7 and 7 1/2 mpg since it was new.

On this 600 mile trip I average 9.5 mpg. I could barely hear my engine on the highway at 65 mph. We drove in some of the Missouri Ozark hills and I am amazed at the performance of this motorhome. Second gear over is an absolute thrill to use in the mountains. I read and studied all the literature I could get on the Gear Vendors under/overdrive before purchasing the
unit. However, nothing prepared me for the mpg increase, or the performance change it made in my motorhome. Thank You, Thank You, for building a product that does everything you say it will and then some. I’ve just retired and I feel like a kid with a new toy. Feel free to use my name as an endorsement on this fine product.


Tom W. Johnson
Wichita, KS


      I am writing this letter to thank you and your company for the GEAR VENDORS Under/Overdrive you installed in my pick up on, Sept 9, 1995. I have already saved on fuel economy, about 24%. That is worth the unit alone. As far as towing with the unit, it is great.

      We ask ourselves, how did we get by without the Gear Vendors Under/Overdrive? I have demonstrated the unit to at least two people already. One a past student, and also my new instructor. Both will be installing units in their vehicles soon.

      Please feel free to use me as a personal reference as to how great your Gear Vendors Under/Overdrive works in towing and driving. I am looking forward to seeing you at the RV Manufacturers’ Show in Pomona.

Sincerely yours,
Richard (Dick) Reed
Ontario, CA