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OD On Performance

With US Gear's V2OD You Can Have A Stiff Gear and Be Economical, Too!

Nov 1, 2002

When it comes to acceleration performance, nothing sets you back in the seat better than low rearend gears. There is a price to pay for that stump-pulling experience, however: not so good fuel economy. Of course, the introduction of the overdrive transmission has provided a compromise between both worlds. You can have a relatively stiff set of rear cogs, couple it with the low First gear of the tranny, and you get a decent amount of performance mixed with acceptable fuel mileage. However, there are limitations with these gearboxes, not the least of which is their vulnerability to high-horsepower/torque applications. Therefore, a need has risen for a simple overdrive that can provide you with the ability to run low rear gears and still take to the highway with that 600hp boulevard bruiser.

There are a couple of popular overdrives on the market, but besides being a few-thousand dollars (prior to installation), few will take the abuse that the new V2OD from US Gear will. The biggest difference between the others and the V2OD is that the US Gear unit is a manual gearbox, not an automatic. Like a Muncie or Borg Warner four-speed the V2OD has a slider mechanism that engages a set of gears, not a set of clutches, drums, and wet plates. In short, it was designed with performance in mind, not towing capacity. U.S. Gear's new unit features an aluminum case that simply replaces the tailshaft and bolts to the back of the existing transmission. It's available in either a 20 or 30 percent reduction version, depending on what gear you currently have in your car.

The V2OD is a perfect addition to a street machine that is geared low for cruising Main Street and then blasting down the strip. With its 20 or 30 percent reduction, you can literally drive to the track without getting only 2 gallons to the mile.

Recently, the gurus at US Gear approached us with the idea of putting one of their units in the ongoing Classical Resurrection '68 Camaro project. Along with the idea came the fact that it had never been done before. With a resounding "yes" we agreed to the challenge and tackled the project to make the V2OD fit the tight confines of the First-Gen's tranny tunnel.

If you haven't noticed, we tend to get excited about doing these types of "firsts." We do them as often as possible, so with that in mind, we jumped on it. This is somewhat of an R&D situation, and we knew going into the install that there could be some complications. With a few attempts at putting the unit in place, we quickly realized what needed to be done. This allowed us to orchestrate a chain of events to best complete this project.

After a quick glance, we knew that clearance would be an issue. We also needed to reroute the previously done exhaust system. Luckily enough, the Camaro doesn't have dual mufflers. It has a traverse-mounted, stock-style Flowmaster muffler. All we had to accomplish was to get the overdrive unit to physically fit in the tunnel, and the rest would be simple.

We also knew that the driveshaft that was in the car would have to be shortened a considerable amount--close to 13 inches as it turned out. Fortunately, the solution for the driveshaft was literally right next door to the shop performing the installation.

The final solution, or the best idea we could come up with to make the housing work, required applying a little heat to the tunnel's sheetmetal and using a small sledgehammer to increase the size of the tunnel. It may sound scary to some, but the amount of pounding required to make room for the V2OD was minimal and easily accomplished. Once the room for it was created, the unit simply bolted in place. The linkage, which was redesigned, based on our experience, to be leveraged from under the unit rather than the side, is cable operated and easy to install. As for the speedometer cable, it, too, was a simple hookup.

Though we were exploring uncharted ground with this install, we came away from the experience successfully and with a unit in our car that will make cruising to the Vegas or Phoenix Super Chevy Show a little less costly. With a 450hp supercharged small-block and a 350 coupled to a set of 3.73:1 cogs, this car will definitely give you a rush. With the 20 percent reduction from the V2OD, these 3.73s will come in at around 2.99s. And that should help in the gas-guzzling department. Stick around and see how our install takes shape.


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The V2OD overdrive unit comes with an aluminum-case gearbox, a new tailshaft that adapts the box to your existing tranny, a new driveshaft yoke, all the necessary mounting hardware, a new speedometer cable, and a shifter pull cable. It also comes with a very detailed instruction manual.

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Thankfully, the guys over at Muffler Man, who originally installed the exhaust on our Camaro project, agreed to help us with the V2OD install. They began by cutting out the old exhaust just behind the cross pipe and just below the collectors. We used most of this later, with some minor modifications.

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The first operation was to replace the original tailshaft. We simply unbolted the old one, and the new one fit directly in its place.

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The next step was to measure the amount of room we had in the tunnel. At this point, we knew that the floor had to be pushed out roughly 1 1/2 inches per side at both the top and bottom.

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We went to work with a torch and a sledgehammer. It took a little heat and a few whacks with the hammer to slowly move the sheetmetal the needed amount.

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We didn't want to risk too much heat and the potential to burn a hole in the tunnel, so it took an exceptional amount of time. When it was all said and done, though, the proper amount of clearance was achieved.

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Here is a good view of the overdrive bolted to the new tailshaft. If you look around the edges of the unit, you can see how far back the floor of the tunnel had to be pushed. Clearance is still somewhat tight, but it does fit.

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The old exhaust was used, and as you can see, it was shortened and slightly modified. Once again, the sparks were flying.

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When the exhaust was remounted, the bends cleared the overdrive nicely. The good part about it was that only one straight piece of tubing was needed. It was welded in to fill the gap from the X-pipe to the collector.

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This is an overall shot of the finished product. The overdrive fit snugly in the "modified" tunnel. The new exhaust routed neatly around the new driveline addition and tucked up by the crossmember.

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With the V2OD in place, we needed to have a new driveshaft made up. The guys from Inland Empire Driveline began by taking a precise measurement.

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This is the new yoke that was used with the V2OD. It is a larger, stronger, Turbo 400-style yoke.

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Our old driveshaft was cut about 12 inches.

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The yoke was assembled onto a new driveshaft end cap with a new U-joint. The new yoke also uses a larger U-joint.

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Here is the new end cap and yoke we mounted on the assembly machine. The end cap was pressed into the cut driveshaft and was then welded.

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Once welded, the driveshaft was balanced using a dial gauge at both ends. A small weight was needed on this end and was welded in place.

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When the driveshaft was done, it fit perfectly into place.

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Remember, we said this was an R&D project. Well, when we got the car back to the garage, we found that we did not have enough room for the side mount linkage made for this unit. So the team at U.S. Gear sent a new unit with different mounting for the linkage. Instead of pivoting horizontally, this one pivoted vertically. This means that First-Gen Camaros now have their own specific overdrive bracketry.

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For the final assembly of this project we needed to use the gasket offered for the tailshaft. A little gasket sealer was all it took.

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When it was all mounted, we needed to run our pull cable. This is the driver-side of the undercarriage. The cable was run under the car, through this square bracket, to the lever itself.

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We mounted the handle for the cable at the bottom of the dashboard. We needed to run the cable to the underside of the car, so we made a small cut in the carpet. This also helped in marking for the hole.

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A 1/2-inch hole was needed for the cable to fit through. You can carefully pull the carpet up to keep from damaging it.

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The cable was run through this bracket and held in place by these two jamb nuts. You can adjust the length of the cable with these also.

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We mounted the end of the cable to the engaging bracket. This piece can also be slightly adjusted and finally mounted by using a cotter pin.

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This is the pull handle mounted to the lower right corner of the dash. The overdrive needs to be engaged while driving at a speed lower than 35 mph; simply pull the handle and turn it 'till it locks.

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For anyone concerned with appearance, here is how much exposed cable is shown. It is hidden nicely behind the corner of the console. It really isn't very visible by just looking through the window.

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This is the small pimple that is formed from pounding on the floorboard. With the carpet in and the seats installed this little bump isn't visible at all.

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This large rubber gasket is very important if you want to keep the fluid on the inside. This new gasket is supplied with the new tail shaft.

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When it's time for the final install. You will have to slide the hub from the overdrive onto the splines of the transmission tail shaft. It is very critical that the overdrive itself not be pulled down into place by tightening the bolts. It should set flush with the splines lined up.

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This is the new linkage that has been specially made for the 1st gen Camaro. This arm will pivot up and down, instead of sideways. This was done because of the lack of clearance in the tunnel

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The new drive shaft is another major part of this project. This shows just how accurate they are built. Using thick welds and rotating it slowly (by hand) is a positive way to ensure a deep


The Muffler Man
Placentia, CA 92870
Inland Empire Driveline
Ontario, CA 91761
US Gear
Chicago, IL 60617

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