Gear vender units are the same ( different ratios i think ), they make many different adapters for different transmissions. It all replaces the tail housing.
235/70R15 which are 28” in diameter. I’m happy with the stance as it is, so don’t want to use larger tires.
I think there's a major point being missed here in as much as a GV overdrive is more than just an overdrive, as an extra gear over the 2, 3, 4 whatever transmission gears. Its a gear splitter effectively doubling the number of available ratios, enabling the engine to be kept near the sweet spot more of the time. Useful for trucks and motothomes, lugging loads up hills, but also used by some racers. Usefulness in a light hotrod over a straightforward additional gear is I suppose debatable. Spendy though, but transmissions aren't exactly cheap, and rear gear swaps affect all of the gear ratios. Chris
Well, running one in a drag car really isn't a test of a Gear vendors strength as it is in DIRECT when going down the strip.Thus, driving straight through. A Gear vendor is a great device if used properly. Sounds like many here are. The troubles arise when #1 they are used for engine braking while in overdrive...should be in direct. The other issue is driving in the auto feature when in town or traffic. The tendency is for the unit to "hunt"....which leads to early failure. If I had one I would also devise a system to increase the amount of fluid and run it trough a cooler.
Ok guys, I bought a truck with a C-6 in it years ago and the guy threw in a GV over drive unit. I asked why he didn’t have it on the truck and he said it made “ noise” while driving in overdrive, not much, but too much for his liking. I am thinking of putting it in my avatar car when I update the engine to a 462. But I am scared it will make too much noise. Do any of you guys with the GV overdrive experience noise while in overdrive? TIA Edit! I just remembered, mine is a Doug Nash unit! Any thoughts? Bones
With a 454 in a pickup and 235 width tires, wouldn't it be traction limited? In which case the 2.76 differential gears might be suitable, since you couldn't use full power on takeoff anyway. Maybe not the best for racing, but on the street it might just be fine.
I don’t know about the Doug Nash, but GV used to have an exchange. You sent them yours, and got a rebuilt one back. Time for a phone call, etc. Did he mention if it was a new or used unit, etc?
In my BBC in the pickup, TH400 and 3.08s. L60 tires was around 2100 at 65/70, but Speedo never calibrated. Seemed fine
I have GearVendor’s behind a T400 and 392 in my ‘51. Been running it about a dozen years now, with 6.70x15 and 3.25:1 9” Curie and too loose torque converter. Mostly trouble free, but last longer trip (250 miles) drive in heavy rain it had problem of slipping in and out of OD rapidly. Think it was just a moisture issue. The problem is not current. It can be a bit clunky going from reverse to drive. My biggest mistake when I put it in was likely not going with a lockup version of the ****** and converter, only 13 mpg freeway driving.
My truck has more gear and less tire, it’s turning about 3100 @ 70 mph. A 30” tire and 3.08 gear should be around 2400 @ 70mph. I believe that would be close to ideal for my engine combo. A set of 2.76 gears or my current 3.55’s with the GV would also run about 2400 @ 70.
The Doug Nash (later US Gear) units are a totally different functional design than the Gear Vendors unit.
Rotational inertia is fifteen times more than adding regular weight to the body. Get a seventies 454 with a th-400 and use a 2.73 or 3:08 rear end.
Is Doug Nash still selling/servicing them? Regardless, you are the kinda guy who should just sit down with it on the bench, take it apart and see what’s up. Me? I’d lose 1/2 of it before I could look for the right wrench.
For street driven applications this is very true, especially in pickups that don't carry a load. All the torque of the 454 would make it near impossible to go full throttle from a standing start, and probably make traction shaky going into 2nd. The more torque you have, the taller the gearing you can comfortably run, and the less need for any form of overdrive. Maybe try a different rear ratio first and see what you think. Using mopar 8/3/4" ratios and your tire size, a 2.93:1 would give a touch over 2500 rpm at 70 mph, and a 3.23:1 would give just under 2800.
A 454 has very manageable torque, heck, even going full throttle with a mild SBC can get you side ways Mine is only 390 rated HP, but yes, I could smoke the tires, but rather not. Very easy to control. Unsure on a “built” engine though. Probably will never do that.
As I said in an earlier post, the GearVendors 22% overdrive will not result in 22% better fuel mileage; 25% not gonna happen. At highway cruise, the only savings is in reduced ring friction. If the cam is long enough duration, the lower RPM might actually have the cam fighting being out of the efficiency range. GM equipped the '60s performance big blocks with gears for a reason. It's only since EFI and computer ignition enabled double-overdrive transmissions to put engines in a strain at low RPM have our perceptions changed. Today, we are accustomed to cruise at 1500 RPM. Back in the day, 3,000 was more the norm for performance engines. jack vines
I think Doug Nash is out of business! I would try and fix it….but I am scared if it whined new…..it will probably whine again! And me being the lazy guy I am……well you know! Bones
What I'm saying is that the 454 will have more than enough torque to run a 3.23 or 2.96 rear end and still be nippy enough off the mark. But...... running a Gear Vendors overdrive or an overdrive transmission will get you the best of both worlds, and really bring a smile to your face.
Early 80's 454 truck motors are lucky to make 250 HP & 400 LBS ft torque stock not exactly tire shredders . you'd need to go back 10+ years before these motors were choked by the insurance companies & the EPA , to find any real power
Sell you "Less than 10K" trans and converter and pony up for a 4L80E which has a lockup converter and 4th gear O/D [these are tough as nails] A few hundred $$$$ for a controller is a lot cheaper than a gear venders O/D. You can still use the column shift [P R D 3 2 ] instead of [P R D 2 1] After selling the TH400 and replacing it with a 4L80E it will end up a lot cheaper overall . [a and it would be a better more user friendly driver] here is a 4L80E Vs the Gear Vendors TH400 There is a huge difference in length
I fully agree with this, as long as @Black_Sheep isn't against running an electronically controlled transmission. The 1st-2nd-3rd ratios of the 4L80E are exactly the same as the TH400. It would bring the truck alive. With the 28" tires and the 3.55 rear ratio, cruising at 70 mph in overdrive (0.75:1) would be 2237 rpm....... Sweet. If you just can't get your head around having to run a computer controller, have the trans fully manualised and shift it yourself.
A complete "Painless Wiring" kit including the controller and harness is only $699 which is a sh**load cheaper than a Gear Vendors Overdrive [Lay**** De Normanville reproduction] https://www.painlessperformance.com/wc/66501 I think a manual 4L80 valve body would cost more than this The GV Overdrive still needs electricals to operate properly [on/off switch, vacuum/kickdown switches ,reverse lockout etc] And there is driveshaft issues etc. @Black_Sheep don't be scared off by electronic controls, they are no worse than all the HEI or Pertronix conversions that people do here.
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