History of Divorced Overdrive Units. Laylock. Gear Vendor

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87vette81big

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Grumpy,
Been thinking of overdrive units again today.
Did a search on your site of factory installed divorced overdrive units.
Just Harry had a T85 Borg Warner 3-speed with overdrive from A 390 ci 1962 Ford Galaxie.
I undestand they were popular back in the 1950's & early 1960's.
Can you provide more reading material on these Vintage overdrive units ?
Some had to be Very Strong.
I recall reading a Magazine article from 1987 about Mickey Thommpson using an Overdrive unit in a 1969 Ford Mustang with a Boss 429 Semi Hemi Shotgun Engine.
He was at Bonneville Salt Flats in Utah.
He ran 191 mph on a closed timed track setup on the salt.
Recall he switched an Overdrive Unit manually On while driving.
A shift lever Pulled Or Pushed .
I believe it was a Laylock Divorced Unit. Pre Gear Vendor.
 
Re: History of Divorced Overdrive Units. Laylock. Gear Vendo

The history of Bolt on Overdrives is real Sketchy online Grumpy.
Google Searching is not enough. Shows Squat......
Millions were made by Laycock in England.
About 3 million before Gear Vendors took over in 2008.
2 million of those Laycock overdrives were installed on Volvo station wagons of all things in 1970's & 80's.
Torque capacity is unknown by me still.
Just I know that the late model race version of the gear vendors overdive is rated to 2500 Hp.
Equates to 2,000 Ft/lbs @ 7,000-8,000 crankshaft Rpm's in a true race engine.
No modern overdrive trans like the 200R4, 700R4, 4L80E, Ford AoDE, E40DE
 
Re: History of Divorced Overdrive Units. Laylock. Gear Vendo

No modern Overdrive Trans can be built this Strong with todays Technology.
Only The Turbo 400, 2-Speed Powerglide, Ford C6, &!Chrysler 727 Torqueflite Automatics are up to the Task. Add a Gear Vendors.

Borg Warner Overdrives were made too.
Have a Collection of old car books. My personal Hotrod Library .
Research this week in my spare time.
I recall articles from 1985-present never put online.
Just have to find those articles again.
Have High Performance Pontiac Magazines put away from 1979.
Kool reading every now & then.
 
Re: History of Divorced Overdrive Units. Laylock. Gear Vendo

Also the Summers Brothers 4 Chrysler Hemi Engine Streamliner from 1964 That Ran over 406 mph used an Eaton 9-speed Truck manual transmission. Turned it sideways to. fit between the framerails.
They had close to 4,000 Horsepower . Single Eaton Trans used.
Old Technology still works.
Often Best Still.
 
http://gearvendors.com/hrgm4s.html

http://www.gearvendors.com/install.html

http://www.superchevy.com/how-to/corp-0310-corvette-transmission-swap/

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Corvette Transmission Swap - Overdrive Upgrade
Updating Your '63-'82 Corvette To Five-Speed Status With An All-In-One Kit
Andy Bolig Dec 28, 2009
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Back in the '80s, when the speed limit was 55 mph, not having an overdriven final gear didn't seem like such a big deal. But times have changed, and anyone who has driven his or her Corvette on the highway for any extended period of time quickly realizes what an inconvenience not having an overdrive gear can be. Enter the Keisler five-speed overdrive transmission available for fitment in your '63 to '82 Corvette using the original shifter and mounting points. It's so sneaky, even your fanatical Corvette resto freaks won't know it's there until you shift into Fifth. Plus, the Keisler five-speed comes in two flavors to suit all needs: the TKO-1 for applications up to 475 hp and the TKO-2 for engines cranking out as much as 650 hp.


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For those of you who aren't sure what "overdrive" means, the term refers to the transmission-output rotation speed versus engine-output speed. In a nutshell, with an overdrive, the transmission-output rpm will be higher than the engine rpm, thus sending more driveshaft output shaft revolutions to the rear wheels with fewer engine rpm. As a result, your Corvette will cruise at higher speeds with less wear and tear on the driveline and your ears. In addition, with fewer engine rpm, less fuel is used. Just think-you'll actually be able to cruise in your Corvette and carry on a conversation without straining your vocal chords or your engine and save gas! Times are good.




Keisler's speed table on page 70 shows the huge impact its overdrive will provide. For example, a 3.73:1 differential ratio combined with the 0.68 overdrive (OD) ratio of the TKO-1 will yield a final ratio of just 2.54 (3.73 x 0.68 = 2.54). This yields a whopping 25-mph speed boost from 52 to 77 mph at 2,500 rpm! A 4.10:1-geared car will jump from 47 to 70 mph on the highway at 2,500 rpm. Keisler states that V-8 musclecars make so much torque they can easily use Fifth gear from 45 mph. The super-duty TKO-2 has a smaller final overdriven ratio of 0.83, which is sometimes beneficial for competition.

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Just having an overdriven gear in a musclecar is a major technological leap forward. But the benefits don't stop there. Tremec designed the TKO with a tire-scorching 3.27 First gear. But if spine-pressing launches aren't your style, you'll appreciate the lower First gear's ability to motivate the car from a stop by letting out the clutch with only the slightest throttle effort. Gone are the days of burning up the clutch or fancy foot moves just to get the car parked. All of this is clearly laid out in Keisler's Speed Table. As you can see, a 3.42:1 differential will have the equivalent launch of a 4.44:1 ratio when combined with the TKO's First gear. A 3.73:1 ratio will instantly become a 4.84:1 launch! This deeper gearing gets the car moving. The remaining gears are more closely spaced at 1.98, 1.34, 1.0, and 0.68 (TKO-1) or 0.83 (TKO-2).


It should be made clear that the Keisler-modified Tremec TKO is vastly different from the standard unit as shipped from Tremec. In addition to the case modification, a complete new patented shifter mechanism is added which brings the shifter to the side, placing the original shifter handle in exactly the correct position to the side and back. The internals are the same as factory delivered, with some additional enhancements for reliability and quiet operation. Spare parts should be readily available for many years to come, as these transmissions are the largest selling aftermarket transmission on the planet. An added benefit of this transmission conversion is that Keisler installs the kit at its Knoxville, Tennessee, facility-just 10 minutes from the Tremec factory.

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So now that you realize Keisler's Tremec TKO five-speed has all of the credentials worthy of your Corvette, let's see what it takes to install one into your favorite Stingray or shark, '63 through '82. The installation shown is for a '66 roadster. Differences in the installation for the mid-year and shark variants are noted. Each Keisler kit is shipped with instructions and each set of instructions finishes with a quality checklist.

Publisher Jerry Pitt, on a recent trip to Keisler's Knoxville headquarters, had a chance to drive a mid-year overdrive conversion. He said, "Nothing was sacrificed in appearance, and the Corvette drove like a modern, manual-shift sports car. In traffic, the Corvette easily ran in the fast lane."
 
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A Gear Vendors Overdrive Unit Be nice to have yet Grumpy.
For my 1963 Pontiac Grand Prix.
I want to keep the Turbo 400 Transmission I installed.
A 4L80E won't bolt up to A Pontiac & Olds V8 without an adapter plate.
Or cutoff the stock bellhousing and use an aftermarket Blowproof bellhousing.
Then the Super added expense of a decent high stall converter for a 4L80E .
Also need a stand alone trans controller.
The Light Switch method of makung upshifts and downshifts is Free still.

I seldom see a Gear Vendors for sale used. Most are in motorhomes.
Must pull yourself and travel out of state.

The C4 Corvette I am leaving alone as is for 2016.
Main focus is my 1970-1/2 Teans Am.
Its staying Muncie 4-speed as factory built.
All those Pro Touring 5 & 6 speed transmissions failed to beat rhe Hellcats or anywhere near close.
Waste of $$$$& $ to me.
Muncie 4 has the lowest HP Loss pf any GM Trans ever built.
 
The TA Will be built to Scream Rpms again.
Super Titanium inside. Everywhere.
 
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