John Kilgore is still perfecting these transmissions. He worked with the GM engineers many, MANY years back. He also had input on the 4spd. version of the T-400. http://www.kilgoretrans.com/ Mike
No prob! I recently went back in and updated some of the picture links, where still available. ~Jason
Not at 35 but coming off the highway at a good clip pulling down into 2nd for the grade retard removes the boss that holds the band in place. After that everything still works except grade retard in 2nd. Might have been brought up already but the th400 will shift from manual 1st into 2nd with out moving the shifter and shift point can be changed with a governor spring change. From a stop stick it in 1st leave it there mash the gas and check the tach when it shifts. Remember governor allows upshift. MW
Here's more info about what John does: http://www.kilgoretrans.com/html/how_transmission_works.html Super Chevy Magazine explains how the Superlite works: POWER TO WEIGHT A Strong Turbo 400 Doesn't Have To Weigh A Ton By Jason Walkner, August 2001 issue Super Chevy Magazine www.superchevy-web.com One of the most tried and true methods for building a faster race car is making an effort to eliminate excess weight from the body, ch***is, and any other significant parts that are sure to cause slower track times as well as added strain on the engine. As the old saying goes, there's no better way to improve performance than by improving the power-to-weight ratio. For this story, we want to address the problem of heavy internal transmission parts and how they slow the power distribution, which causes a notable loss in horsepower from the engine to the drive shaft. To explore this problem further, we contacted John Kilgore, who has been building race-proven transmissions for longer fro more than 30 years. Kilgore's philosophy on building a better TH400 - the tried and true workhorse of racing automatic gearboxes - starts out with simple laws of physics: the heavier an object is the more power it will take to move. The answer then seems pretty simple; why not lighten it up? To begin with, there is an incredible amount of inertia produced inside an automatic transmission. For example, shifting from First gear to Second gear, will mean instantly stopping the 14-pound direct drum, which is turning at 84 percent engine speed, while the 8-pound front reaction carrier starts turning at 50 percent engine speed. All of this happens in the short time it takes to shift gears. Additionally, there is an equal amount of force generated when shifting in and out of all three gears. Keep in mind, when General Motors designed the TH400, it was for an entirely different purpose than racing. The Turbo 400 had to handle the torque of a big-block powerhouse as well as deliver a comfortable and reliable drive. This is the reasoning behind having heavy internal parts. On the left is the lightweight Kilgore TH400 internals compared with those from a factory unit. What you can't see is the 30-plus pounds removed from the OEM TH400 parts. What Kilgore has done to whittle away at this problem is use lighter parts to make a better transfer of power. The components used inside one of Kilgore's TH400s, adds up to losing an amazing 30 pounds of reciprocating m***! This may not seem overly significant, until we consider most of that 30 pounds is stopping and starting instantly at a very high rpm, under extreme stress, no less. In addition to the weight savings, the use of smaller hollow hubs, in lieu of the oversize and "weighty" factory TH400 drums, allows more space so that twice as many friction disks (or clutch disks) can be employed. Since friction disks are what stop the drums, it goes without saying that more is better. The added space also leaves room for thicker steel friction disks, which get sandwiched between the clutch disks and add much more cooling surface than their thinner counterparts. Not only is Kilgore's TH400 lighter, but when used with the correct gear rations, it becomes a bullet-proof automatic to launch any high-torque, big- or small-block racer down the quarter mile easily an reliably. So follow along as we go about putting a basic TH400 on a weight-reducing diet. We think you'll agree that the finished product will make a difference in your m***ive weekend warrior or obese boulevard bruiser. These two photos represent what is happening when the transmission is in First gear. The forward drum (or the top drum) is turning with the same rpm in the engine, while the direct drum (the lower drum) is turning 84 percent engine rpm in the opposite direction. This gives us an idea of how much easier it is for the transmission to spin and stop with the hubs in Kilgore's ******, compared to the heavy drums in the factory transmission. Remember the factory drums are 14 pounds each, while the hubs used in Kilgore's weigh about 4 pounds each. To shift from First gear to Second gear, the ****** will need to sp the direct drum instantly and start spinning the reaction carrier at 50% engine rpm. The reaction carrier pictured on the near left is an 8-pound factory piece, while the one shown on the far left is made of aluminum weighing in a 4 pounds. This means, the transmission is working half as hard when shifting. Kilgore offers a reaction carrier in sheet metal as well, which he designed to weigh less than 3 pounds. All of these changes are done to relieve stress on the rotating parts inside the trans, not just to make the transmission lighter. When the transmission shifts into high gear, everything must now instantly turn at engine speed. This means the direct drum is going from zero rpm to full engine rpm immediately, while the reaction carrier jumps from 50 percent engine speed to full engine speed. This is a whole lot of pressure on the rotating internal parts. Imagine stopping or starting a 14-pound drum at 5,600 rpm instant. It makes good sense to free the internal transmission parts from heavy rotation when it is simply robbing horsepower from the engine. The top two pieces are the factory reaction carrier ***embly, while the lower two are Kilgore's designed carrier ***embly. The differences here are not just weight, but also a change in rotating parts. Kilgore's carrier changes rotation from the drum (lower left) to the hub (lower right). Thinner frictions allow more plates to be added to the clutch pack, up to ten in the direct clutch. Kilgore uses high performance Alto Red Eagle clutches Sources: Kilgore Transmissions & Weld-Done Services 727 Ruberta Ave., Dept. SC Glendale, CA 91201 818-246-9471 http://www.kilgoretrans.com/
Really interesting and helpful info here. Thanks "Abomination". Using what I learned from this thread I checked the 400 I have behind a 455 Buick in my 49 Sedanette in relationship to whether or not to purchase and add a kick down cable. The tag on the 400 indicates a 1979 build date. Back in the late 80's I used a 400 behind a 350 small block in a 47 chevy I built. I never added a kick down and put almost 50,000 miles on it with no problems. Now, from reading the posts here I realize that the kick down will give you some extra power for p***ing BUT MY QUESTION IS: if I'm worried about that is the kick down cable set up really necessary. Also, I ***ume the small canister on the p***enger side is for a vacuum line. Right???
The 400 has an electric kickdown, it requires a switch on the throttle linkage, and a wire. Not a cable. The vacuum modulator requires vacuum. From the manifold, not the carb.
Jim, Sorry for the misuse of the cable notation. So, you are saying it is REQIRED! And thanks for the clarification on the vacuum origin.
The kickdown wiring is not required for the transmission to work. It's just a good idea to install it.
From what I understand, the top terminal is for the converter and the bottom terminal is for the p***ing gear. See post #31
OK. Sorry, I don't know.... I've not seen one like you describe. One terminal may be for the ground or one side of the solenoid coil and the other terminal may be the power side of the coil. Might use a multi meter to determine if they opposite ends of the coil. Providing one side of the sol. coil isn't grounded to the trans. case, it shouldn't matter how the terminals are connected.
Searching for BUICK Switch Pitch info I found this 19 year old Article containing contact for the builder of S-P Controllers - It Worked. https://www.chevelles.com/threads/switch-pitch-convertor-who-makes-em.59827/ Switch Pitch Controller 2020 - Updated_Solid State Circuitry Contact Bruce at: bcroe@juno.com *bcroe replied: I built a hundred of this version, there are less than a quarter of them left. I have had to rework the design every decade or so, to stay in step with the constant evolution of electronic parts and their prices. But the function has not changed, except for a few custom units. The 65-67 Olds, Buick, & Cad TH300s & TH400s were Switch Pitch transmissions. Each brand had their own electrical control switch arrangements. However they all did the same thing. Kickdown was done with 12V applied to the bottom trans lug. 12V is applied to the upper terminal to set high stall (performance) mode, at idle or near full throttle; otherwise low stall (economy) mode is close to a conventional fixed converter. These controls were rather clumsy and unreliable, in my opinion. They ONLY used the SWP feature at idle or near full throttle. Getting parts to keep these controls working is increasingly a problem. I found the high stall can be used to improve midrange drivability, where the car operates most of the time. High stall during modest launches still gets up to speed faster, and also considerably smooths shifts. After braking for a turn, a burst of high stall pulls you back to speed. A request for more torque at speed can be done with high stall, often avoiding a downshift altogether. All this can be done, using an electronic controller sensing brake and torque (low manifold vacuum) and with delay timers. You still need a kickdown switch. I use a 70s style inside the car, mounted just above the gas pedal. The original may be used if it is still functional. There are pictures of all of these on my PHOTOBUCKET site. The interior factory switch 1242101 is still available, another is the B&M 20297 KICKDOWN SWITCH KIT. Both are on Ebay now. Note its satisfaction or I'll buy it back. For my controller send a check for $150 postpaid in USA. A recent rework has allowed me to change to all solid state, at this lowered price. There are pictures of linkage, various SWP control methods, parts, and my SWP controller with its flow diagram on my PHOTOBUCKET. Click on albums SWITCH PITCH TRANSMISSIONS, and BUILD A SWITCH PITCH TRANSMISSION. https://app.photobucket.com/u/bcroe BRUCE ROE 5719 EAST SKINNER ROAD, STILLMAN VLY, IL 61084-9215 phone 815 234-8039 solar powered since 2013 K9MQG since 1958
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