Building A Powerglide Transmission For Ultimate Reliability

Typically, when you hear about someone starting a build, the go-fast-goodies are first on the to-do list. I’ve been highly involved with diesel drag racing over the last few years, and the “power adder” modifications have always come first. This usually results in a tow truck after the first pass. With Project TwoFace, we are going in the other direction.

We are looking for complete and total reliability. Of course, we want to go fast and have fun, but there is no fun in getting carted off the track because you didn’t back your engine up with the driveline needed. Before we start churning out serious horsepower numbers, we want to build a transmission that can handle anything we throw at it. So, we called TCI Automotive.

TCI Automotive has been involved in performance transmission parts since 1968. Because of that, we knew we could trust their newest parts for our upcoming build. We could’ve just ordered directly from TCI and got a ready-to-go unit but we haven’t actually taken a stock unit and built it from the ground up. After you read this article, you will have the part numbers and information needed to take your stock-case Powerglide to the next level.

To better understand the products we acquired, we talked with TCI’s Ondre Terry. Terry, one of their WD transmission sales associates, gave us the scoop on why a Powerglide is a perfectly viable option for a street/strip unit.

“The Powerglide itself can serve as a dual-purpose unit. It works great for both street and strip applications and offers the consistency you desire. These transmissions can utilize the turbo spline shafts that will handle a ton of power,” Terry said. “For example, the 1.76 planetary is good up to around 800-horsepower. That is good for most street/strip builds. If you change to a 1.80 planet, you’re now safe for 1,100-1,200-horsepower street car use and even 2,000-horsepower on the track. This transmission covers a very wide variety of builds.”

What Is Included?

Project TwoFace will be a truck that can drive to and from the race track. Our idea is to build an extremely reliable and consistent truck that we could take to the races on Saturday and the grocery store on Sunday. To reach that goal, we’ll need to use the parts listed above. If you’re familiar with some of these parts, you’ll notice that these are some of the beefiest parts available.

Seems a little overkill for our 5.3-liter LS, right? Well, yes. We are wanting to take this one step at a time and offer a one-stop shop for track data. Stock torque converter and stock engine, let’s see what it will do. We need a foundation to be able to properly handle all of the power increases we have planned through the life of this build. Before we can do that, we’ve got to harness that power and transfer with this ‘glide.

When using a transbrake valve body on a Powerglide, you're forced to modify the housings of the transmission. It isn't an extreme job at all. Simply use the correct size bit and drill the correct hole out.

Our master rebuild kit contains the performance clutches, frictions, and steels necessary to hold big power. The TCI internal parts are made from some of the strongest, most durable materials available. Since these are designed for applications exceeding 450-horsepower, the choice was simple. Also, a notable fact about this kit is that it is rated for extreme performance and even RV/ heavy-duty towing. Will we be towing? No, but it is nice to know this kit will handle the abuse of street/strip fun.

“Like the spline shafts, this rebuild kit covers everything. Our rebuild kit is more than a stock replacement kit. Because of the better materials we use on our frictions and steels, the life of this build will last much longer.” — Ondre Terry

Delicately placing our clutches and steels down into our hub, our Powerglide is that much closer to track testing.

Hard Parts And Tolerances

The hard parts that will be handling all of this upcoming power are the hardened input shaft and the bolt-together planetaries. The input shaft is constructed of high-strength steel that is designed to distribute the stress along the entire shaft rather than one spot. This shaft has more than double the tensile strength a factory unit does.

Moving on to the planets, this part is built with two things in mind: strength and ease of use. This clever bolt-together design, offered in multiple gear ratios, is available for all different driving scenarios. Because it is bolt-together, this makes for easy rebuilds, gear ratio, or output shaft changes and we wouldn’t have to send it into TCI.

Other features include straight cut gears, roller thrust bearings (rather than washers), and steel-backed, bit-metal washers with a wear-resistant PTFE layer that reduces friction and heat. An additional feature we are using is a 10-pack steel drum kit. With an extra-tall, forged-steel clutch hub, we will now have extra frictions and steels which will inevitably increase lock-up surface area and hold more torque/horsepower. Oil holes have been added to allow fluid to escape the drum and permit the piston to engage quicker.

How we’ll control this Powerglide is with a StreetFighter valve body and an Outlaw shifter. The StreetFighter was developed for street/strip use and features transbrake capabilities. Since we’ll be doing quite a bit of testing and racing, a transbrake is an absolute must for consistency. When you leave off a footbrake, you may not leave the same every time which will cause flawed results.

“Our Outlaw shifters are great and easy to use, regardless of the application. We offer them in all transmission patterns but what I like most is the feel of the pistol grip handle,” Terry said. “It’s easy to use, it’s easy to install, and shifting is effortless. This is universal to virtually any application.”

"Unlike other pump stators, this is bolt in. This is pinned into the stator which means you're getting even more reliability," Terry said. "Factory pumps have a tendency to spin and because of that, we offer options like this. Since it is bolted and pinned, it will not break, it will not twist, and it will be much stronger than factory."

To top off our Powerglide build, we need fluid that will handle the horsepower and torque we throw at it while maintaining shift quality and performance. TCI’s MaxShift ATF (Automatic Transmission Fluid) is what we’ll be using. MaxShift has been tested in very harsh conditions and has proven to be a true competitor in the fluid space. With properties that reduce internal friction and heat build-up as well as friction-eliminating and extreme heat additives, we should be covered in both street performance and on-track abuse for days to come.
Our built transmission is finally ready to rock and roll. We’re currently waiting on the chassis shop to have a bay open and we’re off to stab this and the LS powerplant into their new home. Once we’ve addressed the other items on the to-do list, and it’s ready to move, it is time for shake-down passes to establish our baseline numbers.

 

 

 

 

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Artie Maupin

Artie Maupin is from Southeast Missouri and has an extreme passion for anything diesel. He loves drag racing of all kinds, as well as sled pulling competitions.
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