Looking for a manual transmission but don’t know where to start? This handy guide to Tremec transmissions should help you out! From the OEM-sourced T-5 and T-56 transmissions, to the TKO and TKX transmissions you can buy today, this in-depth look at Tremec’s group of manual transmissions is designed to help you choose which gearbox is right for your project car. https://www.holley.com/brands/tremec/…https://www.holley.com/products/drive…
After driving my Model-A for a while with the stock 3-speed non-synchro transmission, it seemed like the car would be much more compatible with modern-day traffic if it had an overdrive gear. A company in Muncie Indiana, called Auto Restorations makes a kit for installing a Borg-Warner T5 transmission in a Model-A. The kit costs $895, and includes transmission adaptor, driveshaft, brake linkage changes, clutch disk, speedometer cable, etc. Presumably everything you need. After a call to get information (765 288-3291, they don’t have a web site) I ordered a kit.
The only thing you need to know before ordering is how many splines there are on the input shaft, so that you can get the proper clutch disk. The donor transmission comes from a Chevy S10 2WD pickup. These T5 transmissions are unique in that they have the shifter placed further forward than a standard T5. Even though the shifter is further forward, it still is about six inches rear of the original Model-A shifter once the conversion is done. T5 transmissions are synchromesh in all gears and high gear is 0.72:1, a nice 38% reduction of RPMs while cruising. My transmission had the 14-spline input, but some of these T5s have a different spline count. I believe all have a standard 27-spline output. I found a transmission at the local Pull-A-Part for about $70 including tax and the core-charge. They aren’t very difficult to pull out, but I did donate a nice socket to inside the frame of the donor vehicle while I was taking off the cross brace. Here’s what it looks like:
The kit arrived, well packaged, in two boxes. Many of the parts were primed in red oxide. I though that it would have been a nice touch if the supplier had powder-coated them, and I considered doing that myself, but decided instead to paint everything in black prior to installation. In retrospect, I’m glad that I didn’t powder-coat them, since several parts needed to be modified.
Instructions are included, but they are pretty sketchy and in unusual order. I suspect that no word processing was used so that modifying and updating the instructions had long ago ceased. They do include some good pictures and drawings though, that I found to be very helpful. I didn’t have any idea if this was going to be a half-day or week-long job. As it turns out, the latter was the closest guess. If you want to see the instructions that come with the kit, here’s a copy…T5 Installation Instructions.pdf
First thing I did was to modify the transmission. This involves cutting off a tab behind the shifter and drilling a hole below the shifter to accommodate two thick steel plates that bolt to the rear of the transmission. These plates are the new support for the rear control arms connecting to the axle. As was going to be typical in this job, the plate on one side had to be machined to fit the transmission, and the spacers from the kit weren’t quite the right size, so I ended up making new ones. Also, the hole in the T5 needs to be bored to a larger size to work with the kit.
The next step was to start disassembling the car. This involves unbolting the rear spring, brake rods, and shock absorbers from the car so that differential can be lowered and moved back to remove the torque tube. Here’s one step in the instructions: “Go to the back of the transmission and remove six bolts holding the torque tube. At the differential this torque tube should release so it can be taken down. If not, you may have to persuade it.”
Those two sentences turned into hours and hours of work. As it turns out, removing the torque tube at the rear involves pulling the pinion bearings (complete with races) from the differential. After several hours of unsuccessful persuasion, I found a note tacked onto the end of the instructions about how to use a disk and some studs included with the kit to help. Finally, success! Here it is at work:
Once the torque tube is out, the transmission can be removed. It’s not a bad time to also take out the brake linkage since it will all be modified anyway later on. When the transmission is out, the new clutch disk can be installed, using the existing pressure plate. The instructions tell you that you need to get an alignment tool, but they actually included a decent plastic tool for this purpose. The kit also doesn’t mention, but includes a new pilot bushing that slips into the existing flywheel bushing, and extends it out and to the correct diameter for the T5. Forgetting that would be something you would remember for a long time since it would require pulling out everything again. You can see it in this picture.
This week Davin tackles upgrading our 1946 Ford truck’s transmission. This was a truck assembled in 4 days on the grounds of the Hershey Swap meet in 2015 and ever since the plan has been to upgrade to a T5. Well, six years later Davin finally found the time. Watch along as we take you through the process. We’ll show you what it takes to do an upgrade like this, and worse case you might learn what not to do..
What is overdrive? Simply stated, any overdrive transmission turns the driveshaft faster than the engine’s crankshaft when overdrive is engaged.
To get underway, the crankshaft must turn faster than the driveshaft; the driveshaft is underdriven. This gives the engine a mechanical advantage over the driveshaft. Once cruising speed is reached, however, if the engine could turn a lower rpm than the driveshaft, through overdrive, it would reduce engine wear and yield better fuel mileage.
Both automatic and manual transmissions may have overdrive. With today’s manuals, though, the driver must depress the clutch and physically shift into overdrive. It wasn’t always that way.
Engineer William B. Barnes is credited with designing and mating a secondary overdrive unit to a common three-speed manual transmission, using a planetary gearset to increase the output shaft speed. He shopped it to Borg-Warner’s Muncie Gear Division in 1932, where it was further developed and presented to Chrysler Corporation. Chrysler first made it available in 1934 Chrysler and De Soto Airflows to augment their gas mileage.
Barnes’ original design required that the unit’s sun gear be held in place with a manual control to engage overdrive. Subsequent development added electric components to control that function, resulting in what became known as “automatic electric” overdrive. Simply known as “overdrive” thereafter, it became a popular option on many cars and trucks during the 1930s and beyond.
Manual transmissions are an icon of the automobile hobby. The ability to operate a car with three pedals sets an individual apart from the mass of drivers who just see cars as point-a-to-point-b transportation. “Driving a stick” lends a certain air of mystery and adventure to a car owner.
Still, how many devotees of the clutch pedal can tell fact from fiction when it comes to the innards of their beloved gearbox? Most of us don’t know a lot more than the number of forward speeds and how many of them are synchronized. It doesn’t need to be that way. The selection, installation, and maintenance of what was once called the standard-shift transmission can be quite straightforward.
From a three-on-the-tree to the seven-speed in a C7 Corvette, all manual transmissions have certain points of commonality. The muscle-car four-speeds of the ’60s and ’70s are likely the most familiar to Hemmings readers, but five-speeds like the Borg-Warner T-5 have been with us nearly 40 years. Even the beloved T-56 six-speed came on the scene in 1992, with the Dodge Viper. That’s a lot of accumulated knowledge. To get the latest information for gearjammers, we consulted with TREMEC dealer Silver Sport Transmissions. Below are five things to consider when contemplating a manual transmission in your ride.
1. Overdrive in Moderation
Historically, a transmission’s top gear transmitted power from the engine in a 1:1 ratio (“direct drive”) where one turn of the engine causes one turn of the driveshaft. Starting in the Seventies and Eighties, however, manual transmissions adopted overdriven top gears, meaning the engine can be turning slower than the driveshaft. When selecting an overdrive ratio, keep in mind that the lower the number, the more overdrive. On a TXK five-speed trans (shown above), the buyer has a choice of 0.81:1, 0.72:1, and 0.68:1, which offer 19-, 28-, and 32-percent overdrive, respectively. Beware of falling into the “more is better” trap, however. As with camshafts and carburetors, too much overdrive will work to your disadvantage. Unless you have an engine built for it, matched to the proper rear-end ratio, you may find yourself lugging the engine in overdrive
2. Keep things in Sync
Synchronizer rings and cones smooth the transition from one gear to another, so that you only have to press in the clutch once per shift. They may date back to the 1930s, but they’re not limited to the technology of that era. While traditional brass construction still persists for most applications, Silver Sport’s experts note that they wear faster than some options now available. Worn synchros lose their grip and exhibit crunching where crisp shifts used to be the norm. “If you plan on high-rpm shifts or if you’d like to extend the life of your transmission before it needs a rebuild, carbon-lined synchronizers are the way to go,” said Silver Sport’s Misty McComas. Carbon linings come in both partial and full varieties. With partial (shown above), only the blocker ring or cone is lined, but with full, the whole synchronizer is lined. The latter is recommended for situations where more grip is desired. Even if you’re not power shifting, a harder-wearing consumable means more fun time versus maintenance.
After removing the shift tower from the car (see Part 1) I took the it over to see John Cochran and we got a good look at what was quite a bit of wear in the lever and the selector forks, which I hope is the source of my 2/3 shift issue.
In this video we discuss the wear in the components
Step by step pictures of the assembly as much as I could take whilst actually assisting!
We replaced the shift lever, the selector forks and inspected all the other components were found to be serviceable. The worn detent bullet you can see in the pictures is from an old gearbox and is being used for comparison only.
As you can see we used the special tool to ensure we didn’t get taken out by the famous “killer spring”
Thanks to John Cochran for his assistance as always
Now to get the tower reinstalled and see if it improves the 2/3 shift.
The Explorer, (also know as The Exploder :)), was the replacement for the Bronco II which had it’s problems rollover wise. the Explorer ran into tyre issues resulting in many lawsuits. The Exploder tag appears to be in reference to the transmission