TR6 Transmission Tools
by Bob Lang, email@example.com , of New England Triumphs
Several years ago, syndicated columnist Dave Barry wrote an article that fully explained the mystery of the automobile transmission. In short, he explained that nobody really knows where transmissions came from, but that they were probably left here by aliens. He further postulates that automotive engineers felt that transmissions should be incorporated into cars anyway. Of course, this is a gross simplification of Mr. Barry’s epistle, but it does make a good point.
I have always been fascinated by transmissions in several ways. On those occasions when I had to work on a transmission, I started out thinking that there was no way I would ever understand how they worked. This was followed by a smitten of understanding as I dismantled the unit and eventually some real understanding of the process as I reassembled the unit and reinstalled it the car. When I finally actually used the car, I felt I had reached a notable goal. And in every case everything worked just fine.
Well there was a unit on a certain ‘Mericun car in my past that didn’t last too long after the rebuild, but that as they say is another story.
At any rate, after recently rebuilding the TR6’s transmission I realized that I actually learned things in the process that I could share with New England Triumphs readers. Specifically, I learned a small amount about fabricating special tools and I also figured out a few tricks that make the assembly process a whole lot easier than that offered in the Robert Bentley TR6 manual.
The first article is about tools.
A quick look at the Bentley manual indicates a list of several “special” tools used to get everything apart. For instance after taking to top off of the unit, the next step is to remove the “constant pinion” shaft. This step requires one of the dreaded special tools.
Flip to the back of the manual, and pictured there on page 596 are tool numbers S-4235A and S-4235A-2. Now, I have had the Bentley manual for over 10 years, I have looked at that transmision tool just about every time I have thumbed through the book, and I only recently realized exactly what that tool is. It is a slide hammer, aka a dent puller.
Tool number S-4235A-2 is merely a device that clamps onto the constant pinion shaft. I wound up making this tool by taking a piece of pipe that was about an inch and a half inside diameter and about ten to twelve inches long. On one end, I welded a piece of steel across the open end and welded a 1/4 X 20 nut in the middle of that. At the other end, I put a couple of 1/4 X 20 bolts that are attatched perpendicular to the pipe. These bolts clamp against the constant pinion shaft. Note: the splines on the constant pinion shaft are symetrical, so you may want to put three bolts instead of two. This will eliminate the possibility of making the tool slide up the shaft too easily. The slide hammer attaches to this “tool” and you basically “yank” the constant pinion shaft and bearing out. This is a pretty simple tool.
Armed with this valuable knowledge, I set off to determine what the next special tool needed was.
The manual indicates that you need a pretty elaborate tool to remove the center transmission bearing. I found this to be not true. It would be easier with a special tool, but you don’t absolutely need one. Warning: if the center bearing is tough to get off, your transmission should be reassembled and worked on by skilled professionals.
My experience was that the center bearing was relatively easy to take out with a very small amount of heat and some big-ish hammers and some soft drift material like some scrap aluminium or brass.
You don’t need any special tools to remove the countershaft, you just need to be really careful that the countershaft thrust washers do not fall into the case. More on that later. I did use a 1/4″ wood dowel to push the countershaft