Tim Suddard
Tim Suddard Publisher
9/26/18 12:54 p.m.

This story ran in an old issue of Classic Motorsports. Want to make sure you're reading all the latest stories? Subscribe now.

Story and Photos by Tim Suddard

In the world of ’60s British roadsters, the Triumph TR is a standout. However, even a well-sorted TR6 has a few weak spots, and the transmission is one of them. The four-speed box is nice, but the car really needs an overdrive or fifth gear to purr instead of howl at highway speeds. Our 1969 Triumph TR6 would definitely benefit from that extra cog.

Sure, a Laycock de Normanville overdrive unit was a factory option when these cars were new, but it was rare then and is even rarer today. Finding one that isn’t worn out is rarer still. This overdrive unit can be made to work, but it’s also heavy, expensive to restore, and a bit cantankerous to maintain.

Through the years, enthusiasts have figured out how to install any number of five-speed transmissions into a Triumph TR. They’ve used everything from Ford T-5s to units from Ford Sierras, Nissans and Toyotas, but these swaps have had varying levels of success.

Swapping a five-speed into an old TR is rather tough. In addition to simply finding the space for the new transmission, you have to figure out how to mate it to your engine, clutch and driveshaft. Then you have to get the shifter to appear in the right location. As you can imagine, compromises are common.

Read the rest of the story

Gary SuperDork
9/26/18 9:34 p.m.

Well, I have a terminally garage-bound '68 Spitfire. But I have learned a lot from it. And that's why I bought it originally. I definitely learned a lot. One of my desires is a roadworthy TR6, and my budget definitely permits this. I would definitely go for a 5-speed conversion. Then again, how do I want to maximize my available capital? I saw a beautiful 912 for sale in LA selling for about as much as I'd have to put into a TR6 to make it as nice.  I'm not bragging, but it's good to have the financial resources to make these choices. I will have a great car.

wspohn Dork
10/2/18 11:06 a.m.

Seems a retrograde step to take a car that had an optional 7 speed gearbox (or 'only' 6 speed, if you have the later J type OD unit) and putting a 5 speed box in it, although I agree about the scarcity factor.

Personally I much prefer OD stock box - if you are driving along a winding road in Autumn enjoying Fall colours, you can flip back and forth between 3rd and 3rd OD by flicking a switch, without touching the gearshift.

I've done both, and have a T5 in my rebodied MGA with V6 - the shifter ended up located just right; not sure how that would work out on a TR.

Tim Suddard
Tim Suddard Publisher
10/8/18 7:17 a.m.

The shifter does come out in the right place and our TR6 did not have the overdrive. While I like the overdrives, they are delicate, heavy, and getting harder and harder to find and rebuild. When we moved our TR3 from overdrive to T5 five-speed, we knocked over 50 pounds out of the car.

Our Preferred Partners