TR6’S oozing gearbox and clonky exhaust made to behave
In my previous Staff Car Saga, I described how the TR6 was suffering from a flickering speedo needle and a rattling exhaust system. The diagnosis was a sticky speedo cable and a broken exhaust bracket that mounts from the back of the overdrive/gearbox. While I had the gearbox tunnel cover out, I also decided to try and stem the multiple oil leaks from the gearbox and overdrive that have plagued the TR ever since I bought it around 12 years ago. It was obvious EP90 was oozing from pretty much every place it could on the gearbox and overdrive. Reasoning that it’s unlikely every gasket and oil seal would fail simultaneously, I started wondering if the breather was blocked. Removing the filler plug resulted in a gentle whoosh of escaping air, again suggesting a breathing problem.
I looked for a breather to unblock, but found nothing. The ever-helpful chaps on the TR Register forum explained that TR gearboxes have two possible breather locations, either a tiny hole on top of the gearbox cover, or a cylindrical breather on the overdrive. My TR had no breather hole on the top cover and a blanking plug screwed into the overdrive casing where the breather should fit. With no breather at all, it was little wonder the gearbox was pressurised and leaking.
Feeling optimistic that I might have found the cause of the long-term leakage, I purchased a breather and fitted it to the overdrive in place of the blanking plug, then topped with fresh EP90. Since then, the gearbox has barely lost a drop of oil and the drip tray on the garage floor is now redundant. A small victory perhaps, but after so long it felt good to finally nail this problem – and not a single gasket or oil seal needed replacing!
Up the bracket
My next port of call was the exhaust, which had been rattling at tickover due to a broken bracket that connects it to the overdrive mounting and crossmember. I expected I’d have to weld up the old bracket, but found that Rimmer Brothers had new ones on the shelf at a reasonable price. The bracket was ordered and bolted in, then I replaced the exhaust, hanging it carefully to avoid pipes knocking on the chassis rails.
Time to move on to the speedo cable. Speedy Cables lived up to their name and quickly supplied
New breather means EP90 stays in the gearbox rather than on the floor. Also in Nigel’s garage 1977 RELIANT SCIMITAR GTE The Scimitar is my daily driver at the moment. It’s smooth, comfortable and eats the miles easily.
Work done Finishing off jobs around the TR6 gearbox; they turned out to be bigger than expected. GT6 body repairs completed – it’s now ready for paint.
CONTRIBUTOR 1970 Triumph TR6 Engine 2498cc/inline 6/OHV Power 150bhp@5500rpm Torque 164lb ft@3500rpm Gearbox 4-speed man + o/d 0-60mph 8.2sec Top speed 119mph Fuel economy 28mpg