Engine, Transmission including Annular release

Annular release bearing kit

Pierre has fitted our annular release bearing kit and tells us his experiences so far: -

It is well known that the clutch control of the TR5 / 6 has become an Achilles heal. Indeed, it has remained broadly the same since the old TR's, but the torque to be transmitted has increased and therefore the efforts on the control system have reached its limit.

The annular clutch release kit as proposed by RevingtonTR, i.e. RTR1009-1K completely resets it. https://www.revingtontr.com/engine-transmission/flywheels-clutches/clutch-release-mechanisms/annular-release-kit. The hydraulic bearing acts directly on the diaphragm, so there is no longer any binding, nor any play, nor weak point in the system.

The kit is really simple and easy to install, (just respect the instructions) but it is important to check the distance between bearing and diaphragm. For me, it was right at the first time with the original Laycock clutch cover. I used a 0.625 master cylinder from the Triumph Spitfire (GMC205) without a pedal stop. You just have to match the diameter of the pipes, which are different when using this cylinder, but is not really a problem. The master cylinder control rod of the Spitfire. must be adjusted in length, or replaced by the original rod of TR5, nothing could be simpler.

The purge is done by itself by simple gravity, without even having to "pump"!!

In use, it is a real pleasure, the clutch pedal is very soft, very precise, without any hard point. It is also clear that the gear change is faster, because the control is really very direct. So I can highly recommend it if you have to work on your clutch, it totally changes the driving.

Only question mark, it is to be hoped that the hydraulic seals have a good life expectancy, because the removal of the gearbox will be necessary in the event of a leak.........

Engine Sump

 Gearbox

Overdrive

My choice was for a type A overdrive (22%) on 2, 3, 4, this gives almost perfect staging.

KPH vs RPM with 3,7 axle ratio

Normally only the J type (25%) was fitted with the CC gearbox of TR6 and was only functional on 3 & 4 and therefore had a specific secondary shaft that does not match with the A. So I kept an old big nose imperial TR4 secondary shaft, but it is necessary to drill it to put the ball that blocks the washer on the CC box. You have to pierce the nitride layer, it's quite hard, but manageable.

"Big Nose" shaft drilled for the ball which prevents the stop washer from turning on CC G.B.

Logic Overdrive device

In the 1970s, I made an electric flip/flop overdrive control with a cascade of relays that did work quite good. At this time of the rallies with the Dolomite Sprint, I had put a very long control rod. With the bumps of the road, the inertia made the rod move and the overdrive engaged or disengaged by itself and the pilot went crazy!

Now Neil markets the same functionalities with a full electronic small box. He calls it "logic overdrive."

So I succumbed to modernism and I installed Neil's box. It works well, no problem. (but I put a shorter control rod (40 mm) on the fascia just in front of gearbox lever !!) (RTR comment Parts are listed below)

Rear Axle and Drive shafts

The original ratio of the rear axle (3.45) is irrelevant here where the speed is limited to 110 KMH on pseudo highways and there are a lot of mountain roads. I tried a 4.1 and finally went for a 3.7 which is a good compromise with 185/70 x 15 tires on 5.5 x15 72 spokes wheels

Constant velocity (CV) joints have been proven for a long time so this was my option which also allows better AR hub bearings to be fitted. (RTR comment, A word of caution. Pierre is a competent engineer and his drive shafts will therefore be correctly specified. Be aware though that there are parts on the market with insufficient 'plunge' such that the drive shaft bottoms out on full bump and tries to punch the hub off the 6 studs. we have seen several cars in the workshops with the hub attachments studs pulled out! Very dangerous. We offer an uprated driveshaft of the traditional design that works well too. Parts are listed below)