Triumph Spitfire Gearbox Problems.

The customer of this beautiful Triumph Spitfire convertible reported that he was having problems with the gearbox.

What he was finding is when in third gear, all was fine, but when accelerating the gear lever would move and the gearbox dropped out of third gear and into neutral.

The only way he could drive it would be to hold onto the gear lever, whilst in third. This was the only gear that had the problem.

Four speed transmission with Overdrive.

Following a test drive the gear lever jumped out of third gear every time. No horrible noises, rattles or clunks and the overdrive worked perfectly.

Time to start dismantling. 

Gearbox cover.

The transmission tunnel on the Spitfire is removable so after removing radio, centre console and carpet we expose the cover.

Gearbox exposed.

After the removal of the cover, the whole transmission is exposed so we can start to investigate what the root cause of the problem is. 

The gear lever is remote with the selector shaft much further forward. Seems the best place to start. 

Worn gear lever selector slot.

First thing I spotted was quite a bit of wear in the gear lever where the selector pin engages into the gear lever. This would cause quite a bit of play. 

Will do some weld repairs on this. 

Disintegrated lever pivot bush.

Also found that the plastic selector shaft pivot bush had completely disintegrated inside the housing. For some reason there was also a panel clip for self tapping screw in there too.

New bush fitted.

Could the wear in the gear lever and the disintegrated bush be the root cause? Here is a new bush fitted into the selector rod. This will make the changing gear far more positive.

Repaired gear lever.

I filled the worn areas with weld and then neatly filed and polished the surface.

With the new bush and the repaired gear lever will this solve the issue?

Put it all back together and go for a test drive.

Not resolved.

Although the gear lever is now really firm and the gear changing feels much better the gear lever is still dropping out of third gear.

Reconditioned gearbox will be required.

Transmission removal.

With everything disconnected from the transmission, including the prop shaft, it is possible to lift the transmission out from inside the car.

Needed to also remove the passenger seat.

Transmission out.

The transmission is made of three parts, the front bell housing, the middle gearbox and the rear overdrive unit. We just need to replace the middle gearbox part.

Clutch replacement.

As we have come so far and due to the low cost of the parts, it's prudent to replace the clutch and pressure plate. Would be a shame if it all had to come apart again in a year or two to replace it.

Customer had no knowledge if it had ever been replaced.

Transmission disassembled.

There are several specialists who recondition gearboxes and have them on the shelf. They exhange your old one for a reconditioned one. Very easy.

New gearbox assembled.

Now the transmission is assembled just a case of popping it back into the car and re-assembly and fresh oil.

Once completed a test drive confirmed that all is now perfect and should be good for, probably, the rest of the vehicles life.

New exhaust.

The customer also decided, whilst the Spitfire was with me, to have a brand new stainless steel exhaust fitted.