Intermittent Overdrive Fix

[Aldpilot]

For the last 9 months the overdrive on my TR5 has been getting more and more inconsistent. It did not always engage when the column switch was thrown, but could engage at any time later and stayed in once set. It always disengaged when asked. As usual with these types of intermittent issues, I got various suggestions (but never the answer), with the most prolific being “is the gearbox oil level low?”

 

After checking the power supply from the switch to the solenoid, there was nothing else for it but to remove the Gbox tunnel to get a good look. It was at this point that the overdrive inhibiting switch became visible. When I removed it the spring loaded round end looked worn. A call to Pete at Overdrive Supplies suggested swapping the switch with the reversing light switch (they are identical). This switch did not look worn and Eureka it fixed a long standing and annoying problem. Posted here to highlight something that no one had suggested to me. I hope it will help someone else in the future.

Photo of the worn unit below. Part No BAU1074A from Rimmers at £7.44

Mike

[RogerH]

Hi Mike,

   well done - super sleuth.

I am surprised nobody mentioned the inhib switch. That is one of the main contenders. Usually the fibre washers are too thick and can be reduced.

Not seen wear like that though. Looks like the ball has not rotated at any time.

 

Roger

[Drewmotty]

Thanks for the update Mike. Threads need rounding up with a conclusion to assist future searches. 

[stuart]

4 hours ago, RogerH said:

Hi Mike,

   well done - super sleuth.

I am surprised nobody mentioned the inhib switch. That is one of the main contenders. Usually the fibre washers are too thick and can be reduced.

Not seen wear like that though. Looks like the ball has not rotated at any time.

 

Roger

Probably because its not an original switch, the repro ones have never been particularly good quality.

Stuart.