View Full Version : Transmission Speedometer Drive

03-25-2012, 05:45 PM
The speedometer has not worked from the day I purchased the car almost a year ago and in the process of diagnosing the cause this is what I found. The connection for the speedometer cable on the transmission, (the cable end was taped in place) is a 3/4 inch tube exiting the transmission with no threads on the outside but with fine threads on the inside. There is a shaft in the center of this which the square cable end will go into and there appears to be a rubber washer behind at the back end of the 3/4 inch tube.
My question is this. Is there a part that threads into this tube so the speedometer can be attached? All of the Triumph speedometer cables appear to have the same female threaded end to attach to the transmission so something is surly wrong.
Can someone set me straight here as the speedometer itself works and I am at a loss.

03-25-2012, 06:01 PM
Always helps if you mention what car you are asking about; all Triumphs are not the same. But assuming this is your TR4A then yes, there is a piece that goes there, with external threads on both sides.

03-25-2012, 06:19 PM
Here's a complete one for sale on eBay right now and you can zoom in on the picture (shows it from the wrong angle though).

eBay speedometer gear for sale (https://www.ebay.com/itm/Triumph-TR3-TR4-TR6-Brass-Speedometer-Bushing-Steel-Gear-VGC-/330617724938?hash=item4cfa5a200a&item=330617724938 &pt=Motors_Car_Truck_Parts_Accessories&vxp=mtr)


03-25-2012, 08:46 PM
Thanks TR3 Driver

You have answered my question and you were right about my Triumph being a TR4a. The illustration makes everything clear. Possibly someone before me needed the part and removed it then just taped the cable back in place. Looks like an easy fix!!! Thanks

03-25-2012, 08:51 PM

Thanks for the lead on the complete speedometer drive unit. I would assume what is offered on e-bay would give me the outer portion I need to screw into what I already have.