View Full Version : TR2/3/3A TR3a Spedo question

09-23-2009, 07:41 PM
When I first started working on my non O.D. TR3a I noticed that the spedo cable is disconnected. I disconnected the cable at the spedo to see if the cable would turn. I was hard but I could just turn it by hand. I decided to remove it to clean it out and did every thing seems well so I replaced it an was able to turn it and move the needle. Then I looked at the tranny and where do I put the cable end? I'm not sure but after I look at the workshop manual I'm pretty sure, but the bearing and gear appear to be missing and a bolt put in their place. No wonder at $42 and $20 each I assume that's why it was disconnected. Can someone show me a pic to let me know for sure where it goes?

09-23-2009, 08:38 PM
I don't have a photo, but her is a diagram. The speedo drive is on the left side of the gear box just behind wear the tail shaft housing bolts to the gear case and just forward of the rear mounting bracket. It is a brass color and is angled slightly downward. It is labeled 74 in the diagram.

09-23-2009, 09:51 PM
Note that there is also a threaded adapter (item 21 in this diagram) that doesn't appear to be available new anymore.

But if you can wait until after TRfest, I've probably got one I could part with, somewhere. Or you might be able to talk Bill C. into pulling one from his bone pile.

09-24-2009, 06:41 AM
my problem is where is the hole in the tranny. It was late and from the diagrams that I have seen it appears to be aft of where I was looking. I'll take some time this afternoon and look again. All I saw was the plugs on the side of the gearbox and appears to be behind the flange there.

09-24-2009, 10:43 AM
Yes, it's on the tail housing, just behind the flange. Here's a shot from Nelson, your gearbox won't look exactly the same, but the speedo drive is in the same place.

09-24-2009, 11:31 AM
Awesome thanks I' ll let you know what I find when I'm home later.

09-24-2009, 01:13 PM
Well here's what is in place of the connection for the spedo cable. Looks like a blanking plug. My dad used a couple of "mechanics" over the years and evidently on of the blocked it off for some reason. Could a bad bearing have caused a problem with the gear?

09-24-2009, 02:03 PM
Almost looks like that is a different tailhousing. Could this gearbox have come from some other car in the past?

There could have been a problem with the bearing I guess, but I've never seen or heard of someone having trouble like that. The usual way to break the gear is to forget to pull it out before trying to remove the tailhousing for a rebuild.

09-24-2009, 02:12 PM
I don't know of any changes but I guess it is possible. After 1986 I wasn't around the car much. My dad is getting old, but I'll see what info I could get out of him and see if the mechanic is still around.

09-24-2009, 02:13 PM
Is the hole on the other side for RH drive cars?

09-24-2009, 03:59 PM
Is the hole on the other side for RH drive cars? No. There are, however, RHD & LHD cables for both speedo & tach. That's where they accommodated the difference.