New parts and speedo cable woes

[dklawson]

Randall, what are the CEI threads used for? They are new to me.

 

[angelfj1]

Sorry, my bad. I guess that I do have one of the lock downs on mine. It's in the last picture, on the transmission. The adapter is as shown.

Paul: Sorry for the dumb question but what is the purpose of the machine screw in the side of the angle drive?

fja

 

[TR3driver]

Randall, what are the CEI threads used for?

All I know is that they are obsolete British threads, listed in one of the "Thread ID" charts I've got squirreled away. According to
https://www.gomog.com/allmorgan/whitworth.html
they actually predate BSW!

Looks like 3/4-26 was carried over to BSC (a slightly later obsolete British thread system), though most of the charts I looked at don't include it.
https://www.classicfasteners.com.au/TechData/THREADCH.PDF

Also, looking again, the nut on my angle drive is plated brass; so perhaps those are 'brass' threads.

 

[DrEntropy]

Sorry, my bad. I guess that I do have one of the lock downs on mine. It's in the last picture, on the transmission. The adapter is as shown.

Paul: Sorry for the dumb question but what is the purpose of the machine screw in the side of the angle drive?

fja

<donning Brosky disguise>

It has a "post" at its end, extends into the angle drive to act as a travel limiter for the internal gear.

</donning Brosky disguise>

:laugh:

 

[2wrench]

Okay. So I have verified that all threads are correct, so I put it into
a vice and screwed the thing together. Very simple, with a little bit of
force (something I try to avoid).

So, I have pictures of the way I think this thing should be going
together. Problem is: It does not turn the cable, one end to/or the
other, as it should.

A shot of one end of the speedo angle might suggest to me that something
could be missing from the insides of the speedo angle. The black hole
is like way larger than the cable end that goes into it. Seems something
should be in there to engage the end of the cable:

And this shot shows how I think the pieces should go together, but still
verifying this with Quantumechanics.

 

[DrEntropy]

WOAH!! The gear and drive "dog" ain't there, man!! It should have a square "receiver" end in there.

 

[2wrench]

HOLY TOLEDO! We've hit on it. The darned insides of the speedo angle
seem to be flat out missing!

First, I'm bummed cause the part ain't right;

Second: I'm delighted to find the problem.

How the heck does this kind of thing happen????

Huge thanks the Forum for all the trouble and support. I'll get it
taken care of in one way or another.

 

[2wrench]

Also, special thanks to Brosky for the trouble in (retrieving part?) and
taking the pictures. Paul, are you able to post a shot of the speedo
angle that shows the "drive dog," that seems to be missing from my unit?

That would be cool. Maybe it will illucidate better my problem and
help others who may run into something like this in the future....but
let's hope it never happens again.

 

[DrEntropy]

I had half a dozen of th' things ~someplace~ in here, have been scramblin' around to find just ONE to make a disassembly photo... Ya think I can locate one?


feh.

 

[2wrench]

Hi 2wrench As has been asked,when the "hat" is screwed in can you move the "hat" backwards and forwards (which I expect it will)or is it butting up properly?If there is no play the adapter is too long,in which case I would measure the depth of the screw cap on the angle adapter and carefully cut the "hat to suit or better get the correct "hat" .If there is play then if the supplier of the angle adapter says that it is fine threads and the "hat" screws directly onto the cable with no problem then the thread into which the "hat" is supposed to screw is damaged in some way or incorrectly cut,Try taking it to a freindly local machine shop for to see if anything can be done, if not the angle adapter needs changing as cutting the correct thread in the cap is very difficult without the correct tap and the cost of the tap will probably buy you 2 or 3 adapters at least

So now that I verified the threads are correct and have screwed the thing on there, she is
as snug as a bug in a rug....okay...no, there is no play in the hat/adapter at all where it
screws into the speedo angle. If there should be some play there, then I have yet another
problem.

 

[2wrench]

Back again for another thing: My speedo cable is one piece. For a
'74 TR6, that would be the correct cable huh?

Paranoia's got me second guessing everything.

 

[DrEntropy]

STOP that!!

Take a step back and deep breathly. The speedo cable will be one continuous length from angle drive to speedo head. The head end may be a smaller diameter than the one at the angle drive (depends on which Smiths instrument was fitted. '74 was IIRC, a smaller end than the drive side. There was a "thingie" fitted to some cars to count "service interval". It was a white box with a window showing what looks like an odometer. You shouldn't have one of those to my recollection.

 

[Brosky]

Here's a few shots that I got. The turning one cable, turns the other. The "square" female hole is down inside the end of the adapter.

 

[DrEntropy]

Dennis, are you pushing the exposed end of the cable (speedo end) in as far as you can before trying to spin the angle drive?

I.O.W. the inner cable needs to be "bottomed" in the angle drive to see if it will spin when the drive is turned. That last shot Paul posted is of a snapped off cable end. it's deep enuff into the drive that it would turn as the trans side is rotated.

 

[Brosky]

I really do have to clean that little guy up if I'm going to be exhibiting him like this. He's actually NOS from a collection that I bought and swapped out to Erik. Just needs some TLC to be lookin' good!

 

[2wrench]

Yeah, Doc, I was sure to push the cable down in -- and I'm sure you might
imagine that it was pushed hard. It ocurred to me: Maybe a metal stretcher?????

Sent more pics to Quantum. Problem is, John was clear he couldn't even
look at things until Monday. Kinda screws things up for the weekend.
I wanted to install the cable and get the tranny topped off with oil.

I'm thinking I might have to just start all over by buying new/proper parts. I mean, there is a point when you expend so much energy....it just seems to make it worth it.

I'll let everbody know how the saga shakes out. Thanks to all.