The Stovebolt Site Forums The Shop Area Engine Shop Speed-o-meter adapter

The speed-o-meter in the 2-ton truck is not working. I removed the adapter and hooked up the cable directly to the gauge. It works now. My question is I have not seen how the 2 speed adapter mounts under the dash behind the speed-o-meter. Where can I find direction for installing the adapter correctly?

Thanks again.

Well, since no one else has posted an answer here I've got a couple of questions. I've never seen an adapter that mounts to the speedometer. Are you sure that's where it goes and not on the transmission end? And, if the speedometer is working without the adapter, do you need it at all?

Waldo - the speedo will work without the adaptor, but won't read correctly on one of the rear gear speeds .... but then who cares if it's not a daily driver

I've got one around someplace that I took off a TF truck - I think it's 2 speed rear was vacuum, but not sure

Bill

I have the 2-speed adapter thats mounted right to the back of my speedo for an ele4ctric shift rear end. Luckily mine works great so makes life easier. if I recall right tho, the one I have wont give correct speed in high gear, only low.

Look up a company called Spedomerter Solutions. they have been very helpful in my dealings with them, can even make custom cables (I have the 1/8" square drive on the speedo, and 3/16" keyed drive on the trans, FUN!). Worth a shot if you need to have the adapter looked at.

Waldo53: Here is what it looks like: http://rides.webshots.com/photo/2149599920080243953rzucGa

As for the question about do I need it? I'm trying to keep it original if possible. But I don't think it is really necessary for the driving we'll do with the truck.

Rd58: I agree it works fine without the adapter but I really want it to be as Chevy designed and built it in 1951. I might not get my way, but I'm not done with it yet!

So I still do not know how the thing mounts behind the dash.
FYI: I started this post before Freq2002 posted but I had to go to a 911 emergency before I could post it.

Great pic! So this thing actually changes ratios when you shift the axle...A great place to get an education here. All I've ever seen is the S-W ones that have a constant ratio & usually attach to the trans. If it bolts together like the others, you may take it apart & find a gear is loose on its shaft. In the S-W ones, they're just a light press fit & at a truck shop they'll usually have a drawer full of gears, shafts, & small parts to repair & re-calibrate them. Possible the parts will interchange into yours. Doug

O.K., I get it now! That's pretty neat. Hope you get it working.

I'm still trying to figure out how this thing mounts to the rear of the speedometer. Anyone who has one of these things (in a 2 speed rearend) have a picture or an instruction guide?

In your pic I assume the 'open' barrel end facing the camera is the end that goes on the speedo & the opp. end w/male threads, the nut on the cable end attaches to it. Looks very similar to a standard S-W adapt. Looks like it splits in the middle for gear changes & has some extra threaded holes on top & bott. to mount the vac. can & linkage. Clean it up & take some pics of the other sides please. Doug

I'll shoot those pictures and get them out for viewing. Thanks for the help.

Ok... the open end (facing camera) threads onto the rear of the speedo...(do NOT lose the small 1 inch piece of speedo cable that goes tween the adapter and the speedo).. and the speedo cable threads onto the other end.... Now for shifting the adapter.... you need a intertie rod that goes between the adapter and the under-dash 2-speed shifter....... Also, after you get the rod installed, you then have to go back and tighten the set-screw where the adapter attaches to the rear of the speedo... to lock everything in it's proper place.....

Basicly the same as on my 48 and 49's

Michael

I think you have found my problem! I do not have the 1" piece of speedometer cable. I think that is why it doesn't spin the speedometer gauge when my adapter was installed. Note: I just looked at the adapter and a picture of the rear of the gauge and that is exactly the problem... Thanks.