Hi everyone,
I am going quietly insane trying to find a Speedo Cable for my 1966 Dynamic 88 as the part is now obsolete, the picture attached is a Delta 88. A few people have said the Delta 88 is the same driven of the drivers side front wheel hub but no doubt this is also as rare as Rocking Horse manure lol. Anyone have any suggestions or contact links I could try. Although I live in the UK I have a shipping address in New Hampshire so anything can be sent there and then onto me here. Thanks in advance.

 

The cable on my 66 is also becoming an issue. I think I'll ditch the wheel driven cable and convert the trans to drive it. Looks like the casting is there but needs opened up, of course I'll have to put gears in it.

 

First, identify the part number and length.

 

I'm not sure you can do that. Wouldn't the speedo cable in the trans be about 3 times (to be exact- whatever your rear end ratio is...) the speed of the front wheel? It is interesting, I wonder if anyone has done that.

 

The gears in trans under drive the cable and there are several different sets to accommodate rear end ratio and tire height. Nearly every GM speedometer is calibrated so 1000 rpm is 60 mph, I am assuming the wheel driven units are the same. I'll have to check the math, if they are then the conversion will be easy.

 

Not the wheel driven speedo. It's different.

 

Math shows a 27.5" tire to be about 750 rpm@60 mph. Will have to see if there are speedo gears out there to make that work. I'm going to guess this isn't an insurmountable problem, especially if the car has a th400 with lots of availability.

Probably even easier to convert to a GPS driven controller and be done with it.

 

How about the electronic route? I currently use an app on my iPhone to check my speed. There is a business here in Wales called Demon Tweeks which supply Automotive racing accessories and parts, I notice they do a range of Speedometer gauges which are electronic. This Gauge has a sensor that can be configurated to a wheel hub or drive shaft, maybe I will look down this route https://www.demon-tweeks.com/uk/smit...ometer-248793/

 

You can get a GPS controller that will drive your stock speedometer for about $400. I have something similar in an old chevy truck.

 

Various manufactures produce similar devices.

https://www.glowshiftdirect.com/3-3-...ter-gauge-kit/

 

Trying to keep it stock looking is the thing, @66_Jetstar that's the route though. The Smiths gauges were fitted to most classic cars here in the UK back in the day as most of your are all aware so my other alternative.

 

https://www.jegs.com/i/JEGS/555/4180...oaAoAJEALw_wcB

You should be able to conceal this somewhere.

 

 

The speedo cable interchanges for all 1965-68 Olds full size cars. The 69-70 cars use a different cable due to the way it connects to the speedo (screw-on for the 65-68 cars, snap-on for 69-60). New ones have been unavailable for decades. The original trans will not have a provision for driving a speedo cable, and that means that not only is the speedo drive gear missing from the output shaft, but the case is not machined for the hole that the speedo gear adapter goes into. Correctly machining this hole requires complete disassembly of the trans and installing the bare case on a milling machine to get the accuracy needed. There are some speedo cable specialty vendors who may be able to make one of these cables up, especially if you have the remains of an old one to start with. Failing that, there are GPS speed sensor boxes that will drive a speedometer cable.

http://www.atrol.com/cablex.htm

https://speedhut.com/categories/speedbox.html

https://www.dakotadigital.com/index....rod/prd886.htm

 

I was speaking more to my two speed. the speedometer gears are in the tailshaft housing and would be obviously much less work to swap.

 

Never knew those existed. Very nice, really.

 

Good luck finding a long tailhousing for a Jetaway. They were only used on 1964-66 Jetstar 88s, 67-68 Delmonts with 330, 69 Deltas with the base engine, and 64-67 Vistas. More to the point, the OP was not talking about a Jetaway, so your information would be confusing and incorrect to the original question.

 

I don't need to find one. I only have to poke a hole in the one I have. I'm not sure who is confused; i though these forums were for open discussion, but once again you need the world to know this is your sandbox..

 

Again, the location and diameter of that opening is not trivial. It's not something you can "poke". Getting a Jetaway long tail housing from a 64-67 Vista (or a full full size from another GM division, like a LeSabre) solves this problem, if you could find one. And I couldn't care less about anyone's "sandbox", I'm simply trying to avoid truth decay. The OP asked about a TH400. Your response, which was immediately below it in the thread, talked about running a cable from the trans. I was trying to clear that up for the OP. It's not always about you.

 

Of course it needs to be in the right spot, i would think nearly anyone on the planet would know that. Given the provison is in the casting, its not rocket science and i would bet many olds cases were opened up at the trans shop back when these cars were on the road and 400s were swapped daily.

And the OP could still convert to a transmission driven cable, and after 60 years his trans just might have been swapped and no longer the odd ball olds case. Its a viable option for anyone in this situation, regardless of their transmission, who just wants their damn speedo to work without searching for obsolete parts. Boohoo man.

 

If you need a used one, check here. But, be sure that you match your cars cruise control option status:

1966 Oldsmobile Ninety Eight 98 4DR Door Hinge Left MISC NUTS & BOLTS PARTING OUT COMPLETE CAR | Genuine OEM | Door Hinge | Left

 

OP,
The tough parts on this repair are really the driver’s side wheel dust cover which drives the cable and getting the right cable length. If your dust cover is still good (i.e. the nylon cable driver with the square inside) you’re ahead of the game.

Here in the US you can buy generic lengths of cable and crimp an end on to it to driver the speedo end of it. The squared off end really can’t be replicated with home tools.

Obviously a 65-68 Olds big car would be the best source. I’d recommend you ring French Lake Auto Parts in Minnesota. I’m out of date there by a year or 2, but they’re a specialist breaker who had a bunch of mid-60’s big cars last time I was there in ‘23 or so.

The other way you could go is to look across at the other big GM cars of 65-68. I have the impression Cadillac, Buick, and maybe Pontiac might have used the wheel-driven approach on their big cars. If so, the lengths of the cables from those cars might work in your ‘66 Olds big car. I must disclaim direct knowledge since I’ve been using cruise control speedos on my ‘66 big cars for decades, but I just wanted to give you some avenues to pursue other than digital.

Good luck on the hunt. This sort of thing is very much part of the game.

Cheers
Chris

 

The cap is P/N 392035. Search that P/N on Google and ebay and you'll occasionally find them for sale.