Toploader speedo cable routing.

[59meteor]

I am trying to figure the best way to route my speedometer cable, with a 428FE and Toploader 4 speed. My Toploader has the hole for the speedo cable on the passenger sire, so I do have a longer than stock cable, but unsure about the best way to run the cable from the transmission to the firewall, without bending the cable too much. I am thinking above the bellhousing, but not sure if I should feed it to the tailhousing above or below the transmission crossmember. Any thoughts or photos? The cable housing is plastic, so keeping it away from the headers and exhaust is a concern.

[lalessi1]

I ran mine under the transmission. I don't remember the exact routing but I will look. I haven't had any issues with it after several years so I assume it is good. I won't get to it until later today though.

[lalessi1]

My cable is 84" long as I recall. I tried to take a couple of pics but they are hard to see. I came out of the transmission following the angle of the boss and turned the cable to the rear  as gently as possible towards the rear of the trans and inside of the right exhaust pipe. I zipped tied it to the end of the tailshaft. I continued to the floor above the left tail pipe and anchored it the floor at the corner of the driveshaft hump. The cable then followed the frame above the left header and up though the floor opening. The last half is what I thought the original routing may have been, but I guessed because there was no cable in my car. I tried to bend the cable with the largest radiused bends as space, length, and obstacles would allow. My exhaust "hugs" the transmission /driveshaft and has an "X" pipe so the biggest issue for me was the first bend to miss the right exhaust pipe. I hope this makes sense. If not I'll try the picture thing again.

[81TTA]

I ran into the exact same problem as you describe when swapping from a 3-speed/driver's side transmission to a 4-speed/passenger side transmission.  The exhaust was routed so that the cable would run into the pipes before there was enough room to "gradually" bend the cable.  Maybe 4-5 inches between the trans speedo output and the exhaust. 

I made a 90deg adapter so the cable could attach parallel (pointing toward the firewall) using pieces like this (not an advertisement and I'd imagine they could be sourced from different places for different prices):
https://www.amazon.com/New-Vintage-USA-99002-04-Speedometer/dp/B005JVGSPG/ref=sr_1_16?dchild=1&keywords=ford+speedo+adapter&qid=1595010841&s=automotive&sr=1-16

https://www.amazon.com/1956-1982-Corvette-Cable-Drive-Adapter/dp/B0043PC9Z2/ref=pd_sbs_263_3/133-0154232-1177860?_encoding=UTF8&pd_rd_i=B0043PC9Z2&pd_rd_r=89d4270e-cb12-459a-ade3-d8a6f400486f&pd_rd_w=0IQ1P&pd_rd_wg=vm7S9&pf_rd_p=bdc67ba8-ab69-42ee-b8d8-8f5336b36a83&pf_rd_r=51HABA3X2VQ3PWGCGV4G&psc=1&refRID=51HABA3X2VQ3PWGCGV4G

Then, I machined a piece that would thread into the output of the 90 adapter on one side and bolt the existing speedo cable on the other.  I don't have immediate access to the car to take a picture right now.  If you're interested, I'll try to take a picture when I get a chance.

Although I made a custom part for the cable-to-adapter connection, I think virtually all speedometer cables are the same internally.  So, if you swapped from a cable with a "Ford/toploader bolt-in" transmission end to one with a "GM/screw in" transmission end, you could probably do something like this without needing the extra piece and connect directly to the adapter.

[81TTA]

And one more thing you might already know but I'll mention anyway....

If you're changing from a passenger side to driver's side configuration, you'll also need to change the driven gear.  The teeth on those gears change (not the number but the angle) depending on which side the cable is mounted.  I did not think of that when I originally swapped transmissions.  Lots of erratic speedometer operation before finally just failing and always reading "0".  Found out two helical nylon gears with opposite "angles" will pretty quickly grind one another relatively smooth!!  

It's been a while since that time.  If I remember correctly, the way they're usually presented by suppliers is as either "manual transmission" speedo gears or "automatic transmission" speedo gears.  The ones that deal explicitly with toploaders will usually call them out by the ID (RUG or HEH) or by the side of the transmission.  Here's an example from David Kee's toploader site : http://4speedtoploaders.com/store/speedometergears.html

If there's any question *and* the transmission internals haven't been changed, I think you can further ID which you have by looking inside the speedo cable hole and identifying the color of the drive gear.  I believe Black is one direction while Yellow is the other.

[59meteor]

Thanks for the replys, I am aware of the different tooth angle on the right side Toploader speedo gear, I already have a longer cable with the toploader angle gear, although I will have to get the car on road to test drive, and see if a different tooth count gear will be needed for my non factory application. I will have to look into the tailhousing to see what color the speedo gear in the transmission is on Monday.

[lalessi1]

I had to switch from a black to a pink drive gear IF I remember right when going from a 3.89 to a 3.25 gear. I bought a whole set of driven gears. I changed the drive gear inside the transmission with the trans in the car. My speedo is dead accurate at 70 mph.