help with speedo cable

[stockgp]

i ahve a post in the want to buy section, but i'm going to post here in case someone can help.

short story, my speedometer stopped working. pulled my cables off and found that it's my lower cable.

what i also found out is that i have a three piece lower cable. i'm just going to copy and paste the rest form my wanted post.

my lower speedometer cable is in three sections. the part that comes down from the cruise control, which measures roughly 60 inches. that cable threads into a little gear box looking thing that measures about 3 inches. said gear box attaches to a shorter cable that then attaches to the speedometer drive. length of the last piece is about 11 inches.

total length of the cable is about 72 inches.

here are pics of both the entire cable and the small piece i need.

i tried a speedometer cable repair kit, but i had to cut open the cable tube to get the broken section out. tried to get it to secure back together, but the speedom still doesn't work.

so what the heck is going on here? what is the little box in my cable?

 

[Bonnewagon]

The little box is probably a ratio adapter for dead rears that are out of the range of available driven gears. Check RockAuto and see if you can get a one piece cable if you don't use the Cruise. Just be sure to measure so there are no hard bends for the cable to make.

 

[stockgp]

i was thinking it was some kind of gear reduction for the speedo. so given that it's on there, wouldn't a one piece cable throw off my speedo.

also, i'd prefer to keep my cruise

 

[G-Body_Vet]

I've never seen one of those either. I know you can get different speedo gears for the trans, but have no idea why there would be a gear reduction or multiplier inline. What year is your car? I wonder if it was an oddball thing that's year specific or dealer installed for some reason.

 

[stockgp]

it's an 82 with a 307 and 3 speed

 

[Bonnewagon]

Often you can screw the adapter directly onto the transmission tailhousing if you have room. You will notice it has the same screw cap end as a regular cable. I only suggest that because I use one also and for some reason the short section of cable between the adapter and trans wobbled like crazy and caused the adapter to vibrate so much I strapped it to the floorboards. Probably defective although it was brand new. So I was lucky enough to later screw it right into my Saginaw 4 speed and used just one long cable. No more wobbling speedo needle..

 

[tc1959]

I have seen those put on by speedo shops to calibrate a vehicle that was modified past the point of getting the proper drive & driven gears in the trans. I have also seen them on 4X4's that drive the speedo from the transfer case.

 

[Bonnewagon]

I'm positive you can get a set with all 3 cables for pretty cheap. You must have really dead rear gears for that adapter to be on there. The smallest driven gear available is the purple with 17 teeth.It belongs with 2:41 rear and 14" tires.

 

[chevy2480]

I had a simular looking block on my 81 olds cutlass supreme but it had wires that came out of it.Turned out it was for an aftermarket cruise control setup.

 

[stockgp]

all i can say is the box is definitely a gear multiplier. it is a dealer item and it can be ordered.

the closest cable i can get from the dealer is 17 inches.

i was messing around with it, and i tried a speedometer cable repair kit from the HELP! section. if you've ever done this, i'd like to know how you use the little crimp tool to get the damn end on the cable. i managed to crimp it on with some wire crimpers 😳

now, i got it all back together, and the speedo worked for all of ten feet.

i've since figured out that after the tiniest bit of pressure is applied to tghe cable, it stops spinning. this happens despite the fact that the driven gear is still spinning.

i have come to the conclusion that the gear multiplier box is binding somehow, and that is causing the short cable to fail.

at this point i'm guesing i am going to have to try my luck with eliminating the multiplier and using a longer cable.

hopefully my speedo won't be too far off.

btw, my rear end is geared at 2.29 and the speedo driven gear is red.