Help..... Speedometer problems, need tech advice.

[Fishin76]

Ok, My speedo doesn't work, and didn't when I bought the truck. But I'm determined to fix it. So here's what I've done so far:

1. Tested speedo cable.
Result: Spins at both ends. Seems smooth enough.
2. Tested Speedometer:
Result: Speedo registers when I spin the back of it counter clockwise, Got it up to 35 mph with ease.

3. Rigged up new clip to hold cable in to cruise control speed sensor. (old one was missing) I thought this was the problem, but it wasn't..

4. Placed the little rod that goes into the transfer case back in and made sure it was engaged. I tried to spin it, it seemed pretty solid, only a little play when turning it, Less than an 1/8 of a turn. So I figured it was turning when driving.

Next steps?

I think I need to take the driven gear out and look at it, but I'm not sure how to do that. I searched and searched here and FTE and TheDieselStop and could find a definitive post that said how to get the driven gear out. Found lots on how to get the DRIVE gear out of the 1345.0

Thanks in advance.

 

[Fishin76]

Nobody has any ideas to try? (bump)....

 

[7bicks]

Hook everything up, remove the cable form speedo and run into cab and drive it.
At least that way you can see if it turns properly.

Have you spun the speedo with a drill on the trans side of the cable to see if it moves and works good?

I don't know anything about removing the drive gears on your model but on most of them it requires a disassembly of some kind.

 

[Fishin76]

I took the whole cable out and tested it by hand with quick spins, with and without the speedometer attached. It all seemed to work fine.

I guess I'll have to get under there with a mirror and a flashlight and see if I can get that gear out to inspect it.

 

[Fishin76]

I tore it all apart, again. tested the speedo and cable with my drill and everything works from the end of the cable to the speedo, up to 80mph, (drill at max speed). So, i guess my problem lies in the TC.

How do i get the driven gear out? All i see is a metal encased hole where the rod goes into the TC. I tested again after putting it all back together and the speedo cable only turns about a half turn then quits. I'm assuming i have a flat spot on the driven gear, but can't for the life of me figure out how to get it out.

Any Ideas?

 

[maddenji]

To get to the Spedo gear in the TC, remove the rear driveshaft. remove the capscrews holding the rear housing to the TC. There is a spacer which is between the the gear and the rear bearing. Remove this spacer and move the gear forward, this should let a 1/4 inch ball out from the keyway. you can then remove the gear. I would look to see if the gear is in the right place or the spacer has let the gearmove forward and it no longer engages the plastic gear or a missing ball

 

[Fishin76]

To get to the Spedo gear in the TC, remove the rear driveshaft. remove the capscrews holding the rear housing to the TC. There is a spacer which is between the the gear and the rear bearing. Remove this spacer and move the gear forward, this should let a 1/4 inch ball out from the keyway. you can then remove the gear. I would look to see if the gear is in the right place or the spacer has let the gearmove forward and it no longer engages the plastic gear or a missing ball

Yep, that works on a bw1356, but not on a bw1345. No tailshaft on a bw1345. I am down to taking out the driveshaft, unbolting the yolk, and removing the speedo drive gear. If I'm lucky, i'l be able to reach the driven gear. Parts of the original speedo driven gear assembly has corroded and froze in the TC. So i'm screwed, unless it just happens to be the drive gear that is bad after all.