Speedometer 15 MPH off

[Lagers4myhead]

I just got and installed a take out speedometer to replace the one I had broken. The one I had just put in is about 15 mph faster than what I am actually going. I still have the original tires so gearing shouldn't be the issue and I searched the tech manual but I didn't find any answers in there. Does this just need to be recalibrated? If so how do I do this?

 

[Westech]

The spedo has no calibration. how it is set is by different gears in the T case out put shaft. If you just swapped heads there should be no problem. I would look in to lubing or replacing the cable.

 

[quickfarms]

First how are you determining your speed?

second check the cable but a bad cable usually slows the speedometer down or makes it erratic.

It would not herat to have a speedometer shop verify that the new head is good

The speedometer is calibrated by changing the gear in the transfercase or adding a little gearbox to the side of the case where the speedometer cable connects.

 

[Barrman]

All the CUCV trucks came with the same gears inside the tcase for the speedometer. Because the 1009 is the odd ball, a gear reduction box was put between the tcase and the speedometer cable. That box however was used to speed up the speedometer cable, not slow it down. Yours is the wrong way off for the box to be missing.

Is it a steady 30 mph fast or is it bouncing that far fast? Mine would be right on until about 40 mph. Then it would jump about 10-30 fast and bounce around up there. Cleaning the speedo helped some, but replacing the entire cable assembly fixed it.

 

[lindyp38]

i used my gps to check my speed against the speedo.........i was only 5mph off....though....so i dont worry about it.....

 

[overkill375]

change the cable if that dont help change the little gear in the tcase per your dealer reccomendations think there are 3 or 4 of them in different colors/ratios

 

[Iceman3005]

Speedometer Gear, Speedometer Gears, Ford, GM, Dodge 700R4
Here is a web site for the speedo gears.

Could be you have a different speedometer, most were 1000 rotations per mile, but some were slower or faster.

 

[Lagers4myhead]

All the CUCV trucks came with the same gears inside the tcase for the speedometer. Because the 1009 is the odd ball, a gear reduction box was put between the tcase and the speedometer cable. That box however was used to speed up the speedometer cable, not slow it down. Yours is the wrong way off for the box to be missing.

Is it a steady 30 mph fast or is it bouncing that far fast? Mine would be right on until about 40 mph. Then it would jump about 10-30 fast and bounce around up there. Cleaning the speedo helped some, but replacing the entire cable assembly fixed it.

It shows zero when i put it in and then as soon as I start driving it shows 15mph and any speed I drive shows about 15mph faster than what I'm going and it stays consistant.

 

[Lagers4myhead]

Update

I just tried another reduction gear and I had the same results so I plugged it directly into the transfer case and it's goes down to 10mph so I'm going to try a new speedo and see how that works. Any other ideas?

 

[Milkman357]

Math?

I just put on 33 inch tires..

so I'm going faster than what the speedo says (M-1009)

Math hurts my head lately...

Any advice for me?

I'm gonna just figure out the percentage it's off then use some white out or something to label 25, 55, and 65 mph...

Maybe I should remove that adapter that's on my transfer case now.. then run my tests....

This is a minor issue as My ears are allready calibrated.. engine noise + tire humm = MPH But if someone else drives my truck it would be helpfull...

 

[73m819]

I just put on 33 inch tires..

so I'm going faster than what the speedo says (M-1009)

Math hurts my head lately...

Any advice for me?

I'm gonna just figure out the percentage it's off then use some white out or something to label 25, 55, and 65 mph...

Maybe I should remove that adapter that's on my transfer case now.. then run my tests....

This is a minor issue as My ears are allready calibrated.. engine noise + tire humm = MPH But if someone else drives my truck it would be helpfull...

change drive gear

 

[RedneckMilenko]

Well where might I find this reduction box? I did a transmission and transfer case swap on my 09 but nether the old or new Tcase had the reducer.

 

[Pballer71]

We changed the old cable which either had the plastic melted off or something then i think mud and water got in that opening and went to the reduction box so that like froze up and wouldn't spin so we sprayed some WD-40 in there and started to spin it with a drill to where it would work again and swapped the cable and then reinstalled everything. Now it works randomly like ill drive and it'll bounce like crazy then stop then ill stop and shift to park and when i shift back to drive again it'll work again but bounce like crazy and eventually stop again. I have no clue why it does this? Any help

Thanks

 

[Barrman]

The bouncing needle is almost always a result of a bad cable or bent cable housing. LMC has brand new 1984 K5 blazer cables for not much money. 2 tie down bolts, a clip behind the dash, the screw at the transfer case and a single firewall grommet push through are all that are involved in the swap. It might take 5 minutes.

 

[Pballer71]

Swapped that already and it still bounces thats where i'm stuck

 

[Varyag]

Mine is 10% off as well.

 

[baddy3]

Mine is 15 % slower with 33x12.5x15 MT tires. Replaced the speedo cable as the old one snapped, could not find anything that remotely resembled anything like the reduction box.

 

[Hanns]

I noticed my speedo jumping all over the place and then it quit working all together. Randomly it will start working again but then quit after a few miles. Unscrewed the speedo cable into the t-case and found the end of the cable is all chipped up. Guess I solved that one, will be replacing the cable.