Bouncing speedo.....

[Coach529]

OK, so I am having some issues with my speedo.

Looks like it stops dead at 70mph and when I slow back down it sticks there for awhile and then finally bounces back to the current speed.

Are there any tutorial post on rebuilding or repairing a speedo?

[nvrdone]

have you tried greasing the speedo cable ? Mine bounced and after greasing the cable the bounce stopped.

[_Ogre]

it sounds like you have a mechanical interference inside your speedo that is causing the hang up
chances are the needle is rubbing on the glass or back, not much else to hang up
maybe your speedo is just shocked at getting into virgin turf

i've had mine apart, they are not that difficult to disassemble or reassemble
not much in the speedo itself; spinning magnet, aluminum disk and a clock spring
the odometer has a lot more parts, resetting the odometer is easy once you do it
my problem is reading mph too low

[Coach529]

Originally Posted by nvrdone

have you tried greasing the speedo cable ? Mine bounced and after greasing the cable the bounce stopped.

No I have not.

[Coach529]

Originally Posted by _Ogre

it sounds like you have a mechanical interference inside your speedo that is causing the hang up
chances are the needle is rubbing on the glass or back, not much else to hang up
maybe your speedo is just shocked at getting into virgin turf

i've had mine apart, they are not that difficult to disassemble or reassemble
not much in the speedo itself; spinning magnet, aluminum disk and a clock spring
the odometer has a lot more parts, resetting the odometer is easy once you do it
my problem is reading mph too low

The speedo is about 25% off. I am reading 70 while doing 55. I need to figure out how to fix that.

I will have to pull it and take a look!!

[_Ogre]

check your odometer to see if it reads the same 25% off. if you have a smarty pants phone or a tablet, check out the speedometer app. the app is free and has a gps speedo and odometer. once the trans is geared correctly for the odometer, usually the speedo is corrected at the same time.

i was able to call the company i bought my 700r4 from and they sent me the right parts to get my odometer spot on. currently with 300 miles on the gps odometer i am within 1% error, but the gps does not subtract for going in reverse.

check out this site transmissioncenter.net/speedometer_calibration to see if you can match your speedo to the trans and gear. there is a driven gear and a drive gear in the trans that both need to be correct. i needed to change the little gear and housing that slides in the side of the trans. it was a quick fix.

[Sethmark]

Cable routing is critical. Making sure all the corners and angles are smooth will let the cable turn without bounce.

If it sticks, it bounces.

[Coach529]

Originally Posted by Sethmark

Cable routing is critical. Making sure all the corners and angles are smooth will let the cable turn without bounce.

If it sticks, it bounces.

Stock routing.

[Sethmark]

Stock routing is 60ish years old. It's worth a look. And maybe a fresh cable.

[Coach529]

Originally Posted by Sethmark

Stock routing is 60ish years old. It's worth a look. And maybe a fresh cable.

True....but it has not been moved in 60ish years......so it is not on the top of my list to investigate. Fresh cable would be a good idea though.....

[msaintg]

I agree with nvrdone... I always check the cable first. it is almost always dry and sticking.

[mr48chev]

I'd go with pulling the cable out and cleaning and lubing it and trying that. No need for a new cable unless yours is damaged.

Ogre nailed it on correcting the speedometer reading in post 5.

They do sell little correction boxes that you put on the speedo drive on the trans and hook the cable to that are basically small quick change gear boxes that you change the gears in to calibrate the speedometer. Those can usually be found at shops that cater to Semi trucks or sometimes 4x4 shops. Not cheap but simple and if you do a tire or rear end change later you just go in and swap gears in the box and go again.

[mr48chev]

Double post deleted

[wuss721]

R u using the stock cable on the newer tranny? If now what cable r u using

[Coach529]

Originally Posted by wuss721

R u using the stock cable on the newer tranny? If now what cable r u using

Stock cable hooks right up to a TH350.