Speedo head help (1 Viewer)

[Its me shaneus]

So, with the nice fall weather we’re starting to get, i am working on a few things. Up next is instrument cluster.

Mine is mostly functional bit not perfect. Just ordered (hopefully) correct temp sender and fitting to fix reversed temp guage from vintage teq.

Now to speedo. It works but reads about 20mph too high. This after a good cleaning and maybe a shot of aerosol lube (would not have been wd40). Needle is smooth, no bounce, but off.

Not sure if I goofed up in how I cleaned and lubed the speedo head, or if swap to H55 and splitcase TC caused me to have wrong speedo gear on final drive. Is there different speedo gear sets available to help calibrate?

Thanks for everyones help on my never ending project.

 

[Mr. Green]

Yes there are different speedo gears for tc but I am unfamiliar on 5speed. Need to also confirm your tire diameter vs stock then that should be able to get you a ratio difference for spedo vs actual ground speed to confirm if you have wrong gear tooth.

 

[charliemeyer007]

You didn't say what you have. There is a like return hair spring on my needle - it is old and weak thus my reading are like 20 mph high. even tho its the factory issued stock speedo, tranny/transfer. Grease pencil a few mark for known correct speeds. Yes number of teeth make a difference that's in the speedo takeoff and the differentials ratio.

 

[Its me shaneus]

You didn't say what you have. There is a like return hair spring on my needle - it is old and weak thus my reading are like 20 mph high. even tho its the factory issued stock speedo, tranny/transfer. Grease pencil a few mark for known correct speeds. Yes number of teeth make a difference that's in the speedo takeoff and the differentials ratio.

All this is in a 3/70 FJ40. Not sure what I have for speedo drive gear tooth count. Would need to look.

Are speedometer cable drive gear sets compatible from old through newer split case? I also see speedometer company makes custom gear reducer / increasers if I had to go that way.

All this driven by decision to keep stock guage cluster and not VHX digital or bunch of autometer bits.

 

[charliemeyer007]

I'd be looking at the online parts people to check the part numbers. I know there were tooth # changes when the ratio was changed from 4.10 to 3.73. No clue about the actual fitting in to the tranny between 3, 4 and 5 speed or the meter which could have a clip or a screw in connection. Take good pic's of what you have and then do the online comparison.

 

[timmyisinthewell]

I believe your year fj40 should have a 17 count gear p/n 33403-69016, if no change from stock.

 

[Its me shaneus]

Part of this is the switch I made to the H55 5 speed and the split case transfer case. Not sure if the speedo drive gears are common across all the landcruiser family, or if split case is different from original old one piece transfer case.

 

[charliemeyer007]

There are speedometer rebuild/ calibration shops. This was first on the google search. A phone call/email them could be very useful in finding solutions. Myself a tachometer with the gears rings could be calibrated to mph. I like a working odometer as its my best gas gauge under normal driving. In low range low then its gallon per hour of operation.

Speedometer Calibration - Speedometer Repair & Calibrations - https://www.speedoservice.com/speedometer-calibration/