clicking speedometer cure

grumpyvette

Administrator
Staff member
BTW on occasion you'll find a speedometer needle that vibrates or a speedo that clicks annoyingly

on most speedometers theres a cable between the gears in the transmission and dash gauge thats spinning in a flexible metal tube, if you slide the cable out of the tube and lube it with a thin drippy slurry mix of moly grease and oil, then slide it back in, it cures that clicking which results from it partly binding during its rotation
yes it will in must cases slide out the problem is that in some cases the cable only slides out from the dash end, IF you find thats the case one old trick is to carefully tape the end of the grease gun to the cable with a few inches of rubber hose between the two and clamped in place temporarily then give it a few shots of grease, the problem with this is that if you get a bit generous it can leave grease dripping from under the dash or a non-functioning speedo, so yeah, disassemblys preferred

molygrease.jpg


some adapters come with a built in grease fitting
speedoadapter.jpg

Core (the part inside that turns) can be removed from one end of the sheild (casing),- and lubricant applied to core along full length, and maybe a small amount put inside open end of cable shield... Then core inserted back into core, - turn a little at finish to make sure it engages in other end (if only one end of "cable" disconnected). Hook end back up and you are finished!

"White grease" is nice if you have it handy, - but regular "wheel bearing grease" wil be fine! Or I think you can buy a special grease at parts store for this purpose, -- (but it will cost more). I have been just using WB grease for more than 50 years, and had no problems with lubricant! Note here also that one end of cable has a "gland" or flange on core, so it will not drop into shield too far and then not reach the fitting to be turned at connection! --- Generally this is at top end of cable, so it needs to be removed from speedometer to get out! But this is not steadfast rule - though it is the sensible way to do it, so it does not drop down far enough to not engage speedometer head connection! I always start at transmission and see if the cable will "pull" from that end though,- as it is easiest to get to! ... "Dry (no lubricant) speedometer cable" gives a sort of "jumpy" action of speedo needle at slower speeds, - possibly "vibrating" a small amount at higher speeds!

Now if it is a "growling", - or sort of "screeching" noise that happens intermittently, and seems to be from speedometer area, - then it might be bearing in speedo head, - Which can be lubricated with speedometer cable unplugged (with head out of dash). This requires a certain type of oil, and it is best to get specific oil for this purpose!
Source(s):
old mechanic

http://delorean2109.blogspot.com/2008/0 ... meter.html


naj posted this info
Way back in the day the cable could be removed from the casing.
You used to be able to buy a universal cut to fit cable with ends you would crimp on.
They also used to sell a graphite lube to lube the speedo cables.
Unfortunatly it has been almost 20 years since I have done this so I do not know anymore.

Service and Repair
The following material covers only that service on speedometers which can be performed by the average service man. Repairs on the units themselves are not included as they require special tools and extreme care when making repairs and adjustments and only an experienced speedometer mechanic should attempt such servicing.
The speedometer has two main parts: the indicator head and the speedometer drive cable. When the speedometer fails to indicate speed or mileage, the cable or housing is probably broken.

SPEEDOMETER CABLE
Most cables are broken due to lack of lubrication or a sharp bend or kink in the housing.
A cable might break because the speedometer head mechanism binds. If such is the case, the speedometer head should be repaired or replaced before a new cable or housing is installed.
A "jumpy" pointer condition, together with a sort of scraping noise, is due, in most instances, to a dry or kinked speedometer cable. The kinked cable rubs on the housing and winds up, slowing down the pointer. The cable then unwinds and the pointer "jumps."
To check for kinks, remove the cable, lay it on a flat surface and twist one end with the fingers. If it turns over smoothly the cable is not kinked. But if part of the cable flops over as it is twisted, the cable is kinked and should be replaced.

LUBRICATION
The speedometer cable should be lubricated with special cable lubricant every 10,000 miles.
Fill the ferrule on the upper end of the housing with the cable lubricant. Insert the cable in the housing, starting at the upper end. Turn the cable around carefully while feeding it into the housing. Repeat filling the ferrule except for the last six inches of cable. Too much lubricant at this point may cause the lubricant to work into the indicating hand.

INSTALLING CABLE
During installation, if the cable sticks when inserted in the housing and will not go through, the housing is damaged inside or kinked. Be sure to check the housing from one end to the other. Straighten any sharp bends by relocating clamps or elbows. Replace housing if it is badly kinked or broken. Position the cable and housing so that they lead into the head as straight as possible.
Check the new cable for kinks before installing it. Use wide, sweeping, gradual curves when the cable comes out of the transmission and connects to the head so the cable will not be damaged during its installation.
If inspection indicates that the cable and housing are in good condition, yet pointer action is erratic, check the speedometer head for possible binding.
The speedometer drive pinion should also be checked. If the pinion is dry or its teeth are stripped, the speedometer may not register properly.
The transmission mainshaft nut must be tight or the speedometer drive gear may slip on the mainshaft and cause slow speed readings.
__________________

Twelve speedometer driven gears are available for the 700R4 / 4L60 transmissions to calibrate the speedometer with various axle ratios and tire diameters. The number on the driven gear housing must match the number of teeth on the driven gear. Unless driven gears with more than 45 teeth and / or drive gears with fewer than 15 teeth become available, it will be impossible without using a ratio adapter to have an accurate speedometer with rear end gear ratios lower (higher numerically) than 4.10:1, unless 27 inch or larger tires are installed.



To determine your tires true diameter in relation to determining what speedometer gears you need, measure from the ground up to the center of the axle then multiply by two. The actual run out of the tire can be as much as 2 to 3 inches less than what the circumference of the tire measures. In effect your tire has two diameters.

To determine your rear end ratio, raise both tires off of the ground, turn both tires at the same time one complete turn, at the same time count the turns of the drive shaft, this is your ratio.





With 15 Tooth Drive Gear
Axle Ratio Tire Height Driven Gear Teeth
4.56 33 42
4.56 35 39
4.10 26 45 will work, but will read about 3 MPH fast at 50 MPH.
4.10 27 45
4.10 28 44
4.10 29 43
4.10 30 41
4.10 31 40
4.10 33 38
4.10 35 35
3.73 26 43
3.73 27 42
3.73 27 1/2 41
3.73 28 40
3.73 29 39
3.73 30 38
3.73 31 36
With 17 Tooth Drive Gear
Axle Ratio Tire Height Driven Gear Teeth
3.73 28 45
3.73 29 44
3.42 26 45
3.42 26 1/2 44
3.42 27 43
3.42 28 42
With 18 Tooth Drive Gear
Axle Ratio Tire Height Driven Gear Teeth
3.23 26 45
3.23 26 1/2 44
3.23 27 43
3.23 28 42

#54-2. 700R4 Speedometer gear housing for 40 to 45 tooth driven gears (aluminum not plastic) (also fits Olds TH350
http://corvetteforum.net/c4/vettenuts/S ... shtm.shtml
c4sps1a.png

c4sps2a.png

c4sps3a.png

c4sps4a.png


http://www.tciauto.com/tc/speedometer-gear-calculator
 
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