Speedo Noise problem

kiwi · Post by **kiwi** » Wed Jun 11, 2008 4:38 am

OK this is something I think can fix but checking anyways?

Basically Speedo stopped working after Head gasket replaced, now this speedos been a bit funny required some wriggling to get working in the past. Well Took it apart this time!

The lower part of cable was turning but upper not! Turns out to be the Male/female split connection the upper cable not going in far enough! So peeled back some foreskin.

Curious thing is the male Connection where of a split plastic design from the upper gearbox end and into the back of speedo! Never seen that before normal metal tipped.

After swapping around I think the reason its plastic is the give and gets rid of the famous BX needle twitch. Thats what I found swapping in with the old Lower cable form my other BX.

Here is the problem NOW!

I have a irritating scratching noise from the speedo head when I reach above 80kph. Seems to be worse when cold (seems) and is intermitant after a good run. Any thoughts on what that is? Speedo head stuffed or just that cable not in properly although I did check?

Just for info not sure if the cable design the cause but got roughly 10% speedo error! sits on 100kph and GPS reads 106kph! ( Most cars tested read 97kph for 100kph).

Post by **docchevron** » Wed Jun 11, 2008 1:14 pm

Inaccurate BX speedo's are fairly common, and easy enough to put right (probably) if you have the long number from the top right hand corner of the speedohead and the tyre size.

The noise will be the head on it's way out, if it shuts up or gets quieter when hot then it's definitley the head on it's way out.

kiwi · Post by **kiwi** » Fri Jun 13, 2008 9:29 am

Thanks Doc

Lucky I have the spare head to replace it with which will get that number off before installing juast incase turns out to have an error. Had funny thing you was going to agree with the head on its way out possibly the reason for the error?

Now this think about the cable? Is it possible to replacing with a one piece cable or is their a reason against you know of? The other thing is this fibre tip design on th cable is that common place? Never seen it before.

kole24 · Post by **kole24** » Fri Jun 13, 2008 9:53 am

I have replaced my speedo cable with one-piece one, and it works ok.

Post by **docchevron** » Fri Jun 13, 2008 10:27 am

They make noise when the lubricant goes off (hardens) and causes the needle to wobble and the drum to make that irritating scratcing noise.
They get quieter in warmer weather or with the heater on as the warmer air makes the lube more, er, lubey!

BX speedo heads are notoriousley inaccurate at the best of times, it's rare to find one that is spot on.
Any friction in the head itself will of course cause it to read low.

I guess you could replace the cable with a one piece unit if you could find a suitable cable, or have one made, but to be honest I dont see the point.
The reason they were made in two pieces was for ease of manufacture between LHD and RHD cars.

Plastic / fibre cable ends are fairly common, it's designed as a weak point so that if the cable itself or the head fails and seizes it doesn't destroy the drive in the diff.

kiwi · Post by **kiwi** » Thu Jun 19, 2008 4:01 am

docchevron1472 wrote:Inaccurate BX speedo's are fairly common, and easy enough to put right (probably) if you have the long number from the top right hand corner of the speedohead and the tyre size.

The noise will be the head on it's way out, if it shuts up or gets quieter when hot then it's definitley the head on it's way out.

Hey Doc replaced the head with the one out of my old BX16. Its quieter BUT its way further out in accuracy than the one before. Revs were higher in 5th at 100kph so thats the first sign checked it against GPS and sure enough 115kph at reading of 100kph speedo.

15 Kph over the speedlimit

Tyre Size 175/65 R14 the correct size for a BX19TZS?

Speedo Head number 09120289900 ironically the head I took out same number the last digit being a 1.

Think this could be sorted?

Post by **docchevron** » Thu Jun 19, 2008 1:29 pm

Theres your problem then.
you'll need a head with the same number, ie finishes in "1". It makes a difference.

As for tyres, I rather thought they should be 165/70 R14??

kiwi · Post by **kiwi** » Fri Jun 27, 2008 5:12 am

FIXED!!!

Bit of good quality lubricant in the head and its running fine. Even managed to limit the speedo error. No wobbly needle no noise and its sweet.

One hitch must knocked a bulb cant see the speedo in the dark now

. Dont you just hate it when that happens.

kiwi · Post by **kiwi** » Mon Dec 14, 2009 8:25 am

but got roughly 10% speedo error! sits on 100kph and GPS reads 106kph! ( Most cars tested read 97kph for 100kph).

This has come back to haunt me 18 months on

And the problem is not in the speedo head, cable or Tyres! It is this

I got two choices! Either calibrate the odometer or pull out the drive shaft and put in this seconhand part from the 16 gearbox I have. Some time in the TZS past I suspect it has had some gearbox work or a replaced gearbox. Which also goes to explain the Torque diferance with the TRS even though they should be the same.

Either way I can not ignore it any longer.