Xm speed sensor drive

[joc]

Hi there
I have 1996 3.0 12v auto ...I have traced the speedo not working fault past the speed sensor that sits in the diff and believe it is the drive gear that attaches to the sensor may be incorrect
I believe they come in different colours
How do I find which colour I should have
Thanks

[xmexclusive]

Hi joc

It is most unusual to have drive cog problems.
At that end of the speedo drive it is normally the electronics in the common drive box that fails, first intermittantly then completely.
There are around 20 different drive cogs to suit engine and gear combinations.
My only experience with new cogs was a few years ago I tried to buy a new one for a 2.5TD to fit with a new drive box.
New drive box came next day labled as a Saxo part.
When I queried this I was told the electronic boxes are common across all PSA cars.
Took 3 more trips to the Citroen dealer before the parts man finally said he could not identify the correct cog for my car.
He suggested that I took the old one in so they could see the colour and check the number of teeth.
When I took the old one out I was surprised to see no sign of wear or damage despite being made of plastic.
So I just made a note of its size, shape, colour and number of teeth then reused it.
From memory some V6's use a metal drive cog.

John

[joc]

Hi John
Thanks for the reply ...from the speed sensor To speedo headis all definitely working
I tested it by using a drill to turn the cog/ sensor
It has grey cog but I know it has been off before and I am wondering if they fitted correct cog because they do not come with new sensor
If you feel inside diff via sensor hole that feels solid although I can't see in there but when you try to put the cog in by hand it does not seem to mesh nicely which made me think possible wrong cog ..the cog itself is in fairly good condition no stripped teeth etc
Thanks
Jo

[Jan-hendrik]

According to the Citroen part list there are two different drive cogs (pinions) for the 4HP18 autobox. One is for Diravi equipped models, the other for Dirass. The injection ZPJ Diravi had a sensor mounted in the engine compartment that was cable driven from the transmission. I've had to replace the sensor on this model.

[Jan-hendrik]

The flange of the speed sensor has to be perfectly flush with the transmission housing. Even a millimeter off and the pinion won't properly engage with the sensor. Another thing I noticed was your non-diravi has a part that Citroen calls a tachometer screw. Could that be missing?

[joc]

Thanks for replies
Fitted the new pinion from Citroen this morning
Green with 20 teeth

All working now

[Jan-hendrik]

Congrats!