Leaky speedo / dash repair & speed sensor fitting

Hi Everyone,

Just thought I'd post up what I have done in the last week in an attempt to fix my leaking speedo & (as it turned out..) broken speedo sensor. Sorry I did not take photos as I don't have a digital camera.
I'm no pro so forgive any errors with regards to terminology. I found the GRiSO Parts Catalogue .pdf very helpful especially page 31. Download it if you haven't done so.

Prologue:
My speedo is a warranty replacement to the first one which went after about 3000 miles - this one has done 7000miles.
This speedo has always misted up after heavy rain.

I now use my GRiSO everyday for work & also general running to town etc at weekends.
My journey to work is 14ish milles so 28 miles (at most) round trip.
I ride in all weathers.
Last week it was snowy here for 4 days so the roads had been salted & were pretty unpleasant.......all in all everything that I hate having to put my GRiSO through! On top of a that it was misty & damp in the air so lots of moisture & salt spray everywhere on the bike.

On Wednesday morning last week I started the bike to ride to work.
Getting onto the road I noticed my speedo was showing 128mph then random numbers all the way to work.
In the evening when I started the bike to go home the speedo showed "0"mph & "SERVICE" at the bottom of the LCD display plus the Red Triangle in the top right.
So I rode home using the rev counter as my guide & did the same until the weekend.

On Saturday morning I removed my speedo/dash from the bike.

...because I thought the reason my speedo had stopped working was because it was full of water & everything was corroding & I wanted to dry it out & seal it up.
It actually wasn't too bad inside; no pooled water at the bottom of the chrome cover or anything to indicate an issue.

How I removed the speedo/dash:
IT WAS QUITE A SIMPE JOB.... so do not be afraid if you are fed up with the mist.

1- I removed the metal speedo-glass cover by undoing the 4 hex screws & lifted it off with no problem.

2- I removed the 2 hex bolts which hold the speedo mount to the frame at the headstock. When these are removed it's easier to access the hex screws which keep the chrome cover & speedo/dash together as the unit can be twisted about a bit as necessary.

3- I removed the chrome cover. A short socket screwdriver woud've been handy but I used my standard length one as I haven't got a short one!
There's one hex screw on the front underside of the chrome cover in the centre plus 2 at the rear of the chrome cover underside (one for each side).

4- I then removed the 2 hex bolts that attach to the black headlight mount on either side (it's the pivot point for headlight beam adjustment, I assume). These 2 bolts also go through holes which line up something MG call the socket support....a plastic frame that attaches to the underside of the speedo/dash with 3 screws---this will be revealed when you remove the chrome cover.
BE AWARE there are 2 rubber grommet/spacers that fit in each side of the socket support & back headlight mount so fish them out before you remove the chrome cover.

5- REMOVING THE CHROME COVER- I just pulled it straight out forwards & it slid out. If you do it carefully the loom wires will just stay in place as they are folded a little bit & I found that quite handy as I was worried I'd have a problem squeezing all the wires back in when it came to the re-fit.

Now you can the see the speedo/dash in place plus the black plastic socket support I mentioned in Point 4.

6- REMOVING THE BLACK PLASTIC SOCKET SUPPORT- It's held onto the speedo/dash by 3 screws on the underside. You see the air temp sensor attached to this which is also connected to the loom with a snap connector so undo the clip on the connector & pull apart to & remove the socket support with air sensor still attached.

7- REMOVING THE SPEEDO/DASH- It's connected to the loom with a connector that has a latch/lever (my terminology!)mechanism- just push the "latch" downwards & this releases the connection so you can remove the speedo/ dash.

At this point I took the speedo/dash in to the house & pried off the speedo-glass with feeler guages. I snapped 2 of the tabs but wasn't too worried as the whole unit was getting the siicon trreatment; it's going to be a lot better than it was when it left the factory!!!ll

I had intended to remove the plastic with the rev counter markings to get to the underside of the speedo/dash so I could clean the circuit board with a fibreglass pen & see how rusted (if at all) it would be..... but I couldn't work out how to.
I did remove 3 screws accessed under the plastic with the rev counter markings on it but the unit was still joined possibly by the rev needle mechanism so I didn't want to risk it!

Then I stuck the speedo/dash & speedo-glass in my airing cupboard for 24 hours where it dried out (I hope). There was some misting in the LCD which disappeared so I'm hopeful it's all going to be fine.

When I was sure the speedo/dash was dry I removed all the old black factory sealant from the surfaces with my fingernails & a blade & stuck it back in the airing cupboard whilst I went out & got some Loctite clear silicon for eletrical purposes (£6).
I used this to stick the speedo-glass back in place & was quite generous with it. I then smeared it all around the side where the 2 surfaces join & all the little bits where the tabs meet so I'm hoping the unit is now watertight.


When the silicon was cured it was back down to the garage to put evrything back on the bike.

How I put the speedo/dash back together & on the bike:
1- I fixed the socket support onto the speedo/dash.
2- I connected the speedo/dash to the loom.
Make sure the "latch" is in it's lowered/undone position & line up the connection.
Pull the "latch" up & it forces the speedo/dash into position & locks the connection.
Don't forget to attach the snap connection for the air sensor to the loom.

3- Slide the chrome cover into position.
You may need to jiggle things a bit here but mine fitted without too much grief.

4- Screw chrome cover & speedo/dash back together.
5- I then fitted the unit back onto the frame at the headstock - I left it loose & tightened it fully after everything below.
6- I re-fitted the 2 rubber grommet/spacers which go into the holes of the socket support & fittings either side of the black headlight mount (headlamp beam pivot point) & re-fitted the 2 hex bolts.

7- I re-fitted the metal speedo-glass cover.

Job done..........BUT I STILL GOT THE "0" MPH/RED TRIANGLE/"SERVICE" message.
So back on the forum & then I find out about the speedo sensor issue...thanks to Sidrat for some email pointers & help.

I order a new speedo sensor:

The speedo sensor is located at the rear of the bike on the CARC unit very close to the brake
If you own a GRiSO with cast wheels THERE IS NO NEED TO REMOVE ANYTHING other than the sensor. You can keep the rear wheel & brakes on the bike!!! This may be the same for spoke wheels but I don't know.

How I removed the speedo sensor:

1. By peering through the rear wheel I could see the speedo sensor is connected to the bike by 2 hex screws.
I put an extension on my small socket screwdriver & undid the hex screws by reaching through the gaps in the casting...MY GRiSO IS AN 1100 WITH CAST WHEELS SO I DON'T KNOW IF SPOKE-WHEELS ALLOW THIS.

2. I then unclipped the speedo sensor wire from it's plastic clip & traced it to where it fits to the loom via a snap connector.

On my bike this snap connector was on the right hand side behind the plastic fairing/ side cover. Take the seat off. There wasn't much room for fingers but after a bit of annoyance I managed to free the connections pushing a small screwdriver onto the "snap" locking bit & gently pulling apart  - it was a bit of a pain!

At this point I thought I'd dry the speedo sensor out, re-use it & keep the one I had ordered for back up.
I could easily see how water could get into the unit as it was 2 pieces pressed together with no seal so not the best design.
I tried to pry mine apart to get in & clean up the small electric parts but it didn't want to come apart & I heard a bit of a crack when I tried a bit harder with it so I thought best just throw it away & use the new one.

The New Sensor Arrives:
i- It's different to the old one!
ii-It looks like MG have tried to address the water ingress problem as the unit looks sealed.
iii- I still smother it in silicon in an attempt to increase it's lifespan & also stick some at the point where the wires join the unit.

Once cured I fix the new speedo sensor to the bike then feed the wire back the way it was to the snap connector.
Again, the snap connector connection process is a bit fiddly due to the limited access but you'll get there.

I put the seat back on & switched on the bike. I was a bit worried when I still saw the SERVICE & Red Triangle but they disappeared the moment I fired the bike up. Took the bike for a spin & all good so I'm pleased to know how fast I am going again!!!

I'm hoping I have also cured the leaky speedo so will let you all know in a while.
Apologies for caning the bandwidth with this post- I hope some of you feel like you can deal with those rubbish speedos now.

Feel free to chip in/ correct/ harangue.

Much GRiSO-ness to you all at this festive time!
Cheers from Rich.
The Red Leader on a black GRiSO

Very informative, thanks! Mine fogs up as well when it rains (roughly the same climate here as the UK), and while the speed indicator has no problems (yet) I do have some minor issues with the tachometer. Last year it suddenly stuck to 5.000RPM as its default position, turning the bike on and off for about twenty times fixed that, but I recently found out its no longer very accurate showing an idle RPM of 1400 while its in fact 1200 (through the computer). I'm worried mine has been corroded a little as well.

Very useful and handy information Red Leader. Many Thanks for the effort

Motor Timothy,
Interesting about your rpm being out...another thing to worry about, hey?
I assume mine's OK although I haven't got any software to tell.

As I mentioned in the original post I'd have loved to have gotten the actual speedo/dash apart so I could see how bad the corrosion might be on the circuit board but it didn't want to come apart so I have no idea how bad mine is.

Having said that I was expecting to see water pooled in the bottom of the chrome outer cover so was pleasantly surprised when I removed it to find it dry. There's lots places (due to how the complete unit is once assembled) where moisture can evaporate so I don't think your speedo/dash will be sitting in a pool of water- that just can't happen..... so that's one good thing!!!

No idea why the revs on your bike are out but it might not be anything to do with the speedo/dash end of the bike.
If you're sick of the misty speedo give my idea a go...it's got to be better that the sealant already on it, of that I'm certain!

Keep your fingers crossed for me!!!
Cheers
Rich


GHTE,
You're welcome.
All the best!
Rich

I'll keep everyone posted re: my misty speedo & whether I have actually solved the issue...time will tell but I am fairy confident the mist will not appear.

Cheers Everyone!

glad you got it sorted and a good write up

Sidrat,
Thanks for the handy info' you gave me. It was a combination of my totally useless speedo & your previous post that spurred me on!

Cheers again!
Rich

Good idea smothering the sensor with silicone.
There is a natural water ingress point for water to wick in where the soft cable fits into the hard epoxy body of the sensor, the silicone will bridge the gap.

I found this problem when working with very expensive industrial pH probes, a few drops of water around the point where the cable enters the epoxy and they were toast, apply a little silicone and you could totally immerse them.

I found that turning the sensor around backwards and mounting it the opposite way, in addition to liberal application(s) of gooey, greasy goop seems to do the trick. Lube it or lose it!

Kiwi Roy
Yeah, hopefully it'll do the trick- I totally mullered mine with silicon with compete disregard to the aesthetics of the sensor.

I'm not sure what the shelf life is for silicon so I will re-apply every summer as part of my winter prep.... I do like Street's idea about turning the sensor. I think that would be beneficial.

Street,
That's a great idea because the way it's mounted is right in the path of water flicking up onto the wire & into the unit . Even though I have sealed that wire up at the potential ingress point I think your idea's worth doing.
There's plenty of slack on the wire so I'm going to do it...it's a 5 min job which could make real difference.

I don't know if fitting a rear hugger would help? It'd certainly keep the rear shock & swing-arm in better condition but might not effect the water on the sensor issue. Has anyone noticed a difference before & after fitting one?

Here's to weatherproofing our Grisos, folks!

Cheers & Happy Christmas to everyone.