• Hello Guest, welcome to the initial stages of our new platform!
    You can find some additional information about where we are in the process of migrating the board and setting up our new software here

    Thank you for being a part of our community!

G80 speedo issues.

Kjets On a Plane said:
The earlier 90-91 type sensor that's a single blade instead of 2 works with 12teeth and and the aluminum cover.


Labscobe

*squirrel*
Click to expand...


So I need to find a 1990-1991 G80?!

That sounds tough. I'm gonna look around at the different setups and see what I can find, but the yards are getting pretty dry for RWD Volvo stuff. Anybody got one? Or at least a pic of what I'm chasing down here?

Thanks.
 
I don't really get why you are jumping to needing a new G80.

Do you have a sensor which is correct for a 12 tooth ring? If not you may need to get one.

If you do have the 12 tooth sensor, is it correctly shimmed so that it is only picking up the teeth and not the G80 body?

Someone here can probably tell you what the "spec" clearance is. Your scope may actually be handy.

I think worst case is that you may need a tone ring which is different somehow - wider bars, thicker material, etc. I can't think of any reason replacing the G80 itself would be necessary.

I just hit up Google and found another thread where people have installed the tone ring the same way, and mention having to shim the sensor.

http://forums.turbobricks.com/showthread.php?t=306102
 
No I don't think I need a new diff, I just am asking if I need to find a 1990-1991 G80 equipped vehicle to take the sensor from.

I guess I can play with the airgap, but there really should be a way to make this work.
 
I could be wrong, but I think the important difference is whether it is a 12 tooth sender or a 48 tooth sender, and whether it has the collar style mount or the single bolt mount.

I did a lot of Googling just now and I can't find a part # for the particular combination you seem to need - 12 tooth with a single bolt mount. They are all listed as ABS/48 tooth (1398321) or have the collar mount (1308024).

KJet says that one exists, and I trust him on that. It might be NLA. I doubt that it is different for the G80 cars but they may have come with a factory shim of the correct size.

The alternative I can think of is to get a 48 tooth tone ring back on there, shim correctly, and purchase/build a "pulse divider" to cut the number of measured pulses in 1/4 between the sensor and the speedometer - effectively "translating" your signal to something the speedometer knows how to read.

It may be possible to use the 48 tooth sensor with the 12 tooth ring, but I don't know enough about how the sensors differ to tell you.
 
The G80 cover I have is already from 1991 740 Turbo, I think....

The sensor was dual blade and mounts via one bolt.
 
Last edited:
I think "playing with the airgap" is your best bet. I didn't read that linked thread too much so I didn't see if anyone specified how much gap they added.

I only have a Bentley manual for 240. It says:

Sensor with 12 tooth wheel (12-window): 0.85mm +/- 0.35mm
Sensor with 48 tooth wheel (1992 and later): 0.6mm +0.2mm -0.3mm
Sensor with 96 tooth wheel (1992 and later): 0.6mm +0.13mm -0.25mm

More appropriate might be the specs from a 740 manual. I suspect they are similar.
 
You could leave the 48 tooth ring alone and use the sensor/cover matched for it. Then install a 91-93 speedo in your cluster which is matched to a 48 tooth trigger wheel. I think that should work.
 
ZVOLV said:
I'm almost at that point. ^^^^ I am kicking myself for listening to turbobrickers and trying to cut windows, add shims, etc. I try to do things cleanly and keep the hack work that wastes my time and $ to a minimum.
Click to expand...

And yet you claim to be the pro when it comes to diagnosing elementary electrical issues.
 
It read 2?x too fast with the 2 blade sensor and 12 remaining teeth/windows on the tone ring. 2-blade late sensor is this one:
https://www.fcpeuro.com/products/volvo-abs-differential-speed-sensor-240-740-760-780-940-960-s90-v90

Installed this one which has the single blade at the exact same depth as the 2 blades if you will (same distance from the (originally) 48 tooth tone wheel (same diameter wheel between 96T and 48T IIRC):
https://www.fcpeuro.com/products/volvo-abs-speed-sensor-0265001187


Labscobe
...
*squirrel
 
Last edited:
Thanks for the part numbers Kjet. Looks like that second sensor is available on ebay for $80-90. May be NLA elsewhere. Sounds like it's boiling down to ZVOLV having the wrong sensor.
 
Thanks for the links. I really hope the single blade sensor will be my final solution!

Looks like it's also used as a wheel speed sensor. I should be able to score that sensor somewhere in the yard.

I concur that the tone ring gets fragile once it's been cut up. Mine distorted on me when I tried to get it back on, but I saved it without issue.

Over a year now on the G80 I installed myself without any drama. Just some fun in the rain dumping the clutch going into second gear and breaking the back end free on my stock 240.
 
Last edited:
This was something that I had problems with myself after putting in an m47.

Tone ring and sensor already on differential swapped in from unknown year. Couldn't ever get things 'squared away', LOL.

Decided to go with a driveshaft sensor. Blew the engine up before I ever got around to that...

Something to consider.
 
I like squirrels and scopes.

Kjets On a Plane said:
It read 2?x too fast...

Installed this one which has the single blade at the exact same depth as the 2 blades if you will (same distance from the (originally) 48 tooth tone wheel (same diameter wheel between 96T and 48T IIRC):
https://www.fcpeuro.com/products/volvo-abs-speed-sensor-0265001187



[color]
Labscobe
...
*squirrel[/color]
Click to expand...


Hey so where do I find this sesnor on a junkyard car? A wheel speed sensor!?I keep forgetting my hex sockets....
 
You must log in or register to reply here.
Back
Top