Have a 84 244ti and replaced from auto trans. to M46,also replaced 3.91 rear to 3.31. What manual speedometer should be used?

Well I should have said how I thought my speedometer was 3 mph higher I got that off one of those speed signs that tell you how fast you are going.The other day I was in my son's car and sign showed the same thing 3 mph faster.

Well I guess you can't trust those speed signs,I should have just checked the odometer mile post to mile post.
Thanks for your replies,
Charlie

Look for a speedo head with r 0,980 in small white print on the face. That is what is in my 83 with M46/3.31. Another factor could involve the speedo drive gearing in the tail of the OD unit, if the trans came from an older 240 with a lower geared (higher numerically) axle.

Volvo parts dept used to carry a range of replacement little nylon gears for the drive...they may not after 20+ years since the last new 240, and probably longer since the last M46.
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Bob: Son's XC70, my 83 240, 89 745 (V8) and S90. Also '77 MGB and some old motorcycles

I know my speedo is a r0,980,the M46 has a 20 tooth gear was from a 84 240 and the 3.31 rear came out of a 88-89 240.
The speedometer is reading 3mph more then it should.

If your M46 came from a non-turbo 1984 car, that car had a 3.31 axle. Turbos had 3.73 with the M46.

A 3MPH error is a little more than one would expect (at what speed, tho'?), but the real test for proper speedo gearing is the odometer. What does it read compared to a known accurate distance? If it is accurate, then the speedo head magnet/spring combo needs to be calibrated.

I sent my 1983 Speedometer head to Palo Alto Speedometer who did a nice job. It came back dead accurate and looking like new. (www.paspeedo.com)
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Bob: Son's XC70, my 83 240, 89 745 (V8) and S90. Also '77 MGB and some old motorcycles

60 mph,I will have to check the odometer out.What did it cost for the calibrating?

10+ years ago so can't remember and undoubtedly more now. Email them and ask.
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Bob: Son's XC70, my 83 240, 89 745 (V8) and S90. Also '77 MGB and some old motorcycles

"The speedometer is reading 3mph more then it should."

At what speed?

You may be able to switch in an electronic speedo as your rear drive is equipped for one.
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1980 245 Canadian B21A with SU carb, M46 trans, 3:31 dif, in Brampton, Ont.

60 mph,electronic speedo is a thought.

As far as I know the 3.31 was in place after the Mechanical spedo's were stopped.
How is taking off in first with the 3.31?

Nope. My '83 has a 3.31 with mechanical speedometer as do the '84-'85 240's with M-46's. The electronic speedometers started in '86.

Does the speedo still have the .980 on it?
If so it must have a different speedo gear.

Yes it has the .980 speedo,if you are talking about speedo gear in trans. yes it does.

Not bad with the turbo,but I may go to a 3.73 better or even better 3.54 if I ever find one. 3.73 would be alot better with the turbo lower end.
Some people think the 3.31 and M46 is the best match because of better highway MPG. But driving around town to me it sucks,always shifting.

Mine is a turbo too. It just seems like first is too low. But I tow a trailer now and then so it's good for that.

I think 3.73 is better all around for the Turbo.