Thank you for that, it is really helpful to know that no other pinions will fit. Having researched this issue a bit it would appear that the M40 and Type D O/D speedometer drive gears are not the same, but the metal M40 one may be machined down to fit. I don't have a M40 gearbox to borrow the speedometer gear from, so this is a bit of an academic issue.

This has been a useful discussion in the posts above, but I have concluded it is a problem that just isn't worth trying to fix. I'm happy just knowing the speedometer is a bit out and mentally correcting for that, or using the GPS app on my cell phone (that I already use for internet radio reception and SATNAV) if I ever need greater accuracy. I like the advantages of the type D overdrive unit, it is a pity Mr Volvo never intended it for a 4.10:1 rear axle - otherwise there would be a 16t pinion that would fit, but never mind.

As is so often the case, this forum is so useful in getting to the bottom of issues. Many thanks to all those that contributed to this one.

:-)

Alan

PS. Another way of skinning this cat would be to have the VDO speedometer re-calibrated. This company would seem to provide that service, but I doubt it is cheap (or easy):

https://speedycables.com/speedometer-calibration/

Rock drill...
 

This is another of my rock drills (mission rehearsals). Readers may recall I fitted some 5x4.5" spacers a few weeks ago and quite liked the results with the original steel wheels. I thought I'd look for some modern alloy wheels that might fit in slow time, and perhaps see if they suited GAM.

I came across this set of Wolf race 17"x7JJ wheels with the right PCD and a 30mm offset really cheaply, and picked them up from Brum yesterday eve:

https://i.imgur.com/CPxdkbZ.jpg

... They are quite nice wheels and in very good condition (previously fitted to a MR2). I had 15 minutes to spare between a couple of jobs today, so I thought I'd try them for fit:

https://i.imgur.com/Q8wmvyw.jpg

The PCD is correct and the clearance is good, but unfortunately the centres are a little too small (60.1mm) for the hub-centric bead (70.5mm) so I'd have to either have them machined at the back or fit some flat spacers (probably the cheaper option). Before thinking about that, this is the rock drill part: would they suit GAM, or are they a bit too ZZ Top?

One has to use some imagination; with 205/45R17 tyres the rolling diameter would be 5% less than the standard wheels (good thing) and I don't think there would be any clearance issues:

https://i.imgur.com/Q8wmvyw.jpg

... the question is would they look ridiculous on GAM, or rather cool? Opinions would be gladly received.

If these wheels don't work out I don't mind, I think I could easily sell them on for more than I paid for them. Before I invest in modifying either the wheels or the spacers and having some tyres fitted I'd want to be sure this was a sensible way to push the project (in the future I think, not this year).

:-)

Alan

PS. My initial thought is they are a bit too ZZ Top.

https://i.imgur.com/EfFK78y.jpg

My initial thoughts, Alan, were that I would not fit them if GAM was my car - BUT, beauty is always in the eye of the beholder! :regular_smile:

They MIGHT work if you also lowered the car, fitted a V8 and did a 4" roof chop, but do you really want to do that to GAM after 60 years? I think that I would preserve her dignity and allow her to enjoy her old age as Mr. Volvo intended.

Regards, John.

No mate!

Give the old girl her dignity. Minilites , yes , Carlos Fandangos, no, please.:teeth_smile:

For info I imported a new set of alloys for my 131 from the US. Even with postage and import duties was £100 cheaper than here and delivered in under two weeks. Some sellers on ebay you can pay the import costs up front so you know the exact price delivered to your door.

The alloys I bought were sold out in the UK, hence why I looked at the US import option.

I have mixed feelings Alan, sprayed a nice silver or silver grey (such as Halfords Steel Wheel) they would really compliment the lines of GAM and IMHO be just on this side of the line between enhancing and an extra in a ZZ Top video.

I'm confused about what you say about the centre-bore. Are the wheels 60.1mm bore and the centre spigot on the hub 70.1mm?

That centre spigot is very important, it keeps the wheel central on the hub, all the nuts do is hold the wheel on.

Thank you for that chaps - 4 valued responses in the time it has taken Bob and I to walk 2 1/2 miles!

I think the majority vote is to leave GAM with the original steel wheels. I tend to agree having tried the alloys for looks (if not for fit).

This was an opportunity, the seller wanted to get rid of the wheels for very little money, so it was worth taking the chance to see if I liked the look. On reflection I'm not very taken (a bit too ZZ Top) but I'm glad I went through the process of having a look before I embarked on expensive machining and tyres.

The ZZ Top wheels can go onto eBay, they will compliment a boy racer very well :-)

That's a "wheely" good idea Alan! Like Andrew suggested, and i hinted at some time back, Minilites (even Minilite replicas) would be the ideal enhancement for the corners. :thumbs_up:

Coco Chanel, “ ….fashion changes but style remains…..”😎

Amazon wheels aren't hub centric, they rely on the wheel nuts for centring. Perhaps spray one up in the colour of your choice and get a cheap used tyre fitted so that you can really see what you have and whether it clears or not. Try a 215 maybe to really check the clearance and have it nearer the correct diameter. Check on the rear too.