Morris Minor Owners Club

Have had 2 new tyres on my Moggie, tread was fine but the sidewalls had started to crack so I thought best to be safe rather than sorry, I checked through my Haynes manual but I cant find a torque figure for the wheel nuts, has anyone any ideas or recommendations? Also, I converted her to negative earth prior to fitting a tow bar, everything works fine but the heater noise is now different, it still pushes out hot air when needed, I assume this noise may be because the unit is running in reverse? Thanks in advance

I don't think wheel nut torque is essential, I tighten mine up as far as the wheel brace allows. No wheels have fallen off yet! Don't use a 'mechanical aid' to tighten them as you risk snapping studs! Just tighten them as far as you can and check in ~ a week. I would be surprised if loose wheel nuts make the sidewall crack though, more likely to be at the wrong pressure or something.
With the heater, mine makes a noise too, think the fan is loose on its spindle if that's possible, never had one apart. What heater does your car have (early round or later with fresh air intake)?
Edit - see here http://www.mmoc.org.uk/viewtopic.php?f=4&t=31742 there's your answer!

Wheel nut torque is 45-50 lbf ft, which is much lower than the typical tyre fitting station air gun will do. Make sure that they only nip the nuts up with the air gun and then tighten them with a manual torque wrench to 45-50 lbf ft (65-70 newton-metre).

I would also witness the torquing up to make sure that it really does actually tighten the nuts; not just click because the nuts are already overtightened!

Just out of interest - does everyone here use a torque wrench for wheel nuts? I've never been taught to use one on them

always,and I've also noticed that Kwik-rip,also do as part of their customer care standard

Thanks for the replies, as always there is someone on here who can help, I did not realise the torque was so low ,
IslipMinor as per your quote"Wheel nut torque is 45-50 lbf" I too normally tightened in the past just using the wheelbrace
my reason for asking was the fitter was going to use a wrench but could not find the data on his chart and I told him i would tighten them myself. I think the reason for the sidewalls cracking is just age rather than anything to do with this, I set a pressure of 28 based on past threads. Regarding the heater mine is the latter model ,the car is a 69 model. as said before everything works fine with it, it is just a different noise from prior to changing from positve earth

The studs are 3/8" UNF, so 50 lbf ft is really the maximum.

I always torque wheel nuts on a minor to 40 lbf. (habit)

I use the wheel brace on the starting handle and they don't fall off either.

The pieces of bent metal supplied in what is jokingly called a tool kit are not sufficient to tighten wheel nuts. A 3/8 whit. socket (in most cases) on a ratchet will give enough leverage.
If you are not able to watch the tyre fitter tighten the wheel nuts then I would recommend trying to slacken and retighten them when you get home. You feel slightly annoyed when you have a puncture and cannot undo the nuts because they have been tightened to 110 lbs.ft with an air gun

I wouldn't go past 40 ft lbf on wheel nuts. Assuming oiled threads!

When I say wheel brace, not the original, it's one of those 4 way jobbies, does a very good job imo..

That's a spider

spiders have eight legs

8 or 4, they can easily tighten the wheel nut to way beyond its safe torque limit!

The BMC manual, page General Data 10 lists: Road wheel nuts ....37 to 39 lb. ft.

Was there all the time! I shall go and make the necessary adjustments. The lower figure makes it all the more important to use a torque wrench on these nuts.

and there`s me cursing manufactures for using monkey metal for the wheel nuts every time I stripped one, when it was me being ham fisted with the wheel brace..........
I am sure I am not the first and wont be the last!!!!

Keep an eye on tyre fitters, on my modern car they did the bolts up with a whizz gun THEN checked with the torque wrench!
None of them needed any more torquing up unsurprisingly.

The torque values in the bmc service guide, not the Haynes manual which doesn’t state wheel nut torque is 37 to 39 lbs/ ft. This was in the days of slippery cross ply tyres, whether radials make a difference I do not know. I’d say 45lbs is ample 50 is pushing it on3/8 studs up