Yule/wheel

Can anyone tell me whether the words 'yule' and 'wheel' are likely to
be connected. My feeling is that they are probably not, but several
people on another discussion group are convinced they are (mainly on
non-linguistic evidence). The earliest reconstruction of Yule I could
find was Proto-germanic *jehwula or *je(g)wula, and for wheel
*hwehwula *hwegwula. Admittedly similar, but how does the 'hw' change
to 'j'?
Cheers,
Brian