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Replacement Timing Gear on a 1934 Hudson 8
  • Old Fogey UKOld Fogey UK
    Posts: 155Expert Adviser
    Worried by a fellow HET'er's dire story about the fracture of the timing gear on his '37, I obtained an aluminium timing gear from the Railton Owners Club for my engine rebuild.
    I'm rather disappointed with the result. Although the engine runs with a reassuring "thrummm", I'm getting an awful metallic screeching from the front end that seems to come from the timing gear.
    Does anyone have any experience of using these replacement aluminium timing gears ? Do they bed in and quieten down after the engine has been used for a while ?
    Or am I going to have to find an original plastic gear and take the front end off the car again (Oh, no !) to put it in ?
    I used to have a boxed NOS plastic gear but I gave it away......sigh.
  • Huddy42Huddy42
    Posts: 1,001Platinum Member
    Did you modify the front engine plate by removing the two bolts behind the gear and replace them with countersunk screws.????? I have used may of these over the years, sold many and yes they do hum for awhile until they match into each other.
  • Old Fogey UKOld Fogey UK
    Posts: 155Expert Adviser
    I didn't do the engine rebuild myself but the fellow who did is a professional who had already rebuilt several engines for ROC cars, so I assumed he had replaced the bolts.
    I'm going to have to look. If that's the problem, it seems easily sortable - particularly if the gear itself will settle down with use.
    The engine has been run for less than 30 minutes so far.
  • Old Fogey UKOld Fogey UK
    Posts: 155Expert Adviser
    Thinking more about it, the engine rebuilder didn't replace the crankshaft gear when he put the aluminium timing gear in. I suppose this will mean that the noise will never go away !
    Will it be easier just to go back to the old fiber gear ? I only changed because of horror stories about them breaking up - how common an occurence is that ?
    If I do need to go back to a fiber gear, will one for any year fit or do I need a specific one for the 1934 8-cylinder ?
  • PAULARGETYPEPAULARGETYPE
    Posts: 1,250Platinum Member
    HI YOUN SHOULD HAVE CHANGED BOTH GEARS AND WHAT EVER YOU DO DON'T GO BACK TO THE FIBER GEAR I HAVE SOLD USED GEARS I HAVE REMOVED FROM 8 CYL ENGINES I CAME ACROSS OVER THE YEARS I ALWAYS TAKE OFF BOTH GEARS AND TELL WHO'S EVER BUYING IT TO CHANGE BOTH THERE ARE 2 DIFFERENT GEAR PITCHS THE FIBER GEARS WERE 16 PITCH AND THE ALUM GEARS WERE 20 PITCH I HAVE A GOOD USED SET OF ALUM GEARS AND THE ALOT CHEAPER THAN THE ONES THE RALITON CLUB SELLS CONTACT ME IF YOUR INTERESTED HET HUDSON1957@AOL.COM REMOVE THE HET FROM THE EMAIL ADDRESS IT'S JUST THERE TO KEEP THE SPAM BUGS AWAY
  • Old Fogey UKOld Fogey UK
    Posts: 155Expert Adviser
    Hi,
    Thank you. I think you've solved my problem. My aluminium gear says "20" on it.
    I'll email you.
    David.
  • Huddy42Huddy42
    Posts: 1,001Platinum Member
    Rather surprised that the gear you bought was a camshaft gear only, these should always be sold iin sets, as Paul stated the pressure angle on the fibre gears are different to the alloy ones,if you kept driving it like that you would most likely do damage to the alloy gear.
  • Old Fogey UKOld Fogey UK
    Posts: 155Expert Adviser
    The Railton Owners Club supplied only the aluminium gear. The motor has only run for a few minutes at a time and less than 30 minutes total so far, so hopefully the damage isn't too great yet.
  • Jon BJon B
    Posts: 4,769Moderator
    Possibly you could install a used crankshaft gear (20 pitch of course), since it may be difficult to find a new one.

    I replaced the fiber timing gear on my Terraplane, back about 1978. I have driven the car about 80,000 km since then, with the same gears, so these gears do last. Thus, a used gear may be just as good as a new one, and anyway, I'd assume the steel gear would wear much less than the allow cam gear.

    By the way, when I replaced the alloy cam gear, the legendary Kelly Hinegardner very kindly machined the web on the alloy gear, to give clearance for the bolt heads on the engine mounting plate. That is an alternative to replacing the hex head bolts with flat head ones.
  • 1934_Hudson_8_Conv1934_Hudson_8_Conv
    Posts: 49Greasemonkey
    David,
    I'm running a NOS fiber gear in my eight that was rebuilt approx 10 years ago. So, far @ 2,000 miles no issues & I've never seen any traces of material in the oil that concern me (and I run my old though a screen when I change it in the Fall).

    Maybe I got the ONE good one left on planet earth or just luck:sick: ...
  • Old Fogey UKOld Fogey UK
    Posts: 155Expert Adviser
    The NOS fibre gear that I used to have is now installed in the engine of someone's Railton and I don't think a duplicate will be that easy to find.
    In any event, alloy gears are supposed to be more reliable - Duke Marley had a bad experience with the fiber gear letting go on the '47 H8 he used to have - and if I'm having to replace what's there at the moment, I might as well take the alloy route if I can and hold the option of going back to fiber as a last resort.