How to test/inspect 8 cyl timing gears before failure?

m_mman

I have a 1942 C8. 
Nice car but as I am refurbishing all the mechanical systems in preparation for touring, I am wondering about the timing gears. I wouldn't want their failure to spoil a long trip. 

I dont want to open the engine just to look at them. And if I did, I think I would just go ahead and replace them. 

Is there a method where they can be easily inspected/tested/evaluated for wear or imminent failure? 

Trevor J

The best option is to put an alloy timing gear on if you can find one.  It is a matter of when not if it will fail if its never been replaced.  Taking the timing cover off and looking at the gear will not help.  Even new ones can fail in short order.  It is not a big job but if it breaks it is a bigger job ie off with the sump to clear out all the debris from the broken gear

Jon B

I agree.  The aluminum ones are not easy to find (you have to find the matching crankshaft gear too) but they're out there.  There's a trick to installing them, though; the web of the gear has to be machined to clear a bolt head on the face of the engine block, as I recall.  It's not a big deal to do.

 In the meantime, buy yourself a replacement fiber one (they're fairly inexpensive) and acquaint yourself on how to do a replacement, should your gear fail.  Pack the replacement gear and any necessary specialty tools, in your trunk.  Your present gear may have many thousands of miles left on it, but "be prepared".  

Once you change to the aluminum gear, you're on Easy Street.  I replaced the one in my '37 back in 1978 and haven't had a bit of trouble with it.

Rocket

Is there some reason that no one has had aluminum gear sets made for 6 an8 Hudson motors is this something worth looking into I im more then willing to look into this if ther is enough people who would buy them.

barrysweet52

A lot of people have talked about this for many years. It took me 3 or 4 years to sell my last 2, cause Im in Australia and the postage.  I like the idea of an aluminium gear for the 1934 to 1940 so that we can keep the original crank gear. 

Old Fogey UK

The ROC had some alloy ones made up a while back.
 I don't know whether there are any left.
 I have one but need the small steel gear to go with it - has anyone got a useable one, please ?

m_mman

 "In the meantime, buy yourself a replacement fiber one (they're fairly inexpensive) and acquaint yourself on how to do a replacement, should your gear fail."

Thanks, that's what I have done.   Both gears NOS on eBay $60 delivered. 
They sure are pretty.  I'll just put them in the spare parts. 

Toddh

The conversion requires, in addition to replacing the timing gear (and crank gear if you have an earlier engine) removing the front engine support plate and chamfering the bolt hole immediately behind the timing gear to accept a flat head machine screw with the same threads.  It’s never a good idea to machine the support ribs on the replacement aluminum timing gear to clear the existing bolt head

You’ll need to confirm that your ‘42 engine has the correct later crank gear on it now.  Then start looking for a aluminum timing gear

Huddy42

When I imported my very original 1942 Hudson (19,093 original miles)with the 212 engine, the first thing I did was remove the timing cover and check the gear. To my surprise it had a 20 deg fibre timing gear and matching crank gear. As I had a new Aluminium timing gear in stock I replaced it just to be sure there would be no trouble later on. Not such a big problem if the fibre gear fails in an 8 cylinder, but, can be BIG
problems in a 6 cylinder 212 cu in. You can end up with a big hole in the side of the block when things get out of mesh due to the fibre gear stripping.

KEL 39

A big hole just like this! 
 
Ivan L.

AndrewB55

  

Huddy42

That's what happens. Tries to jump out of bed .

Geoff

The 20 deg. gears were used from '41 onwards.   I worked on a '38 Terraplane that had a '41 motor in it, and the original fibre  gear failed.  Not completely, but enough to let the rods  hit against the cam lobes enough to cause a noise.    Just bolted an alloy gear in, and it was as quiet as a mouse.   But first I removed each engine plate bolt, took out the thick spring washer, machined the bolt head down to half thickness and used a thin star washer.  Belt and braces, also used thread lock on the bolt threads.    

barrysweet52

I have pulled a few Terra motors apart and have seen evidence of deep scaring on the big ends where something had been hitting them. A good mechanic would have removed the burr. 

m_mman

"Interference engines" are common on modern OHC belt drive set ups.  
I never would have imagined that a loss of timing could cause such a catastrophic failure in a flathead design. 

terraplane8

m_mman said:

"Interference engines" are common on modern OHC belt drive set ups.  
I never would have imagined that a loss of timing could cause such a catastrophic failure in a flathead design. 

The cam and crank are in very close proximity!

35 Terraplane

Does the engine have to be lifted in order to get a puller on the crank balancer and remove the timing cover?  Looks to be a very tight fit.  OR is there a special puller used for this?  Any help would be appreciated.