Dodge timing chain, nylon cam gear issue

[David W. Davis]

Heads up to all you Dodge V8 owners. My 1973 360 timing chain fell off the cam gear just south of Toledo in October returning from New York.  Needless to say, we were stuck on the side of the road. It took two weeks to repair even with readily available parts. A timing chain is better than a belt of course, no replacement interval one would think. Even loose, a chain will still work. The issue, is the cam gear that the chain drives has NYLON coated teeth. Supposedly quieter and long lasting. The fallacy in the argument for nylon gear  teeth is simply AGE! The teeth did not wear out, they simply cracked due to age. 60,000 miles is not too many to expect from a chain set, but there is a time related issue. Most Chrysler and GM v8's from the 70's and 80's used the nylon coated gears, and the nylon cracked due to age, 45+ years.

There is a process for checking chain "stretch", but I recommend a visual check of the cam gear by removing the mechanical fuel pump and using a fiber optic inspection device to determine if you still have the nylon gear. If it has been replaced you are good to go! If original like mine was, it will fail, sooner than later. It is a lot cheaper to replace the timing chain set now than on the road! Rental car, hotels, etc. all add up not to mention finding a good shop to repair it. 

[Lakota Wolf]

So true, been there, done that, but on a pickup truck. Age wins...  Plus I had chunky plastic bits in the oil pan.

[Dawn Michelle]

That's some good information to know!

[S.Heins]

Thank you for the heads up. We have a 72/73 Dodge Concord Class A. We read your post and since we are going to attend The Vintage RV get together in Ohio this July thought we might check out our timing chain and gear.  So glad we did, it was a steel double roller chain and gear,.but it had about  2 inches of play in the chain just about to jump timing.  So nice to get it taken care of at home and not on the road. We will be going to the lake in June (our annual trip with the family) so we have been getting all of the maintenance done before both trips. Thanks again.

[Jeff]

Test

[Jeff]

For anyone who is doing a major overhaul yall can also get replacement GEAR DRIVES that eliminate the chain. This is how big diesels work. These last FOREVER. just contact an online or local speed shop and get a name brand gear drive not some chinese crap.

[David W. Davis]

Jeff,

I agree, but I did not find a gear drive for my small block. Many for Chevy. I was also in a time bind for the out of state repair.

Gears are a great solution.

Dave