Guest baggersbailey Posted January 26, 2014 Share Posted January 26, 2014 Looking at the tappets on my 1938 Chrysler Wimbledon (plymouth p6 in the US) No1 inlet has a gap that I could crawl through, I can adjust it with my fingers, so what stops it self adjusting again ? Cheers from the UK Link to comment Share on other sites More sharing options...
keiser31 Posted January 26, 2014 Share Posted January 26, 2014 Looking at the tappets on my 1938 Chrysler Wimbledon (plymouth p6 in the US) No1 inlet has a gap that I could crawl through, I can adjust it with my fingers, so what stops it self adjusting again ? Cheers from the UKIsn't there a lock nut on it? Link to comment Share on other sites More sharing options...
Guest baggersbailey Posted January 26, 2014 Share Posted January 26, 2014 I was expecting a lock nut, but no, none of the lifters have locknuts and there isn't room anyway. Link to comment Share on other sites More sharing options...
c49er Posted January 26, 2014 Share Posted January 26, 2014 (edited) Doesn't require a lock nut. Edited January 26, 2014 by c49er (see edit history) Link to comment Share on other sites More sharing options...
ply33 Posted January 26, 2014 Share Posted January 26, 2014 Doesn't require a lock nut.Depends on the year. Parts book shows a lock nut on 1938 and earlier engines. Part number 40819.In 1939 they changed the adjusting screw from part 70774 used on earlier engines to part 681544 used on later and the later adjusting screws don't show an associated lock nut. Link to comment Share on other sites More sharing options...
keiser31 Posted January 26, 2014 Share Posted January 26, 2014 Depends on the year. Parts book shows a lock nut on 1938 and earlier engines. Part number 40819.In 1939 they changed the adjusting screw from part 70774 used on earlier engines to part 681544 used on later and the later adjusting screws don't show an associated lock nut.And that is why I asked. Link to comment Share on other sites More sharing options...
c49er Posted January 26, 2014 Share Posted January 26, 2014 My MoPar Master parts book shows part #681544 screw used from 1928-1954 for all six cyliunder car lines. Not that it matters. Link to comment Share on other sites More sharing options...
ply33 Posted January 27, 2014 Share Posted January 27, 2014 My MoPar Master parts book shows part #681544 screw used from 1928-1954 for all six cyliunder car lines. Not that it matters.Interesting. My parts books end at 1948 so it sounds like you have a newer book. Since the tappets have the same number from at least 36 through 48 I can see that 681544 would fit in an older engine. I am guessing that 681544 is in some way self-locking while the older 70774 is definitely not.I wonder if who ever put the engine together for the original poster had your parts book so assumed all the tappet screws were the same. But the tappet screws he used were the older ones which needed nuts.Looks like both the older and newer parts are available through several vendors on PartsVoice.com so which ever ones are needed to fix this engine can be acquired. Link to comment Share on other sites More sharing options...
c49er Posted January 27, 2014 Share Posted January 27, 2014 That 681544# probably came out in mid 30's? So Mopar cars must have used those self locking tappet screws in the mid 30's too. I've never seen anything else on hundreds of Mopars late 30's on up that I have worked on over the years.I wouldn't want to deal with lock nuts when adjusting tappets on an old flathead! Link to comment Share on other sites More sharing options...
ply33 Posted January 27, 2014 Share Posted January 27, 2014 . . my 1938 Chrysler Wimbledon (plymouth p6 in the US) . . .I believe that the '33 Plymouth was sold in England as a Chrysler Kew 6. I assumed that was true for other years too and that models like the Wimbleton were rebadged Dodges or DeSotos. I guess that was a bad assumption.Do you have a cross reference for the mapping between US and UK models? Link to comment Share on other sites More sharing options...
ply33 Posted January 27, 2014 Share Posted January 27, 2014 That 681544# probably came out in mid 30's? So Mopar cars must have used those self locking tappet screws in the mid 30's too. I've never seen anything else on hundreds of Mopars late 30's on up that I have worked on over the years.I wouldn't want to deal with lock nuts when adjusting tappets on an old flathead!Doing the exhaust on #6 can be a bear and you really do need tappet wrenches to do it. Later cars had a removable panel in the wheel well so maybe getting to #6 would be easier, but on my '33 you come in from over the fender. I probably don't check them often enough and it has been years since I actually adjusted them. So long that I don't remember the details but I vaguely recall having the tappet wrenches on the tappet and lock nut in my left hand and going between a regular open end and the feeler gauge with my right. Mostly what I recall is getting burns from the hot manifold as I couldn't manipulate the wrenches well enough with gloves on so I end up doing it bare handed. Link to comment Share on other sites More sharing options...
Rusty_OToole Posted January 27, 2014 Share Posted January 27, 2014 Sounds like the adjusting screw is worn out and needs to be replaced. Link to comment Share on other sites More sharing options...
Guest baggersbailey Posted January 27, 2014 Share Posted January 27, 2014 That's the way I read it Rusty. Am going to try thread locker for a start, but getting ready for a big strip. See if it works while I wait for some new followers. Cheers from the UK Link to comment Share on other sites More sharing options...
Rusty_OToole Posted January 27, 2014 Share Posted January 27, 2014 May not be necessary to strip the engine. If you can lift the valve with a valve spring compressor there may be room to remove and replace the tappet screw.The tappets are mushroom type and can only be removed after removing the camshaft. Link to comment Share on other sites More sharing options...
ply33 Posted January 28, 2014 Share Posted January 28, 2014 May not be necessary to strip the engine. If you can lift the valve with a valve spring compressor there may be room to remove and replace the tappet screw.The tappets are mushroom type and can only be removed after removing the camshaft.Worse comes to worse, you can remove the head and the valve and valve spring which should give you plenty of room to get the old screw out and a new one in. Link to comment Share on other sites More sharing options...
c49er Posted January 28, 2014 Share Posted January 28, 2014 I think you can get the screw out OK without pulling the valve. Get it up as High as you can and remove the screw. Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now