VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1929-1932 29 Camshaft gear help

Hello everyone. I haven't posted in a while but, i need some help. I'll start with i have gone through all 4 pages that come up when you search "camshaft" and wasn't able to find what i need help with. Long story short my original motor decided to drop a rod cap last March, caused enough damage that it really just sat after i took it apart and started ordering parts for it. Still going to rebuild it for a spare but, i was lucky enough to find another 194 out of a 29 and have decided that's the one i am going to rebuild now. The problem I'm having is that in the 29 repair manual there really isn't anything on the camshaft or the gear. unfortunately while taking it apart i broke the fiber gear, i do have one currently on order from TFS. A little worried now after reading the problems BearsFan315 had with the gear he ordered. The only thing i have found in the book is on page 43 for timing marks (Fig. 47). I do have the camshaft and gear from the original motor to compare when the new one comes in.

Reason for going with the "new to me" motor is it was a barn find. It hasn't been in the car for roughly 50 years and everything other than the head components and the cam gear i broke everything is in better condition than my original motor.

The questions i have.
(1) The thrust plate behind where the cam gear would be, if i want to replace that how do i get it off? There is nothing in the repair manual that i have on how to do that.
(2) When i get the new gear and check it is the correct size and everything. How do i need to align it to the camshaft before pressing it on to make sure the cam and crank timing marks line up?

Thanks for the help and happy driving once it warms up some.

1- there are 2 screws that hold it to face of the engine. remove the cam gear first then those 2 screws, then you can pull the thrust washer plate, may be stuck to face of engine after all these years, so may need to pry it off gently, you can soak it with brake clean or pen oil and work it around the circumference. when you put the new one on make sure it is facing the correct direction. wear face/ surface towards the cam gear !!

2-The fiber cam gear i had was same size and gear count but for later Chevrolet engine, how we found it was the wrong gear was the access holes in the fiber gear did NOT line up with the bolts for the cam thrust washer as well as a larger center hub and gear to center hub offset. Steve @ TFS helped us diagnose that it was a later gear, so i sent it back to them and unfortunately at the time they did not have any other fiber gears for 1929. getting hard to come by. if you look at attached photos the 1929 gear has larger access holes, larger steel center hub. gear count & size are identical !!

Taking of the metal center of the cam gear without damaging the thrust washer can be a problem. Automotive machine shops have the tools and techniques to do the job. I recommend taking the shaft with damaged gear and new gear to a shop that has been in business and has grey or white haired machinists. If you want to do it yourself carefully breaking the metal center at the key slot can be done. It will be necessary to press on the new gear carefully with the few thousandths gap in the specifications.

When installing counting the teeth on cam and crank gears from the keyway several times is recommended. Being a tooth off requires a LOT of extra to take the front of the engine apart again then putting it back together. Not a lot of fun when you are cussing yourself the whole time. Even worse when the wife asks what happened!

So I have to motor completely out and apart. I’m actually getting ready to put everything back together. I got the motor/crank and such back about a month ago from Paul’s rods and bearings. The cam/gear is my new problem. I probably don’t need to replace the thrust plate but if I need to I’d like to know how to.

Is there a specific manual that covers the procedure on how to do it? There’s a few shops in Abilene TX that might be able to help but I doubt they have a manual on how to do it.

I attached some photos for reference and you can see how worn the original one is. It’s the one with the gear still.

Thank you for the help.

id replace it since you are there. no manual, just the info in the repair manual and experienced individuals :)
the thrust washer slides on and off easily when the gear is removed (all of it) it is a clearance fit on the cam, you can spin it freely around the cam until you bolt the thrust washer plate to the block (2 screws). its job is to absorb the thrust of hte cam spinning, hence the tight clearance they call out. when the cam is installed and set it should not move in and out very much at all.

i would also have a cam shop do a once over of the cam, check for straightness, fractures/ cracks, check lobes, especially the fuel pump lobe !! sent mine out had them clean it up, weld up, and then grind down to spec. same with bearing journals so that it FITS into the engine do NOT want it loose and bouncing around in the bearing areas. typically have cam to match bearing spots in block. if loose will destroy the cam and motor :!

Copy that, ill get the end of it cleaned up really good and see if it will come off. I will see if i can find a shop around here that can check that. so far i have only found one shop where i live at that is willing to touch a motor that old. I still have questions on how the gear its self needs to be aligned to the camshaft, do i matchup the keyways or are they off set in someway? when i get off work today i will take a picture that should help explain my question better.

post a picture

the fiber cam gear gets pressed on the end of the cam shaft and set to zero clearance bt gear and thrust washer per manual. then crankshaft gear gets lined up to camshaft gear and check for clearance bt the 2.

I have one of the new fiber gears from TFS that I bought about 7 years ago for a spare, it looks like your photo of the one with the larger holes Is that the wrong gear for my 29? I seem to recall a discussion at the time about the correct gear not being available and somehow making it fit.

So here are the pictures. The one with the gear came out of the original motor and doesn’t seem to be to spec for the thrust plate. On the “new to me cam” it’s tight but I can spin it around, I don’t see a way that it comes off/fits over any part of the cam. What am I missing?

When the gear is pressed on, do I align it to the cam using the keys? Both the gear and cam have keys, or do I use the indent on the gear to the key?

The timing gear is pressed on until there is .001'' to .005" BETWEEN THE RETAINER AND GEAR..

Glad to see that Gene has pointed out that THERE MUST BE CLEARANCE between the gear and the retainer. 👍

It's probably a good idea to have at least a .001" or .002" feeler strip between the two when pressing the gear on.
Because, if you press it on too far and it binds...
you're going to need another gear. 🙂

Hello Larry30,
If I understand your question concerning the clock position used when pressing the cam gear onto the cam-shaft because of the lack of a visual keyway on the end of the cam-shaft, you might consider that the cam-shaft has a hidden key just aft of the face of the cam-shaft. You would not want a loose key to slide out the front of the cam-shaft and destroying the engine timing. There should only be one way to align/mate gear keyway and shaft (for proper timing) and that being by employing a key. Well, at least that's what I'm thinkin.
Edit: There should only be one key shared by both gear and shaft.

Exactly as Harry said above.

There is a Woodruff/half moon key in the camshaft.

Yes I am wondering what clock position does the gear get pressed on at. Both the cam and gear it’s self have a key way, if I am using the camshaft key way as my marker (let’s say it’s at noon/top of the cam) what clock position does the gear key way need to be?

I don’t see just pressing it on working out. It has to be positioned a certain way right?

Stovblt, so if I can get that woodruff key out does the portion that the gear is pressed on just slide off to get to the thrust plate?

The key needs to be removed to remove the thrust plate. Not sure why the thrust plate needs to be removed? The replacement gear needs to be pressed on the camshaft with the key in place and located at the slot in the gear. That process locates the gear in the proper position.

Hello Larry30,
As Stovblt mentioned, the cam-shaft is slotted for a Woodruff/half moon key that when installed sits into the cam-shaft key slot and stands proud/higher above the cam-shafts diameter. The only way the gear can go on is to align the gear keyway to slide over the raised key.

Hi Larry

You do realize that as per your picture you don't have all of the gear removed yet, right?

The fiber gear is formed around the metal hub.

You have broken the fiber part off of the metal part and it is still on your camshaft.

Once you get it off, all will become clear to you.

Once the woodruff key is in place in the camshaft, there is only one way the gear can be pressed on.

Stovblt, yes I know it’s still there. I’ll get it all cleaned up before I put the new gear on it once it gets here.

The thrust plate probably doesn’t need to be replaced but if it does I wanted to know how to remove it if need be.

I think once the gear comes in what you and Harrys31coach are saying will make sense. I understand what you’re saying I’m just not seeing it without the gear in hand.

Hello Larry30,
You may not have to wait for your gear to arrive to get the idea/picture. Take a look at: Cam gear install Chevy Inline 6. youtube by 12 Bolt Tom Lowe 4:03 minutes. Remember that these are metal gears in this video. The technique for fiber gears may differ.

Larry30,

The replacement gear does not go on the metal part that remains on the camshaft. It will have its own metal center with groove for the woodruff key. As I posted earlier it will be necessary to remove the center metal part before you can install the new gear. Removing the center metal part is difficult without damaging the thrust plate. I recommend taking to an automotive machine shop for the removal.

Hello Larry30,
If you were able to view the youtube video of the aluminum cam-gear installation with everything disassembled, it should make sense to you now that there is only one way the gear (keyway slot) can go. It must slide over and around the cam (key). OK, as far as a fiber cam-gear is concerned, here is a quote by Dragsix: 'The fiber gears used a steel hub. The steel hub does not have the same issues (as aluminum) so does not get heated up for installation.' This refers to steel pressing on to steel versus aluminum pressing on to steel.

AGREED, SEE PICT BELOW

you need to remove the old gear center hub. if you plan to replace hte thrust washer/ bearing plate then you can use it and a gear puller to remove hte hub. as noted it will get destroyed/ distorted. if you are this deep replace it !! better safe then sorry !!

look at hte gear pictures i posted, you will see that the new gear has the center hub molded in.

as for line up, you need to look at the manual as it tells you how to line them up and count teeth for correct timing !!

Everyone thank you so much!!! My gear came in yesterday and everything makes sense now. I don’t know how I didn’t see that… may have been a late night with some beers but still I don’t know how I didn’t see the that center of it was left. Again late night with beer taking that motor apart…

Alright now that I’m on the same page as everyone what’s the best way to get that off? I’ll get a new thrust plate if needed but with the cam out what do y’all recommend to get what’s left off?

Again thank you for the help!

Side note. I’m familiar with woodruff keys, but is the a special way this one comes out?