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Time to Get Into the Motor - Part 2 (Update)

Started by racertb, January 24, 2015, 08:20:28 PM

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racertb

All:

Starting a continuation thread with this regarding the timing issues I've been having.  I am attaching several photos and a couple videos of the distributor and the distributor base housing to get your thoughts on the appearance and function.  Other than a little play in the distributor shaft (see video) and the small shaft inside the housing (see video), they both look like they're in great shape and the play may be normal - but not sure on the "vertical" play of the distributor shaft.  Also, the gear inside the housing looks good as well.

So, if these pieces appear to be normal/good or not, please let me know your opinion.  I am assuming after my examination that they are both in good and functional shape and I'm going to have to get into the motor and inspect/replace the cam gear.

Please let me know your thoughts.

Ted

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Here are the videos:

http://vid947.photobucket.com/albums/ad320/racertb/Car%20Stuff/VIDEO0029_zps6db3mz19.mp4

http://vid947.photobucket.com/albums/ad320/racertb/Car%20Stuff/VIDEO0028_zpsplm7qqtp.mp4











chetbrz

#1
Questions:


Why is the locating collar split and if you remove the mounting gasket is the flange cracked ?

Why does the ring around the distributor appear to have two pins and a setscrew (or scroll pin) ?  This seems excessive or a previous repair ?

My engine doesn't have the original pot metal piece so have patience with the questions ?

Chet...
http://www.1948Plymouth.info           Web Master - Forum Administrator - AACA member

frankp

Rear view of my "spare," for what it's worth.  Interesting add on zerk makes you think this has been taken apart previously.

frank p

racertb

Guys,

Thanks for looking.  I don't know if I have the answers.  This is the first time I ever had this off myself.  I took the close ups on purpose because I noticed the extra pins as well.  If/when it was repaired, I have no idea when it would have been.  Regardless, I don't think there is enough here to say this is the cause of the problem, do you?

I'm not moving forward just yet, that's why I wanted some of your opinions and expertise.  I emailed Jeff Burton of the POC a couple days ago, but haven't heard back from him yet.  Just wanted to start with this and get some thoughts.

Did you have a chance to see the two videos?  If so, is the play seem normal to you?

Thanks again...

Ted

frankp

Ted,

I did.  I think the play in the bracket shaft is excessive.  Coupled with maximum upward movement of distributor may allow momentary disengagement of gears thus changing the timing.  I don't have any tolerances for either shaft play.

frank
frank p

racertb

Thanks Frank...if I grab the small ring with the pins in it, it is a tad loose.  I can wiggle it a little between my fingers.  Also , as Chet suggested, the ring looks like it was repaired before.  The  "hollow" pin is holding the ring on the shaft.  If it was tighter, the ring would probably be tighter.  The other pins look like the remains of earlier pins and don't feel attached to the ring.  The play in the shaft might be able to be fixed with a very thin washer.

Chet - I pulled back the mounting gasket and it looks good underneath, no cracks, etc.

Ted

chetbrz

Ted,

With the distributor in the assembly how much end play is in the assembly drive and if you max out the end play in the distributor as well as the drive assembly can you get the unit to slip a tooth or bind ?  Any gear system should have some end play but it should not be excessive. 

Can you put a slotted screwdriver into the motor and check how much play there is in the drive assembly in the block. 

It's hard to tell if there is a problem without actually touching and feeling these parts.  How is the internal drive shaft in the assembly and the inner assembly drive gear.  My assumption is no chipped teeth ?

What is that ring being used for does it hold the drive key in place on the shaft ?  If you took the pin out what would be removed and what would the purpose  be to remove the pin ?. 

Just some food for thought.
http://www.1948Plymouth.info           Web Master - Forum Administrator - AACA member

ski

As mentioned, that grease fitting looks "custom".  Have you tried shooting it with heavy grease to see if it restricts some of that play?  If it stays running well longer that may have been the reason it was added.  Not a fix but you'll know the play is your problem and then you can deal with it.

ski

racertb

Ski - you could be right about the grease fitting taking up slack...not sure when that may have been added... The car has been in the family since '62, so not sure if my Dad knew about it or someone did it for him or if it was done before he found the car.

Chet - both the gears (distributor and shaft in housing look great).  I'll take another look at the play when the distributor is installed in the housing.  My main concern is the "ring" on the shaft that looks like a prior repair as you suggested.  It's also a tad loose.

I'll also check out the other end on the cam in the motor...

Ted

racertb

Frank:

On your spare housing, how much play is in the shaft when it is moved back and forth/in and out?  Is there some play or is it in there pretty solid?  I'm wondering if there should be no play at all and just spin/rotate.

Ted

frankp

Ted,

There is no play at all.  This may be due to the casting being "swollen" and the shaft does not turn freely.  It will turn with pliers.

frank
frank p

racertb

Frank:

I'm starting to think the play in the housing shaft might be an issue like you suggested.  After contacting Jeff Buton via email, he also suggested I concentrate on the housing and distributor alignment and check for sloppiness (or if it's too tight, which it is not) and while turning the housing shaft and distributor, see if it's sloppy and if gear slips. 

So I did this earlier today and took some time with it.  What I found was that if the slack is taken out of the shaft (I was pulling out on the shaft as if I added shims and got rid of the slack) the shaft with the distributor engaged and turned smoothly, again no excessive play.

I then did the same thing but this time I was pushing in (as if to take the slack and play out of it) on the shaft all the way while turning the distributor.   This time, the shaft would turn freely for about half to three quarters of a turn and then stop, as if locked up.  I had to pull out on the shaft to get the shaft and distributor to turn again. 

At this point, I feel like this COULD be an issue, if not the issue.  This play in the shaft and the play in the distributor shaft have me concerned, although I feel the housing shaft is the bigger problem.  I could add some thin shims to correct this and take up the slack, but want to make sure I wouldn't do too much and then somehow screw up the housing  itself.   I don't know how I could as long as the shaft turns freely.  But, who knows how much slack there should be?

A couple other things...both the distributor gear and housing shaft gear are good and are not slipping, they are on tight.  Also, when then housing shaft is pulled out to take up slack (and turns the distributor freely), you can look down in the housing at the gear and it appears perfectly centered on where it would align with the distributor gear.   When pushed in, the gear is ever so slightly off (pushed back) so it wouldn't be perfectly aligned with the distributor.

So, did I find the problem?  I have no idea, but these are my observations with the housing and distributor.

Ted


chetbrz

Ted, 

All gears need some amount of play, it's called backlash.

Backlash as it refers to gears is "the difference between the thickness of a gear tooth and the width of the space between teeth in the mating gear, designed to allow room for lubricants and expansion.  Backlash sometimes describes play or lost motion between loosely fitting machine parts.

What Jeff and others have been asking you to check is when the play in both the drive shaft and distributor are at their greatest distances simultaneously from each other.  Can you turn the drive assembly or distributor and get the gears to skip a tooth. ?

When you answer this question you can eliminate all doubt as to what your problem is.  We can't make that call in an email or posted message.   BTW.., What can increase backlash is worn gear shafts or oblonged bearings or shaft pivot holes.

Chet...
http://www.1948Plymouth.info           Web Master - Forum Administrator - AACA member

frankp

Ted,

Chet has given excellent insight, as usual.  If you haven't already, taking off the end cap may help you see how these gears mesh with the shafts in different positions.  Also, the shaft in the bracket might have to be removed to determine exactly what the situation is.  Is there internal wear that needs shimming, for instance?

frank
frank p

racertb

Guys, I know and understand the concept of backlash and that things can't be so tight that they'll bind.  My main question with what I found, along with the photos and videos previously posted, is it showing too much play?  It seems too much to me, but I'm not 100% sure.

I can take off the end cap of the housing (what is the best way to do this without damaging the housing?) to see how the gears mesh together...for what it's worth, the only play in the housing shaft/drive is the "in and out" play like in the video.  There is no side to side or horizontal play.   There is also a little vertical play in the distributor, also in one of the videos.

I really couldn't get the distributor to slip, per se, but it did lock up as described above when the shaft was pushed in and turned.  Again, when I took up slack in the drive when pulling it out and turning, the distributor turned freely.

I do appreciate the input...I just want to make sure these pieces are good before I go any further into the motor.  If these pieces are the issue then that's what I need to know. 

If the amount of play showing is what it should be and normal, then it must be something else.

I looked at the slot on the end of the cam where the drive engages, but I don't see anything visibly wrong with it.

Ted