Noisy distributor drive gear
Thread Starter
Instructor
Joined: Jun 2004
Posts: 182
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From: Sun Peaks British Columbia
Noisy distributor drive gear
What now! I swapped out my old (used it for 200 mi.) Procomp HEI distributor for a brand new Mallory. The Procomp was noisy at times, particularly when cracking the throttle. When I removed it I noticed that the distributor gear had some pretty heavy wear marks from the cam gear. It looked like the cam gear had chewed into the distributor gear somewhat.
Now, with the new Mallory, when I reved the engine to around 2500 RPM to set my timing, I noticed what again sounded like gear noise coming from the distributor.
I know that the oil pump is loading up with more pressure at higher RPM, and may be putting more resistance on the distributor drive gear.
QUESTION???? IS THIS NORMAL? IF NOT, WHAT'S GOING ON?
Now, with the new Mallory, when I reved the engine to around 2500 RPM to set my timing, I noticed what again sounded like gear noise coming from the distributor.
I know that the oil pump is loading up with more pressure at higher RPM, and may be putting more resistance on the distributor drive gear.
QUESTION???? IS THIS NORMAL? IF NOT, WHAT'S GOING ON?
NCM Grand Opening Veteran
Joined: Sep 2005
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From: South of giving a damn
St. Jude Donor '11, '17
What cam do you have in there? If you are showing wear after only 200 miles then there is a problem. Not all dist gears are compatable with the cam gears, especially the roller cams. I forget which you can use together, so I just use a Comp carbon gear on my Mallory.
Thread Starter
Instructor
Joined: Jun 2004
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From: Sun Peaks British Columbia
Yes I'm aware of the compatability issue. Roller cams require brass gear on the distributor. Mine is a Comp cam 268 duration, for hydraulic lifters.
I assume from the lack of response here, that there's no easy answer. Tonight I'll remove the new Mallory, and run a gear pattern on it.
One problem may be that the Mallory has a very thick composite gasket, (app. 1/8 ") which may be raising the contact area where the gears mesh. This was not the case however, with the distributor I just replaced.
I assume from the lack of response here, that there's no easy answer. Tonight I'll remove the new Mallory, and run a gear pattern on it.
One problem may be that the Mallory has a very thick composite gasket, (app. 1/8 ") which may be raising the contact area where the gears mesh. This was not the case however, with the distributor I just replaced.
Team Owner
Joined: Apr 1999
Posts: 21,953
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From: Reno Nevada
2024 C3 of the Year Finalist- Modified
Different manifolds and heads change the dist. installed height. You have to use a gauge to set the correct gear meshing. My tool is from Morroso. It's also a oil primer.
Thread Starter
Instructor
Joined: Jun 2004
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From: Sun Peaks British Columbia
Originally Posted by gkull
Different manifolds and heads change the dist. installed height. You have to use a gauge to set the correct gear meshing. My tool is from Morroso. It's also a oil primer.
NOW, having said that you've got a measuring tool, how do you correct any differences? Do you machine the mating surface on the distributor to drop the driven gear lower into the manifold?
Team Owner
Joined: Apr 1999
Posts: 21,953
Likes: 1,445
From: Reno Nevada
2024 C3 of the Year Finalist- Modified
I could not find my tool on the Morroso tool site. Maybe call them.
First you figure out what you height you need with your dist - manifold gasket in place.
To set the distibuter height you knock the roll pin out of the bottom gear. Above the gear you have shims. The shims raise or lower the distributer body. I coat the dist. gear with white grease and install it. then I hit the starter to rotate the motor over. You can see how the teeth mesh. You want the dist. bodys weight to sit on the manifold. Don't let the gear/internal shaft hold the weight from gear/pump contact.
I just bought a brand new MSD full electronic distrib. last year and it required removing shims because it was so tall that it would not have sealed to the manifold with the standard gasket.
First you figure out what you height you need with your dist - manifold gasket in place.
To set the distibuter height you knock the roll pin out of the bottom gear. Above the gear you have shims. The shims raise or lower the distributer body. I coat the dist. gear with white grease and install it. then I hit the starter to rotate the motor over. You can see how the teeth mesh. You want the dist. bodys weight to sit on the manifold. Don't let the gear/internal shaft hold the weight from gear/pump contact.
I just bought a brand new MSD full electronic distrib. last year and it required removing shims because it was so tall that it would not have sealed to the manifold with the standard gasket.
Thread Starter
Instructor
Joined: Jun 2004
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From: Sun Peaks British Columbia
Thank you extremely much! That solves my problem. I was going to run a gear pattern on the Mallory this evening to see how it sits.
I had never before heard of having to address this problem.
It's a good day when you learn something.
I had never before heard of having to address this problem.
It's a good day when you learn something.
Le Mans Master
Joined: Sep 2001
Posts: 7,739
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From: Unreconstructed, South Carolina
Just last night a fellow brought a brand new procomp hei by the shop to have the mech advance locked-welded for a circle track motor. It sure had a nice shiny finish on it but boy did that POS have TONS of side play.
If your's was like that, it may've damaged the gear on cam.
If your's was like that, it may've damaged the gear on cam.
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Le Mans Master
Joined: Sep 2001
Posts: 7,739
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From: Unreconstructed, South Carolina
Originally Posted by gkull
I could not find my tool on the Morroso tool site. Maybe call them.
First you figure out what you height you need with your dist - manifold gasket in place.
To set the distibuter height you knock the roll pin out of the bottom gear. Above the gear you have shims. The shims raise or lower the distributer body. I coat the dist. gear with white grease and install it. then I hit the starter to rotate the motor over. You can see how the teeth mesh. You want the dist. bodys weight to sit on the manifold. Don't let the gear/internal shaft hold the weight from gear/pump contact.
I just bought a brand new MSD full electronic distrib. last year and it required removing shims because it was so tall that it would not have sealed to the manifold with the standard gasket.
First you figure out what you height you need with your dist - manifold gasket in place.
To set the distibuter height you knock the roll pin out of the bottom gear. Above the gear you have shims. The shims raise or lower the distributer body. I coat the dist. gear with white grease and install it. then I hit the starter to rotate the motor over. You can see how the teeth mesh. You want the dist. bodys weight to sit on the manifold. Don't let the gear/internal shaft hold the weight from gear/pump contact.
I just bought a brand new MSD full electronic distrib. last year and it required removing shims because it was so tall that it would not have sealed to the manifold with the standard gasket.
Use the shims between gear & housing to set end play ... do that first.
Then, use shims/gaskets between manifold & housing to set height/seal.
Thread Starter
Instructor
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From: Sun Peaks British Columbia
Originally Posted by jackson
Respectfully ... and I mean it ... I disagree.
Use the shims between gear & housing to set end play ... do that first.
Then, use shims/gaskets between manifold & housing to set height/seal.
Use the shims between gear & housing to set end play ... do that first.
Then, use shims/gaskets between manifold & housing to set height/seal.
I haven't noticed any side play on either distributor, (the ProComp was new and when removed had only 200 mi.) BUT I have noticed that there;s quite a bit of up & down play on the shaft. I assumed, (there's that word again!) that the up/down was intentional to allow for some height variance w/o damaging the distributor when you sinch it down.
I have also noticed that the Mallory came with quite a thick gasket,
(1/16"+).
Thread Starter
Instructor
Joined: Jun 2004
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From: Sun Peaks British Columbia
My apologies to gkull. I just contacted our local performance supplier, and they tell me that Moroso has two types of shim packs. One type goes above the distributor gear and the other type goes between the intake manifold and the distributor body.
Oddly enough, they tell me that there are no requests for this product?
Oddly enough, they tell me that there are no requests for this product?
Team Owner
Joined: Apr 1999
Posts: 21,953
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From: Reno Nevada
2024 C3 of the Year Finalist- Modified
Your right i wasn't 100% clear on how I worded it. This is the MSD kit. For my new dist.
http://www.msdignition.com/dist_71.htm
Shim Kit
This new Shim Kit will you achieve proper endplay or help in positioning the gear-to-cam mesh. Shims are supplied to go between the gear and housing or the upper shaft next to the advance collar. A variety of shims are supplied including: 0.010”. 0.015”, 0.020”, 0.025”, 0.030” for the top and a brass 0.063” shim or 0.031” steel shim for the bottom.
http://www.msdignition.com/dist_71.htm
Shim Kit
This new Shim Kit will you achieve proper endplay or help in positioning the gear-to-cam mesh. Shims are supplied to go between the gear and housing or the upper shaft next to the advance collar. A variety of shims are supplied including: 0.010”. 0.015”, 0.020”, 0.025”, 0.030” for the top and a brass 0.063” shim or 0.031” steel shim for the bottom.
Former Vendor
Joined: May 2006
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From: Riviera Beach FL
The moroso oil primer tool is in the the tool section of the moroso catalog www.moroso.com, the shims for distributor and the shims for the distributor gear are in the ignition section.
