Pulling distributor gear

[kyleandhisIH]

I haven't looked closely (mostly because I know I'd try it) but I have removed my distributor and checked end play. Using a small 6" machinist's rule, I witnessed ~0.046" end play and tried to take a picture. Unfortunately, my camera isn't capable of fine detail.


What do I need to know before getting some shims and trying to pull the gear? Should I use some kind of tool? Maybe cut a hole in a board, split it, and nail it together around the shaft?

I figure if I can get a way to pull the gear and then find a method of safely pressing it back on, I should have no problem sizing the shims correctly. I'm also told a copper-based anti-seize is a good idea, but where exactly can this be applied?

I haven't gone for a thorough tear-down of the top end, but nothing feels "loose" about the mechanical advance unit, and the vac advance holds vacuum and responds well to signal, performing well with a visual inspection time and time again.

I figure if I can get my timing to "wander" less, having it read 23* btdc isn't so bad. (other posts on the website expound on my specific situation... Regardless, it runs best in the 23-24* area.

 

[ronmc1954]

Kyle, the gear is held in place with a roll pin. Just knock out the roll pin and the gear should come right off. Just watch when you re-install it if it was drilled a little off-centered the hole will not line up, which means it needs an 180* turn. I have not seen that on IH dizzys but I did see it on a Ford once.

Ron

 

[Michael Mayben]

Ron is correct,...but it's not that easy!

Delco distributors,...punch out the spring pin (carefully), the gear "should" pull off fairly easily though it's not uncommon that I have to use a press or puller to help 'em.

Prestolite distributors,...same thing only the gears "usually" pull off by hand if the oil varnish is removed. But those have the hole in the gear/shaft drilled after the gear is installed so each has it's own unique location orientation when they go back together.

Holley "1500" series distributors,...same thing, punch out the spring pin. Then the bitch-session starts! Those gears must be pulled or pressed in some fashion or you will destroy the gear (irreplaceable) along with the shaft possibly. Of the n=7 of those Holley units I have in rebuild stages right now, all the gears were extremely difficult to remove...up to a pressure required of 2 tons. I have a fabricated puller set I've made for doing that.

Installing the gear on the Holley after the unit is serviced can be very tedious as the gear must be pressed back on while maintaining the hole alignment. Do that incorrectly and ya end up with a pile of parts!

Mallory distributors,...those do not come with a drive gear, ya gotta obtain a donor gear from some IH app. The donor gear can be either "tight" or "loose" when ya install. Then the roll pin must be installed and end play measured. Then, the gear is removed, the proper shim(s) installed and then the gear goes back in place for the final time.

All of the IH distributor gears are the same for all of the distributors used oem. Only the prestolite is a "custom" fit which precludes using the prestolite gear on any other distributor shaft once it's been drilled. They have a nominal hole diameter of 0.497". The spec'd shaft diameter is 0.500". So you can see the gears are designed for a light press/interference fit.

When I rebuild distributors, they are all assembled using anti-seize at the shaft/bushing interface. Dealing with the breaker plate assembly and the mechanical advance unit offers some unique challenges on occasion as replacement parts for all the tiny hardware is not available. I have a "system" for repair of the breaker plate, advance, etc., but the stuff is used in an individual fitment for each distributor and is not something I care to disclose.

Each of the above mentioned distributors have their own unique set of "problems" (wear and maintenance-related) that are present after 30>40 years of service, this is not an "all the same" kinda deal!

 

[kyleandhisIH]

Holley "1500" series distributors,...same thing, punch out the spring pin. Then the bitch-session starts! Those gears must be pulled or pressed in some fashion or you will destroy the gear (irreplaceable) along with the shaft possibly. Of the n=7 of those Holley units I have in rebuild stages right now, all the gears were extremely difficult to remove...up to a pressure required of 2 tons. I have a fabricated puller set I've made for doing that.

I have the Holley 1500 series aluminum-body distributor, converted to pertronix and etc. Should have said that in the initial post.

Should I try to find someone who can pull a gear/reinstall it for me? I figure I can't exactly afford to have mine reconditioned, but at the very least the end play could be solved, and now that's even looking iffy. Only problem is, I don't know of any place that would have access to that type of setup nearby.

 

[kyleandhisIH]

Updating with an image of my end play, also testing an image host.

I do have a set of feeler gauges (at a friend's place) and I will try to obtain a correct measurement of end play with those before I fool around with any type of shimming.

 

[Greg R]

A wood support won't do, you need a small bearing splitter to properly support the gear. Witness Mark in some fashion that won't disappear when cleaning, so you can get the gear and and shaft lined up for the hole and roll pin on reassembly. I recently did my Holley dist, and the gear was on tight! I was able to coax it off with a little heat and brass hammer, but that was a highly tedious affair. I constantly worried about damaging the shaft in some manner seeing it had such a long spud for the oil pump, and had to let it cool several times. After I got a shop press, I won't do one again without a press. The gear is on a boss on the shaft, so you only have to move it's width and then it falls off.
The shim kit I used was a mr gasket 2820.
I suggest stripping everything, there can be a lot of hard grease/lube sticking to the advance plate, and pay particular attention to the slider buttons between the plates, they are un-obtainum. They are usually stuck in place, but you only have to lose one to ruin the day.

Btw, Mike: I followed your advice to the tee, I put the spare pertronix in after Everything was cleaned, re-lubed, and checked for play/slop and properly shimmed. It works great, I have better response, little to no ping, less deviation on the scope.

 

[Michael Mayben]

I don't use heat on these gears/shafts since the gears themselves cannot be obtained from any source. Heat is not needed if the proper setup is made with the puller I fabbed, use in conjunction with a five ton equivalent jackscrew.

I can have 'em made, but that will be a huge investment as the tooling must be covered up front and a pre-paid order of 500 items booked. That's several thousand dollars which makes the retail for one of these gears hugely expensive.

I've just returned home tonite from visiting yet another machine shop in eugene that will do the gears 100 at a time but their price per unit is still outrageous. But that company can do some small run jobs for some other items we're looking into at a very attractive cost.

I have two destroyed Holley 1510 distributors here now that have had the oil pump drive tang destroyed and teeth broken off the gear when heat and a hammer were used. So those were broken down for parts donors.

You must measure the endplay between the end of the housing and the machined surface of the gear with a thickness gauge kyle. Record that number and then cal'c the thickness of the shim you need. The shim must be a "hardened" item. I set the 1510 unit up with 0.015" endplay, that is much tighter than the oem spec,...and it also results in much crisper/stable timing, especially when used with a pertronix, or a mag-trigger conversion.

Both the msd and the mr.gasket "re-pak" shim sets include some brass shims, those are for use in certain delco apps which need a thrust shim under the shaft before it's inserted back into the body after rebuild. Those shims should not be used between the gear and the housing on any distributor, they will not hold up and will mushroom out real quick under a thrust load. The shims I use in my work are sourced in bulk from an industrial bearing/fastener supply....some are actually off-the-shelf items from other sources.

 

[kyleandhisIH]

In response to michael's post above...

I had no intention of quitting with the rule. I have a set of quality feeler gauges and I intend on recording the end play to the nearest 0.0015" (since that's my smallest thickness). I do have one question about feeler gauges, though - what determines the measurement you settle on? Do you just keep stacking until it won't clear the gap, or until you begin to feel "drag" along the length of the stack, or what? My experience thus far has been mostly guitar-related, so it's not such a critical science.

And it turns out my uncle did have some smaller gear puller setups that he used on distributors himself for the same shimming purpose, but he ended up getting rid of them for lack of use less than a year ago.

I'd say the best bet at this point is for me to send the Holley distributor to you, michael, since I know firsthand how good you can make a 30 year old mixer look (and perform!) the lack of my own hands-on experience with this stuff, while disappointing, will no doubt be outweighed by the quality of service I no longer question.


However, I do have a 345 with an entirely different (unknown) distributor. here is the thread Containing a picture of that. The only issue there is that my Dad and I would both like to pre-lube and run this motor when it warms up, if only for the sake of its rather pristine condition (as far as we know!) and I'm sure this will end up in a carburetor disassembly thread somewhere down the line.

In regards to sending it in for a servicing/overhaul: please understand that it might take me some time to actually prepare financially for the shipping and etc. Involved with this transaction. College is not el cheapo, but this is definitely one of the items at the top of my list.

also, for mm: Would this kind of servicing be available through Jeff & ihon, or is this something you handle independently?

 

[Greg R]

Mike, the kit that was used didn't have any brass shims, there were many to choose from. But, have there been problems using mr gasket sets? Fancy washers at best, they seem tough as grade 8, or rather like the shims in transmission kits.

 

[Michael Mayben]

in response to michael's post above...

I had no intention of quitting with the rule. I have a set of quality feeler gauges and I intend on recording the end play to the nearest 0.0015" (since that's my smallest thickness). I do have one question about feeler gauges, though - what determines the measurement you settle on? Do you just keep stacking until it won't clear the gap, or until you begin to feel "drag" along the length of the stack, or what? My experience thus far has been mostly guitar-related, so it's not such a critical science.

And it turns out my uncle did have some smaller gear puller setups that he used on distributors himself for the same shimming purpose, but he ended up getting rid of them for lack of use less than a year ago.

I'd say the best bet at this point is for me to send the Holley distributor to you, michael, since I know firsthand how good you can make a 30 year old mixer look (and perform!) the lack of my own hands-on experience with this stuff, while disappointing, will no doubt be outweighed by the quality of service I no longer question.


However, I do have a 345 with an entirely different (unknown) distributor. here is the thread Containing a picture of that. The only issue there is that my Dad and I would both like to pre-lube and run this motor when it warms up, if only for the sake of its rather pristine condition (as far as we know!) and I'm sure this will end up in a carburetor disassembly thread somewhere down the line.

In regards to sending it in for a servicing/overhaul: please understand that it might take me some time to actually prepare financially for the shipping and etc. Involved with this transaction. College is not el cheapo, but this is definitely one of the items at the top of my list.

also, for mm: Would this kind of servicing be available through Jeff & ihon, or is this something you handle independently?

That prestolite distributor in your parts rig might be the hot ticket for ya right now kyle! Swap it in and see what happens.

I don't wanna seem like I'm trying to dissuade anyone form dealing with the Holley distributor, but I also hate to see these things destroyed by not disassembling correctly. I speak from experience in that regard when I was learning this schnizz forty years ago,...I've dam shore scruud up my share 'cause I didn't have the proper procedure for removing/replacing the gear! Once upon a time, those gears were about $5 and available at 7-11...now they are unobtanium and priceless (if ya need one)! That is why mallory cannot supply a gear for an IH-pattern distributor which they offer in at least six versions.

You have probably seen the latest "carb shop" offerings from ihon:

http://www.forums.IHPartsAmerica.com/new-products-IH-only/3479-IH-only-north-fuel-systems-shop.html

And you were the recipient of that "new" venture!

In the next few months, yawl will see a similar "ignition shop" launched. We'll have several different "systems" and services available on an exchange basis, including everything from stock reconditioned units, to several levels of performance upgrades...all done on a "to order/customer-spec" which can be easily serviced in the future. Some of these will be "upgradeable" at a very minimal cost to be able to talk to the efi pooter! Pricing on all this stuff will be very reasonable!

This stuff will be a building block kinda deal, with pre-terminated "plug and play" setup that can be easily installed to each customer's requirements.

Can you work with your uncle to kinda "re-create" what he did previously? Sounds like he understands the correct approach if he also created some tooling!

 

[kyleandhisIH]

Little update here.

Verified my distributor's end play is 0.034", if I try 0.035" it interferes. So this points to needing a 0.020-0.022" shim stack, correct?

Regardless, I haven't discussed with my uncle the possibility of setting up a gear pull any time soon, so for now I'm keeping the cash ratholed for the rainy day when a gear puller shows up.

Also, the prestolite distributor assures me it is perfectly happy where it's stabbed, and it isn't moving without a good amount of work yet. I spent a little less than an hour with it, giving it love taps and plenty of penetrant, but the most I got was a visible "crack" in the cancer weld at the body's base. My efforts widened the crack none, and I didn't want to damage the distributor, so I put away the crow bar and called it a day.

 

[Michael Mayben]

The endplay you have verified is certainly within the "factory" spec. That is not the cause of your strange base timing situation. So don't fret about pulling the gear.

You can easily do the cleanup of the mechanical advance and the breaker plate assembly without removing it also. I'd not remove the mechanical advance unit, clean and lubricate while it's still mounted on the shaft. If you break that special retainer clip that is under the felt wick, then ya got problems also with finding a replacement. I do have a workaround for the broken/missing clip, but I have to have the distributor on my bench to do that!

If you find the nylon advance limiter bushings in the mechanical advance are worn out completely or actually missing (not uncommon), then I have replacements for those also.

The frozen distributor syndrome is also fairly common! It just takes patience and very careful application of small wedges or pry tools along with the penetrant you are using to make it pop out. I bet that engine was exposed to rain with the hood up for an extended period, the corrosion that forms between the aluminum distributor body and the cast iron engine block can act like epoxy!

 

[kyleandhisIH]

When you say "breaker plate," does that refer to the plate that the vac advance actuates? Am I to understand that I will need to remove that and then be careful of a retaining clip while inspecting/cleaning the mech advance stuff? Can I safely extend the springs/weights for cleaning?

...I could keep on asking questions, but then this would go on forever. I have never seen the deetales of what's under the pertronix install, so I'm a little reluctant to start wrench-dancing on the rotor.

Then again, I can't wait until I'm home and able to tear into it as carefully as possible. I will keep the camera handy this time just in case I get to a point where I'm unsure, and I'll try to actually set up a decent workstation. The heater core/fan unit with a set of sockets on top sure makes for a handy field table, but I might step up the style today with some black plastic and fresh toothbrushes!

Also: if I don't have some kind of "sticky" type of assembly lube to cushion initial thrust loads on the dry/cleaned distributor, will my own engine oil suffice or is it too thin? I wouldn't want to destroy a perfectly good 23* distributor.

 

[Michael Mayben]

Don't even be concerned with the volume and type of questions, that is exactly why we are here! How else ya gonna lern shit????

For lubing distributor metal-to-metal surfaces, I use anti-seize, either the copper-base or the nickel-base work just fine.

You can remove the counterweight springs easily with needle nose pliers or I use forceps, it does not matter that they go back in place in the same position, there will be one "light" spring and one "heavy" spring on a stocker! If the nylon bushings look ok, then no further disassembly is needed as long as the advance unit rotates smoothly with no sticking.

Yes, the breaker plate assembly is the part moved by the vacuum can arm. That is the upper plate and is mounted to the lower plate by a spring clip underneath. The upper plate pivots around the lower plate and is supported by three tiny nylon "bearings" (usually gray in color, sometimes black). Those three contact points must be verified, I see many distributors where one or more of those bearings are missing, that really screws up distributor advance and dwell!

All the metallic components of the breaker plate assembly must be nice and bright, no oxidation or contamination present, any contamination leads to a poor ground and increased primary resistance in the system which is a dealbreaker!

 

[kyleandhisIH]

Update time.

Pulled the distributor, started off with a toothbrush on the external, and got to this point with generic carb cleaner penetrant and regular old elbow grease:

Then I started breaking into the internals, and the first thing to come off (after cap, rotor, and my pertronix upgrade) was the breaker plate:

This is post-cleaning, I wish it were that clean when I found it! But it wasn't any severe case, just old grease turned hard, combined with minor dirt.

The stuff on the lower plate (on the right) is a slight touch of grease to each of the three nylon feet, and a more generous "drop" where the two halves get pinned together.

And then, beneath the breaker plate (also after cleaning):

The mechanical advance weights, minus the springs. In the above picture, you can see that the notch in the top of the shaft almost faces directly away from you. Keeping the gear & body in a fixed location, I pulled apart the advance weights to demonstrate the mechanism:

When I was done cleaning and filming this piece, I reinstalled the springs and moved on to reassembly.

Here's my pertronix mag wheel installed & everything buttoned up:

And... Now that I've already "finished" with the distributor, I kinda wonder... How big are the bushings supposed to be? I noticed small soft washers near the top of the slots in the weights, but I really didn't notice anything looking like a bushing on the two pins for the weights. Then again, the mech advance doesn't have any slop or free motion at all before the weights resist the twist, regardless of springs. I think if the bushing were missing, I'd notice a little bit of motionless weights before the pins contacted, correct?

Either way, I'm happy with what now actually appears to be a distributor, instead of some grease spot next to the water neck.