Slant six distributor drive gear

[lowbudget]

Great reply Dan. Very useful info. I did mine last days off, very easy job. This days off is going to be recurve time. Mike

 

[Kevin Johnson]

My picture was to aid in aligning the top advance plate to the lower shaft with the gear on it. If you get them 180 out it will be hard to drop the dizzy back in the same position it was pulled from. This will cause the timing to be off and the car hard to start. The distributor adjustment is on the small side. I made the picture for my own use and felt it would be helpful and a nice reference. This info is not in any shop manuals that I have.

It is important for people to understand that the diagram with respect to the drilled hole(s) is unique to your distributor. The replacement gears that I obtained had only one hole drilled and the one hole could be 180 degrees off and not relatively indexed the same in any event. Your diagram would be very important for people to make when they disassemble their existing distributor for some reason and retain the same gear.

 

[Kevin Johnson]

Hi Dan,

First, I think I should quote you:

EVIDENCE: For people who think reality is more interesting than anything they could make up.

That is a nice line. It would be great if you held yourself to it.

Kevin, it's difficult to tell whether you're a failure as a comedian or a failure at discerning technical drawings from illustrations, but practically speaking it doesn't much matter which kind of failure you are (and I am very pleased to make sure you're a failure at deliberately disseminating false and misleading information to those who asked a legitimate question in good faith).

Thanks, yawn.

Original poster (and anyone else who needs to do the subject repair job): Installing a slant-6 distributor drive pinion properly is not difficult. There is no tricky inconsistency in hole placement to trip you up. There is no substantial risk of getting it wrong and having it fail. All you have to do is follow the procedure—the real, actual, correct procedure that's been used successfully for nearly fifty-one years now, not the one Kevin has made up in an apparent effort to make himself feel important or something—and you'll have a successful result.

Wow. Yawn.

I guess it is a good thing that someone out there took the time to actually look at the "evidence." The evidence is that the replacement gear dimensions provided are not consistent over those fifty-one years.

I took the time in large part because of people such as yourself, Dan, who speak, write and complain, errr... whine very loudly. People who go to great length to project themselves as an expert on a subject but who have plainly not even taken the time to examine easily available evidence.

I think I have made it abundantly clear that my suggestions are for people interested in technically correct period performance enhancement through attention to detail.

Once you've done all of this to 5 or 10 Slant-6 engines, actually doing the job will take less time than it took me to type this out.

Take home lesson, people: just because someone has done something many times does not make them an expert nor should you blindly accept FSM instructions without determining whether everything has remained the same over the many decades since they were written.

Edit: Just a little follow up...

There is no tricky inconsistency in hole placement to trip you up.

Wrong. Stop making things up, Dan: "EVIDENCE: For people who think reality is more interesting than anything they could make up."

There is no substantial risk of getting it wrong and having it fail.

Wrong. Additionally, I point out in the next post that your abbreviated procedure actually greatly enhances the probability that the installation will be faulty. You attempt to exactly replicate the conditions that are present with a known gear failure -- namely the one you are repairing -- with no attempt whatsoever to diagnose the failure. Yikes! The really scary thing is that you did not see this and have been recommending and performing your procedure for Lord knows how many years.

All you have to do is follow the procedure—the real, actual, correct procedure that's been used successfully for nearly fifty-one years now, not the one Kevin has made up in an apparent effort to make himself feel important or something—and you'll have a successful result.

Dan, you are a real trip. You accuse me of doing exactly what you are doing.

My work with the distributor is to go back to first principles and MEASURE and think analytically. I should point out, too, that the OEMs agree with exactly what I am doing -- in writing. They are trying to help people work around what was an industry wide problem with faulty distributor gear manufacturing and installations.

Your solution to the above problem is to be ignorant of it -- now close to a year after having been made aware of it -- and trumpet your procedure which makes things even worse. Yikes.

 

[Kevin Johnson]

I will intersperse some remarks with real evidence.

Here are two versions of the (real) slant-6 distributor drive pinion installation procedure—first, from the service manual:

Align gear teeth with centerline of rotor electrode. If gear is worn or damaged, replace as follows:

A) Install lower thrust washer and old gear on lower end of shaft and temporarily install roll pin.

Evidence: note carefully that the gears have changed dimension over the years and I found different thicknesses of thrust washers provided and/or used, particularly with respect to how old they were. In general, the older the parts, the higher quality they were.

B) Scribe a line on end of shaft from center to edge. The line is centered between two gear teeth as shown in fig 5. Do not scribe completely across shaft.

C) Remove roll pin and gear, use a fine file to clean burrs from around pin hole.

D) Install new gear with thrust washer in place, with hole in gear rotated approximately 90 degrees from old hole in shaft and with scribed line centered between the two gear teeth as shown. If it appears the new pin hole may interfere with the shaft oil groove, rotate gear to the centerline of the next pair of gear teeth, aligning again with scribed mark on the end of the shaft.

Evidence: note that there is little concern in the FSM that the new drilling will intersect the old drilling and weaken the shaft. This might just be because, as indicated in the 1960 factory technical drawing, there were already two installment levels contemplated. Evidence allows intelligent inference.

E) Before drilling through shaft and gear, place a 0.007" feeler gauge between gear and thrust washer, and after again observing that the centerline between two of the gear teeth is in line with centerline of rotor electrode, drill a 0.124" to 0.129" hole and install the roll pin.

CAUTION: SUPPORT HUB OF GEAR WHEN INSTALLING ROLL PIN, SO THAT GEAR TEETH WILL NOT BE DAMAGED.

-----------------------------

Now, my own writeup, with less scribing and more realism:


When you examine the new gear, you will see that a hole has already been drilled in the gear housing, and on first glance it will look as if this is meant to accept the roll pin. No. You must not use the single hole that is drilled in the gear when you purchase it. It's just an index hole for easy visual reference of the gear's position as you install it.

Note above that Dan is now confabulating, which is fine, so long as you present it as such. The predrilled hole actually IS meant to accept the roll pin after you drill through it and the shaft. How do we know this? It is in the FSM.

Push the top (rotor end) of the distributor mainshaft down towards the drive end. Place the new thrust washer over the drive end (bottom) of the shaft. Maintain downward pressure on the mainshaft, and fit the new nylon pinion on the drive end of the shaft with the existing single hole in the new pinion at right angles to the hole in the distributor mainshaft. Hold a 0.007" feeler gauge between the gear and the thrust washer, then ensure that the pinion is fully seated (all the way down) on the shaft.

Okay, now when you have all manner of difficulty starting the engine (stated later on) you can likely trace it back to the above. The replacement gears do not have the predrilled hole consistently located directly over or in between the gears. Dividing 13 into 360 yields ~27.7 degrees of possible location error. This tiny difficulty is why the FSM has you scribe the line.

Once you've positioned the new pinion correctly, drill through the pinion such that you create two holes exactly in line with the existing distributor mainshaft cross hole, taking care not to enlarge or ovalize the mainshaft cross hole, as this would allow the pinion roll pin to come loose.

Lets turn on our thinking caps. We have a failed distributor gear at hand. We know that service shafts are supplied without any holes drilled. A replacement shaft may have been refitted to a distributor that may be as much as fifty-one years old. We know from EVIDENCE that even factory rebuilt distributors did not follow the FSM and this happened even back when the parts were of higher quality. We now are blithely attempting to exactly duplicate what has a distinctly elevated probability of being a faulty installation. We have EVIDENCE that pins that are not installed directly through the centerline of the gear cause abnormal wear patterns and errant timing as well as being more failure prone. Please, Dan, never consider a career as an aircraft engine technician.


Using an appropriate hammer and punch, drive the roll pin home such that it is even on both ends, does not protrude overly much from either side, and engages both sides of the nylon drive pinion.

Now that the distributor's fixed, how do we put it back in in the correct position? The distributor timing was lost completely when the rotor stopped turning and the engine kept on. You'll have to do it from scratch. The timing mark on the vibration damper can't necessarily be depended on as correct, for the outer ring member of the vibration damper—which carries the belt load—tends to slip relative to the inner hub, which causes false indications of overly-advanced timing.

First, you have to find true Top Dead Center. Pull the frontmost (number 1) spark plug, straighten a wire coat hanger, insert the end into the spark plug hole, and turn the engine using the fan and fan belt until the hanger stops moving upwards. This is TDC, and you've got a 50/50 chance that it's the correct TDC (the one between the compression and power strokes). With the frontmost piston at TDC, have the distributor rotor pointing towards the number-one spark plug wire tower of the distributor cap,
which is in roughly the 4:00 position. The drive pinion for the distributor is helical, so the rotor will move about 30 degrees clockwise when you push it home into the block; when you're aiming for a 4:00 position, start at about a 3:15 position before pushing the distributor into the block.

If you're fortunate, this will get the timing close enough for you to start the engine and dial it in correctly, but that helical distributor drive pinion can make a nuisance for even those of us who've removed and installed slant-6 distributors countless times. It can seem for all the world like everything's exactly where it's supposed to be, and yet the durn thing won't start! I usually just remove the distributor hold-down bolt, note the position of the rotor, carefully pull the distributor out, very slightly turn the rotor clockwise and push the distributor back down, thus advancing it by one tooth. Snap the cap back on (don't bother with the hold-down bolt, as long as you can see the hold-down bolt hole in the block through the distributor hold-down plate slot, you're fine), and crank the engine. If still nothing, advance the distributor one more tooth. Keep repeating this, and sooner or later you will get some activity under the hood. It'll likely start with a change in the starter sound — either the starter will struggle and hitch, or it'll spin faster as the engine "tries" to start, or maybe you'll get a "POOF!" spitback through the carburetor. Keep advancing the distributor a tooth at a time until the engine fires and runs. If you don't get a good result within four teeth, go back to your initial rotor position and start moving counterclockwise from there, a tooth at a time. One way or the other, as long as the distributor is hooked up(!), sooner or later you'll get a good result. Once the engine will start and run, move it one more tooth to see if the engine runs better or worse. If better, leave it there. If worse, go back one tooth. Then reinstall the hold-down bolt loosely, set your timing by the normal procedure with a timing light, and tighten down the bolt.

Once you've done all of this to 5 or 10 Slant-6 engines, actually doing the job will take less time than it took me to type this out.

One would think that after performing this operation so many times it would occur to the installer that some of the FSM steps were there for a good reason. It just goes to show you that it is possible to become very proficient at doing something half-assed.

 

[Kevin Johnson]

K. Johnson is over at FABO pissing SSDan off about the famous dual pin distributor gear........Again LMFAO

Yes, and pointing out the very basic errors in his rebuild procedure that you failed to catch. That's certainly worth a chuckle in the morning.

Please tell me that you do not work on aircraft systems of any type whatsoever.

 

[lowbudget]

Sorry I didn't mean to get your panties in a wad.
First the question posted was:

Where can I get a good quality distributor drive gear for my 61 Lancer?

Second my answer was:

got my last one from Napa. Then drill the hole as per FSM.

Third
Originally Posted by lowbudget
K. Johnson is over at FABO pissing SSDan off about the famous dual pin distributor gear........Again LMFAO

that was my opinion as last time I checked I live America and have a right to have it. I figured the guy could get a hold of you for a crank scraper. I provided him with your name, what forum you were on and the thread topic. No I don't work on airplanes I'm a fluids engineer. My 89" N/A HD motor dynoed 95 HP. I'm working right now on a 155 HP snowmobile engine. I have my parts for my slant build but it will be tame. If you want absolute timing, fire it off the crank. The distributor gears I have looked at usually failed to getting brittle due to age and heat cycles. I use the factory service manual to set my distributors up. If you have a problem with that take it up with Chrysler. As always this is just my opinion.
Mike

 

[Kevin Johnson]

Sorry I didn't mean to get your panties in a wad.

No, I just found your juxtaposed comments interesting. Now even more so given your education and profession.

... The distributor gears I have looked at usually failed to getting brittle due to age and heat cycles.

I suggest you look at a few more and a bit more closely. Due to the age of the engines it is likely that well used examples will be on the second or third gear. Maybe a service shaft installed if they have been rebuilt.

I use the factory service manual to set my distributors up. If you have a problem with that take it up with Chrysler.

Hey, I did my due diligence. I looked at a vintage NOS factory rebuilt distributor and it did not follow the FSM.

Industry wide problem -- as I stated about a year ago and as acknowledged by Ford for many years now. But you know that because you read the threads. I am just trying to figure out some sort of an excuse for a trained engineer such as yourself. It is not easy.

That and the fact that he just went off the deep end.

LMAO It's good to have a little humor in the morning

I agree, goes great with coffee.

I went off the deep end by actually investigating the topic analytically. Sadly, an exercise lost on many. I also improved the scraper designs, again. Charlie was kind enough to lend me some blocks. I also designed a girdle as shareware for the slant six community. I also suggested a general design improvement for the slant six oil pump. Oh -- that's your area of expertise. I forgot.

Yup. Right off the deep end. Yikes.


~~~~~~~~~~~~~

Real world, a tray is worth maybe 7 hp about 3000 rpm. A scraper will be about the same.

That is what got Kevin in trouble here, he was making wild claims about his parts, and never produced any proof to back up his claims. That and the fact that he just went off the deep end.

Yes, a scraper typically returns about 2% of the output of the engine. Thanks for confirming my wild claims. My wild claims independently confirmed on multiple engine configurations. I forget though, a BMW slant six is a verboten topic on dot org. Where is that rolling eyes emoticon...