Starter: grind, bind noise

[Canoe]

My starter is not playing nice with the new flex plate. I had to replace the flex plate after what I thought was kickback from a loose distributor ripping some teeth off of the flex plate. https://forums.amceaglesden.com/index.php?topic=42076.msg326956#msg326956
The new flexplate was set against the old and confirmed to be the same tooth count, size, etc..
The engine and bell housing were aligned with the pins and closed together, before securing with the bell housing bolts. (Bolts went in without too much fuss, except the 12 o'clock, which I could get started while holding it in the tips of my fingers, and then it took a number of socket extensions, including wobble extensions, and twelve hours of the socket slipping off and resetting, to secure and torque that one bolt...)

The starter is making a horrible noise but turning the engine over. Sometimes it would sound like the starter motor was binding and it would pause, then continue turning over and the engine starts. The starter appears to have lots of turn-over power.

• I did a lot of searching and there's talk about Ford vs. AMC bendix having different tooth counts, or extention, but nothing seems to be definitive. 
• The bolts appear to be original Grade 5, but are not shoulder bolts, which some say are necessary to prevent any play. 
• To ensure correct mating, I removed the starter. The flexplate teeth on the starter side are very sharp; but not on the other side of the teeth. The tips of the teeth appear and feel fine.
  
• I thoroughly cleaned the plate the starter installs against (grease and some bits of paint in places) and ensured the bolts were properly torqued when re-installed.
  - This has eliminated the binding, but not the horrible noise as the starter turns the flexplate.

I'm going to get shoulder bolts to see if this helps.

I also found the following on shims to limit the engagement. This is different from shimming the GM style starters were you can shim for the distance of the flexplate centre to the bendix drive centre.

Ford/AMC Motorcraft Starters
Subtle changes to these starters over the years do not affect interchangeability
...
In the case of AMC and Jeep, all Motorcraft original starters will have a two-bolt nose. They could have either a two-rib or a five-rib casting; however, you will discover that all replacement starters will be two-bolt, five-ribbed nose units. All of these AMC starters will interchange if you are using the two-bolt, five-rib nose with a 4½-inch case:

Any time you are substituting starters, you need to pay special attention to the flywheel or flexplate clearance. Spacing can be corrected with the use of one or more shims. The Ford part number for the two-hole shim is D7TZ-11N004. These are also available through your local auto parts store; the NAPA part number is 655-1188. These shims are about .10 inches thick. ...

The starter weights a fair amount and its torqued tight when installed. Can I make my own gasket out of the usual fibre material or layers of same, or should this gasket be metal?

Does anyone have any info or insight into this starter issue?

[Mitch]

Sounds like the bendix drive is going in too far causing the grind. The shim may work. Maybe the flex plate was installed backwards..?
The Ford starter differs in the nose length. (Maybe bendix tooth count, too.) Pretty sure the Ford starter will jam on an AMC because of the difference, Ford being longer.
Hopefully someone more knowledgeable will chime in...

[Canoe]

Sounds like the bendix drive is going in too far causing the grind. The shim may work. Maybe the flex plate was installed backwards..? ...

My gut reaction is that the Bendix is going too far, but I don't know. I can't see a way to measure clearance or alignment with the starter installed.

I may have installed the flexplate backwards, but there was something about it that made me think that would be hard to do. But that was a few years ago so it's kinda fuzzy.
Eaglepedia shows it the way I remember.
Easy enough to check by pulling the starter.

[Mitch]

There is some kind of dye or paint that's used to see how well differential gears mesh for shimming purposes, (if I remember correctly). I wonder if it would help see how the bendix gear meshes with the flex plate?

[Canoe]

Cheap water-based craft paint will work painted on the Bendix teeth, but I don't trust that I could interpret it correctly. It may also work on the shaft to see how far the Bendix extends, but I've not seen that use. That step may be necessary.

With the clean mating surfaces, I'm certain that the mounting is square to the flexplate, but I could be surprised and they're not.
Using shoulder bolts is easy.
Making a metal shim is easy enough. Quickly tell if there's an improvement.

I think I just realized that I've got the mating surface as reference, so I should be able to use my calipers to compare the Bendix travel to the distance to the flexplate gears. If that checks out o.k., then the paint would tell the alignment story. I think.

[Canoe]

Took the starter off.
After being used for a few days mounted well torqued against the cleaned flush/smooth plate, the noise is somewhat quieter and the flexplate teeth are not near as sharp as they were before that.

The flexplate is mounted flipped the correct direction.
From the smoothing wear on the Bendix teeth, it looks like it has plenty of engagement, and doesn't bottom out.
From the mounting plate to the teeth is 21.6 mm.
Moving the Bendix by hand, it seems that it extends too far and has intermittent contact with the nose housing.
I got two standard Grade 5 bolt with some un-threaded shank. That makes it a little bit quieter too.

With those bolts in the removed starter, there's still a lot of play. With some wear in the mounting plate, I can see how the weight of the starter taking it a little lower would put the Bendix closer to the centre of the flexplate. The extra width in the mounting holes lets the plate provide the registration. If that plate has wear, I can see how shoulder bolts would provide a more original registration IF the holes are accurate.

Even though the wear marks on the Bendix were in a good position, as a test, I put 1 mm washers in place, with three more along the outside edge. It was noticeably quieter, but still makes more noise than it should.

I'll have to do a full starter bench test to see what the Bendix extension and housing clearance is when powered.

I think I'll have to try either shoulder bolts or something to lift the starter so the wiggle room in the bolt holes let it be farthest from the flexplate centre.

[Canoe]

Thought. It should only take one Shoulder Bolt - in the lower position - to provide the lift/registration correction if that opening has enlarged and is not providing correction registration anymore. One way to find out.

[Canoe]

No luck finding a shoulder bolt that fits. Not even close. The standard 3/8" thread is for a 1/2" shoulder, with a too long shoulder and too short threads. No point in getting the 1/2" turned down to fit the starter's flange hole.

For the lower bolt, the depth of the flange on this starter is 3/8".
Somewhat wider than the 3/8" bolt (bolt at 9.2 mm wide), the width of the hole is 10.7 mm (slightly under 3/8").

I'm considering wraping the bolt with some wire to form a "shoulder", with a coating of JB-Weld High-Temperature putty to help hold it in place. That or make a sleeve, but I haven't the proper tools for that. 

[Canoe]

Frig!
Going with replacing the bolt with a stud.
Will trim down a T-bolt or threaded-insert to match the starter's bolt hole size.
That should match a shoulder bolt function well enough for this use.

No lucking getting a bolt long enough that's threaded the whole length.
Will make a stud from a carriage-bolt that I'll have to grind the sides of the head off of.

[mudkicker715]

definitely keep updating your results. long story here but when I last drove my eagle it was eating starters. throw in a move buying a foreclosed house. than trying to make it a happy home. well I had no time to see my issue. it just sits in my garage. soon I hope to dig into it, meaning someday.

[Canoe]

Starter continues to be quieter than usual with the 1 mm washers. I note there is some pitting on the bearing surface of the starter flange that was blasted clean sometime during the refurb/reman process, so perhaps the starter is sitting closer than it should, but where the wear marks are on the Bendix teeth (seems fine) suggest that's not it.

• For a stud to replace the lower bolt (this should make it easier to install the starter anyway), I got a 3/8" stainless carriage bolt and ground the "overhang" of the head off so it leaves the square portion of the head.
  - I plan to install this from the back side where the bolt threads would stick out if the bolt was long. Leaving this square head will allow me to easily back this "stud" out if I ever need to. 
  - Grinding: with the bolt held in a vice face with hard-rubber inserts to not damage the threads, and with the bolt aimed down and out from the jaw ends at a 45 degree angle, I'd grind a little, then lift a container of water up to submerge the bolt, so the heat couldn't build up and damage the bolt's strength.
• On first install of this stud I plan:
  - To not set the remaining square-cb-head tight to the housing, but leave it a thread or two shy. This will let the threads take the load as it would if a bolt was used, as it does when stock.
  - I'll put a drop of semi-permanent thread-locker on the last three threads that will go into the housing, finishing turning it in to where I want it, then torque the nut over lock-washer to hold the starter torqued to spec while the thread-locker sets.   
• To allow this stud to mimic a shoulder-bolt so it provides some of the position registration for the starter (instead of a worn plate opening allowing the install location to sag the wiggle room of the bolt-to-flange-hole), I'm making an internally threaded-cylinder to thread onto the stud.
  - I used a cheap 3/8" bolt to hold a 3/8" T-nut so I could grind the T-nut flange off.
  - I was aiming for a 3/8" cylinder height left, but got sloppy when I started squaring it off and ended up with an uneven height after I cleaned it up, varying between 4.5/16" and 5/16". It will fit within the flange of my starter and should be good enough for a test of concept.
• I started thinning the internally threaded cylinder that was left of the T-bolt from the prior step.
  - I first used a flat file to get the cylinder's outside parallel to the bolt, and then an even thickness from the bolt.
  - Then I put the bolt in a drill and used a large flat file to start thinning the resulting cylinder down to the target outer thickness. Not exactly a milling machine, but it's what I've got. I expected this to be faster than doing it by hand, but the even roundness also improved significantly. 

(That process was set aside after some fries in a stove-top pan got majorly burnt at my Dad's and distributed some light to medium density smoke throughout the first floor. No heat/flame damage. Box fan in a window cleared out the smoke out, and after an hour nearly all of the smell, with a HEPA air filter unit left sitting in front of the cold-air return for any fine particles left floating around. Tomorrow we'll test to see if any grease on the walls, to see if we have to address that.)

[Canoe]

Aaaand, I realized that with the lower bolt as a stud with sleeve for a tight fit to the starter flange, dropping the weight of the starter when installing could lead to finding out which was weaker: the stud, the starter flange or the housing. I really don't want to find out.

So the upper will be that "stud" I made (with no sleeve), for ease in getting the starter in place and securing it only finger tight so it can move within that stud to flange hole play. Then a bolt with the "shoulder" sleeve can be secured in the lower bolt position, providing the registration. Rotate the starter within the upper play so the starter is furthest from the flexplate. Tighten and torque.
That's the theory.

[Canoe]

I went back to see what I wrote

I thoroughly cleaned the plate the starter installs against (grease and some bits of paint in places) and ensured the bolts were properly torqued when re-installed.

and I didn't mention the raised metal along the lower edge of the hole the starter mounts into, that I filed off level to the plate as part of cleaning the plate. I'm now thinking that at some time the bolts were not tightened adequately and a starter sagged down hammering the plate locator opening over time.

I've marked a housing plate photo I found on the www with the location where the raised edge was.

So, shoulder bolts or equivilent functionality should locate the starter to its correct location. I'd expect pushing the starter upwards in the plate hole and managing to secure the bolts with the starter in that position would work, but I have no guarantee the upper part of the hole wasn't also affected by a sagging starter.

Current plan is to go with upper hole with a stud and threaded-sleeve to act as a shoulder bolt, and let the starter pivot off that down & outwards within the lower bolt play to get the lower bolt in place.

[rmick]

I had an experiance like this on a Ford Van. I found the plate to be the culprit the hole in the plate is supposed to align the starter. At some time the starter had came loose and caused the plate hole to enlarge just enough that even after tightening the bolts the starter never set right again. Ended up replacing the plate and problem solved

[Canoe]

... the culprit the hole in the plate is supposed to align the starter. ...

This is exactly what the issue is supposed to be.
There's the seemingly mythological "stock" shoulder bolts for mounting the starter, but the parts catalogue and all of the stock setups people have found use fully threaded bolts. I couldn't find a shoulder bolt that would fit.

Stud for upper: no go. I forgot the bolt starts from opposite sides for mounting the starter.
Stud for lower: carriage bolt with the found head ground off but leaving the square portion is a no go - square portion won't clear the bell housing when put in from the housing side. Had to grind the corners off the square head to take it back to the thread thickness.


Success!!!
Just a tiny bit of the former noise. Doesn't sound like anything is getting trashed. Starts sooner/faster. People no longer look when I start it.

Lower bolt replaced by stud, with threaded-sleeve to function like a shoulder bolt:

• carriage bolt, head ground down until it's as narrow as the threads, then cut a slot for a screwdriver in what is left of the head
• screw into the bell housing lower bolt hole from the housing side, with a drop of reversible thread-locker on the last few threads
• 3/8" fender washer 1.5 mm thick as a shim goes on the stud
• DIY threaded-sleeve:
  - the hole in my starter flange for the lower bolt is ~1.7 mm wide, 3/8"+ deep
  - 3/8" T-bolt, flange ground off, height left is 9/32 to 5/16 (sloppy grinding, but it's less than the depth)
  - narrowed the resulting threaded-sleeve down to 1.5 mm (using a drill with bolt & sleeve and a flat file)
• the "good" end (unground) of the threaded-sleeve goes on the stud first, threaded down so it secures the shim/washer finger tight

Starter Install:

• Starter easily fits in place, with the lower bolt hole over and on the stud & threaded-sleeve with the starter flange up against the shim/washer
• support the starter and get the lock washer and nut on the lower stud finger tight, then ensuring the starter flange is against the plate/shim/washer, tighten until the lock washer is slightly compressed
  - starter can move slightly with the play between the stud, sleeve and flange hole
  - if the locator/plate hole is worn oversized, the starter can pivot on the lower stud within that hole
• place the upper bolt through its hole, placing the 1.5 mm thick fender washer as shim/washer on the bolt
• hold the starter tight in place and start the upper bolt
• when the upper bolt is finger tight, the starter is sitting with its weight taking up any play between holes and upper bolt or lower stud&sleeve
• tighten upper to firm
• tighten lower beyond firm to snug
• torque upper, then torque lower

NOTE: I don't believe the fender washer as a shim is an essential element of this working; but I might be wrong. I had some improvement using a 1.1 mm regular sized washer, so I wanted to try this with a larger washer for more stability. 1.5 mm was what I had in the bin. As per the MSR, you have to check the extension of your starter's Bendix vs. the distance from the locator plate to the flexplate teeth. A shim could come into play to allow you to adjust the extenion to fall within the range specified.

There may be some optimizing possible by moving the starter within the play available with this setup. If one's results weren't as good as mine with the above stetup, one could try adding a threaded-sleeve to the upper bolt.

I am amazed that given the play in the bolts to holes, such a little difference has so much influence.

The way I did it, the location is determined by the lower stud with threaded-sleeve with its play having the starter "down" and the upper play places the starter down and out from the flex plate as its play "pivots" the starter outwards on the lower stud's sleeve. I think.

The mounting/locator plate surface to flexplate teeth is 21.10 mm. That's the upper limit in the TSM & MSR (19.6 to 21.1 mm). I'm using a washer as shim of 1.5 mm, and there's no longer paint on the plate. I'll have to revisit that shim thickness after some days or weeks, to check the starter Bendix for wear marks. I'll adjust, or make a full size shim or remove the shim/washers.