9N oil pump bushing

Duallie

Member
I'm nearing the end of the cleaning/painting stage
and about to begin assembly of my 1941 9N (12volt,
front dizzy, 9/16 oilpump).
I just had my machinist replace and ream the oil
pump bushing, but three teeth of the new pump gear
hit the housing. We assumed the body moved while
in the mill and we reamed it crooked. Went to get
an oilite brass bushing to try it again, and the
bearing shop owner glances at the original "Ford"-
labelled bushing and mentions that it looks like
the original bushing had more copper and therefore
is harder than the bushing he just sold us.
My first question is: What is the exact dimension
between the two pump shafts?
Number two: Why can't we press in some 5/8" OD
copper tube, drill an oil hole, and ream to fit?

Thanks for the help
 
(quoted from post at 23:40:08 02/01/13) I'm nearing the end of the cleaning/painting stage
and about to begin assembly of my 1941 9N (12volt,
front dizzy, 9/16 oilpump).
I just had my machinist replace and ream the oil
pump bushing, but three teeth of the new pump gear
hit the housing. We assumed the body moved while
in the mill and we reamed it crooked. Went to get
an oilite brass bushing to try it again, and the
bearing shop owner glances at the original "Ford"-
labelled bushing and mentions that it looks like
the original bushing had more copper and therefore
is harder than the bushing he just sold us.
My first question is: What is the exact dimension
between the two pump shafts?
Number two: Why can't we press in some 5/8" OD
copper tube, drill an oil hole, and ream to fit?

Thanks for the help
eal simple....copper tube is NOT oilite
 
Oilite is made with oil encapsuled into bronze. It is made to be self lubing.

The bushing material you should go for is silicon bronze. The silicon content gives it great wear qualities.

The method of installing and then reaming in a mill sounds problematic to setup square and centered.

If you use a single setup (don't unchuch and rechuck) with a lathe to machine both the inner and outer surfaces, the outside of the bush will be perfectly concentric to the inner bore. If the pump housing was manufactured correctly you should have no problems.

Lathe Proceedure

Mount a bar with the full length of the bushing plus 3/8 inch outside the chuck. Drill, bore, ream deeper than necessary, testing for fit. Then finish the outside, chamfer etc. and part off.

If you purchase a bushing with a tight center hole, a lathe is still the easiest way to ream the center, before installing the bushing. hth
 
(quoted from post at 23:40:08 02/01/13) I'm nearing the end of the cleaning/painting stage
and about to begin assembly of my 1941 9N (12volt,
front dizzy, 9/16 oilpump).
I just had my machinist replace and ream the oil
pump bushing, but three teeth of the new pump gear
hit the housing. We assumed the body moved while
in the mill and we reamed it crooked. Went to get
an oilite brass bushing to try it again, and the
bearing shop owner glances at the original "Ford"-
labelled bushing and mentions that it looks like
the original bushing had more copper and therefore
is harder than the bushing he just sold us.
My first question is: What is the exact dimension
between the two pump shafts?
Number two: Why can't we press in some 5/8" OD
copper tube, drill an oil hole, and ream to fit?

Thanks for the help

I have a few observations:
  • [*:0921b879a3]Conventional Oilite (SAE 841) bearings are sintered bronze with the addition of a small amount of iron and harder than plain copper. Super Oilite (SAE 863) contains more iron and is even harder. [*:0921b879a3]The bag of replacement oil pump bushings I have in the shop (high quality Noname brand) do not appear to be Oilite. They are split sleeve bearings and look to be ordinary rolled brass/bronze sheet.[*:0921b879a3]And the $50 question is why do only 3 of the gear teeth hit the housing. If your reamed hole is off center or out of square all of the teeth should hit the housing. Sounds more like the gear is cocked on the shaft or the shaft is bent. Might want to install the shaft in the bushing and check for runout in the shaft before you press the gear on.[/list:eek::0921b879a3]TOH
 
When installing the oil pump kit, pressed the split bushing into the hole with a the side hole lined up with the drift hole in the pump housing used for lubrication.

The machine shop used the same machine as used for the rod bushings to ream the split bushing to size for the driver gear. About .01" had to be removed on the wall of the bushing to fit the new pump shaft.

The reamed split bushing hole was not exacly centered and about .003" offset towards the driven gear shaft.

With both gears installed the gear teeth clear the housing, but two teeth have some sliding noticable friction when rotated by hand. The other teeth have no noticable sliding friction.
Hoping the the two teeth will "run in" when the engine is first started.

Agree that a new separate non split silicone bronze bushing drilled, bored and reamed on the lathe is the preferred method, since assured of concentricity.

Toss the the split bushing supplied with the kit.
 
(quoted from post at 09:43:43 02/02/13) When installing the oil pump kit, pressed the split bushing into the hole with a the side hole lined up with the drift hole in the pump housing used for lubrication.

The machine shop used the same machine as used for the rod bushings to ream the split bushing to size for the driver gear. About .01" had to be removed on the wall of the bushing to fit the new pump shaft.

The reamed split bushing hole was not exacly centered and about .003" offset towards the driven gear shaft.

With both gears installed the gear teeth clear the housing, but two teeth have some sliding noticable friction when rotated by hand. The other teeth have no noticable sliding friction.
Hoping the the two teeth will "run in" when the engine is first started.

Agree that a new separate non split silicone bronze bushing drilled, bored and reamed on the lathe is the preferred method, since assured of concentricity.

Toss the the split bushing supplied with the kit.

The manufacturing tolerances on those cheap offshore silicon bronze sleeve bearings are all over the place. If you ream them on a lathe prior to pressing them in the ID will shrink due to the heavy interference fit and the resulting hoop stress in the bearing wall. You won't even be able to fit the shaft into the bushing. Setup on a mill using a coaxial indicator is trivial and I always ream the bushing after it is installed in the housing. Its's the only way that works. :twisted:

TOH

PS> Don't buy cheap import co-ax indicators. This one didn't last much longer than this job - the Blake that replaced it is worth every dollar I paid for it.

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I had forgotten about the [b:e2b719d31b]split [/b:e2b719d31b]bushing, which I would still consider reaming on a lathe with a collet chuck. No setup, just a tool change.

One of the best tool for my 9x20 lathe [b:e2b719d31b]modified lathe kit[/b:e2b719d31b] from the land of almost right, was my ER32 collets and chuck, opened up the lathe possibilities, rechucking etc. With accuracy to 0.0004 (four ten thousandths), hold fragile tubing tightly with out crushing, no slippage. So good, I got a chuck for the mill, use the same collets. ER32, collets are cut with 16 contraction slots giving each collet a range of about 1/16" hence Extreme Range. 12 collet set will reach down below 1/8 up to 13/16. Brilla Precision Tools, BPT. But they are not cheap.

I still wonder about the squareness of the setup on the mill. You must have set the main cap in the vise with parallels. I guess you can run the tip of the indicator down the inside of the bush housing to check square. Also, deflection from the over hang, but it might not be significant with such a light cut.

http://www.birlaprecision.in/standard_products.html
 
(quoted from post at 15:22:26 02/02/13) I had forgotten about the [b:ae456bc90a]split [/b:ae456bc90a]bushing, which I would still consider reaming on a lathe with a collet chuck. No setup, just a tool change.

One of the best tool for my 9x20 lathe [b:ae456bc90a]modified lathe kit[/b:ae456bc90a] from the land of almost right, was my ER32 collets and chuck, opened up the lathe possibilities, rechucking etc. With accuracy to 0.0004 (four ten thousandths), hold fragile tubing tightly with out crushing, no slippage. So good, I got a chuck for the mill, use the same collets. ER32, collets are cut with 16 contraction slots giving each collet a range of about 1/16" hence Extreme Range. 12 collet set will reach down below 1/8 up to 13/16. Brilla Precision Tools, BPT. But they are not cheap.

I still wonder about the squareness of the setup on the mill. You must have set the main cap in the vise with parallels. I guess you can run the tip of the indicator down the inside of the bush housing to check square. Also, deflection from the over hang, but it might not be significant with such a light cut.


I'm using a 10HP/8500# Cincinnati horizontal mill with an optional 2HP Toolmaster vertical head mounted on the overarm. The head has an NMTB 40 spindle running on extremely high precision bearings inside a 4" quill. The reamer is chucked in the spindle using a top of the line Devlig/Universal Engineering Accuflex collet chuck and my work piece is solidly anchored to the stationary table with a 100# machine vise.

You are holding the work piece in an ER32 collet chuck mounted in the MT3 headstock spindle of your 250# Grizzly/Enco/HF 9x20 lathe. I presume you intend to mount the 8" long reamer in the 1" MT2 tailstock quill on the lathe and feed it horizontally into the spindle with the hand wheel.

And you are worried my clamping setup may be susceptible to deflections from a 2" overhang on the work piece?

TOH
 
And you are worried my clamping setup may be susceptible to deflections from a 2" overhang on the work piece?
Not when you will be skimming half a thou. If you would be drilling or something heavy you could pack behind the piece anyway.

Yes, Grizzley is the flavor of my Chinese lathe. I have it setup in an extra bedroom of my trailer house. It might weigh 250# if you count everything. It has been a great learning experience, bringing it to its functional potential. Improvements include:

New tool plinth support/clamp
Quick change tool post (piston type)
Speed control (inverter, split phase)
Replacing or truing many small parts

Within its limits it does quite well, regularly 25 thou depth cuts in mild steel with bright finish.
 
While the spindle has an MT3 female taper, the spindle nose is threaded 4x39mm with an indexing shoulder. The chuck blank was first threaded and indexed to fit the nose of the spindle, then attached to the spindle, machined, tapered and threaded for the closer nut, which was purchased, more difficult to make than the chuck. That the chuck was machined in situation on the spindle, it can only be mounted in the same position as it was machined.
 
If there not so much bushing material to remove would used the old fashioned method.

Take 1/4" dia aluminum rod, make a hacksaw cut slot from the end about 1" long.

Take a strip of some emery cloth about 200# grit, place it through the slot.

Place the rod in an electric drill motor and start rotary sanding until get the correct fit.
That way you know the bushing is "honed concentric"
 
(quoted from post at 00:15:33 02/03/13) If there not so much bushing material to remove would used the old fashioned method.

Take 1/4" dia aluminum rod, make a hacksaw cut slot from the end about 1" long.

Take a strip of some emery cloth about 200# grit, place it through the slot.

Place the rod in an electric drill motor and start rotary sanding until get the correct fit.
That way you know the bushing is "honed concentric"

And what magic keeps your pilotless free hand rotary sander from walking off center as it eats it's way willy-nilly into the walls of the bushing? It seems you are now becoming an advocate for the shade tree mechanic techniques that you had previously written off as unreliable and unworkable.

TOH

PS>I certainly hope you are not using that technique on any Oilite bearings.
 
I was a toolroom machinist for 20 yrs before becoming a product design engineer, I agree with TOH that setup is the way to go far better than turning in a lathe before pressing in. That said I was always told to bore oilite bushings in place with a single point tool because a reamer can close the pores.Not saying I haven't reamed a few myself.
 
(quoted from post at 14:52:12 02/03/13) I was a toolroom machinist for 20 yrs before becoming a product design engineer, I agree with TOH that setup is the way to go far better than turning in a lathe before pressing in. That said I was always told to bore oilite bushings in place with a single point tool because a reamer can close the pores.Not saying I haven't reamed a few myself.

The "official" Oilite sizing story from NSK: sizing with a single point small radius tool is preferred but a dead sharp reamer is "OK". Honing is a no-no. Their standard practice installation guidelines are attached below.

That said the service parts sold for the N-series oil pump are not Oilite bearings. They are ordinary bronze alloy split bushings with a nominal OD of .625, ID of .567, and OAL of 1.067. Good luck finding an Oilet bearing or silicon bronze bushing that size. The batch of aftermarket service parts I purchased from YT measure .004/.006 over on the OD and .005+ under on the ID when fully compressed in a 3 jaw lathe chuck. From hands on experience I can also tell you that there is no fillet or chamfer on the top edge of the bore in the oil pump housing and when you press one of those bushings into the housing you will peel a significant layer of metal off the OD. Expecting it to be concentric or square after installation is at best wishful thinking.

I've done more than one of these "for hire" and my advice is simple. If you want to avoid problems and comebacks press the bushing into the housing and size it in situ. Either purchase one of the reamer jigs to hand ream it or take it to someone that can indicate it in and ream it on a suitable machine tool.

TOH

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OiliteInstallation.jpg
 
I live in an area of machine shops with MSC store in the center. Most of the shops are all CNC high production shops for aerospace industry.

In fact I saw on sixty minutes there are lots of machine shop jobs out there, but the younger crowd do not want to do this job. They would rather have a "facebook" type job.

The classic hand crank machine shop is difficult to find.

Really do not know what other folks are doing and have searched the archives with no results on this oil pump bushing issue.

Surely not everyone is doing the co-axial indicator method on a vertical mill, which appears to be the high end setup.

Mercury marine shop manual includes this lapping procedure to condition rod wrist pin bushing.

The hand held spindle will find its own center, if the contract pressure from the abrasive cloth is uniform. This method might be OK if only .001" to .002" material removal is required.

Sanded one end of the split bushing to make a champher. It pressed into the cap without any scraping. Then realized that 50% of the bushing wall was going to have to be removed to make it fit the gear pump shaft. Forget hand held abrasive cloth lapping method as mentioned previously for this much material.

Ths oil pump bushing thing is one of the most difficult procedures of the engine rebuild in my opinion.

Like I said before the automotive machine shop used the specialized machine built for doing rod wrist pin bushings using a stone hone to hone the pump shaft bushing to size. Believe this machine is supposed to follow the center of the bushing. The bushing was honed orthonical to the cap face, however.

Anyway the bushing was not honed concentric and was offset towards the driven gear shaft.
Now the gear teeth will have to lap themselves, since there is noticable sliding friction when aluminum gear is rotated by hand, but does rotate and is not locked up.

Is it possible to get an adjustable reamer that is 1/2" nominal diameter?
 
Is it possible to get an adjustable reamer that is 1/2" nominal diameter?

I bought one from an ebay vendor , think it was about $25 a few years ago .


This site sells a kit -

Oil Pump Tool - A complete tool set with jig, punches and reamer. For Models: 2N, 8N, 9N. (Part No: OPT20) $110.55


I think I would pay my neighbor to chuck it up in his end mill though .
 
(quoted from post at 02:53:18 02/05/13) I live in an area of machine shops with MSC store in the center. Most of the shops are all CNC high production shops for aerospace industry.

In fact I saw on sixty minutes there are lots of machine shop jobs out there, but the younger crowd do not want to do this job. They would rather have a "facebook" type job.

The classic hand crank machine shop is difficult to find.

Really do not know what other folks are doing and have searched the archives with no results on this oil pump bushing issue.

Surely not everyone is doing the co-axial indicator method on a vertical mill, which appears to be the high end setup.

Mercury marine shop manual includes this lapping procedure to condition rod wrist pin bushing.

The hand held spindle will find its own center, if the contract pressure from the abrasive cloth is uniform. This method might be OK if only .001" to .002" material removal is required.

Sanded one end of the split bushing to make a champher. It pressed into the cap without any scraping. Then realized that 50% of the bushing wall was going to have to be removed to make it fit the gear pump shaft. Forget hand held abrasive cloth lapping method as mentioned previously for this much material.

Ths oil pump bushing thing is one of the most difficult procedures of the engine rebuild in my opinion.

Like I said before the automotive machine shop used the specialized machine built for doing rod wrist pin bushings using a stone hone to hone the pump shaft bushing to size. Believe this machine is supposed to follow the center of the bushing. The bushing was honed orthonical to the cap face, however.

Anyway the bushing was not honed concentric and was offset towards the driven gear shaft.
Now the gear teeth will have to lap themselves, since there is noticable sliding friction when aluminum gear is rotated by hand, but does rotate and is not locked up.

Is it possible to get an adjustable reamer that is 1/2" nominal diameter?

Here is a link to a little How-To I put together on the subject a year or so ago. I think it is well worth reading for anyone contemplating doing this job. Oil Pump Rebuild

For those that would rather not read the How-To here's the bottom line. You are replacing the bushing because it has excessive wear on it. In doing that you must take care to maintain the original gear spacing. The location of the pump gear center lines is a critical dimension that was carefully controlled when the bores and pumping chambers were originally machined into the housing at the factory. Installing the bushing off center will alter that spacing - center too far apart or off center and the driven gear will hit the pumping chamber walls - too close together and the gears will bind.

That is Gear Design 101 but a lot of professional automotive "machinists" don't have e a clue they need to worry about it when they are given one of these pumps to rebuild or ream. They simply mash the bushing into the bore and then ream or hone to get the proper shaft fit. And when they are done the gears often rub or bind just Like Keith's. Of course the shop says:

" [i:37727c4e86]Not our fault - we used a $25K high precision rod machine to hone it to within .001 running clearance and .0005 TIR. The problem has to be those cheap imported parts you bought - they don't fit right.[/i:37727c4e86]" :evil:

The problem is not the parts - it's the machine work. I have redone more than one pump that was sent to me by a customer that had a professional shop botch the job using their high dollar rod sizing machine. A rod hone doesn't care about keeping the ID and OD of the small end bushing concentric. In a connecting rod wrist pin bore concentricity doesn't matter and the machine doesn't even attempt to control it. But it matters big time in that oil pump bushing.

You don't need a lot of high dollar machine tools to do the job right. I've never actually tried it but a good quality drill press with a solid work table and vise, a dial indicator, and a 9/16" HSS chucking reamer should work fine. I once had the good fortune to work with an old school master machinist and that is exactly the sort of task he would give to one of his apprentices as a lesson/test in hand setup and finishing ;-)

For people who want to DIY a better alternative is probably a hand reaming toolkit like the one Ken mentioned The kits are made specifically for this job, come with everything you need to do the job, and are easy to use:
  • [*:37727c4e86]Drive the the old bushing out of teh housing using the stepped drift provided in the kit.[*:37727c4e86]Insert the centering pilot into the bore in the backside of the housing and use it to center the jig with the housing bore.[*:37727c4e86]Once the jig is centered clamp it to the housing with the cap screw provided.[*:37727c4e86]Now remove the centering pilot and from the backside of the housing press the new busing into the housing.[*:37727c4e86]Flip the housing over and ream the bushing to size using the hand reamer inserted through the guide hole in the jig[*:37727c4e86]Remove the jig and Voila!! - the bushing is reamed to size AND concnetric to the bore in the housing.[/list:eek::37727c4e86]The jig and reamer kits are sold right her on YT for about $110 - I'll make you one for quite a bit less. Or put your your pump housing in a $5 USPS flat rate box and send it to me and I'll rebush it for the price of a case of Yuengling. Or better yet bring the pump and the beer to me and we can share a Yuengling or two when I'm done with the pump ;-)

    TOH

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    IMG_1829.jpg
 
OK, I'll take U up on it!
Would U make a new bushing, since the original one is honed off set.
Or do U need another pump kit
 
Perfect!
noticed new oil pump bushing can be purchased separately,
P/N 9N 6612-A

I know that you are aware of this, but posted info for the benefit of others readers.
 

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