AMC V-8 Oil Pump/Front Cover Rebuild Thread.
What I'm starting with is an AMC V-8 Oil Pump, Front Timing Cover, Filter Head from a '86-Older AMC V-8 engine.
THIS TUTORIAL IS FOR GUYS WITH MORE TIME/AMBITION THAN SPARE DOLLARS...
----------------------------
This is what you might get for front covers,
LEFT is what you might get from E-bay, and is virtually useless.
CENTER is a Fresh Take Off and only has one water pump bolt twisted off on the front.
RIGHT is a scraped one I use for demonstration purposes when I teach this in a class... It's cracked so students dropping it is no big deal.
-----------------------------
This one is virtually useless.
Recently, a customer of mine though that $100 for a completey rebuild and ready USED front cover from me was too much.
This is what he got from E-bay for $75 plus shipping!
All kinds of broken bolts in the front cover around water pump,
Oil pump body was corroded and grooved, unuseable.
The oil pump 'Driven' gear pin ("Idler Gear") pin was missing entirely.
The filter head was missing entirely...
This is what happens when you think you know more than the guy who races AMCs for 25 years.... Scrap Aluminum, and since it's not 'Clean' aluminum, you won't even get 'Breakage' price at the scrap yard...
-----------------------------
This is a fresh take off from a 1975 orignal engine.
One water pump bolt broke off in the cover and greasy, but remember, nothing protects the aluminum/steel/iron parts better than the engine crud!
DO NOT take an engine, transmssion, axle apart until you are ready to work on it!
Leave that crud on there!
Where oil residue, old oil, ect. is, you won't have rust...
Notice some Dilbert used silicone 'Form-A-Gasket' on the water pump instead of correct water pump gasket...
Explains the leaking drool down the front cover from the water pump!
Too bad it didn't steam clean the cover for me
See where the water pump didn't have clearance and was grinding on the timing cover?
The correct gasket would have stopped that...
This is another cover that some Dilbert didn't use the proper gasket, and the water pump was dragging on the aluminum...
If you want leaks, water pump impeller dragging on aluminum, then by all means, go ahead and leave the gasket out and use 'Form-A-Gasket'...
If you want things clearanced correctly, and you DO NOT want leaks,
Then use a Fel-Pro gasket set when you rebuild, and leave the 'Rubber Goop In A Tube' alone!
--------------------------------
All of the filter head/oil pump floor plate bolts came out.
Factory Grade 5 bolts and they look pretty good.
If you twist one of these off, do your BEST to get the broken bolt out and restore the facotry threads!
This is a VERY bad place for drilling oversize and using Heli-Coils for repairs!
Notice the DRIVEN oil pump gear on the LEFT,
The DRIVING oil pump 'Gear' on the RIGHT...
---------------------------------
This is a pretty good looking floorplate/filter head, this one can be saved easily if it doens't have any other problems I'm not seeing just yet.
The grooves from the 'Gears' haven't dug in to the point I can catch my fingernail on them,
So this one won't need a 'Mid-Plate' to fix it, just sanding/lapping the floor plate should be sufficient.
*IF* you have a badly grooved filter head floor plate, then you will need to order a 'Rescue' part called a 'Mid Plate'.
It's a steel shim that goes between the filter head and pump body and restores a flat floor to the pump cavity. Runs about $25.
-------------------------------------
Oil pump Impellers, commonly called 'Gears'...
The DRIVEN is on the left,
The DRIVING is on the right, and now you can see the shaft that goes up to the distributor gear bottom to turn the pump...
A pump too tight will kill your distirbutor gear, stretch the timing chain and cause other problems.
Make sure your pump turns FREELY later on during the pump clearanceing trial fit so you don't wind up with problems else where...
If you decide to run one of those 100 PSI pump ideas,
Remember, the filter is only rated to about 80 PSI,
And somewhere around 80 PSI, you will wear out the distributor/cam gears and stretch the crap out of the timing chain.
Those 100 PSI modifications are for RACING VEHICLES ONLY that have steel gear drive cams and hardened steel cam/distributor gear sets.
Not practical or nessary for a street or trail driven Jeep, and HATELFULLY expensive, along with being very hard on everything in the engine...
---------------------------------------
Now, you come to the part that is ALWAYS fun...
Getting the plunger out of the bypass valve bore.
*IF* You have a running engine, you disconnect the ignition,
Take the plug, seal washer and spring out of the bypass bore,
And crank the engine with the starter.
The oil pressure will build up, push the plunger out of the bore,
When the oil flows... STOP!
With this filter head, like most 'Take Offs', the plunger is stuck in the bore. (RATS!)
About the only way to get this plunger out of the bore with the 186,000 miles of oil sludge built up in the bore is to blow it out with air pressure.
That means blocking several different inlet & output ports at the same time, you will probably need a buddy's fingers for this one!
Don't worry about the plunger, if it gets away it's OK, a new one comes in quality oil pump kits.
This image shows the new oil pump kit, along with some of the old components in the upper right hand corner...
They are setting on the plate glass I acquired this morning for $1 at the local glass shop.
Once the filter head is disassembled and cleaned out (and I mean CLEAN!), then you are ready to do something with it...
---------------------------------------------------
The first thing I usually do is start with making the pump floor surface flat & true again.
This involves a process called 'Lapping'.
What I use is a piece of plate glass laid on something flat.
Plate Glass is floated on liquid tin, so it's 'Gravity Leveled' or as close to flat as the layman can come without buying a lapping block.
(Lapping Block = A piece of hard stone, usually Granite, ground PERFECTLY flat)
These pieces of stone aren't cheap at all!
Well out of the range of 'Common Tools' the home builder would own.
So for a guy doing two or three of these in a lifetime, going to the local glass shop and getting a 'Break Out' piece of plate glass is the best idea.
(Break Out = A plate glass window that has been broken, but glass shop can cut some reasonable size pieces from the Broken Out window.)
If you can't find real plate glass, then start looking for HEAVY mirrors in the thrift store.
You can usually find a cheap mirror large enough to do this project for cheap.
Vehicle window glass is TEMPERED Glass, and you are looking for PLATE glass,
Tempered glass is usually pretty thin and will flex,
Plate glass is usually thick, and it doesn't flex like tempered glass will...
If you use a flat vehicle window, then be VERY careful when using it, it will shatter into small pieces if you bump it very hard!
If you are going to do this fairly often,
Another option is a monument company that sells stone monuments like tombstones and marker stones.
They often get smaller pieces that can be purchased reasonably, look for one that isn't too thick, and is polished flat.
The surface of a flat stone monument is usually flat/true enough to get the desired results for this part of the rebuild.
---------------------------------------------------------------
You will also need some lapping compound.
This can be anything from a fine EMERY CLOTH, SECURELY to the flat surface,
But make sure it's a CLOTH BACKED Emery Cloth, the paper backed kind usually gets holes in and causes gouges.
DO NOT USE SAND PAPER!
Most sand paper is sharp pieces of aluminum oxide, and that cutting compound will in-bed in the work piece and ruin your new pump gears!
Lapping compound, or good quality emery cloth, the grit (Cutting Particles) are ROUNDED edges, and won't in-bed in the work piece and can be cleaned off when you are done so they don't grind away at the oil pump!
I use a true lapping compound, which is a specific size cutting 'Grit' held in suspension by some sort of grease.
This is the same stuff you buy for lapping valve seats, polishing paint or metal, so there are several sources for it.
I have the best luck with 'Garnet' based grit compounds, Aluminum Oxide doesn't seem to do as good a job or last as long.
---------------------------------------------------------
MAKE SURE YOU PUT YOUR OIL PUMP AWAY BEFORE OPENING THE GRIT COMPOUNDS!
Nothing like grit hiding in the pump on on the 'Gears' to ruin you new pump right away!
----------------------------------------------------------
Once you have the flat plate ready, and the proper lapping compound, then you are ready for the 'Boring' part.
I have more time than money, so I sit in front of the boob tube and lap my oil pump parts!
This Image shows the different GRIT SIZE of lapping compound I use for this stuff,
The plate glass I acquired for $1 at the local glass shop this morning,
And the filter head.
What you are looking for is a flat, true surface,
Straight lines, swirls, round and round, side to side it's all good...
Just remember to keep the work piece FLAT on the lapping table at all times!
You don't want bevels, angles, ect.
STOP when you have a smooth, flat surface! Don't remove any more material than you have to...
You can start out with a larger grit compound and finish with a smaller grit compound if you have fairly deep gouges in your surfaces,
But with this filter head, I'm starting with 280 Grit and seeing how it works for me...
If you have heavy scratches, start with a 180 and work toward smaller grit from there.
Lapping the oil pump floor plate in progress.
This part isn't so bad, but lapping the cover surfaces is REALLY AWKWARD!
------------------------------------------------
You will want to check progress every 10 minutes or so,
Wipe off a small portion of the lapping compound where the impellers ('Gears') gouged into the floor plate and have a look...
After 15 minutes of lapping in a 'Swirl' pattern, I still have 'Issues',
So the lapping continues while I catch up on 'Pawn Stars' & 'Headline News'...
Saving hands full of fast food napkins works GREAT for disposable small shop towels, so always keep those extra napkins for checking oil, little jobs like wiping away the grit from this project and a thousand other little jobs!
I usually want to work on a SOLID surface, if your work table rocks or moves around, you are wasting MUCH more energy than you should for this.
The GREASE in the compound will squeeze out and collect in the holes of the work piece, on the sides of the work piece, ect. making it VERY hard to move the workpiece at times,
Feel free to use a 'Q-Tip' to recapture that grease and put it back under the work piece,
Or to add a little bit more compound/grease when the piece starts 'Sticking',
Wants to tip sideways instead of stay flat on the glass....
A little lubricant returned to the lapping surface makes things SO much easier on you!
More comming as I get this thing cleaned up and start working on it...
What I'm starting with is an AMC V-8 Oil Pump, Front Timing Cover, Filter Head from a '86-Older AMC V-8 engine.
THIS TUTORIAL IS FOR GUYS WITH MORE TIME/AMBITION THAN SPARE DOLLARS...
----------------------------
This is what you might get for front covers,
LEFT is what you might get from E-bay, and is virtually useless.
CENTER is a Fresh Take Off and only has one water pump bolt twisted off on the front.
RIGHT is a scraped one I use for demonstration purposes when I teach this in a class... It's cracked so students dropping it is no big deal.
-----------------------------
This one is virtually useless.
Recently, a customer of mine though that $100 for a completey rebuild and ready USED front cover from me was too much.
This is what he got from E-bay for $75 plus shipping!
All kinds of broken bolts in the front cover around water pump,
Oil pump body was corroded and grooved, unuseable.
The oil pump 'Driven' gear pin ("Idler Gear") pin was missing entirely.
The filter head was missing entirely...
This is what happens when you think you know more than the guy who races AMCs for 25 years.... Scrap Aluminum, and since it's not 'Clean' aluminum, you won't even get 'Breakage' price at the scrap yard...
-----------------------------
This is a fresh take off from a 1975 orignal engine.
One water pump bolt broke off in the cover and greasy, but remember, nothing protects the aluminum/steel/iron parts better than the engine crud!
DO NOT take an engine, transmssion, axle apart until you are ready to work on it!
Leave that crud on there!
Where oil residue, old oil, ect. is, you won't have rust...
Notice some Dilbert used silicone 'Form-A-Gasket' on the water pump instead of correct water pump gasket...
Explains the leaking drool down the front cover from the water pump!
Too bad it didn't steam clean the cover for me
See where the water pump didn't have clearance and was grinding on the timing cover?
The correct gasket would have stopped that...
This is another cover that some Dilbert didn't use the proper gasket, and the water pump was dragging on the aluminum...
If you want leaks, water pump impeller dragging on aluminum, then by all means, go ahead and leave the gasket out and use 'Form-A-Gasket'...
If you want things clearanced correctly, and you DO NOT want leaks,
Then use a Fel-Pro gasket set when you rebuild, and leave the 'Rubber Goop In A Tube' alone!
--------------------------------
All of the filter head/oil pump floor plate bolts came out.
Factory Grade 5 bolts and they look pretty good.
If you twist one of these off, do your BEST to get the broken bolt out and restore the facotry threads!
This is a VERY bad place for drilling oversize and using Heli-Coils for repairs!
Notice the DRIVEN oil pump gear on the LEFT,
The DRIVING oil pump 'Gear' on the RIGHT...
---------------------------------
This is a pretty good looking floorplate/filter head, this one can be saved easily if it doens't have any other problems I'm not seeing just yet.
The grooves from the 'Gears' haven't dug in to the point I can catch my fingernail on them,
So this one won't need a 'Mid-Plate' to fix it, just sanding/lapping the floor plate should be sufficient.
*IF* you have a badly grooved filter head floor plate, then you will need to order a 'Rescue' part called a 'Mid Plate'.
It's a steel shim that goes between the filter head and pump body and restores a flat floor to the pump cavity. Runs about $25.
-------------------------------------
Oil pump Impellers, commonly called 'Gears'...
The DRIVEN is on the left,
The DRIVING is on the right, and now you can see the shaft that goes up to the distributor gear bottom to turn the pump...
A pump too tight will kill your distirbutor gear, stretch the timing chain and cause other problems.
Make sure your pump turns FREELY later on during the pump clearanceing trial fit so you don't wind up with problems else where...
If you decide to run one of those 100 PSI pump ideas,
Remember, the filter is only rated to about 80 PSI,
And somewhere around 80 PSI, you will wear out the distributor/cam gears and stretch the crap out of the timing chain.
Those 100 PSI modifications are for RACING VEHICLES ONLY that have steel gear drive cams and hardened steel cam/distributor gear sets.
Not practical or nessary for a street or trail driven Jeep, and HATELFULLY expensive, along with being very hard on everything in the engine...
---------------------------------------
Now, you come to the part that is ALWAYS fun...
Getting the plunger out of the bypass valve bore.
*IF* You have a running engine, you disconnect the ignition,
Take the plug, seal washer and spring out of the bypass bore,
And crank the engine with the starter.
The oil pressure will build up, push the plunger out of the bore,
When the oil flows... STOP!
With this filter head, like most 'Take Offs', the plunger is stuck in the bore. (RATS!)
About the only way to get this plunger out of the bore with the 186,000 miles of oil sludge built up in the bore is to blow it out with air pressure.
That means blocking several different inlet & output ports at the same time, you will probably need a buddy's fingers for this one!
Don't worry about the plunger, if it gets away it's OK, a new one comes in quality oil pump kits.
This image shows the new oil pump kit, along with some of the old components in the upper right hand corner...
They are setting on the plate glass I acquired this morning for $1 at the local glass shop.
Once the filter head is disassembled and cleaned out (and I mean CLEAN!), then you are ready to do something with it...
---------------------------------------------------
The first thing I usually do is start with making the pump floor surface flat & true again.
This involves a process called 'Lapping'.
What I use is a piece of plate glass laid on something flat.
Plate Glass is floated on liquid tin, so it's 'Gravity Leveled' or as close to flat as the layman can come without buying a lapping block.
(Lapping Block = A piece of hard stone, usually Granite, ground PERFECTLY flat)
These pieces of stone aren't cheap at all!
Well out of the range of 'Common Tools' the home builder would own.
So for a guy doing two or three of these in a lifetime, going to the local glass shop and getting a 'Break Out' piece of plate glass is the best idea.
(Break Out = A plate glass window that has been broken, but glass shop can cut some reasonable size pieces from the Broken Out window.)
If you can't find real plate glass, then start looking for HEAVY mirrors in the thrift store.
You can usually find a cheap mirror large enough to do this project for cheap.
Vehicle window glass is TEMPERED Glass, and you are looking for PLATE glass,
Tempered glass is usually pretty thin and will flex,
Plate glass is usually thick, and it doesn't flex like tempered glass will...
If you use a flat vehicle window, then be VERY careful when using it, it will shatter into small pieces if you bump it very hard!
If you are going to do this fairly often,
Another option is a monument company that sells stone monuments like tombstones and marker stones.
They often get smaller pieces that can be purchased reasonably, look for one that isn't too thick, and is polished flat.
The surface of a flat stone monument is usually flat/true enough to get the desired results for this part of the rebuild.
---------------------------------------------------------------
You will also need some lapping compound.
This can be anything from a fine EMERY CLOTH, SECURELY to the flat surface,
But make sure it's a CLOTH BACKED Emery Cloth, the paper backed kind usually gets holes in and causes gouges.
DO NOT USE SAND PAPER!
Most sand paper is sharp pieces of aluminum oxide, and that cutting compound will in-bed in the work piece and ruin your new pump gears!
Lapping compound, or good quality emery cloth, the grit (Cutting Particles) are ROUNDED edges, and won't in-bed in the work piece and can be cleaned off when you are done so they don't grind away at the oil pump!
I use a true lapping compound, which is a specific size cutting 'Grit' held in suspension by some sort of grease.
This is the same stuff you buy for lapping valve seats, polishing paint or metal, so there are several sources for it.
I have the best luck with 'Garnet' based grit compounds, Aluminum Oxide doesn't seem to do as good a job or last as long.
---------------------------------------------------------
MAKE SURE YOU PUT YOUR OIL PUMP AWAY BEFORE OPENING THE GRIT COMPOUNDS!
Nothing like grit hiding in the pump on on the 'Gears' to ruin you new pump right away!
----------------------------------------------------------
Once you have the flat plate ready, and the proper lapping compound, then you are ready for the 'Boring' part.
I have more time than money, so I sit in front of the boob tube and lap my oil pump parts!
This Image shows the different GRIT SIZE of lapping compound I use for this stuff,
The plate glass I acquired for $1 at the local glass shop this morning,
And the filter head.
What you are looking for is a flat, true surface,
Straight lines, swirls, round and round, side to side it's all good...
Just remember to keep the work piece FLAT on the lapping table at all times!
You don't want bevels, angles, ect.
STOP when you have a smooth, flat surface! Don't remove any more material than you have to...
You can start out with a larger grit compound and finish with a smaller grit compound if you have fairly deep gouges in your surfaces,
But with this filter head, I'm starting with 280 Grit and seeing how it works for me...
If you have heavy scratches, start with a 180 and work toward smaller grit from there.
Lapping the oil pump floor plate in progress.
This part isn't so bad, but lapping the cover surfaces is REALLY AWKWARD!
------------------------------------------------
You will want to check progress every 10 minutes or so,
Wipe off a small portion of the lapping compound where the impellers ('Gears') gouged into the floor plate and have a look...
After 15 minutes of lapping in a 'Swirl' pattern, I still have 'Issues',
So the lapping continues while I catch up on 'Pawn Stars' & 'Headline News'...
Saving hands full of fast food napkins works GREAT for disposable small shop towels, so always keep those extra napkins for checking oil, little jobs like wiping away the grit from this project and a thousand other little jobs!
I usually want to work on a SOLID surface, if your work table rocks or moves around, you are wasting MUCH more energy than you should for this.
The GREASE in the compound will squeeze out and collect in the holes of the work piece, on the sides of the work piece, ect. making it VERY hard to move the workpiece at times,
Feel free to use a 'Q-Tip' to recapture that grease and put it back under the work piece,
Or to add a little bit more compound/grease when the piece starts 'Sticking',
Wants to tip sideways instead of stay flat on the glass....
A little lubricant returned to the lapping surface makes things SO much easier on you!
More comming as I get this thing cleaned up and start working on it...