861-D rebuild and hit a snag advice needed

Beltain

New User
Been overhauling and partially restoring an 861-D. The rear seal went out on her in the early Fall so we decided to completely overhaul the engine and give her some lovin that she has been deserving of.

I have had this tractor a few years now and I bought it from a guy who said he had it for over 15 years.

When we split her apart we discovered a few oddities and decided to replace the crank, cam, pretty much everything honestly.

At some point in this old girls life her balancer gears locked up and broke several teeth off the crank shaft. This is where my problem comes in. We replaced the crank and ordered a new balancer assembly but whomever fixed this tractor before us simply took the balancer gears out and ran her without them.

See the pictures below.

The problem is no matter how hard I look I cannot find the right balancer assembly to put back in. If I replace the housing the assembly I have goes into it requires re-boring the crankshaft. All the replacement assemblies do not have the four holes I need and in fact the entire assembly is about 1/16th of an inch wider than the one that was in her.

Obviously I ran her for years without the balancer gears but I cannot find the proper assembly now and no one feels confident to put new gears in the old one. I thought about drilling holes into the replacement assembly but as I said the sizes don't match.

Any ideas or advice on how to proceed? It would be really welcomed at this point.
 
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seems to have worked this time.
 
I have taken the gears out of a lot of them back when we had the dealership.

I could hear them coming for half a mile when those needle bearings and shaft wore out.

The crank gears wore out too. Cost was prohibetive to replace all that hardware.

Just shook the fuel tank loose like it did in the diesels before the balancers were introduced.

Zane
 
(quoted from post at 18:03:28 01/26/16) I have taken the gears out of a lot of them back when we had the dealership.

I could hear them coming for half a mile when those needle bearings and shaft wore out.

The crank gears wore out too. Cost was prohibetive to replace all that hardware.

Just shook the fuel tank loose like it did in the diesels before the balancers were introduced.

Zane

So are you recommending I just put her back together with the balancer gears out? I never noticed any bad vibration all these years with them out. Or should I keep searching for the right balancer assembly?
 
Without the balancer, torsional vibrations in the crankshaft will work harden the metal causing a broken crankshaft. Ford installed the balancer to rectify this known problem.

Yes, it may be years before the crankshaft breaks.

Dean
 
(quoted from post at 18:54:32 01/26/16) Without the balancer, torsional vibrations in the crankshaft will work harden the metal causing a broken crankshaft. Ford installed the balancer to rectify this known problem.

Yes, it may be years before the crankshaft breaks.

Dean

Ok thanks!!!

So my next question. I found a pair of the balancer gears with the same leading numbers (the B9NN) do those numbers match up like I am thinking they do? If so what else do I need to purchase to fit those gears into the empty assembly I have? I am assuming there is a rod and needle bearings on each end?

Frankly I am in way over my head on this and the normal experts I got o for parts are at a loss too.
 
I personally know of an 861 that broke 3 crankshafts,even though it had the balancer in
it.This tractor was used 365 days a year in all kinds of weather and pulled a silage
chopper,mounted picker, roll bailer and a feed wagon in the winter. The last time I rebuilt
it the owner told me it had 32,000 hours on it.He bought it new. He passed away not long
after that and the tractor was sold.
 
A Google search on B9NN6A308C shows that Fawcett Tractors claims to have 2 of them in stock. You might want to give them a call at 888-406-2606.
 
Were the replacement crankshafts new or used? If used, had they previously been used without a balancer.

Once the metal has been work hardened, installing a balancer will only delay the inevitable.

Dean
 
(quoted from post at 06:58:50 01/27/16) A Google search on B9NN6A308C shows that Fawcett Tractors claims to have 2 of them in stock. You might want to give them a call at 888-406-2606.

I called them and talked to a guy named Dave who went and visually verified the housings he has in stock do not have the four holes in the corners of the assembly. Same casting number though which is at least closer.

Thank you for the lead though. I am wondering at this point if the B9NN housing is the same size at least and I can take another stab at getting the holes machined out.
 

Well the old crank was old old. In fact it had a few teeth missing on the gear that normally rides on the balancer gears. I assume it ate the teeth at some point and they just removed the balancer gears completely. I know I have used this tractor for years never knowing it didn't have the balancer operational.

We bought a brand new crank shaft for it so it shouldnt be hardened at all.
 
Dean,If I remember correctly, the owner told me that the first crank broke while the tractor was still under warranty.I was just a youngster at that time. It was replaced with a new one. Years later it broke and was replaced with a used one and it broke and I replaced it with a used one. Our local dealer at that time told me that they had a couple to break while under warranty and destroy the block. Like I say that was before my time.
 
Well at this point I am kinda at a loss what to do still. The B9NN numbered assembly is about a 1/16th of an inch longer than the other one and I am unable to find an assembly that matches with the four holes in the corner.

I am now checking if I can buy the gears and install them into the old assembly but also going to re-examine the machine shop direction once again.

Seems there are many unknowns no matter which direction I go at this point.
 
The B9NN at the beginning is just some engineering information on the design of the part. The B9 means that it was designed or first used in 1969, and the NN means that it was designed by the tractor division for the tractor division. You would need access to the design engineers documentation to know what the entire number actually means.
 
(quoted from post at 13:08:59 01/27/16) The B9NN at the beginning is just some engineering information on the design of the part. The B9 means that it was designed or first used in 1969, and the NN means that it was designed by the tractor division for the tractor division. You would need access to the design engineers documentation to know what the entire number actually means.

Thanks!!! That's good to know.

Well I found another B9NN assembly without the four holes and the bulge on the one side. It's about 60 miles away so my next move is to go there with some calipers and measure the thing. If it's the same size as the old one I will then go back to the machine shop and get holes drilled I guess.

Seems the best course of action at this point.
 
The B9NN prefix in Ford parts world tells us that the part was designed/initially used in 1959, B is the decade of the 1950's and the 9 is the year. The portion of the part number that is 6xxxx says that it belongs to engine. Here is what is impt: The suffix--letter{s}and or digits are what is the unique identifier of the part. Thus, most all if not all of the bracket/support piece in the pix will have the same 6xxx number. The use of letter in 2nd position was to allow for more numbers in the 6xxx range. So, for exact replacement, you need a part with the whole number. Also, it can be superseded with a part with whole different prefix and suffix, but be the functional equivalent. There was a system to the Ford parts id. 6xxx is engine, 7xxx is trans, 4xxx is rear axle 1xxx is front wheels and axle.
 
(quoted from post at 17:37:49 01/27/16) The B9NN prefix in Ford parts world tells us that the part was designed/initially used in 1959, B is the decade of the 1950's and the 9 is the year. The portion of the part number that is 6xxxx says that it belongs to engine. Here is what is impt: The suffix--letter{s}and or digits are what is the unique identifier of the part. Thus, most all if not all of the bracket/support piece in the pix will have the same 6xxx number. The use of letter in 2nd position was to allow for more numbers in the 6xxx range. So, for exact replacement, you need a part with the whole number. Also, it can be superseded with a part with whole different prefix and suffix, but be the functional equivalent. There was a system to the Ford parts id. 6xxx is engine, 7xxx is trans, 4xxx is rear axle 1xxx is front wheels and axle.

Ok so I need to find the assembly with the exact same number then? Which I have but even with that exact same number it still doesn't have the four corner holes and that bulge on the right side.

Honestly I just don't get it. I must just have some oddball attempt at the balancer design that didn't get used often or something because no one seems to have this part and no parts dealers say they have ever seen one.

The funny part (pun intended) about it is the picture of the housing assembly for the balancer in the parts manual shows it with the four corner holes yet no one seems to have one that have them.
 

Not a clue right now I will have to wait until tomorrow when I go into the shop and look since it's locked up right now. I know I had it written down somewhere but I can't find it.

I really would like to put the balancer gears back in this girl if there is anyway I can do it but I just can't find the proper housing to fit. The bulge on the right side for the CoNN housing sticks out past the block wall and the two big center holes for the oil pump and other large screw don't center up either.

I am beginning to wonder if maybe this isn't an even older engine like from a 100 series someone stuck on her.
 
(quoted from post at 22:10:23 01/27/16)
Not a clue right now I will have to wait until tomorrow when I go into the shop and look since it's locked up right now. I know I had it written down somewhere but I can't find it.

I really would like to put the balancer gears back in this girl if there is anyway I can do it but I just can't find the proper housing to fit. The bulge on the right side for the CoNN housing sticks out past the block wall and the two big center holes for the oil pump and other large screw don't center up either.

I am beginning to wonder if maybe this isn't an even older engine like from a 100 series someone stuck on her.

The hundred series never had a diesel engine available, so it couldn't be an earlier engine. It might be a later industrial engine that was retrofitted into the tractor, but I kind of doubt that as it had that balancer in it with the B9NN number on it. What is the casting number on the side of the block? Also, what is the serial number of the tractor?
 
The hundred series never had a diesel engine available, so it couldn't be an earlier engine. It might be a later industrial engine that was retrofitted into the tractor, but I kind of doubt that as it had that balancer in it with the B9NN number on it. What is the casting number on the side of the block? Also, what is the serial number of the tractor?[/quote]


I will get the casting number from the engine when I run into the shop. The tractors serial number is long gone at least the one behind the starter.Eaten away from corrosion.
 
Well I just spent a few hours going through every balancer assembly my regional old Ford tractor place had on hand. I don't know what the parts manual tell us but according to everything I could find no housing lined up the way I needed it to.

There are three problems. None of them but the one that was in the tractor (the B9NN-6A308-C) have the corner holes and they all have those bulges on the side. The bulges will fit under the oil pan but there is no center hole on the main bearing housing that the assembly should bolt to, only those four corner holes. See the pictures below.

Second problem not a one of the other housing was an exact size match. I found an assembly numbered B9NN-6A308-D that was close but it had sloped sides and therefore could not be drilled out.

Third issue was that the main bolt in the housing were the oil pump goes stands up higher than in our engine. We would need to find a longer pipe section to fit it properly in the block if we went with a drilled out assembly.

The Good news is that the -D assembly had the exact right type of gears in it and they were put in with a hex screw method unlike the C0NN assemblies. They also measured out the same as the -C assembly.

So our plan is to move the balancer gears from the -D housing into the -C housing. If that don't work well looks like I am going to have to put her together without the balancer gears installed.
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Oh and the casting number on the side of the block is 310609 so it must be a 58 or 59 engine I guess.
 
Having mostly always been into GM since my 56 Mercury pickup in 1971, all this talk about breaking Ford crankshafts has me nervous.

Is the shaft breakage common to both the 134 and the 172 cu. in?

Thanks,
T
 
P.S.

I'm thinking that tractor cranks, especially suspect ones might necessitate being rebalanced every time they are turned. (?)

Terry
 
A few years ago I spent upwards of $5000 on a complete rebuild of the engine in my 841-D. About 20-30 hours later the crankshaft broke. In the rebuild pretty much every part except the crankshaft was replaced. It had a new balancer installed for the crank at the time of the rebuild. Tony Jacobs, a highly knowledgeable Ford export who posts on this forum occassionally fore-warned that the rebuild of these diesel engines has to be done to stringent standards. I'm not a mechanic, but I recall him stressing that rod bolts of particular high standards are necessary, among other things, that must be adhered to otherwise the crankshaft will invariably eventually break. It happened to me even though I stressed to the shop to follow his advice.
Maybe he will post on your topic. Here is link to my post when I broke my crankshaft and Tony's (and others) comments. Maybe there is some info of use to you in your project.

http://www.yesterdaystractors.com/cgi-bin/viewit.cgi?bd=ford&th=530570

I don't know how to post active links, so you'd have to copy/paste the address, unless someone else can do it.

Also, try Long Lane Tractor in Elizabethtown, PA for a balancer (717-367-8610). They may have one that fits your tractor.
 
Thanks Blair!
Useful info!

When I rebuilt my first engine in '75 and had my first shaft ground (a 235 cu in GM with brass shimmed mains for achieving the correct clearance for the new shells) I found it interesting that the crank balancer was called a Harmonic Balancer.

When I'm striking a drum to tune it, I listen as much to the sympathetic resonant frequency set off in a cymbal across the room, as to the drum I'm striking. Harmonic vibration. :)

T
 
Well switching the balancer gears into the -C housing actually worked. The only trouble was one gear hit a bolt head on the center main bearing housing (whatever that part the balancer housing is bolted to) so we had to grind her down some.

Using a brand new crankshaft so I can only hope it all stays together and runs well. Waiting on some new valves to come in now as a couple were a bit thinner than we first thought.

I did read where some of the engines with the same block number I have never had balancer gears put in them but the old crank we took out had those teeth missing were the balancer gears should have been so I think this one originally did have them.
 

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