Splitting the Tractor and More Surprises | Farmall 856 Restoration Episode 4

Summary

In this home tractor restoration video, the narrator splits his Farmall 856 to inspect seals and determine if they are leaking. He discovers the engine rear main seal and transmission seals need replacing. While disassembling components, he finds damage to the clutch torque amplifier shaft, likely from a prior pilot bearing failure. He debates whether to fully split the transmission to replace the costly torque amplifier, seeking viewer input. Though not urgent, he leans toward doing a complete overhaul for long-term reliability rather than a quick fix.

Takeaways

• 😀 Pete is restoring an IH 856 tractor and splitting it to inspect seals
• 😊 Pieces fell out of the final drive case previously - likely from a broken detent spring
• 👷‍♂️ Pete is disconnecting parts like the pilot valve to prep for splitting the tractor
• 🔧 He uses splitting stands to separate the tractor and inspect the seals
• 🚜 The engine rear main seal and transmission seals are leaking and need replacing
• ⚙️ The clutch can be replaced while split - Pete will also have the flywheel machined
• 🔎 The clutch shafts show wear - the inner one is damaged and may need a new torque amplifier
• 💭 Replacing the torque amplifier would allow fixing it right but is a lot of extra work
• 😕 The clutch isn't worn out but since the tractor is split already it makes sense to replace it
• 🤔 Pete is unsure whether to replace just the clutch or go further and do the torque amplifier

Q & A

What fell out of the final drive case when the oil was drained?

Some broken pieces fell out, including a spring and a roller that rolls around on the detent plate. It was determined they likely came from the broken spring in the range transmission cover.

What is the pilot valve for?

The pilot valve is part of the power steering hydraulic system. It provides hydraulic fluid to the power steering system when the steering wheel is turned.

How does the pilot valve work?

It has a spool valve inside that is nudged off-center when the steering wheel is turned, allowing pressurized fluid from the MCV to flow to the power steering cylinder to provide power steering.

What needs to be done to split the tractor?

Steps include disconnecting the power steering lines, removing some bolts from the clutch housing, putting the tractor on stands, and inserting dowel pins to keep the shaft plates aligned.

What was found when inspecting the split tractor?

The rear main seal and possibly the gasket were found to be leaking. The engine main seal also showed signs of leaking.

What shaft was found to be worn?

The live shaft splines that turn all the time were worn about a third of the way through.

What damage was found on the clutched shaft?

The end of the clutched shaft was damaged in the past when a pilot bearing went bad. It had been dimpled with a punch to try to fix it.

What does the video creator debate doing?

He debates whether to split the midsection further to replace the torque amplifier due to the damaged clutched shaft.

What would replacing the torque amplifier involve?

It would require splitting the midsection off, pulling out the transmission guts, removing the MCV, and installing a new torque amplifier.

Why might it be advisable to replace the torque amplifier?

Since the tractor is already disassembled, it may be worth the effort to replace it and ensure smooth shifting long-term.

Outlines

00:00

😀 Introducing the tractor restoration project

The narrator Pete introduces himself and the tractor restoration project. He explains that this is episode 4 where he will split the tractor to inspect the engine seals, clutch and transmission seals for leaks. He also solved the mystery of some metal pieces that fell out when he drained the oil.

05:00

🔧 How the hydraulic power steering works

Pete explains how the hydraulic power steering system works on the tractor. He describes the key components like the pilot valve, hand pump, multiple control valve and steering cylinder. He also explains how turning the steering wheel slightly provides hydraulic pressure to nudge the spool valve to activate power steering.

10:06

⛏ Splitting the tractor

Pete uses a screw jack to support the rear half of the tractor. He inserts studs in the bottom holes to prevent misalignment when splitting the tractor halves. He removes the top bolts last after loosening all others. The tractor splits open revealing leaks at the rear main seal and clutch housing.

15:09

🚜 Inspecting the parts

With the tractor split, Pete inspects the condition of parts like the clutch, pressure plate, flywheel, pilot bearing, throwout bearing and seals. He finds wear and leakage in many places. He decides to replace the clutch, pressure plate, flywheel bearing, throwout bearing and seals.

20:11

🤔 Debating whether to replace the torque amplifier

Pete finds damage on the clutch input shaft from a past pilot bearing failure. It was temporarily fixed by dimpling the shaft. He debates whether to undertake the major effort of splitting the transmission and replacing the torque amplifier to properly fix the issue.

25:12

😊 Conclusion and asking for feedback

Pete concludes by leaning towards replacing the torque amplifier for a long-lasting repair. He asks viewers for feedback on whether he should undertake the additional work of splitting the transmission case.

Keywords

💡restoration

The overarching theme of the video is restoring a vintage tractor to good working order. The narrator goes through step-by-step repairs and evaluations to bring components like the engine, transmission, seals, bearings, and shafts up to quality standards.

💡splitting

Splitting refers to separating the tractor into front and rear halves along the clutch housing to access internal parts for inspection, cleaning and replacement. This process enables the narrator to check seals, bearings, shafts, etc.

💡clutch

The narrator evaluates the current condition of clutch components like the pressure plate, driven disc, release/throwout bearing, and flywheel. Though still functional, he decides to replace the clutch since the tractor is already split.

💡shafts

There are two key shafts: 1) live shaft - always spinning to power PTO and hydraulics even when clutch is disengaged; 2) clutch shaft - stops spinning when clutch is disengaged. The clutch shaft is worn and damaged, needing repair.

💡torque amplifier

A key transmission component that boosts torque to the drive wheels. The damaged clutch shaft is part of the torque amplifier, so the narrator debates whether to undertake the major task of replacing the entire torque amplifier.

💡pilot bearing

A ball bearing within the flywheel that supports one end of the clutch shaft. Damage to this bearing previously chewed up the clutch shaft, leading to the dimpled temporary repair.

💡seals

Multiple seals show leaks from use and age, including the engine rear main seal, transmission input shaft seal, etc. Replacing these stops oil leaks.

💡judgment calls

The narrator highlights the difficult decisions facing vintage tractor restorers on how far to go in repairs. While debating whether to replace the torque amplifier, he calls it a "judgment call" based on circumstances.

💡MCV

The Multiple Control Valve controls distribution of hydraulic pressure to components like brakes, steering, transmission cooling. Since he's deep into repairs, the narrator decides to inspect the MCV.

💡conventional wisdom

The accepted general guidance is that when you split an older tractor for one repair, you might as well replace wear items like the clutch at the same time since access is already open.

Highlights

Theorizes that the spring broke, allowed a roller to drop down, get chewed up by the gears, and the pieces migrated to the low point

Plans to split the tractor to inspect seals and determine if they are leaking

Explains how the hydraulic power steering system works, including the pilot valve

Notes need to replace worn spline shaft in transmission and debates replacing torque amplifier

Questions if it's best practice to repair slightly damaged clutch shaft or replace torque amplifier

Decides to replace clutch since the tractor is already split

Notes torque amplifier has some lag at high temperatures, so may need replacement

Debates if it's worthwhile to do more extensive repairs while split

Suggests convention to always replace clutch when splitting tractor

Unsure of age and condition of current torque amplifier

Wants feedback from viewers on decision to replace torque amplifier

Tractor not urgently needed, so has time for more repairs

Goal is to do a quality restoration job on this tractor

Replacing torque amplifier means full transmission inspection and rebuild

Extensive repairs now saves future work over life of tractor

Transcripts

hi I'm Pete and welcome to just a few

Acres Farm episode 4 of the farm all 856

Restoration in this episode I'm going to

split the tractor and we'll take a look

at the engine rear main seal the clutch

and the transmission front seal to see

what kind of shape they're in see if we

can see evidence of leaking but before I

get to that I have a mystery I think

that is solved remember these pieces

fell out of the final drive case when I

drained the oil and we figured out what

this BT is so remove that one and I

think I know where they came from this

is the underside of the range

transmission cover and there's a spring

that goes between these two arms here to

put pressure on the detent plates here's

the spring that goes there and here's

that spring against the broken piece

pretty exact match same cover this is

the roller that rolls around on the deta

plate and the width of these pieces

match the roller that cover sits right

here and I think what happened is the

spring broke and fell down inside and

then once the spring broke it allowed

one of the rollers to drop down because

the roller trapped by that silver

bracket I was showing you once it got

out of position the roller dropped down

the side hit the gears and was chewed up

theorizing that I looked at all these

gears very carefully at least the ones I

could turn I can't turn some of them

like that one but I didn't see any

damage

my hypothesis is that the gear teeth are

much harder than that roller material so

it got chewed in the teeth but it didn't

hurt the teeth coming around to the back

of the tractor and looking inside way up

in the forward end there behind that

hydraulic pump the silver thing there's

a passage that connects the range

transmission on the bottom to this rear

end so the pieces migrated back and came

to rest at the low Point down here after

that breakage happened Somebody went in

and replaced the broken

pieces but they didn't take the pieces

out of the back either they didn't drain

the oil when they did the work or they

were still stuck up in the bottom of the

case here where you can't see them

something like that I want to thank a

number of commenters that called that

that said they thought that was what it

was as I thought about it more and

looked through the parts book again and

again for spring that match set there

were no others besides that detent

spring so I'm pretty sure I'm 99% sure

that was what happened it's time to

prepare to

prepare to split the tractor I have to

disconnect the power steering lines that

go up front this here is the pilot valve

for the power

steering this is a funky little Gizmo

I'll tell you what it does in a

minute this is the front of these two

power steering lines that come up from

the pilot valve and they have banjo

fittings on them

you're kind of a pain a little bit guess

I should have got the socket wrench

[Music]

out those lines run inside this Channel

or alongside of it and sometimes there's

a clip to stabilize them but I don't see

one in

[Music]

here and actually I'm going to have to

put removal of these lines on hold till

the front end of the tractor comes off

cuz they're caught in the Cradle here by

the bends and the line so it's good

enough to just have them disconnected

and

back

I'm taking this pilot valve off so I can

clean it well and paint it I do that

with some things that don't require

fixing but have to come off to make a

job that I'm happy

with some moisture got under

there

this pilot valve is part of the steering

hydraulic system I could probably do a

whole video on the hydraulic systems in

this tractor because there's a lot to

them but this is the multiple control

valve down here and it provides

hydraulic fluid to the brakes the power

steering the transmission cooler and the

torque amplifier inside this housing

here it's a it's kind of like an

automatic transmission valve body that

sends oil to various places it sends oil

up through these two ports in the top to

the steering pilot valve which supplies

the whole power steering

system with pressurized fluid and it's

got four ports in it's got well it's got

six it's got two in the bottom that

supply and return for the oil from the

MCV and then it's got the two ports that

go up to the hand pump which is right

underneath the steering wheel and then

it's got two ports that run forward to

the power steering cylinder that's part

of the front bolster on the tractor and

the way this works is if you're sitting

in the driver's seat and you turn the

wheel a little bit there's a spool valve

in here remember spool valve from the

brake valve remote hydraulic valves have

spools in them well that spool valve has

a pretty light spring on the end of it

that holds it centered and when you push

the when you pull the steering wheel one

way or the other you provide just enough

hydraulic pressure running through these

lines from the hand pump to nudge that

spool valve one way or the other

depending on the direction you pull the

wheel and once that spool valve gets

nudged off center then the pressurized

fluid coming from the MCV can flow up

and through and out to the front of the

tractor to provide power steering so the

hand pump is like a hand hydraulic pump

it's moving fluid through the part of

the circuit from the steering wheel to

the pilot Val here and then in essence

it gets boosted out to the front of the

tractor to turn the

wheels an important part of the system

is when you have power steering you need

to maintain feel you know the feel of

the steering wheel is important it just

can't be the power comes on all the way

and so this is balanced so that you get

the feedback through the steering wheel

so you understand how the tractor's

turning and and how difficult of a train

you're going through and there's a lot

to it so this thing is a necessity as

are all things on this tractor I

recruited my lovely wife

Hillary to help me roll the tractor back

we need the room to split

it that's plenty of room you're not

going to hit me in the head of the

shovel again are you

is that what you told everybody I didn't

do

that thanks for your

help

these are the splitting stands my dad

originally made way back in the MD

project and they fit everything you just

have to redrill the holes and the plates

here the width is adjustable with a top

length to hook them together they're

real easy to adjust exact position of

the tractor CU you can jack both Jacks

one or the other they work

great I blocked the rear wheels both

sides both wheels and I'm using my good

old 10 ton screw Jack here to support

the rear half also as easy Insurance you

can lock the tractor in two gears at at

once and that way it won't roll at

all I made a couple of studs by cutting

off the head of a long bolt and I'm

going to put those in these bottom

holes with the idea that as you draw the

tractor apart this wants to Spring it'll

spring down because the weight of the

engine

uh makes it different than this and

these holes become

misaligned I haven't tried this before

but we'll see how it works other

side

put some weight on the

Jacks there's two bolts of the top of

clutch housing

here

more of those 12p Point

bolts we'll get on

[Music]

there other side I'm leaving the top

bold in both sides to take out

last

now the top

bolts and I'll just loosen them up on

both sides and don't take them all the

way out you can see it's starting to

come apart

here

[Music]

break the other one

loose yeah it's opening up there

too I think I'll Jack it up a little bit

and try and get that Gap

even make sure everything's

straight

bring the rear end up

too here we go I think we're ready to

pull it

apart

right now the rail and the plate are

joined by this dowel pin and this bolt

up here if I put a nut on this

bolt then I've got the two of them tied

together and I can slide it off the D

pens okay we should be good to go now

what are we seeing here well in the rear

half of the tractor we definitely have a

leaking seal here and maybe that gaskets

leaking too that's all fresh oil leaking

down from the bottom

there yep I'm sure it needs to be

replaced the engine main seal is a

little bit more difficult to see I don't

know if you can see it but down in there

is a lot of crusty stuff and some of

it's shiny like it's fresh so it's

definitely leaking

too

[Music]

this is fluid out of my parts

[Music]

washer this yellow color you see under

here is the primer on these tractors

they use the yellow primer underneath

the red paint

these days I use brake and carb cleaner

sparingly stuff's getting really

expensive this can go back in the parts

washer what drained

out now for the rear main seal it's got

this retaining ring on

it

this remain seal in my opinion this is a

heck of a lot nicer than the complicated

things they had on the older IH

tractors it's a rubber lip

seal just a big old rubber lip seal and

to make things even better they put a

wear ring on the end of the crankshaft

so this ring is applied to the

crankshaft you chisel that off take that

off and a new wear ring comes with the

new seal now on the rear half of the

tractor I got to get this clutch release

bearing out and to do that I have to

disconnect the yolk it rides

on on the other side of that cross shaft

is the transmission brake linkage down

here which of course is coordinate did

with the

clutch will you come out that way

yep whoops there's a snap ring

here holding this on

now this should come

out these woodf Keys need to come off

the Yol to get the shaft

out yeah I thought maybe it would be

easy since you're so

greasy

[Music]

there's a plate on the bottom of this

housing that's removable so that you can

reach up from the bottom and grease the

throwout bearing it's got a grease Circ

out the bottom of it I need to take it

off so I can wash out this cake

[Music]

nice there's no two ways around it this

one's going to make a mess there's a lot

of gunk in

here cake

on

crud

H I think 75% of tractor restoration is

this kind of

work taking off

[Music]

crud there we go that's a whole lot

better than it was taking a closer look

at this shaft the inside

shaft it's been worn in here where a

pilot bearing went bad in the past and

somebody dimpled it on the low Parts

with a punch to help the pilot bearing

seat in there we're going have to take a

look at that next I'm going to get the

seal out of

here somebody's been in here too we've

got two IH bolts on the seal retainer

and one regular

Bolt

here's a shaft I pulled out there is an

o-ring on the outside

here which was leaking you can tell and

then there's a lip seal on the inside

here both need to be

replaced I'm going to pull this lower

shaft and plate too because there's

shims under it and then a seal rather

than just a simple gasket so that seal

may be

leaking

yeah well come out of there there's a

shim right there so you can't make the

seal with a gasket instead there's an

O-ring around here that's the bearing in

there

time for parts evaluation and sometimes

that's not a cut and dry process in fact

I had to sleep on this one let's do this

in the order I disassembled things

here's the

clutch it's got quite a bit of life left

in it but I figure while I'm in

here I might as well replace it and

probably the pressure plate assembly

too since I have a hydraulic clutch

assist I can get a heavier Duty one and

since I'm replacing the clutch I'll have

the flywheel ground too it doesn't look

that bad there is some cracking in it

here but putting a new clutch in it's

safe to grind the surface here and grind

the step to match the ring gear on the

flywheel looks fine to me it's got some

weere on it but I consider that minimal

this is not a flippable ring gear where

you can heat it up and flip it over it's

got a relief cut here and not on the

other side pilot bearing in the flywheel

it's got roughness to it replace that

same with the throwout bearing or clutch

release

bearing place that just one issue with

grinding this The Machinist I use Dave

Richards who has his own YouTube channel

has gone to Florida for the winter so

I'm going to have to find somebody else

to do this engine rear main seal the

slip seal

we sleeve on the crankshaft replace

those International Harvester made a

special tool for installing them that

it's a ring-shaped tool that presses

first the sleeve and then this lip seal

on gets everything in the correct place

I don't have one they're expensive I

called my local dealer who I've done

business with for 20 years and they

flatly informed me that they will not

loan out any of their tools even for

half a day so I'm on hot to find

somebody fairly local to me that I can

borrow one from to install it as for the

rear half of the split I have

this Square shaped o-ring that goes on

the lower shaft and for the upper shaft

I have this o-ring and this seal in here

everything so far has been fairly

straightforward and here's where we get

to the tough part let me put this back

on where do I start well a little short

explanation there's a spline shaft

within a spline shaft here and the

inside smaller shaft is the clutched

shaft so when you press in the clutch

this shaft stops this end of it seats

into the pilot bearing in the fly wheel

just for reference and as a refresher

the pilot bearing is right here on the

flywheel this outer shaft is the live

shaft so this

turns whether the clutch is in or not

this Powers the PTO in the Hydraulics to

give you live functions on the clutch

The Driven disc here has that smaller

diameter spline in it so it stops when

the clutch is disengaged or engaged

however you want to think about it when

you've got the pedal pressed in and then

on the pressure plate you've got the

larger spline so the pressure Plate's

spinning all the time because it's

hooked directly to the flywheel on the

tractor and it provides constant

rotation no matter the position of the

clutch if I pull this back out remember

this is the live shaft turns all the

time it's worn which is not uncommon

from what I've read on these the splines

are worn probably a third of the way

through it's no problem to find a

replacement it's just this shaft and

this gear is part of the shaft this

clutched shaft goes straight back and

into the torque amplifier I'm mentioned

it's got damaged at some point in time a

pilot bearing went bad that this seats

into in the flywheel and it chewed up

the end of this shaft and to sort of fix

it they dimpled the shaft with a punch

to make its diameter come back out close

to where it was in spots so that the

bearing inter race would stay fairly

tight to it it's really not a permanent

solution

I always run into these things when I

tear into an old tractor remember the

Super C I'm just going to give her a

little freshen up and then you run into

something that makes you think twice

about your original plan this shaft made

me think

twice I believe that the only way to fix

this issue is to pull out the torque

amplifier it's an integral part of the

torque amplifier

so probably looking at a new torque

amplifier will it run all right the way

that it is maybe I'll dimple it a little

more put a new pilot bearing in the

flywheel

probably is it right to do

that I don't know it depends on your

circumstances I guess the reason it

could be okay is because most of the

time that shaft on this side is rotating

along with this the engine crank shaft

except when you have the clutch pushed

in when you want to stop the tractor and

it's not like an old style bushing in

the old letter series tractors

where you've got more friction happening

if this shaft isn't rotating quite right

that is a ball bearing in the pilot

bearing and it's got an inner race that

rotates and if they're a little

different you know as far as rotation if

they don't fit together quite as tight

as Factory spec it's only for the

momentary time you have the clutch

pushed

in it's not the end of the world it's

one of those judgment calls what am I

going to do I don't

know the more I got to thinking about

this Dopey little thing the end of the

shaft the more I thought about should I

go

further going further means splitting

this midsection C off this housing here

splits off the rear

end pulling it off you got to pull the

guts out of the transmission you got to

take the multiple control valve off to

pull the torque amplifier out put a new

torque amplifier in it and not have to

worry about it for the rest of my life

and to know what I've

got I'm debating it last night when I

went to bed I said no way I'm going to

do that it is a lot of work and then as

I thought about it more I thought you

know

it's something that's good to show on

YouTube and it's something that will

give me a nice shifting longlasting

tractor with a good torque amplifier in

it a Snappy torque amplifier that I'll

never have to worry about for the rest

of my life giv the hours I put on this

tractor it'll give me a chance to look

at the MCV and make sure everything's

all right in there the gentleman I

bought the tractor from had said that

the MCV had been gone through but I

don't know how long or how many hours

ago that

was should I do it I guess now I'm

leaning 6040 toward doing it but I think

I'm going to have to sleep on it some

more conventional wisdom is that when

you split a tractor for any reason you

replace the clutch because it's enough

work just to split the tractor you might

as well do it while you're in there and

I'm in that boat my clutch isn't

completely worn out it's got a lot of

life left in it but I'm replacing it

because I split the tractor to fix leaks

the same can probably be applied to the

torque amplifier in this case because

I've stripped down the tractor so far

I've taken a lot of difficult to remove

things off it's right there you might as

well do it I have no idea how old this

torque amplifier is it works fairly well

I ran it hot when I was haying with this

tractor and it does have a little bit of

lag at high transmission oil

temperatures when the tractor is really

warm so it's a judgment call and I

really want to hear what you think I

don't need this tractor for work on the

farm right now or this season I pulled

it in here to do a good job and this is

probably part of doing a good job but I

want to hear what you think thanks for

watching this

video and I'll see you next

time