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Josiah deshong

Allis 620 hydro problems

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Josiah deshong
2 minutes ago, Josiah deshong said:

sm00

Hi i am new to posting a question but I have been reading them for a while I have a 620 that I bought not running and after one problem being conquered another arise. When I put my 620 in gear it doesn’t move but if I jack the wheels up I can get them to turn I have done just about everything in the manual I can manage didn’t know if somebody might have a solution for me

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Josiah deshong

Hey thanks for the info the po had told me quite a few lies when I bought it. The morning I picked it up P.O. already pulled it out of his shed with skid loader and he must have forgot to put in nuetral and stripped the axel. And according to him he drove it in there three years ago so there shouldn’t b anything major wrong haha yeah right

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SimpleOrange

My 9020 sat outdoors with a blown engine for eight years, replaced the Onan with another of the same model. Installed snow thrower and happily cleared my long and steep driveway several times this winter without any problems.

Before putting the old girl to labor changed all gear oil and refilled the hydraulic with fresh, the used engine purred like a kitten the tractor had lots of power and I really enjoyed having that three speed hydro.

Two days ago went out the the garage and fired up the old girl, yes she doesn't mind the cold Manitoba weather that old Onan engine starts way easier than any MTD Kohler I've ever owned.

On the MTD snowblower, when it was cold out you needed a hair dryer to blow hot air into the carburetter to get the fuel to take fire. Horrible machine! And those 115 volt starters ar not cheap. On a warm summer day one short pull on the rope the Kohler would dire right up, Maybe it was my luck to have a machine made on a Monday.

Engine running smooth I hopped into the seat, lifted the blower Er thrower off the floor then engaged the hydro, Hmm only one wheel wants to drive skidding the other across the floor.

Ran fine when I parked it, thought maybe some ice formed inside the transmission or maybe a soring broke inside the limited slip, pulled the cover off and found some evidence of frozen water vapor but nothing that would stop the tractor from rolling under her own power. Jacked both wheels off the floor and could not get the left side to budge.

Off comes he wheel and the bull gear assembly right down to the brake pad, here's what I found. The friction was solidly rusted onto the cover which also acts as a pressure plate. Oh before getting this far I did check the brake rods for free play so I knew already it was not some ice locking the brake in place.

Probably a common problem, anyhow when cleaning the rust from the friction be aware these tractors are old enough to have asbestos brake pads.

 

 

one.png

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Edited by SimpleOrange

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PGL

Gill, did you just sand/grind off the rust, both left and right sides or fix  up the brakes while at it?  I hardly ever use the brakes with the hydro available.  Maybe applying the brakes a bit at each use would keep the rust at bay.  I'd be tempted to try an anti seize coating or even oil.

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720nut
19 minutes ago, PGL said:

Gill, did you just sand/grind off the rust, both left and right sides or fix  up the brakes while at it?  I hardly ever use the brakes with the hydro available.  Maybe applying the brakes a bit at each use would keep the rust at bay.  I'd be tempted to try an anti seize coating or even oil.

Just my thoughts but I wouldn't use either, best just to clean and not let it set out in weather such as top is open where brake rod attaches and allows all rain snow and others in, probably worst enemy is a pressure washer in this area.

Edited by 720nut
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SimpleOrange
9 hours ago, PGL said:

Gill, did you just sand/grind off the rust, both left and right sides or fix  up the brakes while at it?  I hardly ever use the brakes with the hydro available.  Maybe applying the brakes a bit at each use would keep the rust at bay.  I'd be tempted to try an anti seize coating or even oil.

I never once had to use the brakes even on my very long and steep driveway.  In fact I told my better half last night that I could remove the brake parts and sell them on eBay.

I just ued the power brush on my wheel grinder to remove the rust, when it came to the friction disk I only buffed it,  as for the backing plate that doubles up as a pressure plate gave her hell.

Backing plate does show some rust pits but since the brakes are not really necessary I"m going to reinstall the plate with the pitted side towards the friction disk. Purely for aesthetic purposes.

I'm not personally worried about the asbestos friction disk but thought the caution was warranted for some over zealous DIY..

 

No I have not done any remediation on the other side one loaded tire with prickly chains is enough for the time being.

With the exception of cork clutches which run wet in oil, clutch and brakes parts are meant to be run dry.

Heard rumors if a leaking oil seal soaked a clutch disk causing it to slip some mechanics would use the solvent used in dry cleaning cloths.

The name of the solvent escapes me at the moment. Somehow in the far reaches of my mind DSMO is trying to creep forward, the solvent was banned, apparently it had some illegal secondary uses for arthritis.

When applied to skin it would readily soak through, anyhow some folks claimed it worked. I almost sourced some out for my burcitious.

Don"t believe you can purchase the stuff anymore.

Another solvent used to clean oil off of clutches etc.. is Carbon Tetrachloride which was used mainly in fire extinguishers. It's a known carcinogen.

Edited by SimpleOrange

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B10Dave

Not sure if this is the dry cleaning fluid you are referring to or not. In the early 70's we used fluid called PER. ......Perclorethylene dry cleaning grade #2. The lady who did the pressing of the clothes would get higher than a kite breathing the fumes.

Edited by B10Dave

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SimpleOrange
14 hours ago, 720nut said:

Just my thoughts but I wouldn't use either, best just to clean and not let it set out in weather such as top is open where brake rod attaches and allows all rain snow and others in, probably worst enemy is a pressure washer in this area.

From inside the brake cavity I cleaned out the crude, but now that  you have alluded me to how water and melting snow is able to enter the brake cavity I'm going to see if perhaps a drain hole could be drilled at the bottom of the casting. There's no gear lube inside so I don't see why not.

The foam seal is absolutely useless to keep water out.

I'm heading out to the shop for half an hour, when I come back into the warm house and a cup of coffee in hand I'll report my observations.

Also there is no drain plug on the transmission and using a turkey baster sucks, I'm going to see if there's a casting boss where they perhaps intended to have a pipe plug installed.

 

Edited by SimpleOrange

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SimpleOrange

Ok to drain the transmission fluid you can remove the temperature sending unit.

So cold in unheated shop forgot to see if there's room to drill a drain hole in the brake casting and I almost have it assembled.

 

drainPlug.png

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SimpleOrange

With the bolts out of the reduction gear case, jack under transmission the tractor frame is misaligned just enough so that it makes installing the two top bolts a bit nasty. I used the tapered end of my chipping hammer to make things right.

I do have a tapered cat bar but the chipping hammer showed up first.

The brake assembly is now attached, tomorrow I'll install the reduction case. Unfortunately it's secured with bolts with nuts so there's no where to thread in helpers dowels. I use long bolts with the heads cut off then cut in a slot for a screw driver making removal easy.

To assist with the weight of the reduction case and to hold it in place for this job will source out another long bolt, the pair ill go through the top holes and come into contact long before the reduction case makes contact. Anyhow it will leave me with a hand free to insert a proper bolt.

Also when installing a heavy calcium loaded tire the tapered cat bar makes life easy to get a hole lined up.

Last a picture of my newly rebuilt hydro with modified nose that is going into my 720.

hydro.thumb.png.1d62b389aa398de06519bf64e9b9d554.pngchiper.thumb.png.f905aad93f91047b67e1897314bca0ba.pngbolt.thumb.png.ba677fea437f934933191b2a6d7021a5.pngbolt2.thumb.png.bce9bb599b5f413a2a382c2351fcb262.pngNot sure in which order the pictures will place themselves into this thread.

 

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720nut

Gill, did you locate a place to put a drain hole, They did a heck of a job designing these tractors but you would have thought they would have put a actual drain plug in case.

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SimpleOrange
1 hour ago, 720nut said:

Gill, did you locate a place to put a drain hole, They did a heck of a job designing these tractors but you would have thought they would have put a actual drain plug in case.

You can remove the temperature sending unit to drain the transmission.

The tractor is rugged and built sturdy but poorly designed, the 3 point goes in its favor but your not going to till or plow your garden with the mower deck still attached and the deck is not easy to handle then if you have the front end loader accessory you have to remove  the loader and pump then install a bracket  with four bolts either side of the frame just to attach the snow thrower.,

If your starter packs it in you have to remove the complete engine to get at it.

On the plus side, operator visibility and comfort, Onan engine  with cast iron block that will start at -30, Sunstrand hydrostatic. In some tractors found today the original engine and hydro's still working with years of life left.

The Simplicity Allis line was kinds like buying jeans made from Hemp, you pass em along to the next generation.

For the era these tractors were built owning one put your neighbor into a frenzy of envy

drainPlug.png

Edited by SimpleOrange
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SimpleOrange

A story of ignorance, the previous owner of my 9020 parked it because the engine was smoking so bad  it clouded the surrounding air making it difficult to breath.

He removed the original Onan placing it on the ground uncovered to where it sat to the elements for 8 years, tired to install an Onan from a generator then when he found out the crankshaft wasn't long enough abandoned the project leaving the donor sitting cockeyed with hood open.

So I made an offer and came home with the tractor, two engines, tiller, mower deck and the snow thrower.

Now for the kicker, the mechanical fuel pump is located on top of the engine under the intake manifold, the diaphragm had a pin hole large enough to pass raw gasoline into the crankcase where it diluted the oil. The pin hole being small still enabled the fuel pump to function as a pump but part od his maybe contributed to the fact that the fuel tank sits higher than the engine so there may have been some siphoning going on here.

Had he checked the oil would have found it well over the full mark on the dip stick, had he rubbed a dab between his fingers would have notice the oil was solvent like and smelled strongly of gasoline.

By the time I got the engine it was seized up solid.

It's been a long road getting that 9020 operational, I'm a big fan of cast iron engine blocks and would never consider an alternative. Finding Onan CCK parts in my neighborhood not going to happen. Found one in Alberta that I made a trip for then another east of Winnipeg.

The Winnipeg engine wad removed from a 720 to install a modern  aluminum engine, I installed the engine as is and have been using it just as I had received it..

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SimpleOrange

The two bottom holes on the reduction case are threaded so this allows the mechanic to use threaded dowels.. Also once the case is in position the bottom holes use the two short bolts. Long ones will butt up against the bull gear inside the case locking the gear solidly in place.

Don't ask me how I know this.

All that is left to do now is put the loaded tire back on.

With the hub and pto splines worn the 9020 is being used exclusively as a snow machine, one half of the 3 point had to be removed to repair the stuck brake pad. I've decided to remove the 3 point along with the hydraulic cylinder. now I'm off to have a short hydraulic hose made with a pair of males ends.

Later today will post a cheat on how to install a loaded tire.

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Josiah deshong

my 4040 has an onan engine in it that starts with the numbers nhb instead of ccka and it’s crankshaft is long enough for the front clutch although when I got it the motor was not lined up with drive belts and pulley plus it only had one belt on it. I had to take a quarter inch off the motors drive pulley with a lathe to make the belts line up but this motor is very similar and is a viable option for these tractors if u wanted to stay cast iron and original the only other difference I saw was heads r different and there’s no hole for mechanical fuel pump but the engines footprint is the same if u use a ccka starter. I don’t know it’s history because the P.O. is deceased maybe he swapped crankshafts to use the front pto clutch or it came with a long enough stub I can’t seem to find much out about the nhb onan motor

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720nut
3 hours ago, Josiah deshong said:

my 4040 has an onan engine in it that starts with the numbers nhb instead of ccka and it’s crankshaft is long enough for the front clutch although when I got it the motor was not lined up with drive belts and pulley plus it only had one belt on it. I had to take a quarter inch off the motors drive pulley with a lathe to make the belts line up but this motor is very similar and is a viable option for these tractors if u wanted to stay cast iron and original the only other difference I saw was heads r different and there’s no hole for mechanical fuel pump but the engines footprint is the same if u use a ccka starter. I don’t know it’s history because the P.O. is deceased maybe he swapped crankshafts to use the front pto clutch or it came with a long enough stub I can’t seem to find much out about the nhb onan motor

Josiah, on facebook there is a group dedicated to the Onan engine, I'm sure they will be more than able to answer your questions

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SimpleOrange
6 hours ago, Josiah deshong said:

my 4040 has an onan engine in it that starts with the numbers nhb instead of ccka and it’s crankshaft is long enough for the front clutch although when I got it the motor was not lined up with drive belts and pulley plus it only had one belt on it. I had to take a quarter inch off the motors drive pulley with a lathe to make the belts line up but this motor is very similar and is a viable option for these tractors if u wanted to stay cast iron and original the only other difference I saw was heads r different and there’s no hole for mechanical fuel pump but the engines footprint is the same if u use a ccka starter. I don’t know it’s history because the P.O. is deceased maybe he swapped crankshafts to use the front pto clutch or it came with a long enough stub I can’t seem to find much out about the nhb onan motor

I'm not familiar with your Onan NHB but if it had been previously used for generator duty, it's probably governed to 1800 rpm, if this be the case it's an easy fix.

You'll have to remove the timing cover to get at the mechanical governor, remove the small snap ring then removed five of the ball bearings leaving those behind equally spaced.

The thrust plate you removed to uncover the bearings has a plastic insert in one of the holes, this insert must be in the 3 o'clock position to mate up with the pin located on the inside of the aluminum timing cover.

As  the engine rpm increase the ball bearings used as flyweights exert pressure on the pressure plate forcing it forward against a fork connected to a rod that exits the timing case. From there it's connected to the carburetor linkage.

Within the external governor linkage theres a spring to give some resistance, there's an threaded adjustment to to increase / decrease spring tension.

Increasing the spring tension will delay governed  throttle response.

When  I was a kid blew the top of a piston off on our Wisconsin twin by taking it from idle to full throttle and back to full several times. Fortunately for me the piston had broke at the oil ring land and the compression rings held the dislodged piston top at TDC so no further damage was incurred.

Moral of the story, son;t always believe what your kids tell you.

Also always go with recommended factory specs.

Reason I think your engine came from a generator, you said it did not have a mechanical fuel pump, if  you look closely you'll notice the bass for the fuel pump has been cast into the engine block. Chances are the camshaft has the lobe to operate the fuel pump but may not have had that particular lobe ground.

Does your engine have an oil filter, again the boss is cast into the engine block and has been surface machined but the engine blocks used for generators did not move further down the assembly line to be dilled and tapped etc..

I have one CCK with out an oil filter that I'm going to finish up the machine work to accept the filter base.

 

 

 

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