Replacing Oil Filter Assembly 520h

[Rich16 44]

I have a running 520h but when I changed the oil/filter oil ran everywhere - twice. It was difficult to screw the oil filter on properly - and it seemed to go on at odd angles & wasn't seating properly.

 

Also lots of old oil caking around the engine back so....

 

Pulled engine to evaluate/clean and someone crossthreaded the male part of oil filter assembly - fortunately I have another in perfect condition to replace with new gasket.

 

400+ hours so time for head cleaning and valve adjust anyway and easier to work with this way.

 

The top bolt behind the pressure sensor is impossible to access to (with shroud loose) unless the pressure sensor is unscrewed - mine doesn't have the 45 degree brass offset though my replacement does. Bottom bolt is easy.

 

Does the main engine shroud have to be completely removed to replace this or can the sensor be safely unscrewed without damaging to access the top bolt?

 

Trying to avoid doing more than I have to - experience/wisdom here appreciated.

 

Also - does the replacement gasket for assembly need sealant or should it be put on dry? Pipe sealant on the sensor?

 

Thanks.

 

 

[WVHillbilly520H 10,376]

3 minutes ago, Rich16 said:

I have a running 520h but when I changed the oil/filter oil ran everywhere - twice. It was difficult to screw the oil filter on properly - and it seemed to go on at odd angles & wasn't seating properly.

 

Also lots of old oil caking around the engine back so....

 

Pulled engine to evaluate/clean and someone crossthreaded the male part of oil filter assembly - fortunately I have another in perfect condition to replace with new gasket.

 

400+ hours so time for head cleaning and valve adjust anyway and easier to work with this way.

 

The top bolt behind the pressure sensor is impossible to access to (with shroud loose) unless the pressure sensor is unscrewed - mine doesn't have the 45 degree brass offset though my replacement does. Bottom bolt is easy.

 

Does the main engine shroud have to be completely removed to replace this or can the sensor be safely unscrewed without damaging to access the top bolt?

 

Trying to avoid doing more than I have to - experience/wisdom here appreciated.

 

Also - does the replacement gasket for assembly need sealant or should it be put on dry? Pipe sealant on the sensor?

 

Thanks.

 

 

Now if it was me and I already had the engine out and doing the heads I would go ahead and pull ALL the sheet metal and clean it super good like new since you say it has been leaking oil... Now is the time

[Rich16 44]

Appreciate it WVHillbilly - generally agree - my situation is poor health (severe autoimmune arthritis/complications) and limited workspace made much worse by this time of year. Cold and damp don't agree.

 

The screwed up threads on the oil filter seem long established and I suspect it's been repeatedly abused and the source of the oil leaking - feel forced to at least replace the assembly since I have the part & its off.

 

Doesn't seem to be coming from the bearing or around the filter assembly gasket & aside some mild excess smoking (starup) it runs great - so much so I'm even questioning fooling with the valves.

 

The rear cylinder head off piston/valves and cylinder look almost as new - carbon is so minimal I'm questioning just how far to go - and this is my second 520h I'll need up and running in the spring.

 

Guess I'd rather have a running useful machine than one in perpetual restoration which is likely here. Takes me a week to do what most here could do in a half-day (sadly).

[Handy Don 14,062]

@lynnmor may chime in, but unless something is really off in that engine, the front cylinder will look a lot like the rear. If I recall correctly, the service manual suggests de-carbon at 700 hours unless otherwise indicated.

I agree with @WVHillbilly520H about the thorough cleaning. Once the blower tin is off, the head-side tins are only a couple bolts more. Do be gentle thou, with those bolts coming out and going back in on the aluminum block - a broken or cross-threaded bolt is a royal pain.  I followed recommendations and used a tap and die to very carefully clean both the block and bolt threads (respectively) and then oiled them during reassembly.  I also used a torque wrench on every bolt and was surprised that my "feel" for the right level of tightness was wrong about half the time. YMMV. Good luck.

[lynnmor 7,817]

Since you had oil leakage the engine needs a thorough cleaning, so remove the blower tin and do it right.  You probably are having difficulty in the coil area, there are screws in that area that aren't easy to see.  The oil pressure switch is simple tapered pipe threads, so use a sealant that is suitable for oil.  I spray a mist of Permatex Copper Spray-A-Gasket Hi-Temp Adhesive Sealant on the oil filter mount gasket, but it isn't required.

 

1,000 hours is the recommended interval for valve adjustment, I prefer about 700.  Carbon buildup all depends on the type of oil and how the engine was operated, I have never seen serious buildup since I run mine fast and hard.

 

I understand that you have some limitations, but you want it right.  Use plenty of cleaner and get those fins clean and that includes the bottom of the engine.  While you have the engine free, you should check the oil drain pipes for tightness, it is much easier now.

 

Be sure you are using the correct oil filter, I use only Onan 122-0800 or Fleetguard FL-3339.

 

 

[Rich16 44]

Thanks guys.

 

I feel better about skipping the valve adjust for now - it'll take me quite awhile to amass several hundred more hours of use to need the valve adjust.

 

I cleaned everything up really well with the engine off (blower tin loose & fully exposed at bottom) and don't see much else further disassembly will accomplish cleaning wise and 95% of the crud is gone - why my hesitation to pull more hoses (gas pump) and go further maybe with more chance of risk than gain. 6-8 cans of gunk soaking with low pressure hose water rinsing off and everything dried out before it got colder and sunless here - & I'm massively compulsive. Looks good - great compared to what it looked like when I started.

 

Right now I'll be thrilled having it bolted back on the machine and running again. My neck fusion isn't enjoying a lot of this

 

I don't see any torque specs for the oil filter assembly in the manual (unless I'm misreading the labeling) and looks like I can use a regular torque wrench on the top bolt with a rachet extension with the sensor off - but the bottom one is behind the curved area where the filter seats & will require a combination wrench to remove/replace - any thoughts on bottom torque or mechanic's guess and don't overtighten?

 

Will pliers or mild channel lock pressure to remove the oil pressure sensor chance screwing it up? Is there a better way of removing?

 

Also - does the 45 degree angled brass block add anything to the sensor or should I get rid of it on the 'new' assembly I'm putting on. I can see (maybe) not requiring sealant going into brass? It will make it harder to re-install and torque the top bolt using it though.

 

Thanks again! Great advice.

Edited December 5, 2020 by Rich16
Misspells

[Handy Don 14,062]

For bolts not individually specified, the torques are here:

[Handy Don 14,062]

Will defer to @lynnmoron the sensor and brass questions and the inaccessibility of the filter mount bolt via torque wrench.  These are outside my experience.

[lynnmor 7,817]

Onan used two different shapes of oil pressure sensors, my guess is that the one with the 45 degree fitting is done that way to allow for a better air flow to the cooling fins.  Always use a sealant on pipe fittings.  Is there no wrench flats next to the threads on your switch?  You might be able to just grip the body with your hand and screw it out.

 

A mechanics guess is fine for tightening the oil filter mount bolts, as long as you are a good guesser.

 

You mentioned the pulse hose to the fuel pump.  It would be a good time to replace it, that hose is very old and you don't want to do go in there again if you can help it.  Cut a new hose one or two inches longer than the original and feed it thru the opening.  After the tin is in place, hold the hose with pliers and cut it to the proper length.  While still holding the hose, push it onto the pump.  Do not make the new hose much longer than the old or it will buckle.

[Rich16 44]

Thanks much Lynnmor and other commenters - always appreciate the advice (and take it).

[Rich16 44]

Found a replacement Oil Filter Adapter in my parts bin and think it came off a 520 (p220) though possibly a p216 - filter threads perfect.

 

Question - the adapter has one minor difference that may or may not matter - the oil filter holes into the adapters aren't the same size.

 

Pix enclosed - the clean one would be the replacement & the caked oil the original - the brackets are molded differently on the outside where the holes are.

 

The '95 520 I'm replacing has a larger hole (from the filter) and the outside of the aluminum bracket is also larger I presume to accomodate this. Different sensors also - mine is the clip on and the older one I want to use has screw terminals but an easy swap.

 

Anyone think it's a bad idea to use my part with the smaller filter access hole? The bracket gaskets/mating surfaces are identical. Didn't expect this but have learned to expect the unexpected with these.

 

The Onan engine parts site still lists the clip on black sensor but says there are 10-12 different low pressure cut off switches and that this one was typically used on 'early Miller & Lincoln Welder/Generators' though seems it was also used on a '95 WH p220. Would it matter which one I used as to the older white one already installed (can screw clips on it) or should I swap them?

 

Many thanks and Merry Christmas to all!

[lynnmor 7,817]

I know that the adapter was changed and there must have been a reason.  Obviously the oil flow would be improved, I would make an effort to find the newer one.  The switch has a normally open and a normally closed terminal relative to the threaded portion.  The shapes have changed, but make sure they work the same.  There may be lettering next to the terminals such as NC & NO.

[Rich16 44]

Thanks Lynnmor - I was afraid you were going to say that - it makes sense.

 

Rats - I'm definitely not going to the trouble of doing this and not put the correct one on so back to the hunt!

 

I'll just re-use the switch since it seemed to be working OK. Definitely let me know when all the oil ran out & came on.

 

Should be easier getting it back on with the brass angle & maybe getting a socket on it - can't imagine adding that would hurt anything?

[lynnmor 7,817]

33 minutes ago, Rich16 said:

 

Should be easier getting it back on with the brass angle & maybe getting a socket on it - can't imagine adding that would hurt anything?

 

I think that the angle was used for better air flow around that large white switch, only a guess.  In case you wondered how the switch works, the NC terminal grounds the oil pressure light till enough pressure is sensed.  The NO terminal grounds the hour meter when oil pressure is present so that it only rums when the engine runs.  Some models of tractors had the issue of the hour meter running all the time the ignition switch was left on in error.

[Rich16 44]

I know it's another guess but do you think using the brass angle would screw anything up or if there's a reason they stopped using it? I think it'll make it much easer to re-install with it on but it didn't come that way.

 

Appreciate the terminal explanation - now I noticed the labeling on the sensor - many thanks and I won't screw that up.

 

Guess I'll be contacting Lincoln at AZ in Jan and hope he's got the part - sure he probably does & has been very helpful over the years - can't imagine anything catastrophic if I use the one I have & can't find another.

 

Oh - and for anyone that might want to know I got the oil filter adapter off without completely removing the main shroud - the gas pump line was pristine due to all the oil coating & my huge arthritic hands have difficulty in tight spaces & I just didn't want to keep removing stuff difficult to hook back up.

 

With the shroud loose at the bottom and ends it pulled away enough to get in with my 1/2 - 9/16 box end wrench with offset ends - bottom bolt easy but top one you have to get the wrench high enough above the starter gear to have enough room to inch it loose & off. Turned out less impossible than I thought. So far so good!

[lynnmor 7,817]

3 minutes ago, Rich16 said:

I know it's another guess but do you think using the brass angle would screw anything up or if there's a reason they stopped using it? I think it'll make it much easer to re-install with it on but it didn't come that way.

 

I don't think it matters much.  My thinking is one less fitting would be a good thing.

[Rich16 44]

Thanks - will try to make that happen - got it off that way and it should go back on the same.

 

I'm in love with the 60" deck - got it put back together and runs smooth as silk - does the belt go on the same inside pulley on the PTO that the other decks use?

 

I have the stock belt (113072 103") for it but on the inside pulley it's pretty tight - no slack or need to tighten the mule at all (have the 60" mule).

 

When put on a smooth concrete surface like inside the garage installing it was easy just sliding it under with a few twists and turns - read nightmare sounding stories here & was dreading it.

 

Appreciate all your help.

[lynnmor 7,817]

Here is a manual for your mower that may be clearer.  You may have the belts routed wrong.  The proper mule drive is spring loaded and you adjust it till the spring stretches a bit.  You are the first person to use the word "easy" in the same paragraph when discussing the 60" deck.

[Rich16 44]

Appreciate the manual - everything hooked up correctly. Seems only one way to route 'em with flat idler and v-idle (one correct way anyway) without having a weird belt cross/twist - all same as with the 48" deck except for PTO belt attaching to lower deck pulley under drive belt inconvenience when replacing belts.

 

I guess seems reasonable the belt should be tighter new given the heavier load to allow for future stretching / mule tightening - read about others seeming to have a short pto belt lifespan with the 60 deck & got extras. The PTO belt seems undersized given the massive deck pulley belt and build of it.

 

I was happy the old PTO belt pulled out of the mule without much trouble - new belt went in a bit tighter but didn't have to take any of it apart like I've always had to do with the 48" mule.

 

About the easy part installing - I'd say the 'secret' if there is one is removing/re-installing on a smooth concrete surface like inside garage, pulling it out/reinstalling on the correct side, and putting a jack under the PTO side of front axle (same side to remove) to raise it up several inches for clearance. I took it off on my pebble concrete driveway and it was a real pain - then the light went on about what to do to re-install.

 

I'd read so many horror stories here about running the tractor over it, etc. that I almost never got one. Had several opportunities and passed up due to all the negative posts about weight/size/issues. I'm not in good physical shape anymore though I'm not small - 6'2" and 180# with long arms - 10 years ago age 57 I was three times stronger and 225# - bad health issues have taken it's toll. And I got it on myself without help in 10 minutes no strain to neck fusion

 

The 520 low hours (even with oil issues) and the nice 60" deck for 650 & close to home was too good to pass up so I was going to find out & I'm tickled pink. Maybe that's why it doesn't seem so bad to me. The 48" never seemed 'light' but now does in comparison - but knowing I can lift the front of the 60 & set back on tires to replace bearings and now get it in and out is an unexpected delight. So easy is relative to expectations I guess. I would never attempt to move it on the ground - two sheets of plywood at least to simulate garage floor.

 

 

[lynnmor 7,817]

My barn floor is concrete with a smooth, shiny finish but it still is a bit of a wrestling match to slide that 340lb deck in place.  If only they would have made it so the wheels and rollers turn 90 degrees like some off color brands.

 

I have no belt adjustment issue with two different tractors, I wonder if you have the deck mounted properly.  Check that the fork is around the shaft.

 

I like to keep the decks cleaned out by rinsing the bottom after every mowing.  At the end of the season I remove the deck and use a come-along to hang it up for a proper scraping, sharpening and rust proofing. 

[Rich16 44]

Lynnmor - I'm glad you brought up the fork - mine doesn't have one - it's the newer style 60" with the adjustable gauge wheels in front & doesn't seem to have one in parts diagragm? The guy that had it allowed bolts with the inner spacers on the rear deck attachment bracket to come loose and one rear bolt was gone when I got it - no wonder he didn't like it. All replaced with Toro parts/bushings & washers & feels as new I suspect. Even replaced the gauge wheels as they were shot - Toro parts values them highly! I don't miss that fork - it's always fussy keeping it in place while mounting my 48. Feels solid driving around with it & not loose.

 

I probably exaggerated the tight belt issue and not familiar with anything other than the 48" - with the mule on in the lowest position & me putting the belt on the PTO by slipping it over the pulley edges & rotating in place on each pulley it was moderately snug when it got to the inner one it runs on - I can still get a couple turns of the mule knob tighter though it seems about tight enough & didn't want to overtighten - just used to 48" being a bit looser. The spring inside the mule isn't pulled very tight - should it be and what is it for? I greased the fitting but can't really tell what it does. All is probably OK.

 

One thing I noticed not adjusted correctly is the 'transport level stop adjustment' & glad we had this back and forth - it's set to the top and not bottom & need to level. Another quickie - do you measure the blade distances front to back & set the rear adjustment rod (I presume so) so the front tilts higher a bit by 1/8" & how do you measure? Pretty tight getting under it at all much less doing that level of precision.

 

Thanks & hope you're having a nice holiday season.

[HorseFixer 2,013]

I have the Onan Oil Adapter 4 Sale Brand New at 75.00 a Pop I Have a Thread When I rebuilt my 520 Tractor When I Did it Here you can go to page 10 on my rebuild after I rebuilt the Onan Engine I Ise a Big FL1A Amsoil cross reference Filter which is located at the rear of the tractor.   ~Duke   

[lynnmor 7,817]

Here is a gauge that can help, but still not easy.  Many decks are to be run with the front low, some of the Wheel Horse decks are to be set level to front high, these 60" decks cut very low so adjusting level to 1/8" up helps a bit with that.  I was wrong about the fork, just thinking of possible causes, the 60" has none.  The spring helps to keep the belt tension correct as the distance varies as the deck moves, if you adjust to the middle of its range that should work well.  The bearings are replaceable in the gauge wheels if the rest is OK, I grease them and the fittings on the front axle every time I mow.  Now I must confess, the mowing is now mostly done by a zero-turn and the Wheel Horses are on light duty.

[Rich16 44]

Appreciate the gauge & comments Lynnmor - for that money it's worth a shot - I find it impossible to do any accurate measuring as it is - I wonder if measuring the deck frame distance would give a close approximation? Wish now I'd have measured the blade distance to frame front and back to do it that way when I had it off.

 

I've never done any roller bearing cleaning/regreasing of the PTO assembly on any of mine and a testament to it's durability given some clutch pad dust getting in - decided to clean/re-grease the one using the 60" deck with extra load on it - figure it couldn't hurt & will get around to doing all my others.

 

Definitely want a new oil filter bracket if it has the larger hole to the filter - can you get it here yesterday ?

Edited December 28, 2020 by Rich16

[lynnmor 7,817]

Those gauges are not very accurate from new and the base may not be flat, I drilled and tapped the base for adjustment screws and now have something I can depend on.

 

I have used a yard stick across the flat surface of the 60" decks and measured to the floor, you should be fine doing it that way.  Of course the spindle mounting isn't perfect and a baseline measurement to the blades would prove the method for future adjustments.

 

The outer small bearing in the PTO is cheap, the large needle bearing is expensive. but they last a long time.  I would replace the smaller one, thourghly clean the big one and apply a high temperature grease, then replace the seal.