Tractor Repair/differential repair

[MarcIssan]

I bent the output shaft of my earth auger being careless.  I backed up over a small shrub which happened to have a stump at the center and the tip of my auger hit it and as I proceeded to back up I bent the shaft, the auger, and cracked the case.  Fast forward and I had the shaft straightened, the auger fixed, and the case welded and my question is about assembly.

 

Every cast iron cover that mounts to the main case had a paper or fiber type gasket attached to it with some type of adhesive...not silicone though.  The main case also had a gasket attached in the same way and these two parts mated seal to seal.  There didn't seem to be any gasket sealer in between them...and yes it leaked before I bent the shaft.  I couldn't find matching gaskets so I had custom gaskets made to fit...but I only bought one of each.  The gasket material is rubber and 1mm thick.  

 

In my old-school auto repair days we used one gasket mating two parts together and applied liberal amount of gasket sealer before torquing the bolts but now I wonder which method is better.  Considering this is the one and only time I want to pull this apart, I absolutely want to make sure it seals the first try.  I'd kick myself in the <deleted> if it leaked once I get it all together, filled it with 90 weight oil, and began using it again.

 

It's the same concept as any differential housing so I'm asking those with experience what is my best approach here and what type of gasket sealer do you like.   I rebuilt my rotary tiller last year and used a silicone sealer from the tractor parts store and it worked on that machine plus it was easy to peel off when I subsequently had to remove the cover plate a few months later.

 

For those interested, Westbound Engineering has a custom gasket service and all you need is a drawing like attached.  They do a fast turnaround ...for me it was 2 days.  You can visit their website at WWW.Thaiseal.com.

 

Thanks in advance.

[farmerjo]

Normally a gasket would be fitted to get correct end clearance on bearings and mesh of the teeth.

If it is just for the oil seal you could go a thicker gasket to change the contact position on the shaft if a groove is worn or do away with the gasket and use silicone gasket maker.

Check if there is a breather,if it has one most likely blocked from hornet nest.That will cause it to leak.

Can always add some light grease to mix with the oil to stop leaks.

Edited September 11, 2021 by farmerjo

[MarcIssan]

Thanks.  I really only drilled fewer  than 10 holes with it so far so there is no wear marks on the spline or ring gear. I see where gaskets would change gear meshing but every cover had 2 gaskets even the ones not associated with gear meshing so I think this was just their method.  I can order more gaskets...they are 350 bt for a custom order...I was just fishing for information from others with more experience.  Thanks for your comments...it will be interesting if others have something to add.

 

Cheers

[kickstart]

Looking at that 3ed photo looks if they were a paper gasket ?they ,you can buy gasket paper, กระคาษปะเก็น , in Thai ,and you can make your own looking at this not difficult,  I get the paper  from my locale shop at our market ,I have seen it in Home Pro /Watsado.

I have had to repair the front drive units on my tractor  and I have made my own gaskets ,

Using your homemade gaskets and some sealer it should make a seal ,not a vast amount of pressure they as FJ said add some light grease to the oil will help. or use  a 120 SAE oil .

I would say using any form  of gasket would not interfere will teeth meshing .by the time it has been bolted down the gasket would have been squeezed up they will only be a few thou of gasket. 

[MarcIssan]

So you think that one gasket with proper sealer will do?  I have all but one, which I forgot to order, but really wondered if I needed to double them up.  For me it's worth spending 350 bt to get one premade.

[MarcIssan]

7 hours ago, farmerjo said:

Normally a gasket would be fitted to get correct end clearance on bearings and mesh of the teeth.

If it is just for the oil seal you could go a thicker gasket to change the contact position on the shaft if a groove is worn or do away with the gasket and use silicone gasket maker.

Check if there is a breather,if it has one most likely blocked from hornet nest.That will cause it to leak.

Can always add some light grease to mix with the oil to stop leaks.

I forgot to respond to the comment about a breather...there isn't one.  Are you suggesting that from use the lack of a breather could cause a leak?  Does that expand the fluid and gas inside or something?  I did have a leak around the seal of the output shaft.  It even leaked when it wasn't in use and I chalked it up to bad seals.  I bought new ones but I haven't gotten that far on the reassembly.

[MarcIssan]

14 hours ago, farmerjo said:

Normally a gasket would be fitted to get correct end clearance on bearings and mesh of the teeth.

If it is just for the oil seal you could go a thicker gasket to change the contact position on the shaft if a groove is worn or do away with the gasket and use silicone gasket maker.

Check if there is a breather,if it has one most likely blocked from hornet nest.That will cause it to leak.

Can always add some light grease to mix with the oil to stop leaks.

I have PTT brand 90 weight oil.  What type of grease do you suggest I mix with it? I have 2 types of grease.  One is that green long fiber grease I use in my gun for lubing my tractor and the other is some semi transparent vasoline-looking stuff that I used to coat new bearings and gears when I rebuilt my rotary tiller.  Neither one I would call light grease and I wouldn't want to put products in there that didn't blend well.  Any suggestions will help.

[farmerjo]

2 hours ago, MarcIssan said:

I have PTT brand 90 weight oil.  What type of grease do you suggest I mix with it? I have 2 types of grease.  One is that green long fiber grease I use in my gun for lubing my tractor and the other is some semi transparent vasoline-looking stuff that I used to coat new bearings and gears when I rebuilt my rotary tiller.  Neither one I would call light grease and I wouldn't want to put products in there that didn't blend well.  Any suggestions will help.

My implements that have gearboxes have a breather fitted.(post hole digger and brush hogs) 

The pressure build up has to go somewhere. (usually out the seal if the unit is over filled)

When you put it back together,put a breather on one of the inspection plates and you might not need anything other than 90 grade oil.  

I have used a 50/50 oil/grease mix in the past if it's required.

90 grade oil and EP2 grease,mix together in a bucket. 

Edited September 12, 2021 by farmerjo

[MarcIssan]

Ok thanks By the way, I think I know why the factory doubled up on the gaskets.  See pics...they did minimal milling on the  cast iron mating surfaces and I suspect they use the tar-like sealer and 2 gaskets to make  up the  difference.  Each gasket is 1 mm so to keep the gears meshing the same (in case that was a consideration) I think I'll do the same.

 

 

Edited September 12, 2021 by MarcIssan

[kickstart]

13 hours ago, MarcIssan said:

I have PTT brand 90 weight oil.  What type of grease do you suggest I mix with it? I have 2 types of grease.  One is that green long fiber grease I use in my gun for lubing my tractor and the other is some semi transparent vasoline-looking stuff that I used to coat new bearings and gears when I rebuilt my rotary tiller.  Neither one I would call light grease and I wouldn't want to put products in there that didn't blend well.  Any suggestions will help.

Your  grease the long fibre grease is axel grease ,all right for diffs and slow moving parts .

The Vaseline type is HMP high melting point grease the type used in bearings , what I use on my chipper/shredder for the past 10 years about the best grease available in Thailand .

Your leak could be because the shaft is pitted, wearing on the seal, and the pits will let oil past them and the seal  .I have had this problem on the front stub axles on my tractor ,I put the shafts in a vice and used some wet and dry paper on the shafts to smooth them down to take out  the pits out .

And you could put the mating surfaces on a very flat surfaces  ie. plate glass with some wet and dry paper and flatten the surfaces a bit ,it will not be easy as cast iron is very hard steel ,like  said just make some paper gaskets should do the job. 

[MarcIssan]

On 9/12/2021 at 9:14 PM, kickstart said:

Your  grease the long fibre grease is axel grease ,all right for diffs and slow moving parts .

The Vaseline type is HMP high melting point grease the type used in bearings , what I use on my chipper/shredder for the past 10 years about the best grease available in Thailand .

Your leak could be because the shaft is pitted, wearing on the seal, and the pits will let oil past them and the seal  .I have had this problem on the front stub axles on my tractor ,I put the shafts in a vice and used some wet and dry paper on the shafts to smooth them down to take out  the pits out .

And you could put the mating surfaces on a very flat surfaces  ie. plate glass with some wet and dry paper and flatten the surfaces a bit ,it will not be easy as cast iron is very hard steel ,like  said just make some paper gaskets should do the job. 

Thanks.  And what is the mixing ratio of HMP grease 90 wt gear oil? 

 

This machine is all slow moving.  I run it on the lowest PTO speed..540 RPM and I run my Kubota is just above idle. ...1000 RPM.  The imbalance of the auger causes it to surge side to side if  I run it any faster.  

 

I did see where the fill bolt was also a vent so at lease that is covered.  Thanks for the advice.

[phetphet]

If I didn't have any jointing sheet, I used to use old map paper. The rolled maps, not the  folded ones. Used to cut the gasket out of the maps (tap them out with the ball of a small ball pein hammer and then grease them up before fitting.

 

If you want to buy gasket sheet you might want to try the link below. try and get the same thickness as original.

 

https://www.thaipolymer.co.th/en/product/21317-17223/non-asbestos-fibre-sheets-na-jointing-

 

HTH

[kickstart]

2 hours ago, phetphet said:

If I didn't have any jointing sheet, I used to use old map paper. The rolled maps, not the  folded ones. Used to cut the gasket out of the maps (tap them out with the ball of a small ball pein hammer and then grease them up before fitting.

 

If you want to buy gasket sheet you might want to try the link below. try and get the same thickness as original.

 

https://www.thaipolymer.co.th/en/product/21317-17223/non-asbestos-fibre-sheets-na-jointing-

 

HTH

Many years ago I used to use old corn flake packets for base gaskets on motorbikes ,as you said  use a small hammer ,as I said I still make my own for the tractor ,an imported second hand from Japan ,things like this you just can not buy .

Photo of the paper I use. this one meter roll was about 150 baht.

 

[farmerjo]

3 hours ago, MarcIssan said:

Thanks.  And what is the mixing ratio of HMP grease 90 wt gear oil? 

 

This machine is all slow moving.  I run it on the lowest PTO speed..540 RPM and I run my Kubota is just above idle. ...1000 RPM.  The imbalance of the auger causes it to surge side to side if  I run it any faster.  

 

I did see where the fill bolt was also a vent so at lease that is covered.  Thanks for the advice.

How aggressive is the the auger?

And does your digger have its own external clutch on it.

Tractor internal clutch packs can get expensive when they start slipping.

But in saying that the Kubota PTO has been the best and most reliable of the tractors i've had.

Just be careful with the swaying as you say otherwise it will be the tractor axle seals you will be fixing next.(i know from letting the FIL do some contracting once)

Slow and steady wins the race while raising and lowering regularly to keep the hole clear of dirt.

Here is a pic of one of my augers,the cutting edge plates can be replaced. 

 

 

[MarcIssan]

22 hours ago, farmerjo said:

How aggressive is the the auger?

And does your digger have its own external clutch on it.

Tractor internal clutch packs can get expensive when they start slipping.

But in saying that the Kubota PTO has been the best and most reliable of the tractors i've had.

Just be careful with the swaying as you say otherwise it will be the tractor axle seals you will be fixing next.(i know from letting the FIL do some contracting once)

Slow and steady wins the race while raising and lowering regularly to keep the hole clear of dirt.

Here is a pic of one of my augers,the cutting edge plates can be replaced. 

 

 

Yup I go slow.  We have mostly sand here and no buried rocks  so far.  Easy digging and yes I clear the flutes often.  Can you tell me what amount of grease I would mix with 3.2 liters of oil?

[farmerjo]

22 minutes ago, MarcIssan said:

Yup I go slow.  We have mostly sand here and no buried rocks  so far.  Easy digging and yes I clear the flutes often.  Can you tell me what amount of grease I would mix with 3.2 liters of oil?

I'd go 1 litre of oil and 1kg grease to start,then add as required.

[MarcIssan]

23 minutes ago, MarcIssan said:

Yup I go slow.  We have mostly sand here and no buried rocks  so far.  Easy digging and yes I clear the flutes often.  Can you tell me what amount of grease I would mix with 3.2 liters of oil?

By the way, I think my Kubota L4508 PTO is slipping.  I used a trencher that was built for a larger tractor but I used it anyway as I ordered it from China based on what the rep said about my tractor size.  Anyway, I ran it pretty hard just to get it done and afterward the PTO clacks when doing easy work.  when I till soft soil on low and slow I hear a harsh rattle from the PTO and the hi-low speed selector wriggles pretty harshly when that happens.

 

In the USA Kubota recalled a bunch of tractors and replaced the PTO over-running clutch plates with non-over running ones then suggested putting an external clutch over-run system externally.

 

Anyway, what do you figure it will cost at the local dealer to fix that?  I know they need to split the tractor..but hey..labor is cheap here.

[farmerjo]

Not sure how the Kubota is figured internally,never had it apart as all my implements barr the rotovater i brought with external clutches.

On my Ford for memory there is a splined shaft that goes from the flywheel to pto clutch pack then another to back of tractor.

At a guess you have stripped the spline at the flywheel.

Price,member grumpy john had a thread on here with the cost to replace spigot bearing on clutch so it would be roughly the same,maybe you could PM him if he's still around.

[MarcIssan]

I got on a tractor blog 6 months ago asking where that clanking might be coming from and everyone agreed it was the over-running plates in the PTO.  I guess they have a locking mechanism but the ramped plates allow for over-run as in the case of a mower etc where the inertia of the blade keeps pushing the tractor while applying brakes to stop (before disengaging the clutch I guess).  There is a matching ramp on each of two plates and then a notch where they catch again.  Maybe some springs to apply pressure when in use but also to allow over-running if the force is exceeded.   The clacking is where the plates or the ramps on the plates are worn and don't lock (or I suppose the springs have failed). The PTO still works but any medium force causes the clacking like running the tiller at 1500 RPM engine speed whereas at 1000 the clacking is reduced.  One Kubota owner said they were recalled in the USA and replaced no charge but that was years ago.  Since they don't have the L4508 in the US, they sent a diagram of a different model with similar HP to show the issue.  Since I am done with the trencher and plan to sell it, I want to fix the PTO for tilling and mowing...and of course before some small failure causes a more expensive one down the road.  Thanks.

[Cake Monster]

I would just make a new Gasket from a Corn Flake Box

 

[kickstart]

7 hours ago, MarcIssan said:

I got on a tractor blog 6 months ago asking where that clanking might be coming from and everyone agreed it was the over-running plates in the PTO.  I guess they have a locking mechanism but the ramped plates allow for over-run as in the case of a mower etc where the inertia of the blade keeps pushing the tractor while applying brakes to stop (before disengaging the clutch I guess).  There is a matching ramp on each of two plates and then a notch where they catch again.  Maybe some springs to apply pressure when in use but also to allow over-running if the force is exceeded.   The clacking is where the plates or the ramps on the plates are worn and don't lock (or I suppose the springs have failed). The PTO still works but any medium force causes the clacking like running the tiller at 1500 RPM engine speed whereas at 1000 the clacking is reduced.  One Kubota owner said they were recalled in the USA and replaced no charge but that was years ago.  Since they don't have the L4508 in the US, they sent a diagram of a different model with similar HP to show the issue.  Since I am done with the trencher and plan to sell it, I want to fix the PTO for tilling and mowing...and of course before some small failure causes a more expensive one down the road.  Thanks.

Give your local Kubota a call tell them the problem  and see what they say, they should be able to give you an estimate  to do the job ,as you said labour is relatively cheap here.

Ask if they will do it on-site or take it away ,could be haulage costs .

I have read on here that the L series was built to cost ,to keep prices down ,so some problems are expected .

As FJ would know and other farmers the old Fords built 20-30 years ago were well engineered built  to last .

I have a local guy ,a one-man band ,I have a Hino tractor the  sprigert bearing in the clutch seized,  he split the tractor took the clutch apart ,just cleaned everything up 1000 baht.

[MarcIssan]

Kubota is only 10 km from here so haulage shouldn't be that much.  The will likely want to come out here and test it first so I'll wait until the rains stop and I can hook up my tiller.

 

I learned that the double gaskets were to adjust the meshing of the pinion and ring gears.  I used one gasket but the gears were locked so now I am making another.  I may look for a rubber material..one that doesn't compress too much as I don't what the meshing to change from use.  Today I will use some washers to see what gap offers the best end result then look for gasket material of that thickness.  I think 2 mil compressed will achieve the factory spec.

[farmerjo]

20 hours ago, MarcIssan said:

I got on a tractor blog 6 months ago asking where that clanking might be coming from and everyone agreed it was the over-running plates in the PTO.  I guess they have a locking mechanism but the ramped plates allow for over-run as in the case of a mower etc where the inertia of the blade keeps pushing the tractor while applying brakes to stop (before disengaging the clutch I guess).  There is a matching ramp on each of two plates and then a notch where they catch again.  Maybe some springs to apply pressure when in use but also to allow over-running if the force is exceeded.   The clacking is where the plates or the ramps on the plates are worn and don't lock (or I suppose the springs have failed). The PTO still works but any medium force causes the clacking like running the tiller at 1500 RPM engine speed whereas at 1000 the clacking is reduced.  One Kubota owner said they were recalled in the USA and replaced no charge but that was years ago.  Since they don't have the L4508 in the US, they sent a diagram of a different model with similar HP to show the issue.  Since I am done with the trencher and plan to sell it, I want to fix the PTO for tilling and mowing...and of course before some small failure causes a more expensive one down the road.  Thanks.

All about getting to know the machine and some of those forums are very handy for specific issues,i quite often refer to them for troubleshooting.

I also had a look for you and besides what you found they did also mention to check the cable adjustments.

My Morooka has a dog clutch setup as well,it has clunked from day one when enguaging it but runs smooth once in and is more likely to stall the engine than slip.

On the RPM,besides the post hole digger i always run to the specs using the hand throttle as i'm sure the implements are designed at 540 or 1000 rpm for a reason.

Thai's tend to use the foot throttle which i think is more for comfort rather than the interest of the machine.

Hope you get a few holes dug when digger back together.

 

  

 

[MarcIssan]

Thanks for all the comments.  I think the cable is adjusted ok  as it is smooth upon engagement and light duty work but once the RPM increases or the resistance on the tool in use increases I hear an irregular clacking coming from just below the seat..in that area anyway.  Holding onto the the engagement/RPM lever I feel a jolt on every clack.  It is not mundane like if I gear tooth were broken and every time it came around it complained..it's not that.  In fact I can lift my rotary up off the ground and run it at normal tilling speeds and it is smooth as silk..but when I ease it down into the soil the clacking starts with the frequency depending on how hard the soil is.  Soft soil not that often...hard soil..yikes all the time. 

 

The group on one USA tractor forum who often do their own repair with some venturing into case-splitting came to the conclusion it was the PTO over-running clutch plates and considering how hard I was pushing my little tractor while trenching for irrigation and down-pipe water management, I'm sure that is what it is. I'll deal with that later.

 

I've almost gotten my auger differential put back together and found the double gaskets were to set the ring/pinion gear mesh so the last bit is a seal plate on the output shaft.  Of course that is at the bottom.  Alas I needed my hoist to lift that <deleted> up off my workbench but that darned winch went sideways on me.  Here it is 2 days later and the winch is back from the shop so tomorrow I'll finish up.  Hurry up and wait seems to be the slogan of the week for me.