I Still Hate My Tractor II

[The Fred]

Wow really did wear the ring lands badly,
wonder if Kubota uses steel ring land inserts for the Turbo spec pistons?

I caught it before the bore went really bad, I believe a touch up with a straight line hone will take off .0002" and clean it up nicely, otherwise off to the boring shop. The pistons for the Bobcat S185 (V2003T) that I sourced the turbo from use a completely different design , the chamber is in the piston itself, not in the head. I should have the new pistons tomorrow.

Kubota said they only have 6 pistons scattered throughout the USA which tells me I'm a lean shooter when modifying Diesels......back away for the Kubota Fred.

 

[TexasBoy]

I caught it before the bore went really bad, I believe a touch up with a straight line hone will take off .0002

Drop it in a Sunnen CV616 and knock that out in a flash.

 

[k0ua]

No clue about yer neck of the woods, but around here; crooked folk generally can't afford to do much shooting, so they mostly all shoot crooked. Generally when speaking of the crooked, folk swap 'shooter' out for other things like "he's a crooked S o B" or "he's a crooked S--t" and so on...

"Crooked as a dog's hind leg."

 

[Sysop]

That too! :thumbsup:

 

[dstig1]

I have a friend who sells Kiotis for a living. He recently took in trade a decent L5740 cab with low hours. He rented it once for a job and it came back with the infamous split pin leak so he had his guys split it and replace all the seals including the one in the front diff.

He wasn't too happy and doesn't want to take these lemons in trade toward an outstanding quality new Kioti:licking: I can't say as I blame him.

Wait... You have a friend that sells Kiotis, you feel they are a much better product, and you bought a Kubota???? :confused2::laughing:

 

[sd455dan]

I caught it before the bore went really bad, I believe a touch up with a straight line hone will take off .0002" and clean it up nicely, otherwise off to the boring shop. The pistons for the Bobcat S185 (V2003T) that I sourced the turbo from use a completely different design , the chamber is in the piston itself, not in the head. I should have the new pistons tomorrow.

Kubota said they only have 6 pistons scattered throughout the USA which tells me I'm a lean shooter when modifying Diesels......back away for the Kubota Fred.

Yeah- not sure if this is the deal but I think many of the diesels with the chamber in the piston are actually direct injected.

Kubota also makes indirect injected diesels but didn't know they made both versions in the same displacement.



Was doing some looking at some of the aftermarket high performance truck turbo diesel parts, they actually make steel pistons which have the added benefit of a closer relationship of the expansion rate of block and piston.

Can't imagine the rings did any damage or real wear to the bores , like you say a real light hone, new rings and she should be good to go.
No thoughts of buttoning the engine back up with the stronger piston lands, replacing the failed seal and just keeping the tractor with a maybe 8-10 psi of boost ?

maybe add an intercooler?

 

[The Fred]

Wait... You have a friend that sells Kiotis, you feel they are a much better product, and you bought a Kubota???? :confused2::laughing:

I know right? I bought a CK2610 from him for mowing and light duty stuff, I love the thing so far for 3 years. Not to change the subject but the Kioti equal to the L series is 3 cylinders up to 60 hp. The cab has MUCH more room but there is no high and low for the HST, just a pedal and 3 ranges. I haven't actually tried one for more than 3 minutes to tell if I like it. Obviously I can't bad mouth him if I buy one and don't like it; we drink some beer together so not happening.

Maybe I should have installed an exhaust temp gauge but the reason I didn't is because right after a HARD pull with the snowblower running full tilt I open the hood and put my hand on the boost pipe after the turbo and it is always ice cold so not sure an intercooler would help (with under 7 lbs. boost).

I work on cars for a living, about 50 years now, almost every engine I tear down has steel ring lands for the #1 ring these days because everything is boosted. If I could find steel pistons I'd most likely leave the turbo on because it made such a big difference for snowblowing.

Does anyone know if the FWD shaft can be removed without separating the transmission from the clutch side? Been trying to figure this out for 3 days as I have a new shaft coming.

Thanks for the input, good bad or ugly.

 

[moship]

The Fred

I'm intrigued by the amount of top piston ring side clearance. It seems a bit unusual even considering the addition of the turbo charger and the 6 to 8 lbs of boost your running.

In doing some research of diesel piston failures, I couldn't find anything where the ring groove increased in width. Typically the failure mode is just the opposite where the groove gets compressed limiting the rings ability for it to move within the groove.

If over fueled it seems this would either cause piston side wall and ring wear due to lack of lubrication (fuel wash) or would generate excess temperatures resulting in piston damage (burning, cracks, etc...). It's hard to tell from the photos, but there doesn't seem to be any evidence of this.

Pistons for the turbo charged L5740 appear to be 100% solid aluminum without the top steel ring groove. (Qualifier: Online photos are not the best, so I'm not 100% certain the pistons are 100% aluminum (ie: no steel at top ring groove). If this is true, how does this piston prevent expanding ring groove width and provide long term durability?

So how does the groove wear? Is it due to the ring rotating within the groove and ring gap edge scrapping way the groove? Is it from material displacement due to the piston yielding? Is there evidence this is occurring?

Like I said in the beginning, my interest is peaked with this failure mode and just trying to learn.

If pistons cannot be found with the desired top steel ring groove, can you have the new pistons sent out for hard anodizing of the ring groove? I'm using hard anodizing as an example as there are other methods being deployed with ring grooves.

I found this document when researching piston failures and found it very interesting.
https://www.memoparts.com/img/cms/Documents/Piston%20Failue.pdf

 

[The Fred]

I read that pdf thank-you.

Talked to a Diesel truck puller friend in Ohio today and described the damage, he thinks simply too much cylinder pressure and agrees the thing hasn't gotten too hot.

Pistons came in and look nice, new shaft and seals should be here tomorrow for a weekend marathon. Leaving the turbo off and all put back to stock.

The 4wd shaft pulls out by clamping a large pair of Vise-Grips over it and tapping out with a hammer, I am able to look in with a light and see the next collar at the very rear is in place and I can install/remove the shaft with no problems. The shaft is 34 inches long and mine runs out .040" in the lathe. I don't see any damage I thought maybe running front chains in the Winter and jigging the machine in deep snow maybe caused it to bend, not sure but the splines are nice and straight, there's not much meat to that shaft for a 5500 lbs. machine.

I had a friend who once told me I'd been shot at and missed, $h!t on and hit.

 

[The Fred]

I'm starting to think my oil leak is the HST input shaft not the FWD shaft seal as the seal for the HST has no tension when you slide it over the input shaft. I was reading this thread and it makes sense and the part numbers listed in this invoice show the repair. My clutch is dry but the diaphragm fingers have oil on them and looks like it could have spun off to the housing which is wet.

https://www.tractorbynet.com/forums...-l5240-hydraulic-leak-need-2.html#post5465204

My old FWD shaft seal has plenty of tension where it slides over the collar. Back to the dealer for more parts.

Also the new driveshaft runs out almost as much as the old one, oh well what's $80 bux these days.

I used double seals for the front shaft by removing the spacer between the bearing and the seal an extra oil seal goes right in.

Looked at a new L5460 this morning, didn't really impress me but after this one what would. The Deere dealer is right next door but I didn't have the balls to stop.