We have a Yale KGP51AT-40 S/N 551398 Can't believe the local dealer says parts are not available It has been jumping out of low forward for a year or two, anyone have some ideas? Below is a picture of the gears in the transmission, anything look out of the ordinary? Have been told several times over the last 10 years that a newer one has been approved in the budget. Maybe I should have been dumpster diving for deposit bottles all these years could have purchased a new one by now!
Looks like if it stops in the right spot it won't even move.
I think I can trump that. We had a 789 the other week that wouldn't build air. The initial diagnosis was a seized air compressor but when the compressor was pulled out the boys discovered that the idler gear between the crankshaft and the compressor drive gear had no teeth on it whatsoever............l The best part was that the crankshaft gear didn't have as much as a scratch on any of the teeth.
Looks like a visit to a scrap yard is in order. Drop a whole "new to you" tranny in it instead of hunting for ghost gears.
I would count that a a very lucky find. Did you decide to buy a lottery ticket after that one?
Is that frosting and sparkles? Are you secretly practicing to be a cupcake artist?
Well looks like it is low on oil?.
Hydrolube, that is mostly water and air with a bit of gucky grease and rust flakes for giggles. Build those teeth back up with some modified stainless, Eutectic 680 or similar, grind them into shape, or find a good machinist, put some good old roller lube in there, LOL.
that's just those tapered gears, designed to take the place of synchronizers.
The best part of it is I now have to make a plan to inspect 34 engines in service using a borescope to see if we can see any initial signs of the same failure mode on any others, starting with those engines we've already had rebuilt and where the gear was reused, many of which are well past 20k hours by now. Apparently it's a "known problem" but the failure mode is so random that there is no official service support, just an agreement to support any engine where this gear fails. Neither is there a way of predicting it from oil sampling, but we're planning on fitting a mag plug into the oil pan just below where this gear runs in case it might just pick up some fragments and give us a heads up ........ The other issue is that if the gear fails the particles that air produced from the initial stages of the failure get sucked up by the oil pump and scratch the crankshaft bearings, so that's engine out time. Even if it can be picked up at any early stage the air compressor, fan drive, aux water pump, front engine mount, and crankshaft damper have to come off just to get at 2 of the 3 bolts that hold the shaft for the idler gear in place. Once the shaft is out the gear will slide sideways then come out the hole where the air compressor mounts.
A large handful of these is what came out of the oil pan ...........
I have seen that before in a 3176C, loose idler shaft bolts in that case, wallowed out the block where shaft sits in.
Nothing loose, no bearings worn out, just the teeth totally missing off one gear in a set of 3 ..................
Too hard, or not hard enough.. weird. Nige, what's your sampling interval?
Hey Nige, Maybe you could grind that gear smooth, er, smoother, then wrap a bunch of layers of old inner tube around it, then patent it as a "friction compressor drive", no wait, a silent compressor drive?
Like you said Nige, fatigue. Compressor surely been changed several times, crank maybe reworked or replaced at rebuild? Overworked
Reminds me of a Deutz engine in the old Terex artics, guy laid one over, filled the air compressor with oil... the drive gear had a torque limiting setup with a large belleville washer, when the compressor hydro-locked the clutch popped over, saved the whole gear train from catastrophic failure. Sometimes ya just gotta love those crazy Germans and their over engineering.
Nothing so exotic. Rather than being a forging or a milled blank it's a powdered metal gear, made in a press. Every so often one comes out of the mould that hasn't been squeezed quite tight enough.
250 hour oil sample interval. The only one that showed a jump in iron, and even then it still wasn't enough to trigger a monitor compartment alarm, was taken 5 days before all the teeth landed in the oil pan.
Cranks are all original. Never replaced a single one out of all the fleet, well so far anyway.........air compressors we have very little trouble with, despite the engines being air start.
Hi there, we run around 140 of those trucks. We have never had this happen. Can you forward the serial number of the engine that failed ?
Nige, Maybe you could send me about a dozen of those with some JB Weld to fix my trans. As this is a very low priority machine all that is going to be done is some repair work to the shift rails to try to make it less of a guess as to what gear it is in. The detent balls had grooves worn in the rails and the interlock that prevents it going into two gears at once was totaly not functional. I would like to be able to do a good job either swap in a used trans or new parts if they were available but that's not my call. It's a shame because with a hand full of parts and a bit of labor this unit could out live me!
140 789 Cat Trucks? I can't begin to wrap my head around the support team need for that kind of a fleet:notworthy You must move more material before lunch on Monday than we do in a years time!
That's only the 789's. We have 785's too. You would be amazed how few of us keep them alive.
Nige, do those air start 789s use an air starter motor, or do they start like an EMD, by blowing air into the cylinders? Wonder how well that'd work on a 4 stroke?
Do tell! Maybe I'm just lazy but keeping 2 769's on 773 a 988H, 3 980's 3 skidsteers, 1 Back hoe, about 10 pick-up, 2 Miller welders 1 Antique Yale fork lift going along with keeping records on work done, oil samples and the odd crusher pump or stationary air compressor running, repairs to water recycler for washbay functioning, cleaning shop and chasing parts for the above while working 40 hour weeks 10 ten months a year leaves little time at work to read these forums!
trackdoc, the one that failed was S/N 7TR02736. The gear is a 153-1243 - been in use since 1998. It's been replaced by 420-2042 since mid-2012. A new gear is about $300, so we're now replacing all of them (every engine we have bar one has the former Part Number gear) as a one time only deal with the new gear when we pull them for overhaul. Previously that gear was only replaced based on condition when the engine was overhauled at 20k hours. The main problem we have is a number of engines that have already had 1st overhaul - what do we do with the gears in them..? Don't get too wound up, the failure mode is sporadic (allegedly) but since we've had the failure it's focused our efforts wonderfully. Mitch, they are actually an air turbine starter motor bolted into the flywheel housing. One TDI Turbostart will replace 2 x 50MT electric starters and is about 1/10th of the weight. Why anyone would want to use electric start (including the 6 8D batteries it needs - the air start version of the truck uses 2 x 4D simply to light up the dash panel) on an engine this big I have no idea. http://tdi-airstarter.com/t50.php KSH, We have a very small fleet where I am now. The biggest fleet I worked with was 140 trucks, a mixture of Cat 797 & Kom930E, the fleet moved 1.2 million tonnes of dirt a day. We always used to joke that was despite the management not because of it....................
After wrestling 50MT's too many times I would love to have one of those T30 starters on our Cat 769C&D. Would be a problem on our 980's and 988H, no air! Every-time I mention our WA600 with the K19 that has the original 1996 50 MT that was installed at the factory and as of yesterday, with just short of 25,000 hours, is still starting the engine like the day it was bought I think I'm going to go in in the morning to find smoke coming out of it
They use 2 50MTs, when they need more power? I would think you would have trouble with one lagging just enough to accelerate wear on the drive gears. The only big stuff I work on is EMD 16v645s. To start them, you start a 6-71 that turns an air compressor, then blow air into the cylinders to direct-start them.
I need to confirm on our 773G Truck, but as I recall it has the "Cold Weather" option and it has two 50mt's if I recall. I know when we still had a D399 V-16 genset it had two 32 Volt 50MT starters or were they 36 volt? Been many years since I worked on that one!!
When I worked the tugboats they were all air starters, Detroits, CAT D399's and 3500 series.... always had one auxiliary generator engine started on battery which we kept in top form. If you lost air, you had to have that one to power the compressors.
That's what these EMDs are in, tugboats. They're just big Detroits. The captain who owns them, (83 y/o) will correct you in a heartbeat if you call his 71s and 53s Detroits, they are old enough to be General Motors Diesels.
Mitch, Kinda what I figured, something marine with the high voltage systems.... locomotives are usually started off the DC generator I believe, they start them with a gas drive welder in the field?
These tugs are mechanical drive, not electric. I think you are right about the locomotives, but I'm not sure.
In the power station world we used to call them "black starts" - because before you cranked that one engine up, everything was black ..........
Nige, Exactly! Had that happen on a boat once, luckily in calm seas and open water. The auxiliary was a 6-71, burned a valve for some reason. When the air compressor started the gennie stumbled and went to it's knees and as I was trying to get to the backup the lights went out. Engine room on a tug is not a good place to be with the boat moving and everything hot and the battery lights of course failing to work. Pocket penlight to the rescue again. Of course the Cajun Captain screaming "I got no steering!!!!" every ten seconds didn't help belay the panic I was in, LOL
Yair . . . mitch504 . I posted pictures of English Mirlees powerhouse engines some time back . . . four strokes, air start with #1 cylinder on TDC. The old style English diesels start very easy. Some of the early pearling luggers had 50hp 4LW Gardiners for the simple reason they could be hand cranked and there was no need for batteries or electrics on the boat. Even the "big" 24 litre 230hp 8L3B was supplied with hand start tackle and could be decompressed and started on one cylinder . . . possible with one bloke, easier with two. Cheers