279D right side drive motor issue

[Tonkatoy]

I have a 279D sn GTL04445 and the right side is locked up. It made a bit of a grinding sound, and the abnormal speed warning flashed. I think it is something in the drive motor. I have taken the drive motor out and accidentally cut two wires on the speed sensor doing so. Should the drive motor turn freely if the parking brake is released and the drive hydraulic lines are not hooked up? I was going to try and test the motor to see if it would spin with park brake released with the other lines capped. Would a faulty speed senor engage the park brake on that side? Also I was thinking that Cat shoudl be able to test the motor on a test bed, is that the case? In the event it needs replaced any thoughts on cat reman vs new? thanks.

 

[Nige]

First thing would be to look at the hydraulic filter. Can you see particles in the filter or the housing.? If not then see below.....

Did you take a look in the planetary side.? Drain the oil by removing the plug on the outer case. See if it is full of sparkly bits. Maybe that is where your grinding noise is coming from.?

Also I was thinking that Cat shoudl be able to test the motor on a test bed, is that the case?

There is no such thing as a "test bed". All the dealer would do is open it up for inspection just the same way that you are proposing to do, and remember they would charge you $150/hr for the privilege. Personally I would suggest to open up the planetary yourself first.

I'll try to upload a parts illustration of the Motor Gp but it doesn't want to co-operate at the moment.

 

[92U 3406]

I would put the machine on stands and run a case drain check on that side. A healthy motor will put out about a pencil lead sized trickle when in normal operation, slightly more when stalled (Cat does not have a case drain volume spec, at least that was what I was told by Cat's tech team anyways). If you're getting a lot of case drain flow then odds are the motor has failed or is failing.

If the motor case drain flow is good, I'd pull the cover off the final drive and see if something came apart. If it looks good, you're probably going to have to pull the motor/drive and disassemble it.

 

[Tones]

The first thing to do is check the condition of the planetary oil. If it's good then do the casedrain flow check as mentioned above. Testing and checking is a lot cheaper than guessing.

 

[92U 3406]

The oil will come out black, it always does even if you change the oil regularly. So don't worry too much about that. You're looking for chunks and lots of glitter.

 

[Tonkatoy]

I will check filter tomorrow. Is there any special procedure for taking off the outer cover? From what diagrams I have seen the motor end of the housing has springs inside.

 

[Tonkatoy]

Also the reason i asked about testing was that i saw a video of a hydraulics shop testing one in a vice with a test rig. Just out of curiosity, if you released the park brake how freely should the motor turn with the other hydraulic lines off?

 

[Tonkatoy]

Here is a drawing I found for the part number to fit my machine.

 

[Junkyard]

It won’t turn very free even with the brake released. There’s a lot of stuff in there. I’ve had them break the swash plate and lock up. Speed sensor won’t make the brake lock. Tear it apart and see whatcha got.

 

[Nige]

I will check filter tomorrow. Is there any special procedure for taking off the outer cover? From what diagrams I have seen the motor end of the housing has springs inside.

Yes, but don't go into the motor end yet, go into the opposite end. All you have to do for a start is to remove the plug #9 and check the oil condition for sparklies and/or metallic chunks. After draining the oil there is a large circlip holding the cover in place. It's shown as part of #2, which from right to left is the circlip, the cover, and an O-Ring seal on the inside.
That would allow you to inspect the planetary assembly #3.

 

[Tonkatoy]

Thanks guys, I will tear into that tomorrow.

 

[Tonkatoy]

Took the plugs out of the planetary side and there is metal shards inside. My largest snap ring pliers are not up to removing the retaining clip so need to figure something out there. Amazon sells a set by Lang that looks like they will work.

 

[92U 3406]

You'll most likely need a slide hammer to pop the cover off, they get stuck in there. You'll also need an adapter that matches the ORB plug in the middle of the cover.

 

[Tonkatoy]

Got the end off today, several of the gears have chipped, missing teeth. At this point I am not sure if it is worth the time and money to replace gears, get a reman unit, or just purchase a new one.

 

[Nige]

At this point I am not sure if it is worth the time and money to replace gears, get a reman unit, or just purchase a new one.

Price up all the possible options before making a decision would be my first suggestion.

 

[CM1995]

Well I went to SIS to see what a drive motor is running now a days in order to give you an idea of cost new but on both of our 279D serial #'s it said contact dealer.

IIRC several years ago we had one replaced under the PT warranty and it was around $5K including R&R at the Cat house.

 

[Tonkatoy]

New lists as $6375 and reman at $4143 with a $2231 core. The fine print says they have to inspect core to see if they will take it. Gear kit is $3100 or so. How do you feel about cat reman parts Nige?

 

[Nige]

The fine print says they have to inspect core to see if they will take it.

I would suggest to ask what the Core Acceptance Criteria is. A lot of components have to freely turn 2 full revolutions - which your motor obviously won’t unless you pull all the planetary gears out of it (now there’s an idea, but I didn’t say that.!) before you hand it over. Also there could be a clause that states components must be in original condition with no evidence of recent disassembly before being handed in as a Core. I’d guess your motor shows clear signs of the cover having been off it. It will pay you to check what specific conditions apply to it.

How good the value of Reman would be in your circumstances would depend on how many hours a year your machine clocks and what warranty is given on the replacement motor.

If the hydraulic side of the motor is good (cut the filter & check for particles if you haven’t already) then maybe a new planetary gear set would be a cost-effective solution. Hard to say without having the parts in front of you. Also the total hours on the machine would play a part. I don’t think that you ever mentioned the hourmeter reading.

 

[Nige]

It's a bit late to ask now but was the oil you drained out of the planetary compartment black.?

That compartment takes 1 litre of full synthetic 75W/140 per side. There have been a lot of posters on this forum recommending to change that oil every time you change the engine oil because the quantity is so small and the fact the oil is under so much stress. See this thread.

299d2 final drives REALLY hot

Running full throttle moving dirt back and forth at 100% efficiency for about 1hr; I got out to swap to my box grader and felt the drive housing... They were... Hot, I could smell the 2 month old fresh paint burning. Both sides were the same. How hot can they get? Is this because of the 155...

www.heavyequipmentforums.com

 

[savman]

I changed my final drives (289d3) at 250 hours per the dealer recs and there was enough flakes in there I got on the phone and sent pics/email of what came out. He swore up and down that's normal wear but man there was some metal in that fluid.

They recommend every 500 hours after the initial 250 but I change mine every 250 hours. That synthetic stuff isn't that much money and it's super easy to do. Cheap insurance imo.

Buddy of mine was there when I did the initial 250 hour change and he was shocked at what came out as well.....then he said....well I guess I should change mine too; problem is he has 1300 hours on a 299 and has never changed it. Oops.