so someone im working with over tensioned the tracks on our new to us excavator. should have checked, trusted they knew what they were doing. anyway, noticed some difficulty turning then noticed a pin was partially out of one of the links, and the travel motor was leaking hydraulic fluid. so first question is, i pinched the track back together and pounded the pin back in, it seemed to go in easier than i would expect. both the pins on that link (the master link?) move with some semi firm hammering on a drift punch. this is the type of track that goes between pads that rub on the pins (well, this is the only link that seems to have visible pins?) and i remember seeing something similar where the pads keep the pins in every time the track goes around. is this the case, or do i need to be concerned about the pins being that easy to move? second is the travel motor. my guess is the extra stress from the over tight track caused a possibly ready to burst seal to go ahead and burst. not pouring out, but leaking steady. we are on a fairly tight timeline with the excavation and id like to not deal with the motor till later. would it be a bad idea to run the excavator, with minimal movement, and then deal with it later? my main concern would be the motor going completely out and getting stuck where we would have trouble recovering it. how difficult would it be to remove the travel motor and rebuild it? im fairly experienced with mechanical stuff and have a decently set up shop, but obviously dont have a ton of experience with machinery.
also does anyone have a track tension measurement for that machine? manual is in the mail
With some track pins being loose I can only imagine the track chains are likely whipped. Tack weld any loose pins in place to get you by. Where is the oil leak at the travel motor ? Is it leaking gear oil , hydraulic oil or a combination of both ?
This is for your 493D correct ? The screenshot below is from the 490D operators manual. On your 493D when measuring the sag ,you will have to take in account the height of the full length rock guards.
looks like hydrolic fluid but ill look closer and smell it. its leaking right inside / inboard of the sproket
yes 493d. thanks
That is often gear oil from the grease seal. Pull a plug and check the final oil. You'll learn a few things. 1) I it is overfull and looks like hydraulic, drive motor seal is out and pushing hydraulic oil in. 2) If it is low, then add the appropriate gear grease and watch that. If it goes down again, then the grease seal is probably out. I ran the 120 for a while like that, adding oil until I got the tools made to take it apart. I think it may be the same tool set for the 490, @Diesel Dave probably knows.
thanks for the info, i will check it. i did take a 2nd look at the oil coming out and im fairly sure its only hydrolic fluid, no smell and very clear. if hydro fluid is getting into the gear case, i assume thats a problem as it wont lubricate properly?
The final drive tool set for a Deere 120 is not the same as Deere 490D. The bearing preload nut has different retainer spacing.
so i checked the level and sure enough its overfull. so what does that mean in terms of continuing to use it?
Keep using it until you finish the job. Don't let it get over full for to long. My guess is the output shaft seal on the hydraulic motor has failed. At this point only the motor needs to be removed and repaired. Often the seal failure is caused by worn bearings in the hydraulic motor or worn pistons,worn valve plate etc which then increases the casedrain pressure then popping the seal. Drain, flush and refill the planetary gearbox after doing the motor repairs.
thanks for the info. thankfully the job im doing dosent require a lot of travel, but ill keep an eye on the level. since i may be using a fair amount of hydrolic oil, is it ok to use the cheap stuff on this machine for this job? i plan on doing a complete service and flushing out the system / replacing with the specified fluid
update, looks like the motor is getting fluid even when not moving, and going through mabey a gallon or two an hour, which is consistant with the drift on other functions. will flush the system and put new filters in, but if that doesn't work to stop the fluid getting to the motor might have to look at a rebuild. i saw that the seal kits arent bad price wise, is that likely to solve the problem? and is this something that i could likely do myself? also what is the process for removing just the motor?
Removing the motor involves coming at it from inside of the track frame, so remove the cover plate which exposes the motor. Every hydraulic connection has to undone, pipes should not be bent out of the way. If they are they'll never reseal properly so move them. Tag every connection, makes assembly easy. With the lines out of the way unbolting the motor can begin, usually about 6 Allen head bolts. Crows foot wrenches if you haven't got some will become your new best friend. Repairing for the first time should be done with a mentor at least IMHO otherwise it's a job for a hydraulic shop. Most important thing last. CLEANLINESS IS NEXT TO GODLINESS. Keeping everything clean saves a world of pain.
thanks for the info
The original leak you discovered is at the final drive in the area of the sprocket. You will need to replace the final drive duo cone seal as well as removing and inspecting the motor to address the overfilling . Short story is , split the tracks before removing the motor. See parts screenshot below, duo cone seal item # 2 .
Hey Dave, I've had the duo-cone seal leak because of the high pressure in the planetary hub. Fixing the leaking motor thus reducing that pressure stopped the duo-cone seal leaking. The bearing at #4 is a hexy item to buy for no good reason other than, should do it while we are here.
Hey Tones , I hear what you’re saying about the duo cone but I think if the machine is down anyway for the propel motor why not replace the duo cone seal at the same time. Hate to find out after installing the propel motor the machine is still down, it’s not that big of a deal to replace the seal. If the #4 bearings aren’t horrible re-use them.
thanks