RK55 Hydrostatic 50-hour Service: My first big RK post

   / RK55 Hydrostatic 50-hour Service: My first big RK post #1  

markie61

Veteran Member
Joined
Mar 31, 2001
Messages
1,370
Location
Northern Virginia
Tractor
2019 Rural King RK55HC with Loader & Backhoe; 2001 New Holland TC40D with Loader
This is a long post and took me about a week to do the service, take pictures, communicate with RK, and edit. Please let me know if anything should be corrected. With my comments below, I am assuming the person doing their own service has a level of comfort and familiarity with fluid changes on a car, lawn mower, or other internal combustion engine. In addition, this is my own experience - RK is the ultimate authority on how their tractors should be serviced which is why YOU SHOULD READ THE MANUALS: https://www.rktractors.com/manuals/Operator Manuals/RK55 Hydrostatic Open Station & Cab Tractor.pdf https://www.rktractors.com/manuals/Loader Manuals/L110 Loader Operator Manual for RK55 Tractors.pdf https://www.rktractors.com/manuals/...Backhoe Operator Manual for RK55 Tractors.pdf In addition, the parts manual was very helpful in determining TYM part numbers, locations, and names https://www.rktractors.com/pdf/parts/RK55S RK55SC.pdf. It's a good practice to download all of these PDFs and keep them on your computer (you can print out the disposable pages you need and not worry about getting your hard-copy manuals messed up with oil and grease.) In other words, don't blame me if you do what I did and it's wrong!

My cab tractor has L110 loader, BH85 backhoe, optional 3rd remote, and 3rd function control.
PreDelivery Pic Front.jpgPreDelivery Rear.jpg
Before servicing my tractor, I removed both the loader and backhoe to improve access, then ran it to operating temperature to warm up the fluids, lowered the grill guard, opened the hood, and removed the engine side panels.

Prior to draining fluids, I collected all the necessary filters, fluids and tools. Note that the RKTractors.com website has a list of recommended filters and fluids https://www.rktractors.com/pdf/brochures/maintenanceproducts.pdf, but the document has a several typos under the RK55 Series specs (SKU3261176 is 2-not-1 gallons and SKU3261053 is 1 quart-not-gallons of 80W-90; SKU3262304 is 1 gallon-not-each of 10W-30; and SKU3261927 is 2-gallons-not-1-quart of THF and missing SKU3261930 is 5-gallons of THF). I used:

Filters
Engine oil TYM-12915035153 SKU21260378
HST (small, white) TYM-15532302100 SKU212160532
Hydraulic (big, black) TYM-17975152100 (or ending 01) SKU??

Fluids/Lubricants
Engine 10W30 Rotella T4 (my preference over Harvest King oil), manual accurately says about 1.4 gallons
Transmission Harvest King Premium Universal (gold label) SKU3261930, manual says about 9.24 but I used all 10 gallons
Axle Harvest King 80W-90 Gear Oil GL5 SKU3261176, manual accurately says about 2.64 gallons for the total 3-part front axle service (see below)
Coolant NAPA Premium 50/50 Premix ethylene glycol/water ASTM D4985/D6210 (what I had on hand), topped off about 8 ounces
Tractor Supply Company's Traveller Extreme Duty 3% Moly Lithium NLGI #2 grease, less than one 14 ounce tube

In addition to traditional metric tools socket set, combination wrenches, spanners, etc. I needed very large sliding jaw pliers, small blade/scoring tool, suction gun, funnels, and a plumber's propane torch. RK recommends a 3/8 socket extension with open end wrench.

Coolant - needed to top off with 50/50 as it was slightly below minimum. No leaks noted at hose connections, but the weather is significantly cooler now. I will monitor for future drops in level.

Air Filter - knocked dust off primary and blew out housing. The secondary was clean.

Engine Oil - fluid and filter changed. The magnetic drain plug had no signs of metal. If you have ever changed oil before, the procedure was normal with the following exceptions:
*The factory used two heavy-duty zip ties to hold two hydraulic lines and a wire to the engine oil filter housing's pipes. They had to be cut to get the spin-on filter off and on. In addition, the filter was WAY overtightened and painted at the factory after it was installed. Needed large sliding jaw pliers to remove after scoring paint at filter base. Filter was destroyed during removal.
IMG_1065.jpg

*The owner's manual diagram (page 5-9) leads you to believe that there are two oil drain plugs - there is only one. It was painted over by the factory, but it came off easily since it had a washer. The backhoe subframe's front mounting plate covers the oil drain plug leaving a gap of about two inches between the plug's bottom and the plate's top. The mounting plate has two very large holes, but they do not line up with the drain plug offset by nearly two inches. If you tried to drain oil as it exists, you will have oil everywhere.
IMG_1066.jpgIMG_1067.jpg
I used an upside-down lid from a 5-gallon bucket to divert the oil into the catch bucket (still messy, not as bad as it could have been), but for future engine oil changes, I purchased a funnel tray/sorting tray SKU37081 from Harbor Freight for $3.49 which should do the trick for catching and diverting the oil.
Sorting Tray.jpg

Transmission fluid - fluid and two filters changed. The single magnetic drain plug was painted over but was removed fairly easily. The magnet captured a few small "pencil shavings" on it that resembled manufacturing debris. Like the engine oil, the procedure was normal with the following exceptions:
*HUGE *HUGE* TYPO IN THE OWNER'S MANUAL LUBE CHART on page 5-10: do NOT use API GL-4 80W gear oil in the transmission case! Use the hydraulic fluid here https://www.rktractors.com/pdf/brochures/maintenanceproducts.pdf.
*Both filters were WAY overtightened and destroyed when removing. Unlike the smaller HST filter, the large hydraulic oil filter was installed then painted over at the factory making removal especially difficult. I scored the paint at the filter base and used the large sliding jaw pliers combined with a strap wrench to get it started.
IMG_1069.jpgIMG_1068.jpg
I almost gave up and had prepared my drill in order to cross-drill a hole in the filter and put a bar through it before trying one last time.
*Almost 10 gallons of fluid drained out. A 5-gallon bucket fits perfectly under the drain plug, BUT the subframes will not allow you to get it out without tipping it over; whatever catch basin you use, it has to be shorter than 12.5 inches. In addition, most containers are less than 10 gallons, so be prepared to temporarily reinstall the drain plug to change containers. The magnet is very strong and wants to stick to the transmission housing.
IMG_1070.jpg

Front axle and two final reduction gear housings fluid change - these three items are NOT connected via common sump as the owner's manual (page 5-15) may lead you to believe and must be drained/filled separately. The procedure was normal with the following exception:
*The four square-head drain/fill plugs (one upper and one lower) in the two final reduction gear housings were WAY overtightened and thickly painted over. I started on the right side.
IMG_1072.jpg
A 12mm open-end wrench or 14mm 12-point box-end wrench or socket could have removed pre-loosened plugs easily, but they would not budge for this first service. I bent two 12mm open-end wrenches and rounded off the plugs shoulders in my attempts. Ultimately, I used a plumber's propane torch with a pencil-point tip for about two minutes on each plug to burn off the paint (it turned whitish-gray). I then hammered on a 14mm socket with 12" extension, then exerted significant force with the ratchet to complete removal. Two plugs heads were destroyed I requested replacements under warranty via the parts link on www.asktherktractorguy.com, but had to use another contact to receive acknowledgement. They said "I'm afraid we can't replace the plugs under warranty as it is a square head plug and they do not round off if removed with a 3/8 or 1/2" extension over the head and crescent wrench on opposite end as shown in the attached photo. They round off due to using a hex socket or open end wrench."
square plug[7852].jpg
On the left side, I started with the torch-then-14mm-socket-wrench process which did not destroy the plugs heads. My advice: try RK's socket thing, but you may have to start with the torch, even if the thought of applying fire to your $45K tractor makes your "boys" hug you tighter. Subsequent changes will be easier since I reinstalled the plugs with just enough torque to keep them from oozing and there is no paint.
*Filling the final reduction gear housing via the vertical upper plug hole is a pain (as it was on my New Holland too), but a funnel and the hose off my non-functioning $13.99 Harbor Freight suction gun SKU95468/63902 combined with patience did the trick. Normally, I use the suction gun to suck fluid out of the jug and squirt it in the hole.
Suction Gun.jpg
*The 2.64 gallons of fluid appears to be for all three items: the axle and the two gear housings. I tried to dump in the 2 gallon container to the axle fill port and overflowed it.
*The front axle fluid level dropped significantly below the dipstick lines once the tractor was moved. There must be an air pocket somewhere in the axle that doesn't fill when gears are static, so topped off a second time.
*The 80W-90 gear oil is very thick and on a cloudy 60-degree day did not flow well. In the future, I will leave the container (which was black) out it the sun to warm it up to flow a little better.

Fuel filter - no leaks noted.

Fuel bowl/water separator - removed, cleaned, reinstalled, bled fuel system.

Grease fittings - between the tractor, loader, backhoe, grapple, and implements I added, there are a gazillion grease fittings. The owner's manuals for the backhoe (20 nipples) and loader (16 nipples) are accurate and I hit them all. However, the tractor owner's manual diagram on page 5-9 is inaccurate - there are 5 nipples total, not 9 as indicated: 2 on the axle pivot, 2 at each end of the brake shaft (one is behind the HST filter hard to see), and 1 on the 3PH tilt link cylinder. I confirmed this officially with RK.

The bottom line: unless you prepare properly, this service will be significantly more time consuming than subsequent ones because you will be breaking factory connections for the first time (in addition to time learning the layout of your new tractor!)

Side notes: I had to make two 100-mile round trips to my RK store over two days before I could begin service. The first was to get a second 5-gallon pail of hydraulic fluid since I wasn't sold enough when I picked up the tractor new (I wanted to get all the 50-hour supplies at tractor delivery so I didn't have to make the trip...The second trip was because I was provided the incorrect HST filter at delivery (I'm told it was for the RK37); when I arrived, they did not have any (even though I called first and was told they did; the guy I spoke with says they had yet to do a 50hr service on a RK55H and didn't realize they had none). The main salesperson was off for two days, so from the store's parking lot I directly emailed our RK-TBN friend Brain Evans (as he requested of us) explaining what had transpired. He called me within an hour, apologized, and air-freighted the correct filter to me (and a bunch to the store - now in stock!) In other words, Brian committed on the TBN forums to supporting RK tractor owners and HE KEPT HIS WORD by making it better. I understand why they won't send the drain plugs under warranty since I buggered them up.

In addition, he wanted to know more about my overall experience, so I shared with him almost everything that I noted above (I sent him the pictures too) which he has shared with TYM engineers. I commented that the best thing they could do for the brand is improve the owner's and service manuals; he says that manuals are among the top of RK's list given to TYM's engineers in a meeting last week. There was a "hunger" for feedback in his questioning and an explicit statement that they want all feedback - the good, bad, and ugly - and that they will act on it in order to improve the brand. Everything RK has done in words and deed makes it appear that they are truly committed to making everything - product, sales, service, parts, etc. - better.

I volunteered my almost 20 years experience with the TBN community: that it was made up of folks from various walks of life, that most of us wanted to learn from others and share our experience, etc. I thanked him for the uniqueness of actual official brand participation and encouraged him not to give up his and/or RK input. I suggested that he react (and sometimes NOT react) in the forums with "thick skin" since there were participants who habitually "bash" or "flame" everyone/everything no matter what - that he stick to facts, don't get caught up with opinions or predictions, and keep RK's promises. He has quite a few responsibilities within RK (the signature title on his email says "Associate Category Manager: RK Tractors, 3 Point Equipment, Hardware, Paint, Plumbing, Electrical, Hard Ag, Spraying, Chemicals, Seed Corn, and Soybeans"), but his plan appears to be to "peek in" on the forums every week or two (during business days, not the weekends) and respond where appropriate.

Folks, Brian (and RK's official representation) is a valuable resource and tool for those of us TBNers who both own RK tractors and/or intend to buy one. Please be respectful of him, his time, and his presence and don't be abusive. It would be bad for us to lose this important voice and end up like all the other brands forums who must fend for themselves.
 
   / RK55 Hydrostatic 50-hour Service: My first big RK post #2  
Thx for the detailed post. I fully intended to do my own 50hr service, but my RK55HC developed a leak at the steering shaft, and since it is already going to be in the shop for that, I figure I would let them handle the 50hr.

I appreciate the time/effort expended to make this post!
 
Last edited:
   / RK55 Hydrostatic 50-hour Service: My first big RK post #3  
I use 8 point sockets on the square headed plugs.
You might be able to pickup a set from Harbor Freight.
 
   / RK55 Hydrostatic 50-hour Service: My first big RK post #4  
Wow, thanks for all that info. I have 30 hours on mine now, so it won't be long before I put your experience to good use.
 
   / RK55 Hydrostatic 50-hour Service: My first big RK post #5  
You are spot on with your service notes and instructions. Getting the filters off drove me to a new level of angry - until I got to the axle plugs. Lol.

I also took off the backhoe subframe just to make it easier - something I saw Mike Morgan suggest. I still got a little fluid on my concrete - but really not that much.

I’m really pleased with the tractor and how everything is marked and labeled. Some things were a bit difficult - but not bad.

I noticed my antifreeze/coolant level was low as well.

Getting the hydraulic fluid into the fill hole/area was the biggest pain. Lifting five gallon containers to pour the fluid is just nonsense.

And as far as the manuals - they just need work.

My only complaint is that the stores are suppose to stock the filters and fluids or at least they should. Unfortunately the only person at the store that knows anything about the filters is the tractor sale person. It has to be the single biggest ticket item they carry at the store (the tractors) - people should have access to the knowledge base or replacement parts (wiper blades, bulbs, fittings, fluids, filters, etc).

On a side note, I washed my tractor a couple of weeks ago and noticed the cab leaked around the top. This may be from spraying water up at the top from ground level - but I can’t imagine washing the cab any other way.

I am really impressed with the tractor. I have thrown a lot at it and she’s still going strong. As I know a lot of folks from the forum have as well.

Let’s hope they get the bucket issue solved. I hate seeing my tractor from the front and seeing the bucket tilted.

Gunny
 
   / RK55 Hydrostatic 50-hour Service: My first big RK post #7  
Well done, though I have an RK24 I still find some relevant material in your post and the info about Brain Evans is encouraging, I hope that his attitude carries through to all of the service centers and leads to improvements.
 
   / RK55 Hydrostatic 50-hour Service: My first big RK post #8  
Some people try to claim TYM,Mahindra, RK and MF are all way different...but that sure looks a lot like the 50 hour service on my Mahindra I have coming up. Even the "two oil plug drains" on the manual.

Thanks for the write up, I will use some of your advice on my machine.
 
   / RK55 Hydrostatic 50-hour Service: My first big RK post #9  
May I STRONGLY recommend that you get a Fumoto Valve to replace your oil drain plug. They thread in place of the plug, provide an easy to operate, but locking ball valve actuator and are available in straight or 90-degree options. I have them on 2 of my vehicles for easy and clean oil changes and you can drain the oil while warm to hot because you never touch it. In your case, you would get a 90-degree option with a nipple so that you can slide on a length of hose and drain that oil into a pan with ZERO MESS.

Capture.PNG Buy Fumoto(R) Valve Online | Replace Oil Drain Plug

Once you find the model you need, you can order from Amazon. And since it would be located ABOVE the backhoe subframe, it is perfectly well protected from being impacted or damaged.
 
   / RK55 Hydrostatic 50-hour Service: My first big RK post #10  
Forgot to mention, I also had low coolant at 22 hrs - overflow tank was almost completely empty. I filled it to the max line and now at 42 hrs the fluid is about a half inch below the max line.
 
 
Top