Tuff Torq K46 Fluid Change

[pudge]

All Hydro transmissions make sound, get used to it.

a few years ago, a john deere mechanic told me the same. all hydro transmissions make noise, just the nature of the beast

 

[gman2304]

I changed the oil in my K46 last spring at 585 hours, most likely it had never been done before and had gotten a pretty loud whine over the years. I used Mobil 1 15W-50 which quieted the unit to a large degree but didn't eliminate the sound. The mower currently sits at 614 hours. Not all the old oil drained out(it calls for 2.3 quarts- I was able to get right about 2 quarts to drain). Those last couple ounces of old fluid won't make a difference but this BITOG after all

Would it make sense to do another drain and fill now with only 29 hours on the new stuff? I want to make sure all the old fluid gets replaced but it's really a hassle to pull the gearbox from the mower.

My old 1998 TT K61 i bought new is still going strong entering its 28th year. No hour meter but I’d guess it’s near 2,500 hours and many hours pulling a plugger, lawn cart, and a heavy Cyclone Rake in the fall. I’ve changed the hydro oil about every 500 hours estimated and have used Mobil1 15w50 exclusively. It’s always been a bit noisy but I feel it’s just the nature of the beast. If this little JD LX188 explodes in a ball of fire today my only complaint would be that 1998 was the last year of this model. It owes me nothing!

 

[martinq]

My experience mirrored yours. Not sure when I first changed mine (Deere L110) but it would have been similar hours - I used 15w50 too as that's what the reading suggested. After 2 changes it was still noisy, but quieter than it was prior to changing. Well it came time to sell it and I wanted it to be "right" so I serviced it again, this time using some leftover Mystik hydraulic oil (I forget the exact product) and this time the thing was darn near silent! I had an old fellow bring me his L110 for a bunch of repairs and while it was there, I thought that I'd service it too. Same deal, used the "correct" 15w50 and it was noisy. Same deal with the ZT2800s in my zero - I used Amsoil Hydro 20w50 and it's (a bit) talkative as well. Between my anecdotal experiences and talking with another forum member, I've decided that I'm going to use a dedicated hydraulic oil. The heaviest that I could easily find was an ISO100, which is heavier than the Mystik in a 5 gallon pail so that's where I'm going to start.

John Deere HyGard LV (low viscosity) should be the about the same price as engine oil but much better anti-wear, excellent flow and GL4 rated. If you're in a hot climate then I would try the heavier HyGard which is closer to an SAE 40/50. Hydrostat transaxles need a gear oil with good flow. The noise you're hearing is either from wear or cavitation of the fluid (poor flow).

 

[Backstache]

I did a K46 last year with Mobil 1 15W-50. It was nearly empty of oil due to leaking axle seals and wouldnt go into reverse at all, and was starting to struggle to go into forward. Made a lot of noise too. Silent with the 15W-50, must've gotten to it just in time before any damage occurred.

Recently did my own mower with an old Hydrogear using 15W-50 as well. The old fluid looked like grey paint!

I dont think it's too bad of a job to do again in a short interval. Once you know what youre doing its a lot faster the second time. Maybe check the fluid level if you didn't bleed it while it was out of the mower. IIRC the fluid level dropped a bit after it was bled on the K46.

When I had them out I put them on jack stands, filled with cheap 10W-30 and used a drill on the main pulley shaft to run the transmission while holding it in forward and reverse. This gets new fluid into everything and sort of flushes out any old fluid left inside. Then dumped it and filled with the 15W-50. Repeat with the drill to bleed the transmission before putting it back in the mower.

 

[Sequoiasoon]

It's been multiple years since I changed the fluid in my John Deere LTR166. Last time I'm not sure I got most out either. It was getting worse and worse with no power to where I was just contemplating a new transmission for about $1k with me doing it. The rebuild pumps kit is like $500, this thing is at least 23 years old but got a new motor at some point before I bought it. Tranny gauranteed over 500 hours on it. I'd almost lean to new bolt up tranny between time/energy, chance to mess it up doing rebuild.

I dug in deeper over the last week and got out at least 1.5 qts with my extractor. I went with plain conventional SuperTech 20W-50 as a hail mary, hopes and dreams. It actually seems to have worked, is it great, no still a bit hesitant on my small rises (i wouldn't even call a hill) but I should have no issue cutting the grass for the season I hope. Worst case it pushes the tranny out a couple months maybe as long as I have it.

I didn't want to use the Mobil 1 15W-50 in case it didn't work and all had to be dumped anyway, I probably should have. Not as easy to get but HPL has Hydrostatic Fluid as 5W-50. If I replace this in a couple months, maybe earlier which do you think might be better? The Tuff Torque stuff I bought worked for a couple years but really died beginning of this season. Still mostly worked end of last season and crap this season.

BITOG collective? M1 15W-50 or HPL Hydrostatic 5W-50?

Getting to fill plug to extract requires deck drop, center chute removal, reservoir, pulley and fan. Not hard, annoying.

 

[JTK]

Getting to fill plug to extract requires deck drop, center chute removal, reservoir, pulley and fan. Not hard, annoying.

Good work! Not that it looks horrible under there, but I see some dirt buildup. How did the cooling fins on the transaxle look? I've seen them so hopelessly clogged with debris that the cooling fan can't do it's job and you'll get overheating, loss of speed, etc.

 

[Sequoiasoon]

Good work! Not that it looks horrible under there, but I see some dirt buildup. How did the cooling fins on the transaxle look? I've seen them so hopelessly clogged with debris that the cooling fan can't do it's job and you'll get overheating, loss of speed, etc.

Fan was clean, tranny was clean. I don't cut when wet but do get some dirt that sits on tranny. The top of reservoir had more dirt than the tranny/fins. I used a small flat tip just to knock it loose and vacuum so I could work on it. I do normally take my leaf blower and try to blow everywhere through cracks etc. The deck gets a lot of build up on top so always blowing it off each use.

My loss of speed and power was even when cold, didn't change much when mowing. I only have a 1/2 acre so only about an hour of cutting weekly and basically flat. Longer in fall for leaf clean up/mulching.

 

[Sequoiasoon]

@JTK - you inspired me while it's open. Not crazy. Quick spray everywhere with Simple Green and harder nozzle pressure. Just getting more dirt and oil off. No auto places by me have the 15W-50 in stock.

I ordered some HPL Hydrostatic 20W-50 and will swap out before I reassemble. Hopefully it will survive a couple more years. I got 4 quarts so I can do it again if needed.

 

[martinq]

Engine oil is fine in many hydro trannys, or as a flush, but you should really look for Deere HyGard LV for most Tuff Torq transaxles. Engine oil does not have the GL4 gear protection that you need and engine oil is not optimal for hydraulics.

 

[Sequoiasoon]

Engine oil is fine in many hydro trannys, or as a flush, but you should really look for Deere HyGard LV for most Tuff Torq transaxles. Engine oil does not have the GL4 gear protection that you need and engine oil is not optimal for hydraulics.

I ordered High Performance Lubricants HST20W50-Q Hydrostatic Synthetic Transmission Fluid. There are some threads where members had used HPL. I actually just called HPL back and they are switching it to HST 5W-50 Hydrostatic Synthetic Transmission Fluid for me.

I was looking at the chart you listed here with the K46. https://bobistheoilguy.com/forums/threads/an-equivalent-for-john-deere-plus-4-10w30-class-cd-for-tuff-torq-k55-hydrostat.381301/post-6941506

@SubieRubyRoo had the 20W-50 in his equipment. @Drew7a had a 5W-50 HPL Hydrostatic in 2 Tuff Torq. He doesn't show online since November and name doesn't come up any more?

I'm going to try the above when it comes in and then reassemble the mower. If it acts weird I'll have some extra practice disassembling, extracting and re-assembling. I'm willing to try a couple if needed. It's actually not bad on the ST 20W-50 engine oil but I want a synthetic. The ST will make a good flush at this point. I'll drive it around with no deck, get it warmer and then extract.

 

[ctechbob]

Engine oil is fine in many hydro trannys, or as a flush, but you should really look for Deere HyGard LV for most Tuff Torq transaxles. Engine oil does not have the GL4 gear protection that you need and engine oil is not optimal for hydraulics.

Tuff Torq Recommended 5w50 Mobil 1 for years until they launched their own oil and changed all of their manuals to match.