TuffTorq K46 Repair Guide with Pictures

[bt1287]

I just wanted to thank everyone who made a post on this site in regards to the the Tuff Torq K46 trans axle and their problems and especially their Solutions. After reading and reading and researching the K46, which I have the K46 BA, I had the same problem it stopped pulling in forward and reverse with only 123Hrs. tried everything to make it work before dropping it and disasemmbling. After removing it and seperating the case I found that mind was a lot cleaner than most of the post I read, the oil was a very dark Brown, mine did have the up grade of more maganets, which were not that covered in metal particles. After disassembling the pump and motor and doing a thorough inspection and cleaning I decided to go with reassembling and useing the 5W-50 synthetic oil, I put the transaxle back under the Craftsman Mower and Prayed. I did the air purge as directed by Tuff Torq following it the best I could with very poor results, finally I got the thing to move ever so slightly but moving in forward and reverse, I decided to try and cut grass, slowly and working the forward lever form slow to fast to keep it moving which was diffucult do the the yard I have with hills but it finally started to move alittle better each pass as long as I kept moving the lever back and forth. After and hour of cutting I stopped leaving the mower in park and opened a gate got back on and unbeliveablly started to work like it was brand new, I could not believe how strong it had gotten, finish another half acer and not problems. I am so very thankful I didn't give up. By the way I did add the two drain plugs in the bottom case to drain the oil so that next oil change I won't have to drop the whole transaxle. Total cost not counting my time, $50.00 for RTV, Synthetic Oil, 1/4"mpt tap and hex headed 1/4'' plugs. Again be patient and persistant, and maybe you won't have to purchase the $370.00 in parts. Thank You, If I can help anyone with a question, please post and I will try and get back to you.

 

[wactbn]

I rebuilt mine and upgraded with k57 recommendations from Duane. I had wondered if I could have gotten by cheaper with just the parts you did. Quite a few people have posted that those are the only parts they did. My theory was that if I was going to do the rebuild it was going to be better than before, so I went with all the parts, about $400 worth. Costs even more now I heard.
My center case also was worn, not just the pump and motor. Seems to me the machined surfaces of pump/motor and case wear together. Center case is aluminum, pump/motor are steel. The machined surfaces are what I was told by tuff torq that go bad. Why would the steel wear and not the aluminum? I don't know why people are replacing pump and motor without replacing center case. Am I not understanding something right?
I am very happy so far with the result, hope it lasts. I have mowed 20+ acres so far this summer since the rebuild.

Did you do the rebuild and upgrade yourself? If so, were there any challenges?

My K46AC with 368 hours, which I bought used a couple of weeks ago, slows down as soon as it warms up, and there are multiple blades missing from the white fan. I'm very interested upgrading my K46AC to K57 to get the charge pump feature. I looked up the part numbers given in an earlier post on the TT service website:

Item #/ Part Number on diagram / Quantity / Part Number Description/ Cost
1. 1 1 1A646088840 Pump Shaft (K57A) 25.47
2. 100 1 187Q0026010 Charge Pump Case Kit 8.35
3. 102 1 1A646088350 Inner Rotor 4.61
4. 101 1 1A646088360 Outer Rotor 4.82
5. 103 2 22351030018 Roll Pin 3.0 x 18 0.21 @
6. 97 1 1A646088450 Charge Spring 2.68
7. 96 1 1A646088410 Pin 2.5 x 9.8 0.34
8. 83 2 1A646025300 Spline Collar 1.34 @
9. 26 1 1A646088211 Filter 8.64
10. 87 1 19215489090 Snap Ring 0.26
11. 37 1 187K0099750 Motor Thrust Bearing 28.08
12. 201 1 1A646099530 K57R Repair Kit 373.81
13. 47 1 1A646029010 Magnet Holder 1.83
14. 8 2 19216324360 Magnet 2.94 @
15. 2 1115 1 liter 5w50 Synthetic Motor Oil 8.29 @
16. optional (104) 1 1A646099630 Thrust Bearing/Swash Plate Kit 37.12

But I found that the 100 187Q0026010 Charge Pump Case Kit was no longer a valid part number on the TuffTorq website. The closest part number & description I could find was 100 1A646088370 PUMP CASE KIT. In lieu of the 201 1A646099530 K57R Repair Kit, I plan to get these sub-parts instead:
24 1A646099720 CENTER CASE H W/BALL IDS KIT
31 168T2025090 CYLINDER BLOCK (PUMP) KIT
38 168T2025080 CYLINDER BLOCK KIT (MOTOR)
This is so I can skip the 200 1A646099140 SEAL KIT, since I don't plan to replace every seal in the K46.

I'm also going to drill and tap the two oil drain holes in the bottom pan and buy the 187Q0399940 DRAIN BOLT KIT. Derrick gave me the drain bolt thread size as M8 X 1.25, in case anyone else needed it.

 

[FLinTexas]

What an informative thread!
I have an Ariens Model 93605300/A22H46. It has the K46BA transaxle. It will barely move forward or backward. I think the belt is slipping on the transaxle pulley. I can't see it during operation to check.
The drive belt for the hydro unit seems to be worn. The idlers are at the end of their spring travel and I can manually turn the transaxle fan and pulley with the clutch engaged. I would expect the idler mechanism to be somewhere in the middle of the spring tension travel, and I would expect the drive belt tension to prevent easily turning the transaxle pulley. Any comments?

<Update>
I tried looking through one of those tiny holes in the back panel while the tractor was in gear. At idle I could hold the tractor back against the full hydro drive power. It looked as if the fan slowed down while I did this and I thought I could hear a little belt squeal. I think I'll put on a new belt and see if it helps.

regards,
Leon

 

[smithbro]

Hey, I'm a newbie here..... I've had my 155c for 6 years now and have over 450 hours on it! Summer before last is when I had my first hill climbing problem. Took it in to the dealer and they replaced the drive belt (first one) and both drive pulleys for just a bit over $100 (thought that wasn't to bad...). Worked just fine. Well last summer didn't put more than 20-30 hours on it and the same problem! Had em change the belt again, and it worked fine till winter. This summer I had the misfortune of running the mower through some pretty big stuff (previous years trimmed saplings, etc.), and apparently jammed a stick up under the chassis and without knowing it, neatly trimmed off all the cooling fan blades on the tranny. By the end of that day I couldn't move the thing more than 10 feet without it stopping. So I cooked the transmission but good. Replaced the fan and have been using it quite a bit and it limps along, eventually makes it where I need it. Well anyway, I have been struggling with what to do.... Don't have $600 right now, but I can turn a wrench. So tonight, with your help, I've got that sucker off and draining over a bucket, and will refill it tomorrow with new 5w50 synthetic and see what happens! I post back with the results in a far shorter version!

 

[joebob]

Hey Smith;
Read my post & do it if it comes to that. Seems like not too many guys are doing it. $25 is a lot better than hundys, nomsayin?
Cheers
Joebob

 

[smithbro]

Hey Smith;
Read my post & do it if it comes to that. Seems like not too many guys are doing it. $25 is a lot better than hundys, nomsayin?
Cheers
Joebob

Filled the tranny this morning with full synthetic. Rolled it out and after a few back and forth fiddlings with the foot pedal, it caught and almost threw me off the back! Don't know if it's as good as new, but it's got to be 100% better than before the drain! The oil drain and refill was extremely easy and I will most likely do this every spring when I pull maintenance on this thing... One thing I did notice and I thought I was really cleaning the mower, the very thick build up of dirt and grass on top of the transmission under the fan and pulley. Really a thick heat insulation problem! Won't have that problem again..... I think I'm gonna take the wife out to dinner and celebrate the savings!
Thanks again y'all!

 

[FLinTexas]

I drained the oil from my K46BA in my Ariens 93605300/A22H46. It has about 50 hours, and the oil looked good and the magnet was clean. I replaced it with synthetic 5W50 and replaced the drive belt which seemed loose. It seems to have healed the problems. Hopefully I've added some years to the transaxle's life with the better oil.

regards,
Leon

 

[crazyflyboy30]

I am glad so many are having good luck with the synthetic 5W50 and it fix there problems .Update on my steep hill I made me 2 40lb. wheel weights plus 45lb. barbell on the hitch = 125lb. it will go down the hil and no't slide too bad.

 

[Theodorsen]

Hi.
I did a service on mine K46 and changed the ingoing axel. Afters this session it's going in revers when i'm trying too drive forward. Is there anyone that have exsperience whit this???

Sorry for the languade, i'm from Norway.

 

[pcm3pcm3]

joebob

How about a less cryptic description of what needs to be machined and what is causing the problem. I'm not a schooled mechanic and can't quite understand what you are saying. Your descriptions sound impressive but can you put it in 5th grade language.

Thanks,
Chris