I even towed the root stump of a 60' Eucalyptus about 100 yards with it.I too have a JD120 that is 7 years old at 182 hrs and it too slips in reverse and growls within the HST. Its a worker and also tows a large heavy roller, a large trailer full of logs or ton bags of sand etc etc etc. The Raider 12 is used for mowing 2 acres of field that's a bit bumpy and would destroy the Westwood. Its got a Kawasaki FS481V 16hp twin (built in the USA !) One I'd replaced the ridiculous Chinese bearings which disintegrated in the first two years it has been fine until this. I also have a Westwood scarifier which is PTO driven. It collects the leaves in the fall very effectively. I use the Westwood for mowing my lawns (about 2 acres), because it is unique in that it has a PTO driven sweeper and a roller it leaves a nice striped effect on the lawn which we like.

So thinking about sucking the oil out and filling with 5/50 fully synthetic which I have so just a bit of time. I tried it again today and from cold its not too bad. The degree of the problem has not changed as a result of that. I already put a new transmission belt on over the winter. Now this is out of action after the first cut of the season it's just as well I have my 73 Raider 12 with 42' deck. I have good mechanical skills and a very comprehensive tool kit so doing the work shouldn't be a problem, just need so pointers as to what I should be looking for What is the issue with these that causes this problem? There is a Westwood dealer in UK who sells some new parts for the K46 but I have no idea what I need. I have an engine oil removal electric pump that goes down the dipstick hole in a car but would that be a waste of time, obviously won't get it all out? Looking online I think I may be finding a lot of metal swarf in there. No drain plug on this thing so would have to take it out and tip upside down to do it properly. Some people say change the oil for thicker grade but others say waste of time. Had it since new (2010), 250 hours all mowing work, Transmission getting less and less power and now will hardly move up a very slight slope. Westwood (Ariens IIAC) garden tractor with K46 transmission.

Tuff torq hd k46 problems