The Model number is 944-525800, which I believe is made by Husqvarna. I have tightened the spring tension the to point where the belt will just freewheel when the engagement lever is released. Should I install a stronger spring? There is a possibility that the belt continues to slip even when the lever is fully squeezed due to insufficent tension on the idler pulley. Is this a common problem with this model?

Check the drive pulley on the engine, it may have been coated with congealed oil possibly from a leaky bottom crankshaft seal. If so, and if the engine has been using oil, or you find an oily puddle beneath it, that may be the problem with the belt. Park the tractor on a large piece of cardboard box flattened out, when ever you are thru using it, and you'll soon see if it is leaking there. The seal is not expensive, and can usually be replaced without taking out the engine. Note: I say "usually", but in practice--not always. Also, with the engine NOT running, see if you can stick a finger on the upper side of that pulley, to see if it is leaking at that seal. Rust in the pulley sheave will cause a jerky drive pattern, too.

I did finally get my tractor running the way it should again. It took a lot of patience and persistence. Once I was consistently shifting between forward and reverse, I put it back together and gave it a try. I wasnÂt sure how fast the axle should be spinning, but while it was on the jack and the wheel was off I did note it was up to about 1 revolution per second. When I tested it with the wheels on the ground, the tractor barely moved. I popped the wheel off and opened the vent again. This time I had more trouble getting the "O" rings out, so I left them in place. The vent still had some play and this seemed to work fine. I let the tractor run on the jack in forward for 10 minutes. The axle revolutions gradually increased to about 60 revolutions in 20 - 25 seconds. This rate didnÂt change after another 5 minutes, so I put it back together. I would HIGHLY RECOMMEND checking the fluid level again at this point (especially if your test route is down hill from your work area). Since my filler cap is under the battery, and a pain to get at, I went for a "quick" test drive first. Initially, my speed was actually faster than it had been for the last five years (since the last time I changed the fluid) and the shifting was also tighter. It had been so long, I had forgotten the tractor had lost a step the last time I changed the transmission fluid. As it turned out my fluid was now low, and I didnÂt make it back to the garage. Topping off the transmission fluid where the tractor now sat, wasnÂt quite enough to get it to move under its own power again. Thankfully I had made it up the steepest part of the lawn before it stopped completely, and I was able to push it the rest of the way back to the pavement where I could jack it up, pull the wheel, loosen the vent, and let it run for another 15 minutes. This time I made sure to check the fluid before going any further. I would also recommend that you avoid over filling your unit. I had a bit of a mess when I popped the cap off this time. Once I replaced most of the fluid that was now on the outside of my transmission, I tested it one more time, reassembled, and it was good. I would say the speed of the tractor is close to what it was when it left the factory and my mowing time was reduced by 25%. Thanks for everyoneÂs help! Armstrr, I hope this gets you back to full speed!

I can't believe what I am hearing about the MTD Hydo trans. I have a ranch in Montana. I cut a 3 acres every 2 weeks (11 times a year) It has so many hills I have to ride my 42" cut yard machine side saddle most of the time. I have rolled it 3 times in 14 years of use! I am installing a new (pivot bar) (front Axle) now because 14 years of use has reamed out the axle shafts. (this is a pressed metal pivot bar. Not cast iron. That being said. I have way over 800 hours on the engine (B&S 17.5 hp) and the MTD Hydrostatic tranny. NEITHER HAVE GIVEN ME ANY TROUBLE (AT ALL). I have never changed the oil in the tranny (factory says it's a sealed unit) and I believe them. I have used 3 MTD tractors on my years in the last 40 years! I have sold all of them for 1/2 of what I paid for them. (I did have one B&S engine throw a rod at 250 hrs. Cost $357 in 1993 to get a new long block and 5 hrs to change the motor. My neighbor bought a $4000 JD the same time I bought this mower in 2002. It lasted 3 years and the Kaw. motor blew. He went to JD and they said. That was a really bad motor. We don't replace them and have no other motor to put on your mower. AND we no longer support the trans. on your JD. So he sold it for $600 for parts and was out $3600! (By the way JD said it was really a bad mower they shouldn't have built. But they would be glad to sell him a good one this time. (no discounts mind you!) Ha ha. My little old $1200 (with bags) in 2002 MTD is still running today. So if it runs like a Deere I'd run to the nearest MTD dealer and get a good mower. One with a Hydrostatic trans. that will last I think forever. But I can guarantee you it will last 800 hard hours of use! With no maintenance at all! (Sealed unit) remember. I truly think the MTD lawn tractors are the best value for the dollar of anything I have ever purchased in the past 40 years! Other than my MTD weed eater, but that is another story! You who are look between that auto CVT and the Hydro. GO WITH THE HYDRO. (SEALED UNIT) You will not be sorry! From a 40 year user of MDTS!