Craftsman GT5000 Hydro-Gear 331-3000 Transaxle
Overview
I spent over 30 years working with garden tractors, and I can feel how uncomfortable it is when a powerful tractor does not even climb up the hill or even stops completely when the oil becomes hot. Their longevity of the machine is expected to be long, although the transmission usually breaks down first. If a store tells you the part you need is discontinued, you may be looking for the rare Craftsman GT5000 Hydro-Gear 331-3000 transaxle. This is where the drive system of the tractor is. It is placed between the two rear wheels and converts engine power to motion. A breakdown is most likely to occur when the internal hydrostatic pressure is not strong enough and the tractor turns into a 900-pound paperweight. The Craftsman GT5000 Hydro-Gear 331-3000 transaxle is almost impossible to find now because the factory stopped making it and there is no modern replacement.
Fitment and Compatibility
This real Hydro-Gear gearbox is the exact match for Craftsman GT5000 garden tractors. It is verified using the Sears PartsDirect 176056 OEM assembly breakdown. It is the basic “Key #900” complete unit for models that use the Hydro-Gear 331-3000 platform, so the bolt patterns and axle lengths line up exactly as when the tractor left the factory.
In the Husqvarna line, this unit is called the 532176056 Gearbox. This name is confirmed through 2006 Husqvarna Illustrated Parts Lists (IPL) for the GT and GTH series. Since these tractors were manufactured by AYP (American Yard Products), this transaxle is also compatible with various high-end YTH models which required the high-capacity 331-3000 internal planetary gear set to add attachments.
In the case of Hydro-Gear 331-3000 family owners, this is the only assembly which will allow them to restore the maximum torque without a retrofit which is not standard. Manufacturer service documentation shows that this unit has the high capacity internal 51-T ring gear and 15-T planet gears which made the 3000 series tough. Whether your tractor is Craftsman, Husqvarna, or Dixon, if your manual calls for part number 176056, this is the reliable direct-replacement part.
Frequently Asked Questions
Does it really mean that this transaxle is sealed and therefore cannot be serviced?
The dealer will tell you that it is sealed forever, but that is the reason why it fails. It does not have an ordinary automotive drain plug, but can be serviced by either detaching the oil pump interface or the breather hose. Precisely, this Hydro-Gear 331-3000 requires 122 ounces of 20W-50 motor oil to operate well. You should install this type of unit, this type of oil and that amount of oil in order not to have problems.
His tractor will not move after I put a transaxle in it, am I a dud?
It’s probably not a dud. These units usually need a “purge procedure” to remove air from the hydraulic lines. What you have to do is to pull the bypass arm, pick up the engine and move the motion pedals forward and back a few times to get the internal pump started. The specific steps of an air-purge are to be observed according to the Hydro-Gear BLN-51368 training video, where I recommend watching all the steps.
What assurance can I have that my internal gears are heavy-duty type?
The planetary final drive is a characteristic of the 331 -3000 series. Upon opening it up you will find a planet gear of 15 T, Spur gear of 67 T and a sun gear of 21 T that lead to the big 51 T ring gear. If your old unit has these tooth counts, the 176056 assembly is the exact internal match for your torque needs.