how do hydro's fail ??? repair ? replace ?

[quantico]

I just purchased a deutz 616 hydro that I want to fix up for a backup mower and for a fun project.. it is listed as having a " bad transmission " which I assume is a bad hydro.. I don't exactly know which hydro is inside it... or what simplicity tractor it would be a " clone " of.. So my question for the more experienced tractor fixers is what fails in a hydro ??? and is the thing fixable by normal humans with tools ??? or is it a find a decent used one and make a parts swap time ??? I hear about hydro's being " sealed systems" ... so I am not sure how to add fluid or change fluid on one... Is it a big deal to pull one out with bearings needing to be pressed out and axle shafts removed ??? or a pretty easy swap ?? So if you have some time and experience ... I would really appreciate any information and wisdom you can share on the care / feeding / failures / and fixes on these mysterious devices... I assume that there is a great parts network on these older deutz tractors and believe that they are mostly clones of simplicity machines with maybe a few changes and some different color paint... I believe the 616 is a mid sized machine around 550 pounds or so.. I don't know if hydros are " fixable " or just replaceable.. ??? any help or info would be appreciated.. scott

[goatfarmer]

It's really hard to make a diagnosis on the basis of it having a "bad transmission". Was it diagnosed by the dealer,or the next door neighbor,who knew a guy who knew a guy,etc? It could be low on fluid,out of adjustment,plugged filter,or something else minor. I thought my 7016 might have had hydro problems,but it turned out a freewheeling valve was stuck down. It might even be the bevel box is bad,not getting power back to the trans.Get 'er home,and give it the once over.

[D-17_Dave]

616 won't have a bevel gear box as it's belt driven from the engine. As Kenny said though it could be a lot of different things. All Hydro's still have an oil resevoir so that's as good a place to start as any. Even w/ a hydro tranny it still has mech gears for reduction and they can fail. The closed system of a hydro is the high pressure side of the hydro unit. It also has a low pressure charge pump. Any part of the hydro can get weak or outright fail causeing it not to function. The cost of these tractors being what they are it's more cost wise to get a donor tractor and swap the whole rearend if you find trouble in the hydro unit. A sheared key or other small fix in the tranny might be easy enough otherwise swap it and roll.

[Al]

Hi I believe it is the same as a 5216H. It should have a 500 series Eaton in it. This is a self contained unit about 9 inches square and about 7 inches thick. It bolts on to a Peerless gear case for the gear reduction. Some common problems are: fan missing or broken causing overheating damage. Grass build up insulating the fins, causing overheating damage. Top anchor on the gear case broken along with u bold on axle. The gearcase moves around and the shift lever remains set, tractor bucks and jumps. Pump getting worn, internal leakage. Belt glazed or worn, tightener linkage binding. These pumps can't stand overheating, and the most common failure is a pump that has internal leakage around the balls in the pump. This will work when cold and be weak when warm. Drainging it and putting 15W 40 Mobile 1 or equivalent may buy a few more years of running if this is the case. In these units the pump and motor are side by side in the case and they have the same rules about disassembly and assy as I explained in the article regarding the 850 Eaton transaxle on the 816 DA or something close on ebay about a week or so ago. This pump assy is like the 850 except there is only one motor and no gear train, but the hydraulics are similar. Al Eden

[quantico]

I will drag it home sunday and will know more about the condition of everything.. Thanks for the replies and in any case I can learn a bit more about these tractors going thru the process... Thanks Scott