mackinawdave 0 #1 Posted September 6, 2009 :scratchead: I have 1972 WH, 1-0410 Charger 10 Automatic, Kohler K241S-46636D with a Sundstrand 90-2046 in it. It works fine and I use it every week. HOWEVER, the trans casing was apparenty broken and welded in the past and seeps/leaks a lot of fluid. There is are no obvious source for the leak, so I suspect it seeps from the welding. I came accross an entire Sundstrand 90-1136 rear end that appears to be the same and wondering if it could be swapped directly for the 90-2046? If so, I'll buy it, rebuild it and keep it on hand for future use. Does anyone know if they can be direct swapped? Thanks. Share this post Link to post Share on other sites
defed 0 #2 Posted September 7, 2009 i would say yes, that they are for all intents and purposes, identical. it appears, at least externally, they are the same. and they appear to have the same relief valves (and various other valves) in the charge pump end. as far as internals....there could be differences, but i don't see why it wouldn't work. i should also state, no guarantees that my analysis is correct! Dave Share this post Link to post Share on other sites
mackinawdave 0 #3 Posted September 7, 2009 :scratchead: Thanks for adding to the discussion, I appreciate your thoughts and info about it. I think I'll give it a try. It will make a nice winter project! Dave Share this post Link to post Share on other sites
pfrederi 17,866 #4 Posted September 7, 2009 I believe the older model was a hydro gear (basically a gear pump and a gear motor) teh newer one is a piston to piston. According to the Sundstrand Hydro Manual Quote) SERVICE AND REPAIR PARTS Hydrogear Conversions Many hydrogear units (1 966 to mid-1 973) have been converted to the serviceable piston-piston transmission. Refer to the photosi n this manual to identify the transmissionin a particular tractor Share this post Link to post Share on other sites
defed 0 #5 Posted September 7, 2009 you may be right pfrederi....at least partially! when i search for tranny #90-1136, certain tractors list both a hydrogear AND a piston to piston. some just list the piston to piston. i missed that the 1st time and only saw the hydrogears. in fact, some of the tractors w/ the 90-2046 list both types as well. it looks like the hydrogear has valve ports on the charge pump end cap on the opposite side of the motor while the piston to piston does not (solid steel opposite the motor). so if YOUR particular 90-1136 has the valve ports opposite the motor, it should definitely work. if it doesn't have them, then it's a piston to piston type....which might not work as a straight drop in....i suspect it would still work since it lists both types on some models. it appears the overlap starts in 1973, those models show both types in the parts list. Share this post Link to post Share on other sites
Sarge 3,463 #6 Posted September 13, 2009 I've recently swapped out a couple of the older style pumps for the newer C-series , worked just fine. Nice to have full pressure and ground power too. For their age, amazing any of them even work given the lack of proper care... I wouldn't trade any of my hydro's for a manual trans for any task ! Sarge Share this post Link to post Share on other sites
