psdfield 0 #1 Posted September 8, 2018 Hi, New to Red Square but bought my first Horse in 1974. I just bought a 91 520H, the trans temp sending unit is N.G. ( it has continuity through it all the time ). According to my parts list the part # is 113193, it is not available from Toro. I do not know thread size ( 1/8 NPT ?? ) any help you can give me would be great. Thanks Paul Share this post Link to post Share on other sites
gwest_ca-(File Mod) 11,090 #2 Posted September 8, 2018 Not much on this. 1/8" pipe has an OD of .405" - slightly over 3/8" Click on the picture Garry 1 Share this post Link to post Share on other sites
cleat 6,313 #3 Posted September 8, 2018 There are 3 on ebay right now. Search for wheel horse 520 sensor. It is either 1/4 or 3/8 NPT (I think 1/4). Cleat 1 Share this post Link to post Share on other sites
gwest_ca-(File Mod) 11,090 #4 Posted September 8, 2018 1/4" pipe has an OD of .540" or almost 9/16" 3/8" pipe has an OD of .675" or almost 11/16" Pipe threads require a sealer. Garry 1 Share this post Link to post Share on other sites
Duff 206 #5 Posted February 21, 2020 Bringing this thread back to the top.....I've got a 1990 520H I bought last fall and am now getting around to cleaning up. Where on the hydro is the temp sensor located? The wire was disconnected when I bought the tractor and it looks like the terminal may have broken of the sensor. I've looked at the transmission, the IPL and the wiring diagram but can't figure out where the actual sensor is located. Help and thanks! Share this post Link to post Share on other sites
gwest_ca-(File Mod) 11,090 #6 Posted February 22, 2020 Perhaps this is it. Appears to be under the right axle below the dip stick. The sending unit is shown on the electrical page but that does not help with location. Garry 1 Share this post Link to post Share on other sites
Creapy8x 7 #7 Posted August 5, 2023 Stirring up this topic again! I’ve had my 88 520h for a few years now and just recently after mowing my lawn for roughly an hour or so my hydro temp light will come on, never had this problem before and the only thing I’ve done recently to the tractor was a front axle swap! I did however do a fluid and filter change after the light came one this last time but I’m curious would that sensor on the transmission work with an after market temp gauge or no? Share this post Link to post Share on other sites
lynnmor 7,352 #8 Posted August 5, 2023 4 hours ago, Creapy8x said: Stirring up this topic again! I’ve had my 88 520h for a few years now and just recently after mowing my lawn for roughly an hour or so my hydro temp light will come on, never had this problem before and the only thing I’ve done recently to the tractor was a front axle swap! I did however do a fluid and filter change after the light came one this last time but I’m curious would that sensor on the transmission work with an after market temp gauge or no? Did you remove the seat and fender so the transmission can be properly cleaned? Is the fan in good condition and mounted tightly so it doesn't slip? 1 Share this post Link to post Share on other sites
Creapy8x 7 #9 Posted August 5, 2023 I did have the seat pan off to better access the filter for a fluid change and while it was off I did blow out all the excess debris that was built up but I did not thoroughly check the fan or belt tension! Share this post Link to post Share on other sites
lynnmor 7,352 #10 Posted August 5, 2023 1 hour ago, Creapy8x said: I did have the seat pan off to better access the filter for a fluid change and while it was off I did blow out all the excess debris that was built up but I did not thoroughly check the fan or belt tension! After seeing one get real hot from a slipping fan I now know how important the cooling system is. When I pull the fender off I go one step farther and remove the gas tank so all of the debris can be washed out using engine cleaner and a garden hose. 1 Share this post Link to post Share on other sites
