FrankF 2 #1 Posted August 17, 2015 Replaced the original Onan with an Onan 18 horse. Now I have a lot of vibration, at least I think it's a lot. Hydraulic pump has maybe 20 hours since it was professionally rebuilt. Any ideas? Share this post Link to post Share on other sites
pfrederi 17,171 #2 Posted August 18, 2015 Have you checked the alignment of the pump and engine? Flexing of the rubber coupling due to misalignment may cause vibration. There is a TSB on aligning the units. I don't have it at hand but essentially you needed another tractor and a timing light. You ran the other tractor at about same speed as the D and hooked the timing light to the other tractor then aimed it at the coupling on the d. Changing engine speeds you should get to a point where the coupling doesn't show any "Fuzziness" If the timing light strobe action makes the coupler look fuzzy you have an alignment issue. I just measure the gap between the coupling and the pump mount to make shure it is even on both sides, and on the engine side as well.Curiosity... where did you get the pump rebuilt not many places will do that. Share this post Link to post Share on other sites
FrankF 2 #3 Posted August 18, 2015 (edited) I thought it might be alignment too, but haven't been able to figure out how to check/adjust it.There was a guy, in Delton, Michigan, who retired (?) from Wheel Horse. I can't find the name of the place, but don't think he's still in business. Edited August 18, 2015 by FrankF Share this post Link to post Share on other sites
