RICHARD - re: oil seal installation. Not sure what your using as a "proper tool" maybe something like a large socket or piece of tubing or pipe, or even a flat piece of board wider & longer than the diameter of the seal if there's no shaft installed thru the seal yet. That's what I've used with success. I always apply a thin swipe of some sort of non-hardening gasket sealer to the OD of the seal as lube and an additional gasket between the seal & bore and wipe some grease or oil to the lip so it slides easily over the shaft. Something like non-hardening Permatex Aviation gasket sealer works on the OD but I've been using a blue gel-type sealer called Hylomar lately with excellent results. Tubes I have are made & sold by Permatex but I think you have to special order Hylomar from an autoparts store now since they don't market thru Permatex anymore.
Most times I just use a soft piece of wood about 3/4" to 1" square or round to gently tap in seals. You have to slowly work your way around the face of the seal, alternating sides really helps. A little distortion this way is to be expected. Even with a large socket or pipe the seal will try to go in crooked, so you have to gently tap the portion of the seal that's not as deep into the bore further so it's square with the shaft & bore again.
Just so there's no misunderstanding the seals in a Kohler should be installed with the flat face AWAY from the engine, the lip goes inside the engine. The depth of the seal in it's bore is "somewhat important" but what's critical is where the seal lip rides on the spinning shaft. A groove actually wears in the shaft and reduces the seal's ability to seal. With today's synthetic rubber seals it's not as critical but in the days of RAWHIDE or leather seals very perceptable grooves would wear in the shafts after 1000 hours of use on even low speed shafts. LOTS of leather seals left in my old FARMALL's. And they all leak like Hydro CC's because of those old leather seals.
If you remove the seals carefully and they lay flat on a flat surface you should be able to reinstall them. If they have been bent, I'd get new seals from an autoparts store or bearing supply house. The distortion could effect how the lip rides on the spinning shaft. The seals themselves should have a manufacturer name & number that most places can cross reference. If your using Kohler parts I suspect the seals are from NATIONAL Seal, pretty common & easy to find.
