Posted April 21, 2012 - 06:43 PM
Before you replace the seals you should check the driveshaft coupler to make sure it's in good shape. If it's worn it can cause a lot of vibration at the hydro input shaft. You should also check the vent for the hydro to make sure it's not plugged or assembled wrong. If it's blocked pressure will build up in the reservoir and fluid will find it's way out the weakest spot. There is a piece of tubing that acts as a gauge for fluid level and the top of this gauge tubing should go to what looks like a fuel filter and then back into the top of the rearend. The "fuel filter" has a small hole in it to vent pressure from the case. If it has been replaced with a conventional fuel filter or a piece of tubing it will not vent. You simply drill a 1/16" hole in the outside of the filter and that vents it. My 314 had this problem and in it's case it was blowing oil out the axle seals.
Check JDParts.com and you can see parts diagrams and get part no's and also costs if you are registered. If it's a standard sized seal you should be able to source them elsewhere.