Small Engines (Lawn Mowers, etc.): Hydrostatic drive operates erratically, proper manuals, hydro units

Question
I have a Murray Model 46570X8B.  The last time I used it, the transmission would loose it's pulling power intermittently.  It was almost as if the fluid was cycling and when it was up, the tractor would pull.  I first thought the belt was slipping and replaced it just today it definitely needed to be replaced.  As I took the tractor out of my garage, the intermitten slipping was there almost immediately present.  I have a parts manual for this tractor but it does not identify the type of hydrostatic unit in it.  Is there somewhere I can check the fluid?  What suggestions do you have for this problem?
Thank you for your help.

Answer
Hello Terry:

>>This is a 1999 Model and Murray Used Several Different Hydro Transaxle in this Unit.
>>Some Hydro Units are Sealed and cannot be Serviced by the Consumer and Others you can Perform Repairs on and Add Fluid to if Required.
>>On the Transaxle is an OEM Identification Plate. Send me the Information Off of This Plate, Please. With this Information, I can Locate the Proper Manuals and Better Assist You.
>>Thanks.

Respectfully

John

>>PS: I am Allowed to Answer 10 Questions a Day. If you See I am Maxxed Out, then Try Submitting your Question at or Just After 8pm EST (US). My New Day Starts then. Comments and Ratings are Greatly Appreciated. Thanks.

Respectfully

John