Cub-cadet BDU-10/21 User Manual

BDU-10/21Hydrostatic TransmissionsService and Repair ManualBLN-50327 January 2009

BDU-10/21BDU-10/21Shaft SealsInspect the sealing area on the shaft for rust, wear, orcontamination. Polish the sealing area on the shaft ifnecessary.W

BDU-10/21BDU-10/21Minor RepairPage 11Bypass Valve Easy Ride ValveInspect the check balls (or poppets) and mating seats inthe center section for damage

BDU-10/21BDU-10/21Charge PumpThe correct charge pump orientation is determined by therotation of the pump shaft (CW or CCW). Before removingthe charge

BDU-10/21BDU-10/21For BDU-21L: Install the charge relief valve spring and ball.Install the drive pin. Install the gerotor assembly. Install anew o-rin

BDU-10/21BDU-10/21Page 14Major RepairCharge PumpAssembly ProceduresFor BDU-21L with implement circuit: Install the drivepin. Install a new o-ring on e

BDU-10/21BDU-10/21Major RepairPage 15BDU-10S Center Section RemovalBDU-10S Aligning Pins and GasketFor BDU-10S remove the filter element, filter washe

BDU-10/21BDU-10/21Major RepairPage 16Disassembly ProceduresRemove the motor thrust bearing assembly from thehousing.Remove the swashplate assembly and

BDU-10/21BDU-10/21Inspect the control shaft journal bearing for excessivewear. The BDU 10 control shaft journal bearing should be0.4722 to 0.4733 whil

BDU-10/21BDU-10/21Install the swashplate into the housing. The slot on theswashplate must engage the slot guide block on thedisplacement control shaft

BDU-10/21BDU-10/21Major RepairPage 19BDU-21 Swashplate ComponentsMeasure Control Arm End Play BDU-10 Cylinder Block KitBDU-21 with Swashplate Installe

BDU-10/21BDU-10/21Table of ContentsDescription PageIntroduction ...

BDU-10/21BDU-10/21Install the motor thrust bearing into the housing.NOTE: It will be necessary to have a DRY journal bearingto prevent a hydraulic loc

BDU-10/21BDU-10/21Page 21Major RepairBDU-10For BDU-10 Check to see that the piston springs arecentered in the cylinder block bores. If necessary, posi

BDU-10/21BDU-10/21BDU-10S Parts Drawing & Parts ListPage 22

BDU-10/21BDU-10/21BDU-10S Parts Drawing & Parts ListPage 23PARTS LIST.ONNOITPIRCSED.ONNOITPIRCSED1TFAHSPMUP52ETALPHSAWSELBAIRAV2GNIRGNINIATERERIW0

BDU-10/21BDU-10/21BDU-10L Parts Drawing & Parts ListPage 24

BDU-10/21BDU-10/21BDU-10L Parts Drawing & Parts ListPage 25PARTS LIST.ONNOITPIRCSED.ONNOITPIRCSED1TFAHSPMUP73SLDHTSNIP2GNIRGNINIATERERIW83TEKSAGNO

BDU-10/21BDU-10/21BDU-21L Parts Drawing & Parts ListPage 26

BDU-10/21BDU-10/21BDU-21L Parts Drawing & Parts ListPage 27PARTS LIST.ONNOITPIRCSED.ONNOITPIRCSED1TFAHSPMUP13ETALPHSAWSELBAIRAV2GNIRGNINIATER93GNI

© 2009 HYDRO-GEARPrinted in U.S.A.Rev. P5

BDU-10/21BDU-10/21The fluid supply for the BDU-10L/21L transmission iscontained in an external reservoir and passes through anexternal filter prior to

BDU-10/21BDU-10/21Page 4General DescriptionThe BDU-21L transmission offers an optional Implement(auxiliary) pump. The auxiliary circuit provides a ra

BDU-10/21BDU-10/21Page 5General DescriptionBDU-21L/A Hydrostatic Flow IllustrationBDU-10L/21L Hydrostatic Flow Illustration

BDU-10/21BDU-10/21Page 6MaintenanceBDU-21L/ABDU-10LMaintenanceCheck the transmission cooling fan for broken or distortedblades, and check to see that

BDU-10/21BDU-10/21Page 7Troubleshooting DiagramOPERATING HOT/LOSING POWEROPERATES IN ONE DIRECTION ONLYNOISY UNDER LOAD

BDU-10/21BDU-10/21WARNING!!!THE VEHICLE SHOULD BE ON LEVEL GROUND ANDTHE ENGINE DISABLED BEFORE PERFORMING ANY ADJUSTMENTSPage 8Troubleshooting Chart

BDU-10/21BDU-10/21General InformationMinor repairs may be performed, following the proceduresin this section, without voiding the unit warranty.Cleanl