1979/04/30 Caterpillar

If Loose Bolts Are A Problem, A Modification Can Be Made To The Plate Used To Hold The Leveling Valve For The Cushion Hitch{5313,7107}

Usage:

621B, 623B and 627B Tractors

If loose bolts are a problem, a modification can be made to the plate which is used to hold the leveling valve for the cushion hitch on 621B, 623B and 627B Tractors. The plate is fastened to the hitch casting by five .50" (12.7 mm) diameter bolts inside of five 8J9080 Spacers. In this modification, the bolts are changed to .75" (19 mm) diameter and new stronger spacers are used.

Modification:

... Remove the leveling valve from the mounting plate. It is not necessary to disconnect any hydraulic lines.

... Remove the five retaining bolts from the mounting plate and remove the plate.

... Drill the five bolt holes in the plate to a 0.75" (19 mm) diameter.

Location of plate and bolts in hitch control group.

... Drill each of the five holes in the hitch casting to a depth of approximately 2" (50 mm) using a .67" (17 mm) drill bit.

... Use a .75"-10 Tap to cut threads in the five holes to a depth of 1.4" (34 mm).

... Fasten the mounting plate with five 6G5148 Spacers, two 1D4621 Bolts and three 1D4620 Bolts.

... Install the leveling valve.

NOTE: On machines with the serial numbers that follow, the 9J136 Plate must be removed to drill two .75" (19 mm) diameter holes.

621B-45P1649-up

623B-46P939-up

627B-14S679-up Including 14S676 and 677; 15S902-up

Caterpillar Information System:

1979/04/30 The Service Life Of A Power Shift Transmission Is In Direct Relation To The Maintenance Of Its Lubrication System{3004,3179,3150}

1979/04/30 2P8316 Dowel Now Available For Parts Service{0652}

1979/04/30 New " Drive 6V94 Universal Joint Is Available{0612,1253}

1979/04/30 The 6B5067 Race And Roller Assembly, Used In Final Drive Group, Can Be Either Of Two Designs{4050,4091}

1979/04/23 New Metering Pump In Steering System Has Improved Internal (Inside) Seals{4306}

1979/04/23 Reinforcement Of Draft Frame Gooseneck To Prevent Cracks{6220,6209,6207}

1979/04/23 Dowtherm Test Strips No Longer Available{0651,1350}

1979/04/23 New Retaining Rings Used In Planetary Groups For Power Shift Transmissions{3176,3150}

1979/04/23 New Oil Cooler Bonnets Used On 3408 And 3412 Engines{1378,1354,1380}

1979/04/23 Careful, Correct Installation And Maintenance Of Fuel Injection Lines Is Very Important To Prevent Possible Engine Damage, Fire And Other Problems{1252}

1979/04/23 Dampeners Added To Steering Brake Group To Prevent Noise From Vibration Of Brake Band Assembly{4110}

1979/04/23 New Retainer Used Between Bolt And Gear In The Torque Converter{3101}

1979/04/30 New Ring Gears Used In Flywheel Assemblies{1158}

1979/04/30 6V98 Socket Available To Remove Or Install Tachometer Drive Dowel In Engine Camshaft On D3 Tractors, 910 and 931 Loaders{0612,1210,7462}

1979/04/30 Seals (Double-Lip Type) Made Of Viton Material Are Now Used In Vickers Pumps Which Have Steel-Backed Bronze Plates Between Rotor And End Plates{5055}

1979/04/30 Improved Gasket Now Used Between The Flywheel Housing And The Cylinder Block{1157,1201}

1979/04/30 New Design Exhaust Gasket Used In Air Lines Group{1061}

1979/04/30 Scraper Starting System Now Separate From Tractor System{1450,1402}

1979/04/30 New Wear Guard For Final Drive Case, With Hardened Flat Washers And Increased Torque To Keep Guard Mounting Bolts Tight{4059}

1979/05/07 Torque Turn Adjustment Of Final Drive Hub Bearings{0654,4050}

1979/05/07 New 6V116 Water Sleeve Removal Tool Is Available{0621,1101}

1979/05/07 Part Numbers Of Bearings To Use For Service Replacement In Fuel Injection Pump Housings For Sleeve Metering Fuel Systems; Correction To Special Instruction For Installation.{1253}

1979/05/07 How To Bleed (Remove) Air From The Hydraulic Control Circuits Of The Winch{5163}

1979/05/07 New Stronger Hub For Torque Converter Impeller Is Made Of Nodular Iron{3101}