The purpose of this procedure is to select correct shims to set the cone point and backlash.
If any of the following components in the transmission is replaced, the procedure is performed:
1. Bevel Pinion
2. Bevel Ring Gear
3. Main Case
4. Front Cover
5. Side Cover or Rear Axle Housing
6. Brake Quill
If none of the components has been replaced, the existing shims can be used to reassemble the transmission.
[1] –
Press bevel pinion head bearing (A) on to the bevel pinion shaft and install gear set (B).
[2] – Complete sub-assembly of range and PTO components to main case.
[3] – Complete the sub-assembly of range components and PTO components to front cover.
[4] –
Install nominal size shim, 2.0 mm thick (LVU21956), at location (C).
[5] – Install bevel pinion tail bearing (E) and a second nominal size shim, 2.0 mm thick (LVU21956), at location (D).
[6] – Install a used lock nut (F), with no thread lock on the threads, on to the bevel pinion shaft through the opening in the front cover. Tighten the nut only up to 20 N·m (14 lb.-ft.). Do not install the end plug.
[7] –
Install the front cover sub-assembly on to the main case. However, do not apply sealant to the front cover-to-main case interface at this point. Install the front cover sub-assembly on to the main case using only four bolts (G) at corners. Tighten bolts to specification.
[8] –
Complete sub-assembly of brake, final drive pinion, ring gear, and side cover. However, do not install the backlash shim (H) shown in figure inset.
[9]-
IMPORTANT:
Make sure that the free end of the suction screen is aligned and fitted to the socket in the transmission right side cover during assembly. Improper installation could result in crushing of the suction screen and subsequent hydraulic pump failure.
Make sure the oil suction screen is properly aligned to the side cover before cover installation. (See Remove and Install Oil Suction Screen in Section 70, Group 05.)
[10] –
Install the side cover sub-assembly on to the main case using four bolts (I) on corners of the side cover. Tighten the bolts to specification. At this point, do not install differential or differential lock components. Do not apply sealant to the side-cover and main case interface.
[11] – Put the transmission in the top-side up orientation (same as it would be in the tractor.)
[12] – Reach through the rock-shaft opening and push the bevel ring gear as far to the right, away from the bevel pinion head, as possible. Tap on the ring gear with a rubber mallet to check that it is as far to the right as possible.
[13] –
Insert the “GO NO-GO” gauge block tool (J) in the gap between the head of the bevel pinion and the final drive pinion.
[14] – Push the gauge block to right side such that its one side touches the bevel ring gear (arrows).
[15] –
If the GO portion (K) of the gauge fits in the gap as show, but the NO-GO portion does not fit in the gap, the cone point setting is correct. Skip steps 17 and 18 and proceed to step 19.
[16] – If the GO portion of the gauge does not fit in the gap then:
a. Remove the front cover assembly.
b. Install one size thicker shim in location (C) and one size thinner shim in location (D).
Table 1 lists the sizes of shims available.
c. Reinstall the front cover assembly using four bolts. Go back to step 14.
[17] – If the NO-GO portion of the gauge fits in the gap then:
a. Remove the front cover assembly.
b. Install one size thinner shim in location (C) and one size thicker shim in location (D).
c. Reinstall the front cover assembly using four bolts. Go back to step 14.
Arrange a dial indicator (L), at the end of the bevel pinion shaft through the opening in the front cover as shown in picture.
[19] –
→NOTE:
You can temporarily install an M8 bolt at the end of the bevel pinion shaft to hold as you try to move the pinion shaft fore and aft.
Check the axial play of the bevel pinion gear. The axial play measured at the front end of the bevel pinion shaft should be less than specification. If the axial play is less than specification, then skip steps 21 and 22 and proceed to step 23.
[20] – If the axial play is more than specification, then remove the front cover assembly and install one size thicker shim in location (E).
[21] – Reinstall the front cover assembly using 4 bolts, and go back to step 19.
[22] –
→NOTE:
Apply Loctite TM thread lock to the pinion nut.
Remove the front cover assembly. Install a new undisturbed torque preserving lock nut (F).
Do not tighten nut fully. Complete the reassembly of front cover sub-assembly.
[23] – Apply sealant to the walls of the front cover and install the front cover sub-assembly on to the main case. Install all the cap-screws for front cover-to-main case joint and tighten them appropriately.
[24] – Make sure that the MFWD is in shift arm engaged position, hold the MFWD output shaft stationary using a Vise Grip and tighten the pinion nut (F) to specification.
[25] – Remove side-cover sub-assembly.
[26] – Remove final drive pinion & bevel gear from the side cover and install a 2.3 mm thick shim, reinstall final drive gear and bevel bearing.
[27] – Reinstall side cover sub-assembly on to the main case. Do not apply sealant at this point. Install the brake and side cover on to the main case using only four bolts on corners of the side cover. Tighten the bolts to only specification. (At this point, do not install differential or differential lock components.)
[28] – Clamp the bevel pinion shaft through the opening in the front cover using a Vice Grip and block to prevent it movement.
[29] –
Set up a dial indicator through the rockshaft opening. Make sure that the indicator registers closest to the outer diameter of the bevel ring gear and rests on a tooth that is horizontal at that point.
[30] – Measure backlash in 3 places 120° apart on bevel gear.
a. Backlash measurements should be to specification with at least one measurement
reading between 0.16—0.2 mm (0.0063—0.0078 in.).
b. Maximum allowable variation between measurements is 0.1 mm.
[31] – If the backlash measurements are with in the specifications and proceed to step 34.
[32] – If it was found to be outside of the specifications, change the shim to change the backlash.
a. Increasing the thickness of the shim decreases the backlash, while decreasing the
thickness of the shim increases the backlash.
b. Shims are available in 0.1 mm (0.0039 in.) increments 2.0—2.6 mm.
[33] – Reinstall side cover sub-assembly and repeat steps 27 through 31.
[34] – Once the correct backlash shim is identified and installed:
a. Remove side cover sub-assembly;
b. install differential or differential lock components;
c. apply sealant to side cover-to-main case joint;
d. reinstall the sub-assembly;
e. tighten all cap screws appropriately.
[35] –
Install plug (M) to cover the opening in the front cover. Recess plug to specification.
