Page 342 - CTS - Mechanic Diesel - TP

MECHANIC DIESEL - CITS

2 Remove the lube system connections to the crosshead guides.
3 Remove the capscrews from each crosshead guide. Keep track of the crosshead guide shim packs if the same
guide and crosshead is to be resused.
4 Thoroughly clean and inspect guide for pits, cracks, scoring. Replace if necessary.
5 If replacing a crosshead or crosshead guide(s) due to damage, both the upper and lower crosshead guides
must be re-shimmed.
6 Place the new guides in the power frame, firmly seating the guides in the frame before bolting.
7 Install the crossheaad guide bolts. Do not use the rubber lined washers until the shimming is complete. Do not
allow the bolt to pass above the guide thread.
8 Install the crosshead through the side inspection window. Rotate the crosshead about the center axis (roll
upward and push down).
9 Install the extension rod

10 With the exension rod seals out of the seal bore in the frame, use an inside micrometer to measure the
distance from the extension rod to the extension rod seal bore at the top and bottom
11 Subtract the bottom dimension from the top dimension and divide by two to obtain the shim pack required for
the lower guide (TOP-BOTTOM) / 2. for example, if the distance from extension rod to the extension rod seal
bore is 0.895 inches on top and 0.855 inches on bottom, the shim pack is calculated as follows: 0.895-0.855
= 0.040, 0.040/2 = 0.020. The lower guide shim pack would equal 0.020 inches to centre the extension rod in
the seal bore.
12 Remove the extension rod and crosshead.
13 Remove the lower crosshead guide.

14 Install the calculated shim pack. Shim packs are placed between crosshead guide and each of the two frame
supports.
15 Install the lower crosshead guide.
16 Install the cap-screws into the lower guide.
Do not allow guide bolt to pass above thread.

17 Install the crosshead with both guides in place (lower guide has been shimmed, upper guide has no shims
yet).
18 To shim the upper guide, measure the clearance between the top of the crosshead and upper guide. For best
results, use long feeler gauges and average the clearance along the width of the crosshead.
19 To obtain the upper guide shim pack, subtract the average opening clearance (0.012 inches) from the measured
feeler gauge clearance. For example, if the measured feeler gauge clearance between the crosshead and
upper guide was 0.032 inches the shim pack would be calculated as follows: 0.032 - 0.012 = 0.020 inches shim
pack

20 Remove the crosshead.
21 Remove the upper crosshead guide.
22 Install the calculated shim pack. Shim packs are placed between crosshead guide and each of the two frame
supports.
23 Install the upper crosshead guide

24 Install the cap-screws into the upper guide. Do not allow guide bolt to pass above thread.
25 Install the crosshead.
26 Slide crosshead form front to back, checking for clearance of 0.009 inches to 0.015 inches.
27 Shims make require minor adjustments if areas of tight clearance occur.
28 Once proper clearance is measured, remove guide bolts and re-install with ring of silicone and rubber washers
under the bolt heads with proper torque.
29 Re-assemble crossheads and connecting rods.

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CITS : Automotive - Mechanic Diesel - Exercise 18.5