Oil Pan Cracking Caterpillar

Oil Pan Cracking

Usage:

ENGINES3500 DIESEL COMMERCIAL ENGINES

Problem:

Some 3500 oil pans may crack in certain applications. The rate of cracking is very low. However, any oil pan cracking is unacceptable. The cracks primarily happen on 3500 deep sump oil pans with a few cracks on 3500 shallow oil pans. These cracks typically happen around the mounting bosses that attach the oil pan to the engine rails.

Solution:

The following guideline is designed to both repair cracks and strengthen the oil pans in applications that are cracking oil pans.

In general this is a three step process:

* Repair crack location by grinding out crack and filling with weld

* Weld plate around mounting pad from which crack initiated

* Weld additional baffles to internal sections of the oil pans (Deep Sump Oil Pans Only)

WELD REPAIR OF CRACK LOCATION:

1. Define the ends of the crack by using 4C(4736 Penetrant Kit:

a. Use a wire brush to thoroughly clean any paint or grease from the surface to be inspected.

b. Spray or apply cleaner/remover fluid on the part to remove any oil contaminants from the surface.

c. Spray or apply the dye penetrant on the surface. Let it dry for three to five minutes so that the dye absorbs into the crack.

d. Wipe the dye penetrant from the surface using a clean towel.

e. Spray or apply a light coat of the developer on the surface to be inspected. A crack will appear as a red line in the developer.

f. Mark the complete outline of the crack with a metal scribe or center punch the ends to make the crack visible after removing dye penetrant and developer.

g. Be careful to make sure the true ends of the crack have been defined in order to stop the progression of the crack.

NOTE: Before any grinding or welding is attempted on the oil pan, remove the access cover from both sides of the engine block for visual inspection of the damaged area. Remove oil from the pan until the level is at least 100 mm (4in) below the damaged area.

2. Grind out entire crack in a V shape. Make sure to grind entire length and depth of crack.

3. Clean entire length of ground area:

a. Before any welding on the oil pan is started make sure the area to be repaired is thoroughly cleaned. Use a wire brush or grinding stone to clean the prepared groove and enough area to weld to bare base material.

b. All oil, grease, paint, etc. must be cleaned from the prepared groove surfaces and enough area to weld to bare base material. Surface oxides must be removed from the area to be welded.

c. Good cleaning and surface preparation of the area to be welded is very important, if a quality repair is to be made.

NOTE: Before any welding is attempted on the oil pan, use correct grounding to prevent internal engine damage to bearing and corresponding components. Wire brush an area directly next to the repair on the oil pan. All paint, oil and grease must be removed to ensure a correct ground. Incorrect grounding will result in an early engine failure.

4. Using a 1U(5232 Welding Electrode (3.0 mm, E 7018), fill ground area by full penetration weld along entire ground area.

* Do not let temperature exceed 260°C.

* Make sure welding surface temperature is above 16°C.

5. After entire crack has been filled with weld, this may take multiple passes, grind off weld to be level with previous side wall of oil pan.

WELDING OF STEEL PLATE OVER MOUNTING BOSS AND REPAIRED WELD AREA

This will allow for plate steel reinforcement to be added. Figure 1 shows a view of the two different side plate designs to be used to cover weld repair and mounting boss area. Type 1 design, shown in Figure 2, is to be used on cracks that are located next to mounting pads that are located on the side wall bosses of the oil pan. Type 2, shown in Figure 3, is to be used on cracks that are located at the front right and left rear corners of the oil pan. Type 3, shown in Figure 4, is to be used for the front left and right rear corners of the oil pan. Figures 2, 3 and 4 show the dimensions of the three plate types that are to be cut from 5 mm thick plate. For all of these plate types, a bevel will be cut to form a V shaped grove with the current weld between the mounting boss and the pan side wall. This V shaped area needs to be filled with weld using 1U(5232 Welding Electrode (3.0 mm, E 7018).

Figure 1.

View of Type 1 and Type 2 steel plates welded around mounting bosses. Note Type 3 design not shown.

Figure 2.

Type 1 steel plate (5mm thick) for side wall mounting bosses. All dimensions are mm.

Figure 3.

Type 2 steel plate (5mm thick) for Front Right and Back Left Corners. All dimensions are mm.

Figure 4.

Type 3 steel plate (5 mm thick) for Back Right and Front Left Corners. All dimensions are mm.

1. Decide how many of each type of plate are needed to repair the cracked locations. For further strengthening of the oil pan you may elect add the plates to all pan mounting locations.

2. Before cutting the side plates make sure that the recommended dimensions for the side plates will cover the entire length of all cracks by at least 20 mm. This may require modification to the dimensions in Figures 2,3 and 4, depending on the length and location of the cracks. Remember that round or oval shaped ends of the side plates need to be maintained. Any sharp corners will provide stress risers for new cracks to start.

3. Cut all side plates required to update the oil pan.

4. Prepare each weld area by making sure all surfaces are smooth after weld repair. This includes placing plates over weld area to verify that the plate rests flush with existing side wall. If bevel edge interferes with existing mounting boss weld, then grind back bevel edge to allow for plate to rest flush with existing side wall.

5. Clean entire length of ground area:

a. Before any welding is started on the oil pan make sure the area to be repaired is thoroughly cleaned. Use a wire brush or grinding stone to clean the enough area to weld to bare base material.

b. All oil, grease, paint, etc. must be cleaned from the joint surfaces and enough area to weld to bare base material. Surface oxides must be removed from the area to be welded.

c. Good cleaning and surface preparation of the area to be welded is very important, if a good quality repair is to be made.

6. Using 1U(5232 welding electrode (3.0 mm, E 7018) tack weld along outer edge of plate at 90 degree locations using following sequence: top, bottom, right , left.

7. Using 1U(5232 welding electrode (3.0 mm, E 7018) to complete groove weld, fill in V shaped area, between plate and existing mounting boss weld. This may be a relatively large area, which may require multiple passes. Please make sure following temperature guidelines are not exceeded at all times.

* Do not let temperature exceed 260° C.

* Make sure welding surface temperature is above 16° C.

8. Using 1U(5232 welding electrode (3.0 mm, E7018) weld around entire outer edge of plate. This should be accomplished with a single pass weld with 3 mm fillet size.

* Do not let temperature exceed 260° C.

* Make sure welding surface temperature is above 16° C.

ADDING INTERNAL BAFFLES TO OIL PANS (THIS SECTION IS FOR DEEP OIL PANS ONLY)

In order to strengthen deep sump oil pans on 3500 engines, the number of internal baffles has been increased. The 3508 increased from 1 to 3, the 3512 from 2 to 5 and the 3516 from 3 to 7 baffles. To add baffles to existing oil pans with the original number of baffles, two half baffle sections need to be inserted into the pans and welded together to form a new baffle. Therefore to repair a single 3508, 3512 or 3516 oil pan, 4, 6 or 8 half baffles are required respectively. The half baffle is part number 172-0915 and is released for parts service. Figure 5 shows the half baffle.

172-0915 half baffle for installation internally on deep sump oil pans

1. Order the appropriate number of half baffle sections, 172-0915, for the model of oil pan that your are reworking.

2. Using Figures 6, 7 and 8 determine the appropriate locations for the baffles, for the model of oil pan that your are reworking.

3. Using 1U(5232 welding electrode (3.0 mm, E7018) tack weld each baffle half to the pan side walls at the appropriate locations in Figures 6, 7 or 8.

4. Using 1U(5232 welding electrode (3.0 mm, E7018) tack weld baffle halves to each other at the overlapping center.

5. Using 1U(5232 welding electrode (3.0 mm, E7018) complete continuous weld of each baffle half to pan side wall. This continuous weld should be 3 mm fillet size and should be on both sides of the baffle.

6. Using 1U(5232 welding electrode (3.0 mm, E7018) complete continuous weld of each baffle halve to each other at the overlapping center. This continuous weld should be 3 mm fillet size and should be on both sides of the baffle.

Figure 6.