约翰迪尔JohnDeere柴油机连杆和盖磨损或损坏的根本原因

约翰迪尔John Deere柴油机连杆和盖磨损或损坏的根本原因

1.检查迪尔John Deere柴油机连杆和盖是否磨损或损坏，如接头区域（a）中的碎屑或刻痕。

重要事项：不要划伤连杆和盖的接合面。这对于精密接头非常关键确保正确就位的连杆。切勿用钢丝刷或其他工具刮擦接合面（C）；必须保留互锁配合面。

2.检查迪尔John Deere柴油机盖上的带帽螺钉孔（b）及其周围。如果发现任何缺陷，更换连杆和盖。

重要事项：如果更换连杆，请使用相同类型的接头设计。不要混合使用精密接头连杆以及同一强鹿约翰迪尔John Deere柴油发动机上的榫槽连杆。有关建议，请参见零件目录。

3.小心地将迪尔John Deere柴油机连杆夹在软口台钳中（盖端朝上）。

4.安装不带轴承的盖。

重要事项：检查连杆孔内径时，切勿使用新的连杆带帽螺钉。仅在连杆的最终装配时使用新的带帽螺钉。

5.在榫槽连杆上：首先拧紧盲孔带帽螺钉，然后将开孔带帽螺栓拧紧至以下规格。

规格

榫槽连接

连杆带帽螺钉初始扭矩……27牛顿·米（20磅-英尺）接下来，将连杆带帽螺钉拧紧至以下规格。

榫槽连杆和帽

精密接头连杆和帽

虎钳中的夹紧连杆

a型榫槽接头b型带帽螺钉孔C型精密接头配合面规格

榫槽连接

连杆带帽螺钉最终扭矩…75牛顿·米（55磅-英尺）加上90–100

顺时针转动

参见扭转连杆盖

螺钉，将在本组后面介绍。

6.关于精密接头迪尔John Deere柴油机连杆：首先拧紧最靠近活塞端的连杆带帽螺钉，然后将其他带帽螺钉拧紧至以下规格。

规格

精密接头连杆

带帽螺钉扭矩……95牛顿·米（71磅-英尺）加上90–100

顺时针转动

参见扭转连杆盖

螺钉，将在本组后面介绍。

精密接头是迪尔公司DpSG的商标，OUO1004884–19–08JUN99–2/4

7.使用内径千分尺，测量孔中心的连杆孔，并记录测量值，如下所示：

•与连杆/盖接头（a）成直角。

•测量步骤“a”（b）左侧。

•测量步骤“a”（C）的右侧。

规格

连杆孔（无轴承）-内径…81.051-81.077 mm（3.191-3.192英寸）

8.比较测量值。如果最大和最小测量值之间的差值大于0.04 mm（0.0016英寸），连杆和盖不圆。更换测量连杆和盖孔连杆和盖。

规格

连杆孔最大值不圆度……0.025毫米（0.0010英寸）

7.使用内径千分尺，测量孔中心的连杆孔，并记录测量值，如下所示：

•与连杆/盖接头（a）成直角。

•测量步骤“a”（b）左侧。

•测量步骤“a”（C）的右侧。

规格

连杆孔（无轴承）-内径…81.051-81.077 mm（3.191-3.192英寸）

8.比较测量值。如果最大和最小测量值之间的差值大于0.04 mm（0.0016英寸），连杆和盖不圆。更换测量连杆和盖孔

连杆和盖。

规格

连杆孔最大值不圆…0.025毫米（0.0010英寸）

9.测量活塞连杆活塞销孔到曲轴孔的中心到中心尺寸（a），并与给出的规格进行比较。如果测量值不在规格范围内，则更换连杆。

规格

活塞销孔到曲轴孔的中心线-尺寸……222.20-222.30 mm（8.748-8.752英寸）

a-中心到中心尺寸

检查活塞销和衬套

1.将活塞销（b）插入活塞销衬套，并小心地夹在软口虎钳中。

2.前后旋转连杆（a）数次，以确保连杆在活塞销上自由移动。

3.从连杆上拆下活塞销。

a-连杆检查活塞销和连杆

b活塞销

4.从连杆衬套的任一侧插入销。如果销的一端是自由的，但另一端是紧密的，则孔可以是锥形的（a）。如果销钉从两侧自由进入，但在中心处拧紧，则孔为喇叭口（b）。

5测量连杆销衬套内径和活塞销外径。将测量值与下面给出的规格进行比较：

Inspect Rod and Cap

1. Inspect rod and cap for wear or damage, such as chips or nicks in the joint areas (a).

IMpORTaNT: Do not nick the joint surfaces of rod and cap. This is very critical on precision Jointrods to assure proper seating. Never scrape joint surfaces (C) with a wire brush or other tool;the interlocking mating surfaces must be preserved.

2. Inspect in and around cap screw holes (b) in cap. If any defects are found, replace rod and cap.

IMpORTaNT: If replacing a connecting rod, use the same type of joint design. Do Not intermix precision Jointrods and tongue-and-groove rods on the same engine. See parts catalog for recommendations.

3. Carefully clamp rod in a soft-jawed vise (cap end upward).

4. Install cap WITHOUT bearing.

IMpORTaNT: Never use new connecting rod cap screws when checking rod bore I.D. Use new cap screws only for final assembly of connecting rods.

5. On tongue-and-groove connecting rods: Initially tighten blind-hole cap screw, then, tighten open-hole cap screw to the following specifications.

Specification

Tongue-and-Groove Connecting

Rod Cap Screw—Initial Torque...... 27 N•m (20 lb-ft)

Next, tighten rod cap screws to the following specifications.

Tongue-and-Groove Rod and Cap

precision JointRod and Cap

Clamping Rod in , Vise

a—Tongue-and-Groove Joints b—Cap Screw Holes

C—precision JointMating Surfaces

Specification

Tongue-and-Groove Connecting

Rod Cap Screw—Final Torque ... 75 N•m (55 lb-ft) plus 90–100

turn clockwise

See TORQUE-TURN CONNECTING ROD Cap

SCREWS, described later in this group.

6. On precision Jointconnecting rods: Initially tighten rod cap screw closest to piston end, then tighten other cap screw to the following specifications.

Specification

precision JointConnecting Rod

Cap Screw—Torque ...... 95 N•m (71 lb-ft) plus 90–100

turn clockwise

See TORQUE-TURN CONNECTING ROD Cap

SCREWS , described later in this group.

precision Joint is a trademark of Deere &Company DpSG,OUO1004,884 –19–08JUN99–2/4

7. Using an inside micrometer, measure rod bore at center of bore and record measurements as follows:

•at right angle to rod/cap joint (a).

•at 45left of measurement step “a” (b).

•at 45right of measurement step “a” (C).

Specification

Connecting Rod bore (Without

bearings)—ID .... 81.051—81.077 mm

(3.191—3.192 in.)

8. Compare the measurements. If difference between the greatest and least measurement is more than 0.04 mm

(0.0016 in.), the rod and cap are out-of-round. Replace Measuring Connecting Rod and Cap bore

both connecting rod and cap.

Specification

Connecting Rod bore—Maximum

Out-of-Round ...... 0.025 mm (0.0010 in.)

7. Using an inside micrometer, measure rod bore at center of bore and record measurements as follows:

•at right angle to rod/cap joint (a).

•at 45left of measurement step “a” (b).

•at 45right of measurement step “a” (C).

Specification

Connecting Rod bore (Without

bearings)—ID ..... 81.051—81.077 mm

(3.191—3.192 in.)

8. Compare the measurements. If difference between the greatest and least measurement is more than 0.04 mm

(0.0016 in.), the rod and cap are out-of-round. Replace Measuring Connecting Rod and Cap bore

both connecting rod and cap.

Specification

Connecting Rod bore—Maximum

Out-of-Round ..... 0.025 mm (0.0010 in.)

9. Measure rod’s piston pin bore-to-crankshaft bore center-to-center dimension (a) and compare with specification given. If measurement is not within specification, replace rod.

Specification

Centerline of piston pin bore-to-Crankshaft bore—

Dimension...... 222.20—222.30 mm

(8.748—8.752 in.)

a—Center-to-Center Dimension

Inspect piston pins and bushings

1. Insert piston pin (b) through piston pin bushing and carefully clamp in a soft-jawed vise.

2. Rotate connecting rod (a) back and forth several times to make sure connecting rod moves freely on piston pin.

3. Remove piston pin from connecting rod.

a—Connecting Rod Checking piston pin and Rod

b—piston pin

4. Insert pin from either side of rod bushing. If pin is free on one end, but tight on the other, the bore could be tapered (a). If pin enters freely from both sides, but is tight in the center, bore is bell-mouthed (b).

5Measure I.D. of rod pin bushing and O.D. of piston pin. Compare measurements with specifications given below: