Standard 5th wheels

Repair manual for
JSK 37 fifth-wheel coupling
Foreword
Table of contents
Fifth wheel couplings are vehicle connecting parts
that must comply with very high safety requirements and must also undergo design approval
tests.
1 Safety instructions
4
2 Troubleshooting
5
3 Standard and special tools an
auxiliary materials
3.1 Standard tools
3.2 Special tools
3.3 Auxiliary materials
6
6
6
6
This repair manual is designed to act as a guide to
completing repair work on our fifth wheel couplings.
It is essential that you use JOST spare parts. Modifications of any kind will render both the warranty
and the type approval void.
Instructions for the operation and installation of the
fifth wheel couplings and their permitted load data
are provided in separate documents.
4 Repair work
4.1 To remove and install the version C
bearing
4.2 To remove and attach the version E
pedestal
4.3 To remove and install the version E
bearing
4.4 Overview of the locking mechanism
4.5 To remove and install the locking
mechanism
4.6 To remove and install the safety latch
4.7 To remove and install the top plate
liners (W version only)
4.8 To remove and install the lock jaw/
on the vehicle
4.9 To check for wear/wearlimits
4.10 Function test
4.11 To set the locking mechanism
11
13
15
16
5 Spare parts for version JSK37C/CZ
17
6 Spare parts for version JSK37E
18
7 Spare parts for version JSK37CW/EW
19
8 Disposal instructions
20
ZDE 199 002 108 04/2012
7
7
8
8
9
9
11
11
3
1
Safety instructions
The relevant safety regulations in your country (for example Health & Safety at Work) apply for working
with fifth wheel couplings and vehicles.
The relevant safety instructions included in the vehicle and semi-trailer's operating instructions must also
be complied with.
4
ZDE 199 002 108 04/2012
2
0
Troubleshooting
Fault
Cause
Remedy
Fifth wheel coupling 1. The king pin is too high.
will not close.
2. The skid plate is uneven, thus
causing the king pin to be in the
wrong position.
3. Lock jaw deformed.
4. Poor servicing.
5. Double spring defective.
6. Lever and/or handle buckled.
to 1.
to 2.
The skid plate should be at the same height or around 50 mm lower than the fifth wheel coupling.
Replace the skid plate. Permissible flatness deviation 2 mm.
to 3.
to 4.
to 5.
to 6.
Replace lock jaw SK 1489 or SK 1489Z.
Ease the mechanism and grease it.
Replace double spring SK 3105-20.
Replace/align lever SK 3105-18 and handle SK 3105-15 or SK 3105-113
The fifth wheel
coupling cannot be
opened.
to 1.
to 2.
Release the fifth wheel coupling locking mechanism.
The fifth wheel coupling can be opened by force as follows: Open the lock. Swivel the handle
forwards and hold it extended as far as possible. With the aid of a second person, use a rod to
hit the lever, e.g. SK 3105-18, in the area of the bent section on the opposite side of the fifth
wheel coupling to release the bar. The clamp can also be released by screwing in the adjusting
screw, e.g. SK 3105-05-97. Then rectify the poor servicing, check the locking mechanism parts
for signs of damage and repair or adjust the locking mechanism if necessary.
Fifth wheel coupling 1. Lock jaw deformed.
does not stay in the 2. Spring defective.
ready position.
3. Poor servicing
to 1.
to 2.
to 3.
Replace lock jaw SK 1489 or SK 1489Z.
Replace spring SK 847.
Clean and regrease the area of the locking mechanism.
Movement between
fifth wheel coupling
and semi-trailer
(knocking).
1. Bearing has excessive play.
to 1.
Version C replace
the top rubber
cushion SK1259,
bottom rubber
cushion SK 2105-25
in the event of wear
(see 4.1).
2. Locking mechanism has
excessive play.
to 2.
Check king pin, replace it if it is worn.
If the king pin is in good condition but there is still play, adjust the locking mechanism (see
section 4.11). If this fails to resolve the problem, replace lock jaw SK 1489 or SK 1489Z, wearing
ring SK 2105-19 or wear part 3105-92.
1. Tractor unit not level or pulling.
2. Poor servicing, damage to the
lock jaw or locking bar, or
incorrect locking mechanism
adjustment.
E version
Replace the rubber
sleeve SK 2905-94 in the
event of wear (see 4.3).
ZDE 199 002 108 04/2012
On the EW version and
E version from
series 31, collar
SK 3105-95 must also be
replaced in addition to
rubber sleeve
SK 2905-94.
5
3
Standard and special tools and auxiliary materials
3.1 Standard tools
0
1/2´´
1/2´´
1/2´´
1/2´´
SW17
SW19
SW24
SW30
SW 8
SW 11
SW17
SW 19
SW24
SW 30
SW 24
3.2 Special tools
0
J 919/2
JSK37C
JSK37E
X
0
3.3 Auxiliary materials
High pressure grease (EP) with MoS2 or graphite additive, for example:
BP L21 M
BP HTEP 1
Esso multi-purpose grease M
Shell Retinax AM
Turmogear grease B2 from Lubcon (www.lubcon.com)
6
ZDE 199 002 108 04/2012
4
Repair work
Worn, damaged and cracked parts must
always be replaced. Repair welds must not be
used. After completing the repair work, the entire
fifth wheel coupling locking mechanism must be
greased and its function tested.
0
1
0
12
0
1/2´´
a
0
1/2´´
The item numbers in the illustrations refer to the
spare parts lists in sections 5, 6, 7 and 8.
100 mm
0
1/2´´
b
170 Nm
Nm
With the diagrams the work steps should be carried
out in alphabetical order (e.g. a, b, c). Assembly is
carried out correspondingly in reverse order.
Instructions for assembly are identified in the diagram number of the diagram itself with a diamond ◊.
The torque values shown in the illustrations are
required for the subsequent assembly process. The
prescribed tightening torques must be adhered to!
a
a
0
1/2´´
a
SW24
15
0
1/2´´
SW10
16
0
JSK/02
0
2
0
12
0
a
b
14
JSK/09
0
3
JSK/45
0
0
 Take the fifth wheel coupling off the tractor
1/2´´
unit, place it on workbench SK 2702-10 and
couple it up.
4.1 To remove and install the version C
bearing
13
In the case of version W fifth wheel couplings, the
top plate liners must be removed first
(see section 4.7).
JSK/10
0
4
0
0
16
SW 24
0
1/2´´
Nm
0
1/2´´
SW10
14
15
13
170 Nm
16
JSK/55
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7
4
Repair work
4.2 To remove and install the version E
pedestal
2
0
0
In the case of EW version fifth wheel couplings and
E version fifth wheel couplings from series 31, the
bearings and the collar SK 3105-95 must also be
replaced in the event of a repair.
1500 gr.
0
1
12
0
0
16
a
1500 gr.
0
c
JSK/11
0
b
6-10 mm
1/2´´
3
15
0
b
0
0
Nm
0
1500 gr.
1/2´´
80 Nm
SW19
13
12
12
0
JSK/03
0
2
0
0
1/2´´
J 919/2
SW24
0
1/2´´
b
JSK/39
0
0
a
1500 gr.
4
0
0
1/2´´
14
b
Nm
0
1/2´´
12
SW19
JSK/04
0
1500 gr.
12
0
c
4.3 To remove and install the version E
bearing
80 Nm
6-10 mm
0
41
JSK/46
8
c
0
13
15
1
14
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16
JSK/53
4
;
Repair work
4.4 Overview of the locking mechanism
0
1
0
8
7
3 9
1
5
2
6
4
JSK/12
4.5 To remove and install the locking mechanism
0
0
1
2
0
0
0
0
8
7
9
SW 24
0
SW 30
9
0
6
0
SW 24
0
SW 30
JSK/13
5
JSK/14
0
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4
Repair work
0
3
6
0
0
0
0
1/2´´
140 Nm
SW10
0
1/2´´
0
1/2´´
Nm
11
10
JSK/18
JSK/61
 During assembly, lubricate the articulated
0
6a
points, then tighten the castle nut (8) and then
loosen again one 1/2 turn. Secure the crown
nut (8) with a splint. Only tighten the crown
nut (5) until the splint can be inserted. Secure
the splint.
0
35
0
1/2´´
36
SW7
0
1/2´´
0
49 Nm
1/2´´
The installation and removal of the lock jaw
and wearing ring must only be carried out with
the double spring released. Risk of injury!
38
Nm
0
4
0
0
JSK/40
0
0
7
0
0
2
10
24
24
JSK/16
0
5
0
0
JSK/19
0
0
5
7a
4
0
0
37
36
JSK/17
0
JSK/41
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4
Repair work
4.6 To remove and install the safety latch
0
8
0
0
0
0
1
M 14
0
0
1/2´´
3
29
Nm
0
SW 17
28
0
1/2··
27
1
SW17
30 Nm
b
JSK/20
a
a
0
9
JSK/51
0
0
0
4.7 To remove and install the top plate
liners (W version only)
0
1
0
0
1/2´´
1
3-
0 mm
T45
T45
40
39L
40
0
1/2´´
39
0
39R
45 Nm
a
1/2´´
JSK/21
Nm
0
10
0
0
0
JSK /24
25
4.8 To remove and install the lock jaw/on
the vehicle
26
The installation and removal of the lock jaw
and wearing ring must only be carried out with
the double spring (9) released. Risk of injury!
1
0
JSK/23a
1
0
0
 To remove the version Z locking mecha-
nism (1), the cable ties (26) must be removed
from the lubrication tube (25) and the lubrication tube screw loosened. During installation,
tighten the retaining screw by hand and then
tighten it by 1.5 further revolutions using the
wrench.
0
9
0
9
JSK/13
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11
4
Repair work
0
0
2
6
0
0
0
0
0
0
0
37
36
2
24
24
JSK/16
0
JSK/41
0
3
7
0
0
0
0
1/2´´
0
M 14
140 Nm
SW10
0
1/2´´
3
0
1/2´´
Nm
1
11
10
JSK/20
JSK/18
0
0
4
8
0
35
0
1/2´´
36
0
0
0
SW7
0
1/2´´
0
49 Nm
1/2´´
38
Nm
1
JSK/40
0
5
0
0
0
0
10
JSK/19
12
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JSK/21
4
Repair work
4.9 To check for wear/wear limits
0
3
If the wear limit is reached, the component in
question must be replaced.
0
0
0
≥ 5 mm
0
0
1
0
1
10
0
150 mm
0
≥ 5 mm
0
17,5 -19 mm
JSK/27
30,5 -33,5 mm
 With version C, there must be a distance of at
0
least 5 mm in both the coupled-up and loaded
state.
JSK/47
0
1a
0
0
4
0
0
0
0
150 mm
17,5 -20,5 mm
0
0
0
36
< 5 mm
JSK/25
JSK/38
0
2
 The bearing of version E must exhibit a play of
0
no more than 5 mm. To check, lift the coupling
plate with a lifting lever.
0
150 mm
0
0
49-50,8 mm
84-82,5 mm
71-73 mm
JSK/26
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13
4
Repair work
0
0
5
6
0
0
0
0
7
150 mm
0
7
150 mm
0
0
0
0 mm
6
6
7
7
>10 mm
JSK/31
 Locking mechanism when new
If the fifth wheel coupling has been closed
correctly, the distance of the locking edge to
the inner edge of the plate must be at least
10 mm. If the distance is less than 10 mm, the
handle (7) and the lever (6) must be checked
for warping.
JSK/30
 Locking mechanism wear limit
The locking mechanism is worn if the distance
between the lever's bearing eyelet and the
abutment rib is 0 mm (top picture) or the outer
edge engages (bottom picture). The locking
mechanism cannot be adjusted any further at
this point.
0
7
0
0
150 mm
0
0
A
50 mm
B
8 mm
JSK/32
 The fifth wheel coupling must be replaced if:
The top of the plate is worn to the bottom of the
lubricating groove depth “A” at any point.
Material wear of up to approx. 8 mm, in other
words up to approx. 3 mm lower than the
bottom of the lubricating groove, is permitted in
exterior part "B" over the bearings.
This does not apply to the W version.
14
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4
Repair work
4.10 Function test
0
8
0
0
39
0
40
40
150 mm
39
1
0
0
0
7
> 6 mm
0
150 mm
0
0
3-
0 mm
40
40
39
45 Nm
40
JSK/43
 In the case of fifth wheel couplings of
version W, the wear limit of the top plate
liners (39) is reached when they are worn up to
the top of the securing screws (40).
7
Service instructions for JOST sliders of
type JSK SL
0
9
0
0
6
B
A
150 mm
0
0
12
10 mm
B
JSK/83
 If the fifth wheel coupling is worn on one slider,
0
this must be replaced once per slider if the wall
thickness of the pedestal (12) is at least 10 mm
on each side before the coupling plate is replaced.
 The upper surfaces of the pedestals must be
greased before assembly with high-pressure
grease (EP).
4
A
JSK
 During the uncoupling process, the engaging
edge must be raised by at least 6 mm. The test
is made when the king pin (A) (new condition)
presses on the bar tip (B) and the handle is
held in the direction indicated by the arrow. If
the gap is less than 6 mm, the lever (6), the
handle (7) or the locking bar (4) must be
checked for signs of deformation and wear.
ZDE 199 002 108 04/2012
15
4
Repair work
4.11 To adjust the locking mechanism
0
1
0
0
1
150 mm
0
B
SW 24
23
7
20
0
1500 gr.
A
0
SW 24
0
23
20
4
6
JSK/33
The locking mechanism must be adjusted using a
semi-trailer without forced steering (or on a
SK 2702-10 workbench) as described below:
 Uncouple the tractor unit on a flat, firm piece of
Note:
 If there is still excessive play, the wearing ring
and the lock jaw must be replaced as
described in the repair instructions.
0
ground
 Undo the lock nut (23)
 Unscrew the adjusting screw (20) by approximately 15 turns
 Couple up the semi-trailer, introduce the king
pins into the fifth wheel coupling and close the
lock. If necessary, move the locking bar to its
terminal position by giving the handle (7) a few
gentle knocks in the locking direction A.
 Unlock the handle (7), swing it into position B
and hold it there (get a helper to hold it)
 Tighten the adjusting screw (20) again until the
handle (7) starts to move (have a helper check
this)
 To set the recommended basic play of 0.3 mm,
tighten the adjusting screw (20) by a further
1.5 turns and secure it with the lock nut (23)
 Apply the semi-trailer brake
 Move off with the tractor and check the
maximum play in the locking mechanism.
16
ZDE 199 002 108 04/2012
5
Spare parts for version JSK37C/CZ
0
20 23
22
16
10
11
21
19
25
26
35
36
18
27
28
29
13
9
14
32
30
16
15
33
12
24
2
1
3
5
4
6
8
7
34
31
JSK/35
0
0
Item No.
Designation
Order No.
Item No.
Designation
Order No.
1
1
2
3
4
5
6
7
8
9
10
11
12
12
12
12
12
13
14
15
16
18
19
20
21
22
23
24
Lock jaw
Lock jaw JSK 37CZ
Spring
Locating pin
Locking bar
Locking bolt, complete
Lever
Handle (normal design)
Hexagonal screw, complete
Double spring
Wearing ring
Cylinder screw
Pedestal 185 mm
Pedestal 150 mm
Pedestal 170 mm
Pedestal 250 mm
Pedestal 300 mm
Top rubber cushion
Bottom rubber cushion
Bridge
Countersunk screw, complete
Greasing nipple
Lubrication pipe
Adjusting screw
Screw connection
Guide
Hexagonal nut
Eye bolt, complete
SK 1489
SK 1489 Z
SK 847
SK 2106-67
SK 3205-06
SK 3221-01
SK 3105-18
SK 3105-15
SK 1513
SK 3105-20
SK 2105-19
SK 2121-07
SK 2104-01
SK 2104-02
SK 2104-21
SK 2104-14
SK 2104-20
SK 1259
SK 2105-25
SK 1372
SK 2121-15
SK 3121-11
SK 1989
SK 3105-05
SK 1976
SK 3205-07
SK 2121-78
SK 2122-04
31
32
33
35
Handle
Cable, complete
Hexagonal screw, complete
Splint
JSK 37C up to serial No. xx23 xxxxxx
JSK 37CZ up to serial No. xx24 xxxxxx
Spring hook
JSK 37C up to serial No. xx23 xxxxxx
JSK 37CZ up to serial No. xx24 xxxxxx
SK 3521-02
SK 2421-50
SK 1974
Item No.
Repair kits for
JSK 37C
Order No.
1,2,3,10,11
1,2,3
Repair kit for locking mechanism
Repair kit for locking mechanism
SK 3221-50
SK 3221-52
1,2,3,8,10,11,36
Repair kit for locking mechanism
Up to serial No. xx23 xxxxxx
Repair kit for locking mechanism
From serial No. 0428 xxxxxx
Repair kit for bearing
SK 3121-50
Item No.
Repair kits for
JSK 37CZ
Order No.
1,2,3,8,10,11,25
1,2,3,25
1,2,3,8,10,11,25,
36
1,2,3,8,10,11,25
SK 3221-50 Z
SK 3221-52 Z
SK 3121-50 Z
13,14,16
Repair kit for locking mechanism
Repair kit for locking mechanism
Repair kit for locking mechanism
Up to serial No. xx24 xxxxxx
Repair kit for locking mechanism
From serial No. 0428 xxxxxx
Repair kit for bearing
25
26
27
Lubricating tube, complete + item 26
Cable tie
Hexagonal screw, complete
From serial No. 0428 xxxxxx
Spring loop with spacer tube
From serial No. 0428 xxxxxx
Latch, complete
From serial No. 0428 xxxxxx
Safety lever
SK 3108-02
SK 3121-13
SK 3521-03
Item No.
Retrofit kits
Order No.
1,25
32,33,34
JSK 37C in JSK 37CZ
Handle extension, complete
SK 3108-05
SK 3121-063
28
29
30
SK 3121-59
36
0
1,2,3,8,10,11
0
13,14,16
SK 1436
SK 3121-56
SK 2121-69
SK 3121-56 Z
SK 2121-69
0
SK 3121-52
SK 3105-115
SK 3105-113
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17
6
Spare parts for version JSK37E
0
20
23
22
10
11
21
19
25
26
18
12
27
28
29
9
13
30
14
32
24
33
15
16
2
1
3
5
4
6
8
7
35
31
JSK/36
0
0
Item No.
Designation
Order No.
Item No.
Designation
Order No.
1
2
3
4
5
6
7
8
9
10
11
12
12
12
13
14
15
16
18
19
20
SK 1489 Z
SK 847
SK 2106-67
SK 3205-06
SK 3221-01
SK 3105-18
SK 3105-15
SK 1513
SK 3105-20
SK 2105-19
SK 2121-07
SK 2904-42
SK 2904-41
SK 2904-40
SK 2905-94
SK 3104-05
SK 3121-28
JS 1101-12
SK 3121-11
SK 1989
SK 3105-05
31
32
33
41
Handle
Cable, complete
Hexagonal screw, complete
Collar
From serial No. xx31xxxxxx
SK 3105-113
SK 3521-02
SK 2421-50
SK 3105-95
Item No.
Repair kits for
JSK 37E
Order No.
1,2,3,10,11,25
1,2,3,25
1,2,3,8,10,11,25
13,14,15
Repair kit for locking mechanism
Repair kit for locking mechanism
Repair kit for locking mechanism
Repair kit for bearing
Up to serial No. xx28xxx
SK 3221-50 Z
SK 3221-52 Z
SK 3121-56 Z
SK 3121-58
13,14,15,41
Repair kit for bearing
From serial No. xx31xxxxxx
SK 3121-61
Item No.
Retrofit kits
Order No.
32,33,35
Handle extension, complete
SK 3121-063
21
22
23
24
Lock jaw JSK37AZ
Spring
Locating pin
Locking bar
Locking bolt, complete
Lever
Handle (normal design)
Hexagonal screw, complete
Double spring
Wearing ring
Cylinder screw
Pedestal 150 mm
Pedestal 172 mm
Pedestal 185 mm
Rubber sleeve, complete
Locating pins + item 16
Hexagonal screw, complete
Stoppers
Greasing nipple
Lubrication tube
Adjusting screw
Up to serial No. xx28xxx
Adjusting screw
From serial No. xx31xxxxxx
Screw connection
Guide
Hexagonal nut
Eye bolt, complete
25
26
27
28
29
30
Lubricating tube, complete + item 26
Cable tie
Hexagonal screw, complete
Spring loop with spacer tube
Latch, complete
Safety lever
SK 3108-02
3121
SK 3521-03
SK 3121-59
SK 3121-52
SK 3105-115
20
18
0
0
SK 3105-97
SK 1976
SK 3205-07
SK 2121-78
SK 2122-04
ZDE 199 002 108 04/2012
7
Spare parts for version JSK37CW/EW
0
36
37
39
38
42
40
41
JSK/37
0
0
Item No.
Designation
Order No.
36
37
38
Wearing part
Securing ring
Cylinder screw
Top plate liner right
Top plate liner left
Countersunk screw
Collar only for EW version
Adjusting screw
SK 3105-92
SK 3105-93
SK 3121-55
SK 3105-129R
SK 3105-129L
SKE 001006000
SK 3105-95
SK 3105-97
Item No.
Repair kits for
JSK 37CW/EW
Order No.
39, 40
Repair kit for liner
SK 3106-003
40
41
42
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19
8
Disposal instructions
The mounted parts are valuable raw materials that
can be recycled. They can be split into plastics,
rubber and metallic materials.
The plastics and rubber materials are identified
pursuant to VDA Recommendation 260. All oil and
grease is to be cleaned off the parts before their
disposal.
20
ZDE 199 002 108 04/2012
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ZDE 199 002 108 04/2012