ISSUE DATE:
SERVICE BULLETIN SUBJECT:
VINs or MODELS AFFECTED:
COMPLETE BY:
SERVICE BULLETIN #:

2-4-2020
Grayson Unit Bracket Retrofit
Service Specified Buses
Next Service Opportunity
SC-20-25

NOTICE! It is expected that this process will require 4 hours per bus. Please
schedule appropriately to minimize vehicle downtime.

GRAYSON UNIT BRACKET RETROFIT
Retrofit Description:

This procedure is a updates the Grayson unit brackets to a more robust design.

Headquarters: 1815 Rollins Road, Burlingame, CA 94010
East Coast Manufacturing: 1 Whitlee Court, Greenville, SC 29607
West Coast Manufacturing: 383 Cheryl Lane, City of Industry, CA 91789

1|Page

Tools/Parts Required
Tools and Supplies Required:
•

As Shown in Attached OEM Procedure

Parts Required:
• 054670
KIT, RETROFIT, GRAYSON BRACKET UPGRADE (Consisting of)
o 112-0216
RIVET, MONOBOLT, 0.25IN
20 EA
o 111-9540
BRACKET, GRAYSON, FRAME SUPPORT
4 EA

Headquarters: 1815 Rollins Road, Burlingame, CA 94010
East Coast Manufacturing: 1 Whitlee Court, Greenville, SC 29607
West Coast Manufacturing: 383 Cheryl Lane, City of Industry, CA 91789

2|Page

Procedure
1. Complete the Proterra approved Lockout/Tagout procedure to make the bus safe for work.

2. Use Proterra and Transit Agency approved safety procedures and PPE to safely access the
rooftop of the bus.

3.

Complete the attached OEM procedure that is attached to this document in its entirety.

4. Once the OEM Procedure is complete, remove the Lockout/Tagout devices and power on the
bus.

5.

Return the bus to service.

Headquarters: 1815 Rollins Road, Burlingame, CA 94010
East Coast Manufacturing: 1 Whitlee Court, Greenville, SC 29607
West Coast Manufacturing: 383 Cheryl Lane, City of Industry, CA 91789

3|Page

Standard Operating Procedure:

Replacement of Proterra mounting brackets

Operation Steps

1

This document details the
removal of old brackets and the
fixing of the new style bracket
to the frame.

Replacement
Bracket
HP-4456-490

Please note that cycle time for
the complete operation has
been set at 40 Minutes

IF IN DOUBT ALWAYS ASK
Operation Name

Overview

GFN 568 Issue 2 17.05.17

Tools & Equipment Required

Personal Protective Equipment Required

Reason for Revision Date
Doc No.
Revision
Cycle Time
Originator
Approved

26/01/20
617
A
40 mins
S.REED
T ALLAN

Standard Operating Procedure:

Replacement of Proterra mounting brackets

Operation Steps

2

For engineers reference, the
brackets are numbered here.

4

New bracket part reference:
HP-4456-490
1 = CS Front
2 = CS Rear
3 = SS Rear
4 = SS Front

3

1

2
IF IN DOUBT ALWAYS ASK
Operation Name

Bracket Identification.

GFN 568 Issue 2 17.05.17

Tools & Equipment Required

Personal Protective Equipment Required

Reason for Revision Date
Doc No.
Revision
Cycle Time
Originator
Approved

26/01/20
617
A
S.REED
T ALLAN

Standard Operating Procedure:

Replacement of Proterra mounting brackets

Operation Steps

3

Begin with bracket 1.
Begin by removing all external
covers from the unit. This can
be done with a powered tool or
socket.

IF IN DOUBT ALWAYS ASK
Operation Name

Removal of Cover

GFN 568 Issue 2 17.05.17

Tools & Equipment Required

13mm socket

Personal Protective Equipment Required

Reason for Revision Date
Doc No.
Revision
Cycle Time
Originator
Approved

26/01/20
617
A
S.REED
T ALLAN

Standard Operating Procedure:

Replacement of Proterra mounting brackets

Operation Steps

4

Mask the internal components
with a piece of thick cardboard
or a piece of hardboard as
shown.

IF IN DOUBT ALWAYS ASK
Operation Name

Masking the internal
workings.
GFN 568 Issue 2 17.05.17

Tools & Equipment Required

Card / Hardboard

Personal Protective Equipment Required

Reason for Revision Date
Doc No.
Revision
Cycle Time
Originator
Approved

26/01/20
617
A
S.REED
T ALLAN

Standard Operating Procedure:

Replacement of Proterra mounting brackets

Operation Steps

5

Slit the back of the bracket
using an angle grinder and a
thin ‘slitting’ disc as shown.

CUT
THROUGH

IF IN DOUBT ALWAYS ASK
Operation Name

Slit back of Bracket

GFN 568 Issue 2 17.05.17

Tools & Equipment Required

Angle Grinder, Slitting
Disc

Personal Protective Equipment Required

Reason for Revision Date
Doc No.
Revision
Cycle Time
Originator
Approved

26/01/20
617
A
S.REED
T ALLAN

Standard Operating Procedure:

Replacement of Proterra mounting brackets

Operation Steps

6

Bracket No 2 requires an additional
operation.
Because the fastener which secures
the bracket to the frame is stainless, it
is not feasible to drill the head out, it
must be cut.
It will be found that the left hand stud
is accessible with the grinder, but the
right is not.
Cut the head off the left hand stud and
then slit the bracket as shown. The
section can then be removed and the
tab folded over to create access to the
second stud.

IF IN DOUBT ALWAYS ASK
Operation Name

Remove Stud Heads

GFN 568 Issue 2 17.05.17

Tools & Equipment Required

Angle Grinder, Slitting
Disc

Personal Protective Equipment Required

Reason for Revision Date
Doc No.
Revision
Cycle Time
Originator
Approved

26/01/20
617
A
S.REED
T ALLAN

Standard Operating Procedure:

Replacement of Proterra mounting brackets

Operation Steps

7

Knock the old studs inside the
box section, and offer the
bracket up. It should be found
that the new bracket’s holes
line up with the existing holes in
the box.
Insert a Monobolt into the
holes.

IF IN DOUBT ALWAYS ASK
Operation Name

Fit Monobolt

GFN 568 Issue 2 17.05.17

Tools & Equipment Required

Monobolt Gun

Personal Protective Equipment Required

Reason for Revision Date
Doc No.
Revision
Cycle Time
Originator
Approved

26/01/20
617
A
S.REED
T ALLAN

Standard Operating Procedure:

Replacement of Proterra mounting brackets

Operation Steps

8

Fasten both Rivnuts.

IF IN DOUBT ALWAYS ASK
Operation Name