Tech bulletin (US) - 4900 Series housing styles and through bolts

Leece-Neville is currently manufacturing two different style rear housings on the 4900 (pad mount) series of high amperage alternators. This article shows the differences between the housings and includes details on the through bolts that are being used (TSB-1047 is attached).

The flange of the initial housing style was partially machined in the area of the through bolt. The picture below shows the housing with the machined areas, and also shows the old style through bolts that where initially used:

The through bolts which where initially used on these alternators (part number A111102325, shown left below) are being superceded by the new style through bolt (part number 0371184A01, shown right below):

In addition, new alternators in this series are being manufactured without the machined area for the through bolt, so a longer through bolt is required:

These changes were initiated after we experienced issues with the original configuration where some of the through bolts were vibrating loose after a period of time. It was decided at that point to use a through bolt that has proven to be more resistant to vibration, and to also stop the additional machining process on that section of the flange. All 4900 series alternators where initially planned to be superceded by the updated housing and through bolt design shown above.

However, we found that there are applications for this alternator that are so tight that fitment becomes an issue for the new style housing. Therefore we will continue to provide both style housings, both of which will use the new style through bolts as shown.


  • TSB-1047 describing this issue
  • Excel spreadsheet showing the models of alternators which use each style of throughbolt (as of Sept 2006)
The information contained in this bulletin is intended for professional technicians who have the proper tools, equipment, and training to perform the maintenance described. This information is NOT intended for ‘do-it-yourselfers’, and you should not assume that this information applies to your equipment. If you have any questions regarding this information please contact our customer service department at:
Leece-Neville Heavy Duty Systems
a division of Prestolite Electric Inc
7585 Empire Drive
Florence, KY USA 41042
(800) 354-0560
(859) 525-8801

TSB-1047_4900_T-bolt.pdf421.64 KB
4900_thru_bolt_where_used.xls13.5 KB