GL1000 Swing Arm Pivot Bearing Upgrade

This Tech Tip is provided courtesy of John Evans of Glasgow, Scotland. John is known as “Old Fogey” on the Naked GoldWing Forum

If you have to renew your swing arm bearings, here is a simple and effective upgrade for you.

The last of the 1979 GL1000s in the UK (and possibly Europe too), known here as the KZ, had a different and improved bearing arrangement for the swinging arm.

 

It followed the same general arrangement of having separate pivots on each side, necessary because the drive shaft precluded the use of a through pivot shaft

Most of the parts are identical to the parts used in the previous arrangement:

Swinging Arm 52120-371-000

Frame pivot nut 50197-371-300

Pivot bolt 90121-371-000

Lock nut for pivot bolt 90354-371-000

Pivot collar 52141-371-000

Pivot dust cover 52145-371-000 or 52145-371-010

The difference between old and new is in the substitution of a BK2520 needle roller bearing in the swinging arm, which is 2mm longer than the original BK2518, the deletion of the pivot thrust bush 52109-371-000 and the addition of a 42x25x2mm needle roller thrust bearing and corresponding 1mm thrust washer.

The main advantage of this change is that the old thrust bush could be difficult to remove without it breaking as it was made of some sort of fibrous resin type material and is virtually unobtainable new, whilst the new thrust bearing and washer are “off-the-shelf ” parts available from most good bearing distributors.

There is no other change, such as machining, needed to fit these parts.

Fitting the parts:

Remove the old parts by following the information here:

You will notice that that the old BK2518 is inserted about 3mm below the outer surface of the swinging arm to accommodate the step on the old thrust bush.

The new BK2520 is fitted flush with the outer surface of the swinging arm.

The old thrust bush is discarded.

The new needle roller thrust bearing is placed over the pivot collar followed by the thrust washer.

Grease the assembly with a molybdenum based grease.

Insert the pivot collar into the BK2520 so that the thrust washer is hard up against the swing arm.

Fit the dust seal over the assembly

Fitting the parts:

The open nature of both the needle roller bearings means that they are susceptible to dirt and water. Unlike the BK2518 I have not found a BK2520 RS version with the rubber seal incorporated in it, so it is imperative that the dust seal is in good order.

I found that the OEM dust seal was a little tight over the new bearing set-up and did not seal properly, so the new seals supplied by Randakk and included in my kits are slightly modified to accommodate this. They will interchange with the OEM ones perfectly

Also the pivot collars need to be good or your new bearings will quickly become ruined. The collars were poorly hardened and get indented by the rollers. If yours have these indentations the longer bearing will ride on good metal just 2mm wide! These pivot collars, like the dust seals, are virtually unobtainable new.

I have now had new pivot collars manufactured because of this problem.

Part Schematics:

GL1000 Standard Swingarm Bearing Design (above)

GL1000 KZ Upgraded Swingarm Bearing Design (above)

John Evans – Glasgow, Scotland

Note from Randakk:

1. John Evans now offers these high quality swingarm bearing kits here.

2. The swing arm pivot dust cover (Honda part 52145-371-000 or 52145-371) is no longer available from Honda. I now offer very nice reproductions.