Thanks HM, for picking up on the details I provided!
My L&R main bushings are recessed about 3.5 mm inside the swing arm. The depth of the inner shoulder on the thrust bearing is a full 3 mm deep and my uncompressed aftermarket felt seals (PnM) are about 4.5 mm thick.
There 'tis!
The OEM felt seals are just 1mm thick.
When the new thrust bushings arrive, I'll dig up a fresh scalpel blade and try slicing these repop felt seals in half. If that doesn't work out, can you recommend a supplier of swingarm felt seals that fit? As far as I know, the felt seals have been discontinued by Honda.
And while HondaMan and I seem to have been on the same page here, I think it's important to reconcile the confusion that I and others may have felt with some posts in this thread. These issues are resolved in my mind, but hope others involved will confirm or correct these notions.
I am rebuilding my swingarm with the original OEM pivot bushings in place as per the following diagram from the HPM.
BenelliSEI's description and advice was based on using the aftermarket, flanged bronze pivot bearings where the flange takes the place of the OEM thrust bushing as well...
These pivot bushings are now quite popular and the OEM pivot bushing without the flange have been discontinued by Honda.
The bronze repop bushings that HondaMan recommended against using, were the repop bronze thrust bushings that replace only the phenolic thrust bearings and not the entire pivot bushing...
Do I have any or all of this correct? Including my proposed solution of performing surgery on my felt seals?
ZT
Some of it is right!
The bronze flanged bushings that I have seen (and had to remove before being able to rebuild the swingarm) have too-thick outer flanges, usually by 0.5 to 0.8mm too thick. Once installed into the swingarm, the collar does not protrude beyond those flanges. This is an extremely important point: the finished swingarm and end bushings must leave 0.0008"-0.0012" of collar sticking out, as measured all at one side. That works out to 0.0004"-0.0006" sticking out of both sides when installed into the frame. If this clearance is not there, tightening the swingarm nut will lock the swingarm in position, unable to pivot.
Sadly, I have had to remove MANY of the flanged bushings from an arm after someone spent a lot of time and $$ to rebuild it, only to find out it didn't work.
Another point, which I've outlined in several posts here (but don't think they've been accumulated anywhere) is: the collar's bearing clearance to the ID of the bushings must be tight, at less than 0.0010", because this clearance doubles across the width of this pivot, and then is multipled by 18" at the rear axle. In other words, 0.0010" of clearance in both bushing-to-collar becomes:
(0.001" x 2) x 18" = 0.036" side-to-side 'wiggle' at the rear axle.
That's more than 1/32" and almost Honda's wear limit. It will increase quickly during break-in, to usually become nearly twice that much in about 5000-8000 miles. The Honda usage spec was "less than 1mm" in the only reference I ever found in their bike manuals.
When I rebuild them I make bushing-to-collar clearances of 0.0004", using Oilite so the bushing will not heat up with use like the SAE660 bronze type does. I also have improved collars made for my jobs: not cheap (because of material costs), but the final build gets a Lifetime Warranty as the rear wheel will not 'wiggle' 0.040"/1mm (Honda's limit) before the engine likely wears out, if greased. I also convert the thru-bolts that do not have the grease passages of the early ones to have grease passages that deliver the grease from SAE fittings (so you can actually pump grease into them) thru the holes in the collar (that should be there, if not, add them) in a matched location, to grease-dispersion grooves in the actual bearing surface area, as per the early collars up to the 750K3 and 550K bikes. The 1st-year 350F also had these, the 2nd year did not, from Honda.
The measurement details to imitate this are noted in my book: I wanted everyone to have them so they could successfully rebuild this pivot - so I gladly give them to anyone who will listen!
