I have found a lot of good advise on here, so I'm back again. I have a '96 FLHTCI with over 140K miles, all mine. Many years ago I changed the fork sliders to chrome so I have no problem getting into the front end. As a reminder, the forks on my '96 have air in them. I log around 8000 mile a year and change the fork oil myself annually.

I have noticed a thump sound only when I go over a large bump or during hard front braking. I have checked for play in the neck and triple tree area, that seems to be Ok. This winter I plan to try to locate what might be loose or have extra play in the front end. I plan to remove the front wheel and fender to check for play in the sliders.

What else should I be looking for and what else should I check to try and locate this thump?

 

air pressure good in the forks? (mine had NOTHING for mileage on em, still leaked like a sieve). the thump could very likely be the forks bottoming out. just a sound? or can you feel it too?


if you're gonna go that far, i'd suggest ditching the air setup for a set of Progressive Monotube cartridge insert. best front end mod I made to my bike...no bottoming/dive on braking anymore, and she handles the corners much better too

 

you have 2 timkin bearings that, the fork rides on and they are installed facing each other / so an adjustment can be made to ( zero ) No the end play, but not interfere with the fork side to side travel < that must be loose to turn and no up and down play

its a bit of a thing to miss that adjustment when you go after it, as you will have to take it all apart again if not correct -- look in the OEM book about How - johnjzjz

 

Try new guts in the forks, including springs, preferably Progressive. 140K, most likely everything is worn out.
Sometimes a dry or semi dry fork will do that, how's your fluid?

 

Handleing seems to be good. Sometimes I think I feel it as well as hear it. It's not really a sound of bottoming out, but more of a thump, like something moved that shouldn't. But it only happens when braking hard on the front or going over a large bump on the road.

 

could be neck bearings loose too.

sit on the bike in the garage, lock the front brake, and try to rock the bike forward and back (load up/unload the front suspension). if you hear/feel a clunk, its very likely neck bearings.

 

By all means check steering bearings, but if you find nothing and strip your forks then install new springs. Dump the progressive rate ones and use single rate to match your riding weight. I used Race Tech and they have a calculator on their website. I also have custom-tuned Ricor Intiminators from HDF member fabrik8r. Look him up in the Touring forum where he has a very long thread about them. An economical and very worthwhile rebuild!

 

Ok... I held the front brake and rocked the bike as hard as I could, did not hear the sound. Checked tree movement while rocking, no extra movement. Got out the SM and performed the Anti-Dive check ... air gage moved as it should with switch off ... air gage still moved with switch on, SM says this is not good.

A couple of you suggest doing away with the stock innerds and replace with non-air cartridge. Would this be my best route instead of rebuilding the air front end? I've already had a couple suggestions for replacement, are there any other brands I should consider?

I do appreciate all the suggestions and help ...

 

I've made my suggestion above! As for the air system there is very little that can go wrong with it, just a few O rings and copper washers, plus a rubber hose. Costs pennies and a little time and patience to fix.