Zeb weird clank and oil problem

[Tyjay]

Hi

So for a few weeks I’ve had a weird clank on the Zeb not all the time just intermittently
Started when I changed brakes to mavens

I eliminated the brakes completely and left with the forks. Brakes were just a coincidence I reckon

So went to do a lower leg service to see if anything stood out
Started by stripping the rebound foot bolt ffs then the head snapped off
Managed to remove it by using mole grips. Was lucky there tbh thought it was off to a specialist

So when removing the lowers the air spring side the oil was like milk so clearly a problem somewhere
The rebound side was normal oil that came out
Any ideas what might of caused this
Clearly somethings mixed

Bought new bolt set with crush washers so just need to wait for them to arrive
Before the lowers go back on

Any help info greatly appreciated

Oil damper side

Wrecked bolt which can be removed with grips in relived to say

 

[RustyIron]

Often, milky oil is a symptom of water intrusion. Since you're in there and already waiting on parts, you might as well change out the fluid in the damper.

 

[Tyjay]

Often, milky oil is a symptom of water intrusion. Since you're in there and already waiting on parts, you might as well change out the fluid in the damper.

Thanks will do
Not sure how water has got in
Only place is the seals and they were new on last service with foam rings

 

[steve_sordy]

What do the seals look like?
Are there any scratches on the fork stanchions? They might be a route for water entry. They don't have to be big.

 

[RustyMTB]

Need to take ther air spring out next, that's where the answer will lie since there's nothing between the air side footnut & seal head other than the shaft, the party will be going on above that where the piston lives.

Does look like water's mixed & emulsified the grease but the clanking is a big red flag, points at something broken. Are the lower leg seals good? Obvious route for water to get in.

I'd have the damper out too. If it's a charger, it amounts to a shaft connected to a pair of shim stacks beneath adjustment shafts & a sealed bladder. There's a thread in here where I fully disassembled one.

 

[Tyjay]

What do the seals look like?
Are there any scratches on the fork stanchions? They might be a route for water entry. They don't have to be big.

Seal look ok tbh
but have new ones coming
there is a tiny scratch which can’t be seen anywhere as it’s hidden on the “inside” near the lower leg arch
only seen it when I dropped the lowers
can’t see it now it may be even under the seal but then again it might be above the seal
scratch is smooth no burs but need to have a look at it again when parts arrive

 

[Tyjay]

Need to take ther air spring out next, that's where the answer will lie since there's nothing between the air side footnut & seal head other than the shaft, the party will be going on above that where the piston lives.

Does look like water's mixed & emulsified the grease but the clanking is a big red flag, points at something broken. Are the lower leg seals good? Obvious route for water to get in.

I'd have the damper out too. If it's a charger, it amounts to a shaft connected to a pair of shim stacks beneath adjustment shafts & a sealed bladder. There's a thread in here where I fully disassembled one.

I removed the airshaft everything is normal with that grease is all ok
ordered new footnut bolts for both sides with crushwashers
New lower leg seals coming tomorrow. They “look” ok but obviously that’s where water must of got in

The clank is so intermittent some trails quiet no noise drops and jumps never any noise
more like when hitting kerbs or braking bumps or braking hard
The only thing I could compare it to is if the front brake disc rotor was loose and when braking it moved and made a noise. That was what I initially thought it was tbh

Theres a 3.1 damper in there fairly new
Ill Fully put it back together test it, if it’s still there then I’ll send the damper off for service

thanks for reply

 

[RustyMTB]

Main failure point on the 3.1 is an o ring fails on the lsc compresion adjuster shaft & It starts leaking oil out of the top. Unless you've hucked it to flat like a boss or wrapped it round a tree, it's unlikely to have snapped inside & you'd feel it with every compression anyway. Weird problem.

 

[Tyjay]

Main failure point on the 3.1 is an o ring fails on the lsc compresion adjuster shaft & It starts leaking oil out of the top. Unless you've hucked it to flat like a boss or wrapped it round a tree, it's unlikely to have snapped inside & you'd feel it with every compression anyway. Weird problem.

Thanks mate any input appreciated
No oil leaking anywhere from the damper
But will check it out

One thing I didn’t mention Is I did a service on the headset bearings
It was like sludge in there replaced the top bearing
But cleaned the bottom bearing and regreased it
In retrospect I should of just swapped the bottom as well as a had a set
Don’t know if that’s the problem but I could be
I’ll swap it out while I’m doing the lowers
There’s no play in it but who knows

Thanks

 

[steve_sordy]

How can a headset bearing problem cause water ingress to your fork?

 

[RustyMTB]

Don’t know if that’s the problem but I could be

Yeah, starting to think it's a classic noise coming from here but source is over there thing that plagues mountain bikers. Reason I'm alarmed is because the internals are so delicate, something broken inside could easily destroy the fork in short order.

 

[Tyjay]

How can a headset bearing problem cause water ingress to your fork?

It doesn’t
It could be the cause of the clank on the forks

Water in ingress is a different problem

 

[Tyjay]

Yeah, starting to think it's a classic noise coming from here but source is over there thing that plagues mountain bikers. Reason I'm alarmed is because the internals are so delicate, something broken inside could easily destroy the fork in short order.

yeah sounds like it’s here buts it’s over there kinda problem

I’ll sort the forks first and the headset
Then see if that’s solves it

 

[Tyjay]

Ok so all done with new parts and all running sweet again
No clank but needs a full test in an hr or so when I get out
Forks feel fantastic and new seals look class it’s the details

One thing i changed the bottom headset bearing and in no way could I get it without play or being over tightened to the point of no play but not being able to turn the bars.
After an hr of head scratching decided to put original back in and it turns out that the new one is too small
Bought them ages ago so can’t return them oh well new set ordered