Clunking in front end

[Chillin Dylan]

Before you go tearing into the forks have you checked the static sag?

No I have not. I haven’t done anything with it, 99% of the time it rides great. I just avoid bumps especially at low speeds and if I can’t avoid them, a healthy dose of throttle gets the weight off the front suspension and keeps it from clunking

 

[desert_max]

I wouldn't mess around with a clunking motorcycle front suspension. You can get away with it on a truck - I wouldn't push it on a motorcycle.

A clunk is a warning buzzer.

 

[Fire-medic]

Sounds like it's time to disassemble things. Again, if the forks aren't leaking, no-need to replace the seals. If you get it all back-together and shortly after that it starts leaking you may say my name, "in-vain."

Just keep it together to remove the allen screws in the fork slider bottoms, and a manual impact driver with a well-fitting socket bit or an air tool will allow you to separate the sliders/downtubes. Remember to have a tray or a bucket to use as the allen screw loosens, and you remove it. "Oil, that is, Texas tea, black gold... ."



If you removed the downtube from the triple trees to more-easily access the allen screws, once the slider comes-off, re-install it onto the triple trees so you can remove the plug in the top of the downtube.

Take pics coming-apart for ease of reassembly, they're pretty-simple, but make it easy. The service manual has specs for dimensions and torque values going back-together. vmoa.net/VMX12-Service-Manual01.pdf

 

[Chillin Dylan]

My forks only have a very faint oil ring, so if they’re leaking it isn’t much. For whatever reason, I’ve rebuilt countless engines and all matter of things, including hydraulic leveling jacks for semis and coaches, but these forks intimidate the hell out of me

 

[Fire-medic]

Yeah, they should be dry, do you have any chips or pitting in the chrome? You do have leakage. Once the chrome is damaged, I know of nothing that fixes that, except new downtubes. Re-chroming your old tubes will probably cost you more-than buying new downtubes from a vendor like Forking by Frank in TN.

I just checked, Frank's is moving! They are leaving where they've done-business for decades, and have moved to Mississippi. They hope to return to business by May 1st. I expect that date may get moved-back. You can check here for more info: MOTORCYCLE FORK TUBES BY FRANKS FORKS I'm a Frank's customer, and am satisfied with the product, especially compared-to the price of OEM pieces.

A stop-gap way to fill-in the pits some try is to ball-up a piece of aluminum foil and to vigorously-rub it into the pits. I've never-tried this myself, obviously, it's nothing permanent, I have no-idea how-long it will work, but I guess if someone was really-poor, and just trying to make their only transportation work, it might offer a reduction in the pitting tearing-up your seals. I've used bicarbonate of soda to soda-blast pits in exhaust headpipes, and the megaphone exhaust ass'y. That does work to scour the rust out of the pitting, but then you're left with the pits. maybe something like POR-15 wiped-onto the downtubes, and then carefully sanded-off with a fine grade of wet-or-dry, leaving the POR-15 in the pits, would buy some time. That stuff does dry very-hard! If you're not familiar with it, it's a paint used to stop rust. Of course, you have to remove the loose, flaky stuff/rust, and it probably is good to get to shiny, ferrous metal to paint it on, but look online for info on it, and how to apply it. I've used it on lawn implement wheels, and it does work. Also you can paint over it. An example would be a lawnmower deck, painted with the POR-15, and then painted with J. Deere green, for instance. I've seen people using it on the underside of cars/trucks, and also on suspension components. POR-15 Rust Preventive Coating, Gloss Black, Quart 45004: Advance Auto Parts

POR-15: Professional 3-Step Stop Rust System

 

[Chillin Dylan]

Yeah, they should be dry, do you have any chips or pitting in the chrome? You do have leakage. Once the chrome is damaged, I know of nothing that fixes that, except new downtubes. Re-chroming your old tubes will probably cost you more-than buying new downtubes from a vendor like Forking by Frank in TN.

I just checked, Frank's is moving! They are leaving where they've done-business for decades, and have moved to Mississippi. They hope to return to business by May 1st. I expect that date may get moved-back. You can check here for more info: MOTORCYCLE FORK TUBES BY FRANKS FORKS

No pitting or chips

 

[Fire-medic]

Then it sounds like you're ready for just a set of seals. Many recommend only OEM. They aren't that-expensive. I have used aftermarket, and haven't had issues, some have. I don't buy no-name ones. For the price, just get the OEM, and get a proven durability.

Yamaha 4PU-23145-01-00 - Oil Seal : Ron Ayers

You need two, of course.

Oil Seal

4PU-23145-01-00

Retail Price: $16.99

Your Price: $11.83

And the dust seals: ("Two, please!")

Yamaha 4PU-23144-00-00 - Seal, Dust : Ron Ayers

Seal, Dust

4PU-23144-00-00

Retail Price: $15.49

Your Price: $10.61

If you want to replace the downtube bushings ("Two more."):

Yamaha 5EB-23125-00-00 - Metal, Slide 1 : Ron Ayers

Metal, Slide 1

5EB-23125-00-00

Retail Price: $17.49

Your Price: $12.68

About $72 for dust seals, fork seals, and bushings. FYI, I rarely have found a need to replace bushings. Maybe on something with 50K+ miles it would be a good idea.

I just recalled something. Dirtbike riders use a special tool to scoop-out contaminants from their seals, to help them live-longer. You can make one from a piece of a plastic milk carton. It looks like a long letter "J" with a point on the curved end of the "J." You slip it past the oil seal, (you can easily pop-up the dust seal, to expose the top of the oil seal) and move it around the downtube, and carefully pull it out, along with crud that may-be embedded around the oil seal. It my be worth doing it twice, if your first effort is productive, and you find crud being removed. I'm sure youtube has some videos of people making the home-made tool, and using it.

 

[Traumahawk]

My forks only have a very faint oil ring, so if they’re leaking it isn’t much. For whatever reason, I’ve rebuilt countless engines and all matter of things, including hydraulic leveling jacks for semis and coaches, but these forks intimidate the hell out of me

 

[Traumahawk]

 

[Chillin Dylan]

My bike has 52k on it... I’m sure it could use a full fork rebuild. It confused me though because at speed it’s great. The handling is nice and tight. I ride with my brother who has a 03 R1 and with me in front on the backroads, he says he has to make an effort to keep up with me. Obviously he’s not pushing his bike to keep up but he’s not just chilling either. It only makes the noise and or feels weird on hard bumps at less than 15mph

 

[Fire-medic]

Given your size/weight and the miles on the bike, I think the best way to try to eliminate it is to replace all of what's listed in post #27, and try SAE 15 weight fork oil, and see how that feels. I do like the RICOR wave-washer stacks or the Gold Valve cartridge emulators from Race Tech.

 

[Chillin Dylan]

What are those things you’re talking about now?

 

[Fire-medic]

Front Suspension | RICOR (ricorshocks.com)

RT - Digital Product Search (racetech.com)

1993-2007 VMax front ends are the same, 43mm downtubes/sliders/triple trees. Coincidentally, they also have the 100mm o.c. two-pair opposed piston front calipers/brakes.

 

[Jgas]

My 98 did this only on rebound. Had low fork oil and no air.

 

[apsolus]

i picked up my 2002 a few years ago. cool bike until i hit about 85 mph. death wobble starts kicking in. i replaced the tires with shinkos because the bike came with them so why not. that didnt help. then i decided to rebuild the fork as one of them was leaking. got into them and realized i needed to replace the bushings. so i ordered seals and bushing kits from all balls on ebay. install went great and i learned about the air pressure thing at the same time. adding air also helped diminish the death wobble some too. but it still happened. well i didnt take the bike up that high often for fear of my life so i kinda forgot about it. then i started to notice the bi ke wanted to wander around the road a bit. figured i was high and delt with it. then i started to hear clunks when hitting bumps so i ordered the steering head bearings. front end felt fine and had no play in it but when i moved the triple by hand with no parts attached to it it was plain as day. my bike only had 18000 miles on it and needed a new front end lol

 

[Jgas]

My bike did this but again only on rebounding. Say if i hit a speed bump. Took me purposefully riding back over the same speed bump 15 times to realize exactly what it was. it was very quick but on rebound only. It had low oil no psi and high front tire pressure. Still does it occasionally. I am adding stiffer springs and heavier oil soon. Hope this helps. Could be a free or cheap fix!

 

[Jgas]

My bike did this but again only on rebounding. Say if i hit a speed bump. Took me purposefully riding back over the same speed bump 15 times to realize exactly what it was. it was very quick but on rebound only. It had low oil no psi and high front tire pressure. Still does it occasionally. I am adding stiffer springs and heavier oil soon. Hope this helps. Could be a free or cheap fix!

Sorry. The original clunk not the death wobble. My bushings were ok. Just needed the right oil level with 8lbs. air psi.