What does "friction modifier" do?

[exdeath]

Ford friction modifier stinks like hell, that's what it does.

If you use it, be damn sure you don't get it on you, or nobody will come near you.

+9999

Two sealed bottles I didn't even break the seal on stunk up my house for a week.

Tomorrow I get to soak my new clutch packs overnight. Yummy.

 

[SparkyJJO]

Only downside is they are an open diff if you ever end up with truly no resistance on one wheel.

Brake trick works well in that case.

 

[JCH13]

If you Google "too much friction modifier" you get a lot of forum threads talking about how it turns the diff into an open diff. Do people just not know what they're talking about?

A lot of people don't know what they're talking about.

I wonder how many of those people had worn-out clutch packs, or no LSD at all. I also wonder how they determined that they had a diff acting like an 'open diff' in the first place. It's not too easy to do just driving around.

 

[Ferzerp]

+9999

Two sealed bottles I didn't even break the seal on stunk up my house for a week.

Tomorrow I get to soak my new clutch packs overnight. Yummy.

Sounds like heavy machinery gear oil. I've never smelled such rancid smells out of something that has been dead for millions of years instead of only a few months.

 

[JCH13]

Sounds like heavy machinery gear oil. I've never smelled such rancid smells out of something that has been dead for millions of years instead of only a few months.

I believe it is that sulphur is added to gear oils and machine oil as a 'high pressure additive' that causes them to stink so badly: http://en.wikipedia.org/wiki/Extreme_pressure_additive

 

[exdeath]

Yup. Debating skipping the diff. No problems with the LSD itself, no need to rebuild. Its just a simple carrier bearing howling. I'm just concerned about metal contaminated oil being "stored" in the LSD assembly getting back into the new bearings and causing the same problem again, and figured I would just redo it all clean. Thoughts?

I haven't even opened it up or seen the oil yet, just completely projecting. Bearing going out = likely metal in oil = sanitize everything that had contact with that oil so new bearings don't injest anything.

 

[JCH13]

If you've already bought everything, I'd swap in the fresh stuff. Keep the old LSD, rebuilt or shim it, and keep it ready to install when your current one needs rebuilding. IMO you're worrying about nothing, the residual oil will be so dilute when you add in fresh oil that it won't be a big deal (again, IMO).

 

[Zenmervolt]

Do you ever ride them?

Seriously, they always clunk into 1st gear. Some are more pronounced than others but they pretty much all do it and it definitely isn't just limited to cold starting.

Only about 5,000 miles a summer on the Harley, so not heavy riding, no. The Honda sees more limited use since it's registered as a collector vehicle (30+ years old).

But mine definitely don't clunk into first unless they've sat for a while. The first shift into first each morning is always a "clunk" with a slight jerk forwards. After that, no more forward jerk when engaging first while stationary unless I let the bike sit for a long time. What I describe is generally considered common on every bike forum I've ever been on. You're literally the first person I've ever come across in my life to claim it happens every time you go into first.

EDIT: To be clear, I'm not saying that there's not a definite "ka-chunk" when going into gear from neutral after warm-up. Just that it's noticeably more pronounced on the first engagement when cold.

ZV

 

[JulesMaximus]

Only about 5,000 miles a summer on the Harley, so not heavy riding, no. The Honda sees more limited use since it's registered as a collector vehicle (30+ years old).

But mine definitely don't clunk into first unless they've sat for a while. The first shift into first each morning is always a "clunk" with a slight jerk forwards. After that, no more forward jerk when engaging first while stationary unless I let the bike sit for a long time. What I describe is generally considered common on every bike forum I've ever been on. You're literally the first person I've ever come across in my life to claim it happens every time you go into first.

EDIT: To be clear, I'm not saying that there's not a definite "ka-chunk" when going into gear from neutral after warm-up. Just that it's noticeably more pronounced on the first engagement when cold.

ZV

I'm talking about shifting from neutral into first while stopped. All bikes clunk into 1st gear. I've ridden BMWs, Ducatis, Suzukis, Hondas, Kawasakis, vintage bikes, Harleys they all do this.

http://www.riderforums.com/general-ninja-650r/57285-bike-clunks-into-first-gear.html

http://www.600rr.net/vb/showthread.php?t=221999

http://www.fireblades.org/forums/general-discussion/62321-clunking-first-gear.html

every single bike does it.. don't know why, can't explain it but yes it's totally normal..

every bike does it. honda does it normally...you should have heared kawa ninja i use to have. not just "clunk" but many times it would be really hard to put it in 1st gear without "grrrrrrrrrrr" sound. like im trying to switch to first gear without clutch. kawa has the worst gear box i tried. honda and suzuki have great gear boxes...only clunk without grrrrrrr

http://www.advrider.com/forums/showthread.php?t=570584

http://www.ducatimonster.org/forums/general-monster-forum/107076-clunk-into-gear.html

http://www.fz6-forum.com/forum/garage-mechanical-help/45877-1st-gear-clunk.html

Normal. Ensure idle is set correctly (preferably on the low end). Ensure proper chain tension.

Some say pumping the clutch helps. Some say engaging and holding the clutch helps. (I've had no luck with either)

Because of this clunk, I've adjusted my riding style to minimize 0mph N->1st changes... but that's just me. Nevertheless. It's normal, and it's not breaking anything.

 

[Zenmervolt]

wall of text that completely ignores what I've actually said.

Since you didn't get it the first time, here it is again:

To be clear, I'm not saying that there's not a definite "ka-chunk" when going into gear from neutral after warm-up. Just that it's noticeably more pronounced on the first engagement when cold.

Also, from the more experienced posters on the same links you supplied:

First time you engage them it grabs the plates and makes the clunk. You should not really notice it after several gear changes / riding for awhile.

First time in the morning mine clunks pretty good and then is better the rest of the day.

When bikes sit, such as overnight, I find that the plates just get "stuck" together, so when starting up, coldish oil, its going to be a little sticky.

a clunk is pretty normal, especially before the engine is warm. it should quiet down after it's up to normal temp

There is a difference between "taking up the lash between the input and output shafts" and "the clutch pack is sticking slightly because it's been compressed all night without spinning and the oil has drained from the friction material causing stiction even when the release lever is fully pulled." The "morning clunk" is at least an order of magnitude more severe than what is described in your links. But I said that before and you ignored it then too, so I'm not sure why I'm expecting different now.

ZV

 

[JulesMaximus]

Since you didn't get it the first time, here it is again:



ZV

You could just say that we are both talking about the same thing.

Excuse me for not being able to read your mind...

Edited to be less confrontational.

 

[Zenmervolt]

:whiste: You don't have to be a dick about it.

You could just say that we are both talking about the same thing.

Excuse me for not being able to read your mind...

Not asking you to read my mind. Just to actually read my posts.

I've got nothing against you. You're entertaining and, frankly, a true gear head. You're not shy about disagreeing with people or being confrontational and neither am I. Honestly, the impression I get of you in general is that you'd be a good guy to grab a beer and shoot the breeze with.

ZV

 

[JulesMaximus]

Not asking you to read my mind. Just to actually read my posts.

I've got nothing against you. You're entertaining and, frankly, a true gear head. You're not shy about disagreeing with people or being confrontational and neither am I. Honestly, the impression I get of you in general is that you'd be a good guy to grab a beer and shoot the breeze with.

ZV

Thanks, and ditto.

I did read your posts. First one it seemed like you were talking about the general clunking noise into first that all motorcycles do. And while you did edit your next response I felt that it was worth clarifying what I was talking about.

:beer:

I do notice that my current bike really clunks loudly into gear even when warmed up. It is perfectly normal. The bike lurching forward when clunking into gear is not typical though when warmed up.