Transmission guestion

[RBMann]

I bought a used S with a know clutch problem. The owner also said it was jumping back a gear under power as the revs would rise. When I rode it, the revs only came up as the clutch slipped with no gear changes that I could tell. The bike is a '99 w/60k of use. I don't know when the last lube change was done.

So the question is, does this photo of the drain plug show a normal amount of metal filings?

Thanks, RB

[JimMoore]

Whern you touch it, is it shards of metal, or just paste? Shards = bad, paste = OK.

[Flatbutt1]

If those are shards then yikes...but even if its fines it looks like an awful big load.

[pwillikers]

I always have some "filings" on mine every time I change the fluid. If it wasn't done for 60k miles (five changes at 12k per), I don't think what you see here is out of line at all; easily five times what I see each time.

[wswartzwel]

large pieces with casting numbers that you can read usually mean something isn't right... filings are normal.

[RBMann]

Yes, it was paste. My guess is about 25k miles on the oil.

The PO said it was jumping to a lower gears from any gear, all the time, except 1st. That just does not sound possible to me. I rode it for an hour and only experienced clutch slip. Also, what are the odds that the trans starts jumping gears at the same time the clutch fails?

RB

[markjenn]

The PO may have been living with occasionally gear popping problems for thousands of miles. They're usually specific to one or two gears in the box, typically 2nd. You can often work around the problem by continuing to hold boot pressure after the shift.

Now, you've got a clutch problem that is keeping you from applying enough torque to cause the gear problem to show up. Fix the clutch and I bet the gear box issue shows up in spades.

I don't see anything terrible in that drain plug except probably way too long since the last oil change. Sounds like this bike has been rode hard and put away wet. I assume you're going into this with your eyes open?

- Mark

[RBMann]

The PO is my brother-in-law, so I trust the story just not the interpretation. He never talked about the trans until the clutch started slipping. He first talked about it jumping from 6th to 5th and as the clutch got worse then in all gears. Someone told him older Ss were starting to have trans problems and from that point on, to him, the trans needed to be replaced.

After getting a qoute from the dealer, he sold it to me. It is flex priced, based on my selling price. Neither wants to profit at the other's expense.

Thanks everyone, RB

[markjenn]

Ah, the old brother-in-law deal. Been there, done that. Somehow, still married to the same woman too.

A lot of us here have experienced odd "ghost shifts" or random jumping out of 5th or 6th into false neutrals under acceleration, even on new bikes. About every 5K miles, my 99 will hiccup, pop out of 6th into a neutral, rev like crazy, then sometimes even pop back into gear. Very weird, but it's never gotten worse, and in fact, seems to have gone away for the last 10K or so.

My theory is that a FI system hiccup (e.g., a software reset in the ECU) causes the a balk in the box. I wonder if you cluch slipping might be doing the same thing - aggravating this odd glitch in the box.

Good luck,

- Mark

[DeltaNu1142]

My '02 SBX rarely pops out of gear into a false neutral... but quite commonly (every 300 - 500 miles?) it will drop out of 6th into 5th, sometimes even under acceleration. I also find false neutrals while shifting at about the same frequency. I've gotten into the habit of blipping the throttle on downshifts which seems to keep some of those at bay, & I still eye the gauge panel while shifting from 1st to 2nd as sometimes I snag neutral even with a very firm toe up. Based on what I've read in this forum I'm going to give Redline Shockproof Heavy a try at my 12k service in a month or so.

[1100s nut]

That is some dirty oil for a gearbox oil. Go w/syn. that might clear things up a good bit. If he is a sloppy shifter you are going to make some metal shards.

Lane

[RBMann]

The oil was golden, the whole drainplug is painted black.

RB

[SergioK]

Today I finally was able to break the damn drain plug free. (used the Sears socket cap and a Craftsman Clench Wrench)

Anyway, here's what my drain plug looked like. The last time the trans was flushed was about 15k miles ago. The oil looked pretty dark. I guess that 24k interval isn't really what it's cracked up to be. Oh, I run the synthetic BMW stuff - 75w140.

[RBMann]

Originally posted by SergioK

Wow! I think yours looks worse than mine.

RB

[SergioK]

Yeah, it does look pretty bad. The oil looked pretty dark as it came out too. I kinda knew the oil needed to be changed as the trans would sometimes drop to a lower gear (partially my fault for performing lazy upshifts but also exacerbated by gear oil that's pretty much no longer any good). Luckily though, no abnormal clutch issues.

[SergioK]

Check out the final drive...