Transmission Problem: Metallic Shavings in the FLuid

schmidter91 · 01-18-2009, 10:07 AM

1982 911SC with 73,000 miles on the clock. 13,000 miles since transmission has been rebuilt. I have had problems with the transmission popping out of first gear for about 6,000 miles. 4,000 miles ago I noticed a metallic grinding noise coming from the transmission which was engine/ transmission speed dependent. Replaced transmission fluid 2,000 miles ago with Swepco 201. The magnetic drain plug had little to no metal shavings at that time. Within the last 500 miles the metallic grinding noise has become worse. It is loudest between 2,000 to 3,500 rpm in 3rd, 4th, and 5th gear under acceleration and deceleration. I checked the transmission fluid level today and topped it off. The pictures tell it all. Shown is the magnetic filler plug. Ideas? Thanks for the help!

ruf-porsche · ruf-porsche's Garage

That fuzz is normal. If you have a broken teeth from a gear I would start to worry. I hope you are not speed shifting between first and second.

kodioneill · kodioneill's Garage

doesn't look bad to me either. you could be loading the trans to much. 2500 rpm shifting point going into 4th will make the tranny chatter. don't know about the popping out of 1st .

Jim Sims · 01-18-2009, 11:35 AM

Check your clutch adjustment; you may be spinning the sychro's needlessly. 60,000 miles is way too early for a 915 transmission to fail in normal service. Failure within 13,000 miles is not normal for a good rebuild. Are you practicing the "915 pause" while shifting? Popping out of first sounds like a worn or misadjusted operating sleeve that had to wear in the new first gear synchro ring to match its misadjustment or worn profile.

burgermeister · burgermeister's Garage

Seems like a lot of fuzz for 2000 miles to me.

For the really curious, check the drain plug magnet - anything heavy (and expensive) wouldn't be stuck to the fill plug.

If you're careful and have a few clean, big containers handy (cut open milk or OJ jugs?), you ought to be able to reuse the oil (if nothing else shows up).

RWebb · RWebb's Garage

normal but 2,000 mile thing is worrisome re the shavings...

metallic grinding noise is the biggie - suspect synchros are going or worse...

WHO did the rebuild 13,000 miles ago???

burgermeister · burgermeister's Garage

Grinding when driving (not shifting) doesn't sound like synchros to me ... more like diff gears or bearings. I assume wheel bearings (and loose lugnuts, and odd worn tires) have been eliminated as possible culprits? It's a dumb question, but it never hurts to ask ...

schmidter91 · 01-18-2009, 09:24 PM

As far as shifting goes I never grind gears, speed shift, or downshift into first. I double clutch downshifts and shift slowly. The tires have normal, even wear. I've ruled out wheel bearings because the noise isn't dependent on vehicle speed but rather engine speed. Third gear is the worst under throttle between 2,500 and 3,500 rpm. I believe I'll do a fluid change and make sure no metal chunks in the it. A clutch adjustment might be in order as well. Anything else I can try? Thanks for all the help!