Metal in Tranny Fluid

[DanLazer]

My 1994 5 spd aspire (127000 miles) came with gear oil in the tranny. It was shifting great. I drained that and refilled with dex/merc atf per the Hyanes manual, drove it for a couple hundred miles and changed it again. The atf that came out was still red but full of metallic particles. I refilled it and drove it a couple thousand miles. Now it is shifting hard (particularly first to second gear) so I changed the fluid again the other night. The fluid that came out is filled with metallic particles again. Fluid level is correct per speedo cable dipstick.

Is it normal to have lots of metal particles in your atf? I know when I change the fluid in automatics it looks new still, but those have a trans fluid filter. Is my tranny eating itself up? Can I do anything to stop it? Is this just the syncros going bad? You can buy a new bearing and syncro rebuild kit for this tranny for $150. Should I put one of these in before it eats the gears up? Thanks for any help or similar experiences.

[sedat]

Not supposed to have metal. Very little is fine. Tons is not fine. The gear oil most likely killed your trans. Theres no filter, much less a pump. I'd go ahead and rebuild.


FWIW I bought a 88' a few years ago and drove it 45 miles home. I was doing suspension work the following day and found out there was no drain plug in the trans :shock:


(I *have* seen manual transmissions with oil pumps,filters and coolers, just not from japan)

[FestYboy]

betting one of the bearings is letting loose (typicaly the input bearing or main layshaft rear bearing)

[DanLazer]

Any idea where the metal shavings are coming from? Gears, syncros or bearings?

[bravekozak]

Because of your story, I am going to install a magnetic drain plug in my transmission before I fill it with fluid.
I'm on a roll. I just bled my brakes last night. New master cylinder. Dot 5 silicone brake fluid. No more clouding up due to water absorption.
I will check for the transmission drain plug tonight.
Good luck troubleshooting the source of your problem.
Be sure to post your results. Thanks.

[Kraig]

What color are the shavings?

[DanLazer]

Silver. When I stir the fluid in the drain pan, there are sliver metallic swirls. And a few bigger silver shavings (about 1mm across) in the bottom of the pan when I emptied it.

[bravekozak]

O.K. I took out the drain plug and found it to be M14 X 1.5
Will get a magnetic replacement plug tomorrow.
If any metal sticks to the plug, it's the steel gears.
If it just floats around in the oil, then its aluminum from the walls inside the gear housing.

[Kraig]

What he said....and if it's gold in color (brass) it's synchro's wearing out.

[DanLazer]

I put a magnetic drain plug in last night like the one pictured below. It's a lot longer than the stock one but it's all I could find. $4 at NAPA. It didn't hit anything when I screwed it in and didn't make any horrible grinding noises when I drove it so I guess it will work.

It will probably be a while until I tear this tranny apart but I'll post an update on what components failed when I do.

[DanLazer]

FestYboy. The car shutters when I release the clutch when the car is cold. Clutches smooth when warm. Is this a symptom of a failing input bearing? I figured the friction plate in the clutch just changed shape a little when it warmed up but not sure.