First of all, I'm new to the forum and I'm in need of some help.
My '92 2.5 4cyl, manual trans with approx 150k miles is making a very loud rattle/grinding noise when I am driving in 1st and 2nd gear. Noise is made when a lot of torque is made on the trans and then goes away when at a cruising speed. I'm not sure if it is the clutch or something in the front of the trans as where the noise is most loudest.

Please Help

 

So it is only in 1st and 2nd? Not 3rd or 4th? Or when shifting? 95 318SLT is the manual transmission expert. I'm sure he will chime in soon.

 

1st and 2nd is when its making that noise the loudest. It doesnt make the noise when clutch pedal is depressed.

 

Are you 100% sure its the transmission? When you say the transmission "rattles", can you actually feel it in the shifter?

My first guess is honestly that you have a pinion bearing problem in the rear axle from your description.

But if you are certain that its the transmission, try changing the fluid and seeing if the problem persists. Your transmission takes 75W-90 GL5 gear oil.

 

Ok, when I say rattle, the trans is not actually rattling itself, more like something is loose inside the bell housing making a rattle like noise. I will definitely change the fluid. I'll keep you informed of any changes.

 

Well thats an odd problem! Everything inside the bellhousing is used in every gear, not just 1st and 2nd.

Is there a lot of play in the 1st and 2nd shift gates?

And when you change the fluid, look for any metal shavings or anything that doesnt look right about the fluid.

 

Fluid was topped-off at Jiffy Lube, and they had quickly informed me about the loud noise. They said. lets see what happens when we fill it. The noise stopped 90%, and it was much smoother to shift and drive. About the fluid, just dark, no shavings. The shift gates only seem loose on the outsides, 1,2,5,R but 3,4 are nice n' tight. Its just an old truck that had an new block replaced on it. The trans really never gave me any problems apart from a little leak around the odo cable socket. It was tightned and no leaks since. I want to thank the forum on such a knowledgeable and quick response.

Thank You

 

I'd imagine the noise you're hearing is a worn throwout bearing. My old Civic had that issue. Never caused any problems and I didn't care because it didn't make much noise in higher gears.