B16 tranny issue

[ntenc1]

I have been having an issue as of late with my tranny. I notice when accelerating in 3rd gear there is a constant rattling sound. It sounds just like a heat shield rattle (it's not that). It is def in the tranny. 3rd gear is the only one that does it. It shifts fine with no grinds through all the gears. It's just when I accelerate in 3rd gear(hard are just city driving).

Does it sound like a syncro? I think I will try some Pennisol syncro fluid see if that cures the problem. Would that tell me a syncro or not? Being that the clutch is disengaged when this is happening could it be the input shaft bearing? Would it do it all the time or spraticaly?

 

[craiger]

When's the last time you changed the fluid in the tranny? It does sound like the syncro since it only does this in third gear. Do you hear any sound in third when you just coast, or does it only make sound when you really hit it?

 

[ntenc1]

When's the last time you changed the fluid in the tranny? It does sound like the syncro since it only does this in third gear. Do you hear any sound in third when you just coast, or does it only make sound when you really hit it?

It makes it when giving any amount of throttle in 3rd gear. Also when down shifting it makes a sound that sounds to me like a bearing spinning. It only makes that sound when putting in gear, once in gear it makes no noise will giving gas. If I let off the gas after accelerating it will make this bearing sound as well.

Does it sound like an input shaft/ TOB?

 

[craiger]

Man if it is the TOB you would be doing well. Mileage on car? When's the last time you replaced the clutch assembly? TOB's can do some wierd things like that, so it is possible. To me it really sounds like a synchro because it only makes this sound in one gear and not the others.The TOB would make sound in all the gears. Is there any sound in first or fifth?