open diff question.

[kazuma]

okay here is a question i got for you tech guys . i have a 90 240 and have had a problem ever since ive had it. when i am accelerating in either first or second gear i hear this very loud grinding noise coming from underneath the car(driver and back cant really make it out). now i had it checked out and what they did is they put the car on a hoist and drove the car(rear wheels were free to spin basically no load on them) and this sound wasnt present any more so the guy that looked at it for me told me its my diff and that it either needs to be rebuild or replaced. now yesterday me and my buddy were just testing something out when we noticed something. when the car is in gear(either first or second) the grinding noise is there but as soon as i put it in neutral the sound goes away.

anyways to my question. when the car is in neutral is the driveshaft spinning the diff or is the driveshaft not moving or moving at a very low rate of speed? reason i ask this is because we thought maybe my transmission was fucked but if the transmission was fucked wouldnt it still have the same noise when it was on the hoist with the rear wheels spinning freely?

thanks in advance.

[gasser]

yout driveshaft is connected directly to your diff, so if your vehicle is moving at 35 mph and you put it in neutral, your driveshaft is still gonna be moving at the same speed.

[S14DB]

your tranny is fubar. You only hear the sound when it's in the 1/2 gear-set under load. Any diff or drive-shaft noise is a whine or vibration. Grinding is usually always the transmission. sounds like your syncros or baulk rings are fried and rubbing in the tranny.

Change your transmission fluid and diff fluid and see which one has the metal in it. If you want proof.

[TurDz]

so a diff/driveshaft noise is a whine...nice....I have a small whine all the way to around 3k...sounds good :)

[kazuma]

your tranny is fubar. You only hear the sound when it's in the 1/2 gear-set under load. Any diff or drive-shaft noise is a whine or vibration. Grinding is usually always the transmission. sounds like your syncros or baulk rings are fried and rubbing in the tranny.

Change your transmission fluid and diff fluid and see which one has the metal in it. If you want proof.

hmm the noise is also there when im in reverse. does this help more? or the transmission is still the culprit?

[ranisron]

Transmission.... You can still drive it, but its more like knock on wood.

[Drunk Bastard]

ok, do this: take out your open diff, get welded, then rock it....and if your tranny dies....just do a AUTOMATIC swap..besides, they are FASTER!!!

[kandyflip445]

I've seen this happen with a very worn pilot bushing. Check it out.

[kazuma]

ok, do this: take out your open diff, get welded, then rock it....and if your tranny dies....just do a AUTOMATIC swap..besides, they are FASTER!!!

lol okay...lets go with an automatic that will really make things better :wtf:. thanks to the rest for the responses im going to get a open diff and see if that changes the situation, if not time to do an engine swap :fawk: .

[kandyflip445]

Seriously. Pull the tranny and look at the pilot bushing.

[Wei240]

yeah, check bushings/tranny,
destroying the actual open diff must be some type of crazy abuse which i don't think is the case...