finally replaced my buddy's throwout bearing in his '85 rx-7 last week. that noise is now gone , but now you can hear the diff almost grinding. it almost sounds to me like the pinion bearing (if this design has one, i've seen them w/o) but its a little harsh to be a bearing it would seam. he topped off the diff fluid with no results. definetly comin from the pumkin tho.

ideas




(yeah yeah. poorly worded. sorry, out of practice)

12/29/2006 7:48:13 PM

does the noise change w/ load? like if you get on/off the gas does it change? does it change when you turn or w/ lateral loads?

12/29/2006 8:31:21 PM

sounds like you have too much backlash on worn gears and the teetch are meshing on the edge of the ring gear instead of in the center of the tooth

the teeth are normally ground like this:

)(

your teeth look like this:
II

so the gear set needs to be replaced

12/29/2006 9:13:10 PM

Quote :

"pinion bearing (if this design has one, i've seen them w/o)"

Show me a differential without a pinion bearing (or two) and I'll show you a doorstop.

12/29/2006 11:01:53 PM

^^^i'll check with him today at work

^^that is what i thought at first, this seems to be coming more from the front, where the driveshaft attaches. i checked the u-joints while we had the shaft out and they were kosher.

^well, i didn't mean completely bearingless, instead of needle or ball bearings, it had... ummmm... crap... exact term escapes me right now ( hungover), like crankshaft bearings. wierdest thing i ever saw, i want to say it was in a jaguar rearend this guy had under his tri-5 chevy.

12/30/2006 10:26:51 AM

while we're on the subject, my car is whining back there too. LETS INVESTIGATE!

its an ol' granny 267kmile E30 w/ LSD.

It starts whining like an electric motor almost. higher pitched, sounds squarewaveish. varies in pitch and a bit in volume w/ vehicle speed only. Not w/engine speed, not w/ engine load, not with turning load. It does sometimes do it louder than others.. maybe temp dependant?

The car has new rear wheel bearings, driveshaft (60kish), guibo. original diff. I changed the diff fluid and it made no difference. The LSD seems to work as w/ a side lifted and a side on the ground it takes about all i got to turn the wheel. I also can't get any wheel spin on the streetz.

I can't find a record of the center support driveshaft bearing so maybe thats old.. but i kinda doubt it, thats just half assed.

I'm starting to think its just tires. Theyre old and kinda dry rotted and not so good on tread. but i'd be quit surprised as this is a really almost electric motor/mechanal sort of noise. Maybe CVs.. but no ticking or clicking in turns.. hrm

Or maybe its just the ol' granny being an ol' granny.

12/30/2006 11:18:12 AM

Quote :

"Or maybe its just the ol' granny being an ol' granny."

exactly. you've got a ~20 year old car with 267k. just drive/track it (whatever your plans are), and replace stuff when it breaks.

1/2/2007 2:24:10 AM

267K. You can be worried about driveline noises with that many miles. Arent thoses center drop out rears? If so it shouldnt be too hard to replace it when the time comes

1/2/2007 12:58:20 PM

fix: install loud as shit engine and tranny mounts.

1/2/2007 1:09:44 PM

there ya go. maybe an aftermarket exhaust also.

1/2/2007 1:13:03 PM

Been there..how ya likin that Dan?

1/2/2007 1:13:41 PM

Quote :

"there ya go. maybe an aftermarket straight-pipe exhaust also. "

1/2/2007 4:03:35 PM