Metallic/grinding saw like noise coming from rear after new (used) diff installed
08-29-2014, 05:30 PM
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Metallic/grinding saw like noise coming from rear after new (used) diff installed
Hey there everyone, I'm hoping you guys can help me out and put me in the right direction with the problem I'm having with my car. It's a long story but please just bear with it!
Background:
2004 Honda S2000, 47,XXX miles
Last week, I took my s2000 to it's first track day. Everything was running smooth the whole day until my last session, white smoke started coming out from the rear. I pulled in and assessed the damage. Looking underneath, you could see oil splattered out from the differential. Trying to move the car from a dead stop, it felt like it was ready to stall. While moving slowly forward and turning, you could hear a clunking noise coming from the rear. After about an hour & 1/2 of letting it rest, the car was no longer acting strange. I was still uncomfortable with driving it home so I got the car towed to a shop that one of the main track instructor owns. After his diagnostic, I was told that the differential needed to be replaced. He replaced the diff with a used one from pulled from a 2004 S2000 with a 30 day warranty.
So I picked up my S2000 today and when I was driving it back home, I noticed a grinding noise coming from the rear. From inside the car, the noise reminds me of a table saw. It starts at about 20mph and the speed of the noise is parallel to the speed I'm traveling. I went back into the shop and asked the instructor to ride shotgun and hear the noise. He told me it sounded like something was rubbing against the rotors. He said it couldn't be the differential because any odd noises would only be apparent while making turns and while not going straight. We agreed that I would take it back home inspect the rear brakes and if the issue continues, bring it back to him.
Checked out my rear brakes and it doesn't look like anything is rubbing. NOW I have also noticed that while taking sharp turns full lock on the steering wheel either left or right, there is a howling noise coming from the rear when I'm on the throttle @ 10-12 mph. He gave me the bottle of the differential fluid (75W-85) and it appears that this isn't recommended here on the forums I can't contact the shop because they are closed now, so I'm hoping anyone here can help give me a diagnostic.
I'm thinking it's the diff. Could I have gotten a bad one? Is the 75w-85 oil the culprit? Any info would be greatly appreciated!!
Picture of the Diff Oil used
Video of the noise. It becomes apparent @ 7-8 seconds and gets louder as I pick up speed @11 seconds. From the outside, it almost sounds like bugs in the background, but it's not. That's the noise coming from the rear,
[media]http://www.youtube.com/watch?v=zOjfE4QvPOw[/media]
Background:
2004 Honda S2000, 47,XXX miles
Last week, I took my s2000 to it's first track day. Everything was running smooth the whole day until my last session, white smoke started coming out from the rear. I pulled in and assessed the damage. Looking underneath, you could see oil splattered out from the differential. Trying to move the car from a dead stop, it felt like it was ready to stall. While moving slowly forward and turning, you could hear a clunking noise coming from the rear. After about an hour & 1/2 of letting it rest, the car was no longer acting strange. I was still uncomfortable with driving it home so I got the car towed to a shop that one of the main track instructor owns. After his diagnostic, I was told that the differential needed to be replaced. He replaced the diff with a used one from pulled from a 2004 S2000 with a 30 day warranty.
So I picked up my S2000 today and when I was driving it back home, I noticed a grinding noise coming from the rear. From inside the car, the noise reminds me of a table saw. It starts at about 20mph and the speed of the noise is parallel to the speed I'm traveling. I went back into the shop and asked the instructor to ride shotgun and hear the noise. He told me it sounded like something was rubbing against the rotors. He said it couldn't be the differential because any odd noises would only be apparent while making turns and while not going straight. We agreed that I would take it back home inspect the rear brakes and if the issue continues, bring it back to him.
Checked out my rear brakes and it doesn't look like anything is rubbing. NOW I have also noticed that while taking sharp turns full lock on the steering wheel either left or right, there is a howling noise coming from the rear when I'm on the throttle @ 10-12 mph. He gave me the bottle of the differential fluid (75W-85) and it appears that this isn't recommended here on the forums I can't contact the shop because they are closed now, so I'm hoping anyone here can help give me a diagnostic.
I'm thinking it's the diff. Could I have gotten a bad one? Is the 75w-85 oil the culprit? Any info would be greatly appreciated!!
Picture of the Diff Oil used
Video of the noise. It becomes apparent @ 7-8 seconds and gets louder as I pick up speed @11 seconds. From the outside, it almost sounds like bugs in the background, but it's not. That's the noise coming from the rear,
[media]http://www.youtube.com/watch?v=zOjfE4QvPOw[/media]
08-29-2014, 07:21 PM
#2
I'm pretty sure that is the bad gear oil to use in our diffs. Someone should chime in soon to verify that.
You shotgun rider was begin dumb. When I was pinpointing a tail shaft bearing issue in the tranny it was tough because the noise is VERY similar to a failing diff. You can hear it in a straight line, clutch in or out, in gear or out, any rpm, but is directly correlated to the speed of the car...
That may not be the ONLY way to tell if a diff is failing, but it's definitely ONE of the ways. The fact he said it wasn't related to the diff makes be think he doesn't know what he's talking about.
Edit: sorry I can't listen to your video, the wife is asleep next to me lol
You shotgun rider was begin dumb. When I was pinpointing a tail shaft bearing issue in the tranny it was tough because the noise is VERY similar to a failing diff. You can hear it in a straight line, clutch in or out, in gear or out, any rpm, but is directly correlated to the speed of the car...
That may not be the ONLY way to tell if a diff is failing, but it's definitely ONE of the ways. The fact he said it wasn't related to the diff makes be think he doesn't know what he's talking about.
Edit: sorry I can't listen to your video, the wife is asleep next to me lol
08-29-2014, 10:19 PM
#3
Start off changing your diff oil. This is the absolute easiest and cheapest way to start your diagnosis.
When you drop the oil, if chunks of gears are falling out, game over, go back to start, do not collect $200. Replace it.
Now, if the oil you dropped out is nice and clean, change with more appropriate oil.
Make sure it is a synthetic. OEM calls for 75w90. I personally use Mobil 1 full synthetic Limited Slip 75w90 gear lube. You'll be okay with any GL-5 rated gear oil that is 75w90, 75w110, or 75w140. You may need a friction modifier additive depending on the oil you choose. I've heard friction modifiers aren't needed because the gear we use isn't a true LSD, but I haven't done my research on that to give you a straight answer. There are a lot of people out there that recommend different oils so honestly it's up to you. I'd run down to Advanced/Auto Zone/Walmart/wherever and get one quart - maybe two - of the oil I mentioned above (because I know it works well for a fact), but like I said, any gear oil that meets those requirements SHOULD be fine.
I've heard that if you call your local Honda dealer and ask for s2000 gear oil, they will give you the oil used in the CR-V rear end. THIS IS NOT WHAT YOU WANT.
If the differential is still grinding after changing the fluid once, maybe twice, I would pull it and rebuild. (or replace with another if that is what you choose to do.)
I hope this helped.
When you drop the oil, if chunks of gears are falling out, game over, go back to start, do not collect $200. Replace it.
Now, if the oil you dropped out is nice and clean, change with more appropriate oil.
Make sure it is a synthetic. OEM calls for 75w90. I personally use Mobil 1 full synthetic Limited Slip 75w90 gear lube. You'll be okay with any GL-5 rated gear oil that is 75w90, 75w110, or 75w140. You may need a friction modifier additive depending on the oil you choose. I've heard friction modifiers aren't needed because the gear we use isn't a true LSD, but I haven't done my research on that to give you a straight answer. There are a lot of people out there that recommend different oils so honestly it's up to you. I'd run down to Advanced/Auto Zone/Walmart/wherever and get one quart - maybe two - of the oil I mentioned above (because I know it works well for a fact), but like I said, any gear oil that meets those requirements SHOULD be fine.
I've heard that if you call your local Honda dealer and ask for s2000 gear oil, they will give you the oil used in the CR-V rear end. THIS IS NOT WHAT YOU WANT.
If the differential is still grinding after changing the fluid once, maybe twice, I would pull it and rebuild. (or replace with another if that is what you choose to do.)
I hope this helped.
08-30-2014, 01:39 PM
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**UPDATE**
So switched out the differential oil to Mobil 1 Full Synthetic 75w140. The differential oil drained out was clean, no metal shavings at all. After swapping to the new oil, the howling noise coming from the rear during tight turns, full lock left or right with the throttle applied is no longer there. Unfortunately that metallic grinding noise that sounds like a table saw is still there. It still starts @ 20mph and increases in volume and rate with speed. You can be in gear, neutral, clutch in or out all while moving and the noise is still there. As dangerous as this may sound, I lifted the rear of the car and put a camera underneath the car to record the exact noise. I can't pinpoint where specifically it's coming from, but it's definitely from the rear.
Noise starts at 7 seconds.
[media]http://www.youtube.com/watch?v=1iu5UczPuWI[/media]
So switched out the differential oil to Mobil 1 Full Synthetic 75w140. The differential oil drained out was clean, no metal shavings at all. After swapping to the new oil, the howling noise coming from the rear during tight turns, full lock left or right with the throttle applied is no longer there. Unfortunately that metallic grinding noise that sounds like a table saw is still there. It still starts @ 20mph and increases in volume and rate with speed. You can be in gear, neutral, clutch in or out all while moving and the noise is still there. As dangerous as this may sound, I lifted the rear of the car and put a camera underneath the car to record the exact noise. I can't pinpoint where specifically it's coming from, but it's definitely from the rear.
Noise starts at 7 seconds.
[media]http://www.youtube.com/watch?v=1iu5UczPuWI[/media]
08-30-2014, 03:59 PM
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So I picked up my S2000 today and when I was driving it back home, I noticed a grinding noise coming from the rear. From inside the car, the noise reminds me of a table saw. It starts at about 20mph and the speed of the noise is parallel to the speed I'm traveling. I went back into the shop and asked the instructor to ride shotgun and hear the noise. He told me it sounded like something was rubbing against the rotors. He said it couldn't be the differential because any odd noises would only be apparent while making turns and while not going straight. We agreed that I would take it back home inspect the rear brakes and if the issue continues, bring it back to him.
His answer makes no sense. Any one of the many bearings in the case, if bad, would make noise going straight. The noise is new, so either it's the diff or something else happened at the shop. If he says it's not the diff then obviously he missed something during diagnosis. He didn't offer to look it over more closely? He's stalling. Waiting out the 30 day clock. Take it back. Now.
Don't do anything to it. Don't drive it. Anything you try will weaken your case, muddying the water on what caused the problem or what the problem is. Take it back. Insist on exercising the warranty.
Was there a written work order? Is the Warranty in writing? If not be prepared for a long argument. Don't be surprised if you are asked to pay for further work. You might start researching your state's consumer protection laws regarding auto repair. Don't leave the car at the shop with any work authorized, unless the work order states no charge.
08-30-2014, 06:09 PM
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Originally Posted by mintswack' timestamp='1409362240' post='23308288
So I picked up my S2000 today and when I was driving it back home, I noticed a grinding noise coming from the rear. From inside the car, the noise reminds me of a table saw. It starts at about 20mph and the speed of the noise is parallel to the speed I'm traveling. I went back into the shop and asked the instructor to ride shotgun and hear the noise. He told me it sounded like something was rubbing against the rotors. He said it couldn't be the differential because any odd noises would only be apparent while making turns and while not going straight. We agreed that I would take it back home inspect the rear brakes and if the issue continues, bring it back to him.
His answer makes no sense. Any one of the many bearings in the case, if bad, would make noise going straight. The noise is new, so either it's the diff or something else happened at the shop. If he says it's not the diff then obviously he missed something during diagnosis. He didn't offer to look it over more closely? He's stalling. Waiting out the 30 day clock. Take it back. Now.
Don't do anything to it. Don't drive it. Anything you try will weaken your case, muddying the water on what caused the problem or what the problem is. Take it back. Insist on exercising the warranty.
Was there a written work order? Is the Warranty in writing? If not be prepared for a long argument. Don't be surprised if you are asked to pay for further work. You might start researching your state's consumer protection laws regarding auto repair. Don't leave the car at the shop with any work authorized, unless the work order states no charge.
I'll call them and ask about it. I just want to get it to a shop that specializes in Honda's, more specifically S2000's. Regarding the bearings, I would love for anyone to chime in with bearing replacements on if they experienced the same noise & the cost of replacement.
Thanks everyone for their input!
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08-30-2014, 06:51 PM
#8
A mechanical stethoscope is your friend right now. If you don't have one, use a long screwdriver and put the handle pressed up against your ear. This should help you pinpoint the location of the noise.
When you do this, only lift the rear of the car. use two jack stands on the rear jack points. In my opinion this is safer than jacking it up level. Put it in gear (2nd or 3rd is what I use if I remember correctly) and ease the clutch out. The car will bog a little but should stay in gear even with no gas since there is no load on the rear. You should be able to hear bearing noise (tail shaft, diff pinion bearing, or internal bearing of the trans) more clearly by using the stethoscope method.
I don't think your noise is typical bearing noise though But I'm not an expert so please don't quote me lol.
When you do this, only lift the rear of the car. use two jack stands on the rear jack points. In my opinion this is safer than jacking it up level. Put it in gear (2nd or 3rd is what I use if I remember correctly) and ease the clutch out. The car will bog a little but should stay in gear even with no gas since there is no load on the rear. You should be able to hear bearing noise (tail shaft, diff pinion bearing, or internal bearing of the trans) more clearly by using the stethoscope method.
I don't think your noise is typical bearing noise though
But I'm not an expert so please don't quote me lol.
08-30-2014, 06:55 PM
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A mechanical stethoscope is your friend right now. If you don't have one, use a long screwdriver and put the handle pressed up against your ear. This should help you pinpoint the location of the noise.
When you do this, only lift the rear of the car. use two jack stands on the rear jack points. In my opinion this is safer than jacking it up level. Put it in gear (2nd or 3rd is what I use if I remember correctly) and ease the clutch out. The car will bog a little but should stay in gear even with no gas since there is no load on the rear. You should be able to hear bearing noise (tail shaft, diff pinion bearing, or internal bearing of the trans) more clearly by using the stethoscope method.
I don't think your noise is typical bearing noise though But I'm not an expert so please don't quote me lol.
When you do this, only lift the rear of the car. use two jack stands on the rear jack points. In my opinion this is safer than jacking it up level. Put it in gear (2nd or 3rd is what I use if I remember correctly) and ease the clutch out. The car will bog a little but should stay in gear even with no gas since there is no load on the rear. You should be able to hear bearing noise (tail shaft, diff pinion bearing, or internal bearing of the trans) more clearly by using the stethoscope method.
I don't think your noise is typical bearing noise though
But I'm not an expert so please don't quote me lol.
08-30-2014, 07:00 PM
#10
Originally Posted by jkelley' timestamp='1409453466' post='23309212
A mechanical stethoscope is your friend right now. If you don't have one, use a long screwdriver and put the handle pressed up against your ear. This should help you pinpoint the location of the noise.
When you do this, only lift the rear of the car. use two jack stands on the rear jack points. In my opinion this is safer than jacking it up level. Put it in gear (2nd or 3rd is what I use if I remember correctly) and ease the clutch out. The car will bog a little but should stay in gear even with no gas since there is no load on the rear. You should be able to hear bearing noise (tail shaft, diff pinion bearing, or internal bearing of the trans) more clearly by using the stethoscope method.
I don't think your noise is typical bearing noise though But I'm not an expert so please don't quote me lol.
When you do this, only lift the rear of the car. use two jack stands on the rear jack points. In my opinion this is safer than jacking it up level. Put it in gear (2nd or 3rd is what I use if I remember correctly) and ease the clutch out. The car will bog a little but should stay in gear even with no gas since there is no load on the rear. You should be able to hear bearing noise (tail shaft, diff pinion bearing, or internal bearing of the trans) more clearly by using the stethoscope method.
I don't think your noise is typical bearing noise though
But I'm not an expert so please don't quote me lol.1. Your engine should be running well and without any major concern or anything bogging out and shifting the car too wildly.
2. Jack up only the rear, much safer in my personal opinion
3. USE WHEEL CHOCKS on the front wheels
4. Follow what I said above
Wait for someone else to confirm my recommendations if it freaks you out. It freaked me out the first time too lol. But it's really not that bad after the fact. wouldn't hesitate to do it again.