Noises from rearend?
Thread Starter
Intermediate
Joined: May 2005
Posts: 29
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Noises from rearend?
Ha, ha, ha, i just re-read my title and it is not what you think.
My 93 6-speed has had a weird clicking/ratcheting noise from the rear only after I start it and move it for the first time of that drive. It does not do it after I start, just when it moves for the first time in the day. It is not loud and does not sound "bad", just curious.
Kind of sounds like the limited slip taking up slack or something.
Anybody have a clue?
My 93 6-speed has had a weird clicking/ratcheting noise from the rear only after I start it and move it for the first time of that drive. It does not do it after I start, just when it moves for the first time in the day. It is not loud and does not sound "bad", just curious.
Kind of sounds like the limited slip taking up slack or something.
Anybody have a clue?
Elite Torch Red Member
Joined: Sep 1999
Posts: 57,805
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From: Exit 89 GSP,Lakewood,NJ The Land Of Mojo
Cental/South NJ Events Coordinator
CI 1-2-3-4-5-6-7-8-9-10-11-12 Vet
CI-II Burnout & Drag Champ
St. Jude Donor '03-'04-'05-'06-'07
I believe most six speed cars encounter this. I have heard so many different answers that I'm going to just say don't worry about it. Mine's been doing it since I bought it with 57,000 miles and now at 131,000 it still does it, but nothing has ever gone wrong with the rear or any related components.
Melting Slicks
Joined: Dec 2000
Posts: 2,719
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From: Fremont Oh
Sounds like you may need to add some limited slip conditioner to the gear oil... if it seems to "creak" mosstly like on turns etc.
You an get it from the dealer it's like a little 4 oz bottle...
Mo
You an get it from the dealer it's like a little 4 oz bottle...
Mo
Race Director
Joined: Oct 2001
Posts: 19,653
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From: Melbourne Florida
Cruise-In IV Veteran
I don't have an MN6 but every time I move the car for the first time the ABS system makes a grinding noise for a couple of seconds in the rear as it trouble shoots and sets the system...perfectly normal...really got my attention till I found out it is supposed to do that...lol
Thread Starter
Intermediate
Joined: May 2005
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Originally Posted by Fuzzy Dice
I don't have an MN6 but every time I move the car for the first time the ABS system makes a grinding noise for a couple of seconds in the rear as it trouble shoots and sets the system...perfectly normal...really got my attention till I found out it is supposed to do that...lol
Looks like I wont worry about it and if someone asked what that noise was, I will tell them it is a insanely expensive locker in rear diff for ultra tough dragway performance.
Melting Slicks
Joined: Dec 2004
Posts: 2,137
Likes: 5
From: Howard PA
I keep seeing posts like this and have the same noise on mine. I've never seen a definate fix for it. Last weekend I decided to try some investigating into it and took the half shafts out, removed the u-joints and inspected the bearing surfaces. Indeed some were pitted, some looked like they were probably frozen so I changed them all. End result was new u-joints and same wierd clicking noise when first moved for the day.
One thing with my ZF6 though, while it was still on the stands I fired it up, turned off the ASR, put it in fourth gear and let the drivetrain freewheel. I heard some horrible clunking and rattling in the transmission. Strange thing is the tranny feels just fine driving it and there's no audible noises from it.
One thing with my ZF6 though, while it was still on the stands I fired it up, turned off the ASR, put it in fourth gear and let the drivetrain freewheel. I heard some horrible clunking and rattling in the transmission. Strange thing is the tranny feels just fine driving it and there's no audible noises from it.
Elite Torch Red Member
Joined: Sep 1999
Posts: 57,805
Likes: 23
From: Exit 89 GSP,Lakewood,NJ The Land Of Mojo
Cental/South NJ Events Coordinator
CI 1-2-3-4-5-6-7-8-9-10-11-12 Vet
CI-II Burnout & Drag Champ
St. Jude Donor '03-'04-'05-'06-'07
Originally Posted by SupaVette
We had a clicking noise on my dad's 90, when u 1st moved forward or backward, it would click. We found the needle bearings on the half shafts were shot
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Race Director
Joined: Dec 2002
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From: SCMR Rat Pack'r Charter Member..Great Bend KS
Originally Posted by ALLT4
One thing with my ZF6 though, while it was still on the stands I fired it up, turned off the ASR, put it in fourth gear and let the drivetrain freewheel. I heard some horrible clunking and rattling in the transmission. Strange thing is the tranny feels just fine driving it and there's no audible noises from it.
This does not surprise me, nor would it worry me. The ZF seems to have a LOT of internal clearances, and being in gear, with the engine running and the wheels off the ground would mean there is zero load on the gears and they could very easily rattle audibly.
Next time try applying the brakes lightly to load the driveline. The noise will stop.
Now... I hear about this "ABS-setting noises at first pull-out" and I'm worried: my car does not do this. Never has. Yet the ABS seems to be working (I've had it activate several times). Even the Helms mentions this noise!
Second concern: my ZF does not make any noises at first pull-out. Mojo says most ZF's do. Why is my C4 such an odd-ball?? I'm thinking I should sell it...cheap...before it gets any quieter.
Larry
code5coupe
Last edited by rocco16; Jun 16, 2005 at 11:34 AM.
Drifting
Joined: Nov 2004
Posts: 1,484
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From: Nanaimo, BC
Originally Posted by Fuzzy Dice
I don't have an MN6 but every time I move the car for the first time the ABS system makes a grinding noise for a couple of seconds in the rear as it trouble shoots and sets the system...perfectly normal...really got my attention till I found out it is supposed to do that...lol
Mine does that too. My Dad's 87 also does it, we both have automatics - it's perfectly normal - ABS setting up. 
Team Owner
Joined: May 2002
Posts: 24,337
Likes: 25
From: San Diego , CA Double Yellow DirtBags 1985..Z51..6-speed
I don't have abs and I get the same noise. The wheel bearings are fine. The ujoints are fine. Axle splines on one side are rusty.
I'll let you know if I find the fix.
I'll let you know if I find the fix.
Race Director
Joined: Jul 2001
Posts: 14,604
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From: Glendale, AZ
Originally Posted by SupaVette
We had a clicking noise on my dad's 90, when u 1st moved forward or backward, it would click. We found the needle bearings on the half shafts were shot
my 92 is doing this now - i "tested" it last night by holding on the break and revving the engine as i thought at first it was coming from the front!
man, i'm afraid of changing those things - i'm looking for tech tips, and haven't found any as of yet.
Team Owner
Joined: May 2002
Posts: 24,337
Likes: 25
From: San Diego , CA Double Yellow DirtBags 1985..Z51..6-speed
Originally Posted by CentralCoaster
I don't have abs and I get the same noise. The wheel bearings are fine. The ujoints are fine. Axle splines on one side are rusty.
I'll let you know if I find the fix.
I'll let you know if I find the fix.
I think it could also be something in the rear, it's worse when starting out through a turn.
The frequency seems to match with wheel speed, not driveshaft speed.