Strange rotating sound while driving our 94 - ZR-1 Net Registry Forums

Norwegianmopar · 09-01-2020

We have a strange unknown sound while driving, a slow growl-like rotating sound, we notice it more when two ride in the car than one. It is slower than the speed of the wheels (no brakes hanging) and more noticeable when turning right. It is there both when releasing the throttle and/or pressing the clutch in, both in gears and in neutral. Noone can figure it out.

Could it be the differential? Maybe the transmission? Wheel bearings (not likely)?

It reminds us of the sound tires make when touching the inner fenders, only rotating slower than that and more of a mechanical sound. A low growl/scraping rotating sound (hard to explain in words). A bit of the same frequency or growl type like the transmission in the first gears at low rpm, but an uneven rotating sound...

Brake pads rubbing uneven discs could maybe make the same sound, but then according to wheel speed, not more or less constant like here.

We do have a lightweight flywheel that makes some sound too, but this is a mystery to us.

The car had a full tune up and service at Haibeck's last summer and has ran less than 1000 miles since.

I know it's a long shot tho but have to ask since we have no clue what it can be.

Sent from my SM-G955F using ZR-1 Net Registry mobile app

Paul Workman · 09-01-2020

Without hearing it, it is hard to pinpoint. But, without knowing exactly what/where it comes from, elimination my be the only recourse until you have more information.

Wheel bearings: Put the car up on jack stands first. Then rotate each of the front wheel/tires to see if that will create the sound. Also, push and pull (wiggle) the tire to see if there is any give in the bearing. Then rotate the wheel about 1/8th of a turn and try again and keep doing the push/pull/rotate until you've gone 360? of rotation. Repeat for both front wheels before moving to the rear wheels: same procedure.

How are your brake pads? are they wearing evenly or is there more wear on one end of the pad(s) that the other (assuming the pads are not worn out, i.e., metal on metal)?

Next, start the car, put it in gear, and let the clutch out and listen while the engine idles. Go thru all of the gears and see if the sound appears.

Try the brakes

Try turning the steering wheel from stop to stop. Any gear noise/pump whine?

NOTE: Especially in the lower gears, and in the 90 to 92s, the angle of the helix cut in the transmission gears was such that they made a low growling sound whenever under load, which is normal for those early Zs. It isn't that, is it?

Well, let us see what you discover after this experiment: either the sound is re-created or is it now gone? Either way, that is good information to have.

Let us know what you find or don't!

viper107 · 09-01-2020

sounds like a hub bearing possibly

GOLDCYLON · 09-01-2020

My guess would be a hub bearing, Or a service needed for rear diff and adding of rear diff lubricant. Hard to know without hearing it. GC

32valvesftw · 09-02-2020

As other stated its probably Hub bearing or maybe rear u-joint. But maybe my early experience with my car can be helpful. When I first received my car about 5 yrs ago I stupidly took it for a drive right after it got off the trailer, and had a weird growling noise when I made a turns. It turned out to be a loose wheel. Just saying...sometimes it's a simple thing.

09-01-2020	#1
Norwegianmopar Join Date: Mar 2018 Location: Norway Posts: 345	Strange rotating sound while driving our 94 We have a strange unknown sound while driving, a slow growl-like rotating sound, we notice it more when two ride in the car than one. It is slower than the speed of the wheels (no brakes hanging) and more noticeable when turning right. It is there both when releasing the throttle and/or pressing the clutch in, both in gears and in neutral. Noone can figure it out. Could it be the differential? Maybe the transmission? Wheel bearings (not likely)? It reminds us of the sound tires make when touching the inner fenders, only rotating slower than that and more of a mechanical sound. A low growl/scraping rotating sound (hard to explain in words). A bit of the same frequency or growl type like the transmission in the first gears at low rpm, but an uneven rotating sound... Brake pads rubbing uneven discs could maybe make the same sound, but then according to wheel speed, not more or less constant like here. We do have a lightweight flywheel that makes some sound too, but this is a mystery to us. The car had a full tune up and service at Haibeck's last summer and has ran less than 1000 miles since. I know it's a long shot tho but have to ask since we have no clue what it can be. Sent from my SM-G955F using ZR-1 Net Registry mobile app __________________ Roy Martin 1994 ZR-1 #112 Admiral Blue/Black Dana 4:10 Aluminum flywheel Corsa exhaust Watson headers Haibeck chip 470 HP/399 RWHP 1991 ZR-1 #400 White/Red (SOLD) Dana 4:10 Powder coated engine Haibeck performance chip Borla exhaust

09-01-2020	#2
Paul Workman Join Date: Nov 2007 Location: Squires (near Ava MO in the Mark Twain N'tl Forest) - Missouri Posts: 6,493	Re: Strange rotating sound while driving our 94 Without hearing it, it is hard to pinpoint. But, without knowing exactly what/where it comes from, elimination my be the only recourse until you have more information. Wheel bearings: Put the car up on jack stands first. Then rotate each of the front wheel/tires to see if that will create the sound. Also, push and pull (wiggle) the tire to see if there is any give in the bearing. Then rotate the wheel about 1/8th of a turn and try again and keep doing the push/pull/rotate until you've gone 360? of rotation. Repeat for both front wheels before moving to the rear wheels: same procedure. How are your brake pads? are they wearing evenly or is there more wear on one end of the pad(s) that the other (assuming the pads are not worn out, i.e., metal on metal)? Next, start the car, put it in gear, and let the clutch out and listen while the engine idles. Go thru all of the gears and see if the sound appears. Try the brakes Try turning the steering wheel from stop to stop. Any gear noise/pump whine? NOTE: Especially in the lower gears, and in the 90 to 92s, the angle of the helix cut in the transmission gears was such that they made a low growling sound whenever under load, which is normal for those early Zs. It isn't that, is it? Well, let us see what you discover after this experiment: either the sound is re-created or is it now gone? Either way, that is good information to have. *Let us know what you find or don't!* __________________ Good carz, good food, good friendz = the best of timez! 90 #1202 "FBI" top end ported & relieved Cam timing by "Pete the Greek" Sans secondaries Chip & dyno tuning by Haibeck Automotive SW headers, X-pipe, MF muffs Former Secretary, ZR-1 Net Registry

09-01-2020	#3
viper107 Join Date: Dec 2019 Location: st louis mo Posts: 748	Re: Strange rotating sound while driving our 94 sounds like a hub bearing possibly __________________ 95 admiral blue z(sold)/ / 93 ruby z(sold) 91 steel blue z/95 aqua z haibeck 510, 91 callaway 415 areobody #5

09-01-2020	#4
GOLDCYLON Join Date: May 2007 Location: Peoria, AZ Posts: 9,155	Re: Strange rotating sound while driving our 94 My guess would be a hub bearing, Or a service needed for rear diff and adding of rear diff lubricant. Hard to know without hearing it. GC __________________ GOLDCYLON - 91 ZR-1 #2014 GOLDCYLON - 90 ZR-1 #2794, 4L60e (Formerly Schrade's) GOLDCYLON - 11 CTS-V Arizona State Director 91 WHITE/BLACK #2014. 380 P&P&PCed,Ported Heads, Jeal Long tubes, Corsa Exhaust/FIKSE FM-5s /LED TLs, LED Headlights, Front Wilwood 6 piston narrowlite calipers and rear Wilwood caliper street shop mod,CNCed Coolant Pipes,TPI Cvr,Filter cover,Stainless Bolts, DRM/DOM PROM /ZFDOC mod build #102,DRLs,BMAD with stainless Debris Screen,Coplan Air Blaster, Pioneer APP Radio 4,Brey-Krause HB,Sub Bar,Fire extinguisher seat mount,DRM Coilovers,LEDs everywhere,Compass mirror (orange),V1 DIC hidden display, Homelink sun visor, Carbon Fiber top x3 and APSIS Carbon Fiber interior, APSIS CF Steering Wheel/NAPA Leather, Banski trailing arms, Guldstrand front suspension,urethane bushings from Prothane (total suspension) ZFDoc drive shaft safety loop, raptor shift light (orange),AO engineering louver front plate, Console seat cushion, 96CE seats with black custom Sheepskins, ss billet catch can,Viper remote entry/alarm,Cragar Rear Louvers,LED side louver lights, Dewitts Radiator with SPAL fans and a Woods 160 T-Stat 90 RED/BLACK #2794. 4L60e Automatic Stage V by RPM Transmission, TCI Dedicated TCM, OBX Stainless Headers, Corsa Exhaust, SAN Secondaries and Haibeck PROM, Exotic Muscle Coil overs, LED Interior Lights, LED Tail Lights, LED Headlights, 94 Sport seats with black custom Sheepskins , Cragar rear louvers, GS Front calipers, Banski Trailing arms, APSIS Carbon Fiber steering wheel, Front and Rear Baer Eradispeeds, DRLs, Guldstrand front suspension,urethane bushings from Prothane (total suspension), Dewitt's Raditor with Dual SPAL fans and a Haibeck 170 T-Stat 11 RED/GREY CTS-V

09-02-2020	#5
32valvesftw Join Date: Jun 2015 Location: Texas Posts: 530	Re: Strange rotating sound while driving our 94 As other stated its probably Hub bearing or maybe rear u-joint. But maybe my early experience with my car can be helpful. When I first received my car about 5 yrs ago I stupidly took it for a drive right after it got off the trailer, and had a weird growling noise when I made a turns. It turned out to be a loose wheel. Just saying...sometimes it's a simple thing.