kleecker

Lately on left hand corners I have been hearing/feeling a noise come from the car. It sounds a bit like driving on rumble strips which they cut down into the asphalt on highway shoulders (to keep you awake), but not as loud............. that's the best that I can describe the noise.

I haven't tried a million different operating conditions (high speed vs. low speed, uphill vs downhill, for example). It first came to my attention when taking a few mid-speed (80 mph) sweepers. Due to the low frequency of the noise, it's not easy to discern where the sound is coming from - front, mid, or rear of the car.

So far, the noise only occurs when taking left handers. I took the same couple of sweepers where I heard the noise, but this time in neutral (at about the same speed as when taking then in gear) and no noise; instantly lead me to think it's in the rear. But why only on left handers?

I ran a couple of tighter, slower left handers and could hear/feel the noise as well. Just kinda poor conditions to be experimenting - cold conditions (45-50F), and quite a bit of drive train noise from the turbo and exhaust.

Thoughts welcome. My sig shows my mods, including the rear. Rear is about a year old................ and about 1K (aggressive) miles with forced induction.

thanks, and hope the title of the post gave some of you a lol,

Mark

kleecker

a bit more info................. the noise is heavily dependent on the load placed on the right side of the carl................ for example, taking a very broad left sweeper at 100+ will bring it out............... it's as if the noise comes when there is a strong lateral load on right side.

SpitfireS

Thoughts : rear wheel bearings.
Maybe because the axle nut wasn't torqued down enough or not torqud down to the new spec.
Are you lowered on the Koni's?
If so, maybe the CV's, but pitted CV's make noise driving straight too IIRC during accelaration.
What oil are you using in your diff?

Twice the milage = twice the wear.
Twice the power = four times the wear?

kleecker

w.r.t. wheel bearings, shouldn't the noise be there regardless of whether in neutral or in gear?

'New" spec for axle nut torque?

Yes, I am lowered................. via the Koni's.............. but only a whopping 1/2" compared to stock (running stock springs).

Diff fluid is LE-607 90W Almasol. I have not changed it out since first receiving and installing the reinforced diff with 4.77's from HTG............... that was perhaps in February, and I have put on about 5K miles on the car since then. Car has 11K total miles............ first 6K were quite "easy", from previous owner............. the other 5K have been quite aggressive........ about 1K miles with forced induction so far.

Appreciate the leads.

SpitfireS

kleecker Posted on Dec 4 2006, 12:50 PM
It was raised to 220 lbf/ft.

kleecker Posted on Dec 3 2006, 10:15 PM
Load on the bearings make it rumble?
IMO worn bearing.

Or.... wild guess.. a tire rubbing somewhere?
What wheels/tires are you running?
Check all the upper/lower arm bushings, sway bars etc on the rear suspension.

We're running out of options here, how much more is there to check at the rear?
The diff.
Do the diff test:
Rear on jackstands - be secure - be safe.
In first gear - do not start engine.
Turn one wheel - other wheel should turn opposite.
Listen for noise - it should be quiet and easy to do.
Perform on both wheels.
LE-607 is the recommended (SAE 90 GL-5)oil, should be ok.

Let us know what you find.

kleecker

OK, I've had the turbo kit installed (by InlinePro) for a few weeks now, and planned out getting under the car to give it a look-see for anything obvious in the front end of the car after a month's shake down - I'll just check out the rear end while I'm there.

Yes, Torsen T-2 diff - understand, and will listen for noise. Think it makes any difference if my check is done cold, or with fluids/bearings up near operating temp?

Running AP2 wheels with stock 050's, so no rubbing.

By "load" I am unable to separate lateral from vertical, as they are related during cornering.............. proabably knew that, but just pointed it out for clarification......... I'm not into fat chicks, so can't think of an easy way to seperate vertical from lateral load.

thanks for the tips. Temps in the 40's for a high this week, so car will not see much action - I'll update when I do a check.

kleecker

looks like there's no need to further diagnose this problem - blew the rear end last night.
The diff's Comptech reinforced, but I don't pansy around with the car....... there were certainly a fair number of wheel hops that I did try to keep under control, but sometimes it's too late, especially with the turbo - with turbo, it's something akin to tire shake in it's nature - depending on the surface of the road, opening the throttle full bore while in 2nd and 3rd gear tends to lead to some wheel spin........... and hop, depending on the circumstances. Have attempted to catch the hop and back off as soon as possible, but guess I was not quick enough. Stock street rubber (050's).

Anything besides the InlinePro full rear kit that is more durable than a the Comptech reinforced diff, but doesn't cost $3K?

SpitfireS

kleecker Posted on Dec 13 2006, 01:24 PM
That's bad news.
Are the 17" Bridgestone RE050 the OEM tires for MY03?
Have you seen the diff open yet, if possible take some pictures.

Succes with your new rear kit.

Mr. Eryozgatliyan

I think this topic title should be stickied! "Got a noise coming from my rear, MMMMMMM!"

kleecker

'Stones are AP2 OEM tires from an '04 (along with the AP2 wheels)............... they are now bald, both from a few track days and ................. well, as for the rears, turbo power.

Assuming I get Holiday chores taken care of, I will remove the diff this weekend and open the rear cover. I have been told by several sources that the 4.77's, which are supposedly made OEM for the KIA Sportiage (sp?), are not the strongest or the R&P sets out there............ exactly WHY they are not as strong as OEM 4.10's is a unclear to me right now........... I have not seen the ring and pinion sets back to back to arrive at any first hand logical conclusion.

Anyway, I am hoping it's the R&P and not the housing; if so, I will get 4.10's installed and see how things hold up (approx $400-500, parts and labor). If not, a completely rebuilt diff, with Comptech reinforcement, will run about $1500......... so the InlinePro kit would be a no brainer in that case.

Will update with pics.