I have been told that my 2002 Subaru WRX Imprez has a bad center differential and that I was looking at about $2000 in repair. Questions:
Thank you for any advise you can offer.
What symptoms are you experiencing? Have you checked the circumference of all the tires to see if they are all within allowable tolerance?
Symptoms:with a hard turn to r or l a deep thumping sound starts
I have not checked my tires but will tomorrow. Can I make a long drive with it?
I’d be very hesitant to go very far until I knew for sure what the problem is.
I don’t think the center diff does much when you are driving straight down a paved road, like an interstate highway, there is no differential action going on…I suppose it depends on exactly which parts are failing before you can determine if it’s save to drive…If the gear case contains any meaningful amount of metal chips and filings, then the shaft support bearings are going to get torn up on a long trip resulting in catastrophic failure…Taking a vehicle with known mechanical problems on a long trip is always risky business…
Thank you both for your reply. I agree that it would be foolish to go on a long drive knowing that something catastrophic could happen. I’m going to the mechanic tomorrow.
Found this on www.wrxtuners.com The two things that the car will exhibit if it is failing, is a tendency to hop or bind when the steering is at full lock (think low speed, parking maneuvers) The other is a whining, space ship-like noise on accelerating indicating the bearings in the transfer case (specifically the coupler, most of the time) are bad.
One of the problems that can develop when the center differential viscous coupling siezes up is that the front and rear drives bind against eachother. If a tire or tires on one axle has a larger or smaller circumference than the other axle, the difference in rotation will not be relieved by the center differential. What happens is that both the front and rear ring and pintion gears are under excessive load. The front ring and pinion gear oil is cooled by the engine and transmission thermal mass. However, the rear drivehousing does not get much air cooling; the oil can over heat; and in some cases the rear oil catches fire.
So I would not take this on a long drive until the center differential problem is resolved. If you do take the trip, stop after 40 miles and ascertain the temperature of the rear axle drive housing. Be careful because if my be burning hot. You might be able to smell the oil vapors venting.
Hope this hellps.
Get another opinion. You can repair the differential also or get a used part.
It is not a typical wear part for a Subaru unless neglect, abuse, bad luck or mismatched tires(replacing a single tire) happened along the way.
OP when you get the center differential replaced, see if you can retain the defective part. If you do, see if you can disassemble the viscous coupling part. I am curious about what fails when these couplings sieze. I am thinking the plates could become warped and bind against each other. Another possiblity is that the viscous fluid being used solidifies effectively locking the plates together.
Anyway, examine and report so the rest of us know.