2004-2007 Cadillac CTS-V Performance Mods Discussion, Rear end whine in Cadillac CTS-V Series Forum - 2004 - 2007; so I brought my car in yesterday for the whine in the rear
they will replace the pinion bearing
Automobile(s): 2009 CTS4 Blue Diamond AWD Performance Sedan
Michigan 'da UP'-Lake Superior
Re: Rear end whine
They are probably replacing the pinion bearing in hopes (long shot) that it will cure the problem. According to what my dealer SM tells me the only problem is the noise, most owners would disagree. He claims before he can replace a rear axle he has to get the approval of his zone maintenance rep. Basically he does not want to stick his neck out in the chance that when he returns the parts (and he must return the replaced parts) they decide nothing is wrong and he does not get paid for the repair. It took 2 months to get the approval to replace the Rear in my girl friends '09 CTS4. The R & R of the complete rear diff asm was at about 15,000-20,000 miles (+/-) and when she traded it in last winter (with approx. 50,000 miles) the noise was back. She did not buy another Cadillac, disgusted with the many problems she had and the indifference of the Cadi dealer service dept.
PS - When my CTS was new, I replaced the factory gear lube right away (less than 100 miles) with AMSOIL Severe Gear 75W-90 and 5 yrs and 38,000 miles later I don't have any noise.
They claim the first 100 to 500 miles in very critical in these differentials and if they generate too much heat, problems such as this can result. I seen that in writing because they gave my gf a copy of something that stated that. I made a copy of that notice but have misplaced it or I would post it.