[drivered]

I have read through previous posts on this and haven't seen it, but if it is I apologize. I have an 04 V8 AWD with 65,000 miles that makes the "chain slipping on a sprocket" sound only when you hit the gas hard from a standstill. I went to trade it in a 08 CTS and they offered me $7500, stating the noise could be a problem. I do not want to pass this problem on to anyone and definately would be forthright with a private party (if a dealer checked it out and didn't see it.....). I am thinking my best case is to find one to install. My questions are:

1. Is there any good places to find one besides car-part.com

2. Do I have to know the part #?

3. Can I use a different year (and should I)?

4. How hard is it to do yourself?

I have decent automotive repair skills. I tore down a Jeep CJ 7 down to the fram and removed the trans and transfer case and reinstalled. With the SRX being 20 years newer and with a lot more electronics-does it change it that much?

I will be able to put it on a lift.

Thanks for all your help.