SaabCentral Forums banner

1 - 8 of 8 Posts

·
Registered
Joined
·
5 Posts
Discussion Starter #1
Hi friends, I'm Rob the new kid on the block. We have a 2008 Saab 97-X that we purchased back in 2010 with 39,000 miles on it at that time. Now here we are almost 10 years later and the car is running great and just racked up 95,000 miles on the odometer. I'm trying to follow the suggested maintenance items as outlined in the manual that came with the car so that we can keep her running for the next five years or more and want to do as much preventive maintenance as I can to extend the auto's useful life. The manual says you only need to service either the front or the rear differential when you hear a noise or see any type of leak which may indicate there is a problem needed to be fixed. But, isn't that rather counter productive advice when if you wait that long the damage could already be done and if you intervened earlier one might have been spared a costly repair ? Also, advocates for regular fluid changes say that no fluid will last forever and that it should be changed out at least every 50,000 miles to keep the axles running smoothly. So, hit me with your best shot of advice so we can decide what's best for our lovable gear horse so she doesn't get put out to pasture prematurely before her time.
 

·
Super Moderator
Joined
·
1,648 Posts
I’d say it’s definitely time. I used Royal Purple’s gear lube in both differentials when I had my 9-7X 5.3 and it worked perfectly. I was getting some “chatter” when trying to make tight, low speed, turns and the Royal Purple fixed it. Also ran RP in my transfer case as well.
 

·
Registered
Joined
·
5 Posts
Discussion Starter #3
Thank you for your comments Josh. I'm still a little bit on the fence about this one as a lot of places that recommend changing out the front and the rear fluids have a self interest. They make money doing the service and perform it whether or not the vehicle even needs it. Some recommend changing it out every 30 K which on our Saab would be about 3 x $130 = $390 for the miles we have driven it already. If there is no leaking at the axle with oil or any noise coming from the boxes I'm reluctant to pay money or time for something that would be of no benefit. I could see taking a sample of the oil periodically to just check its body and color and level with just a top off if needed since the manufacturer tells you that no regular changing out of the fluid is necessary except for the conditions cited above. Playing the devils advocate here though, one might take a conspiracy theory approach and think that, " hell yeah, don't change it out, we would rather see you be complacent about changing the fluid so that when your axles go we make even a bigger buck fixing a bigger problem " ???
 

·
Super Moderator
Joined
·
1,648 Posts
The gear oil will contain multiple additives (friction modifiers, etc) that will wear out over time. And metal particles, etc will all contaminate your gear oil over time too. Both of these mean you‘re not doing your diffs any favors by stretching your maintenance out. While there’s no reason to go crazy and change it way too frequently, I’d say 30K to 50K is not unreasonable for diff fluid change on a 9-7X. I had chattering at 70K miles. 95K is too long, in my humble opinion. But it’s all based on what you’re seeing when you service it. For example, I’d recommend a max interval of 30K miles on an eLSD diff (NG 9-5 Aero) based on past results on that platform.
 

·
Registered
Joined
·
5 Posts
Discussion Starter #5
The gear oil will contain multiple additives (friction modifiers, etc) that will wear out over time. And metal particles, etc will all contaminate your gear oil over time too. Both of these mean you‘re not doing your diffs any favors by stretching your maintenance out. While there’s no reason to go crazy and change it way too frequently, I’d say 30K to 50K is not unreasonable for diff fluid change on a 9-7X. I had chattering at 70K miles. 95K is too long, in my humble opinion. But it’s all based on what you’re seeing when you service it. For example, I’d recommend a max interval of 30K miles on an eLSD diff (NG 9-5 Aero) based on past results on that platform.
 

·
Registered
Joined
·
5 Posts
Discussion Starter #6
I am in agreement with what you are saying Josh. I do plan to have both differentials serviced within the next few weeks. I'm a little stuck on whether or not you have to add the 5.5 oz. anti slip additive that they call for in the manual to go along with the vehicles equipped with the SS package whatever that is ? The book calls for SAE 75W-90 synthetic to just top off low fluid, and then that same gear oil plus the additive for a complete refill. But don't they have this synthetic now that has the additive already in it and is this the one that should be used in my application ? http://www.amazon.com/ACDelco-10-4034-Dexron-75W-90-Gear/dp/B008BZS6J8
 

·
Super Moderator
Joined
·
1,648 Posts
That Dexron LS already has the limited slip additive, so you should be good.
 
1 - 8 of 8 Posts
Top