997.2 Front Differential “probably going to fail”
Thread Starter
Track Day
Joined: May 2012
Posts: 17
Likes: 2
997.2 Front Differential “probably going to fail”
At dealer (Morong in Falmouth Maine) for annual maintenance at 57,000 miles and 9 years on 2012 997.2 C4. I was told “the tech saw a little bit of oil leakage from the front differential. That usually means the differential is going to fail soon, and it’s better to replace it before catastrophic failure while you’re driving.” Estimated cost “it’s probably going to be around $10k, but hopefully we can get Porsche to work with us on this.” I asked if it was the diff or the AWD torque controller, and the service rep didn’t really know but he said the tech noted it’s the diff. This car is my tame, all-year daily driver, so it does see snow and road salt etc, but no tracking etc.
ADVICE PLEASE: does this sound legitimate? Is failure of the front differential possible at such low mileage? Why does a small fluid leak at shaft seal indicate failure is imminent? Why/how does mechanical diff gearing fail? Any advice is appreciated. (There are other issues causing me to lose faith/trust in this dealer).
ADVICE PLEASE: does this sound legitimate? Is failure of the front differential possible at such low mileage? Why does a small fluid leak at shaft seal indicate failure is imminent? Why/how does mechanical diff gearing fail? Any advice is appreciated. (There are other issues causing me to lose faith/trust in this dealer).
Rennlist Member
Joined: Oct 2014
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The seals on these diffs can fail. It is one of the few repairs my 135K mile 2010 C4S has required. A friend had the same failure on his C4S.
Leaking oil is not a symptom of a failure of the entire diff. Replacing the seal is straight forward. Find a dealer you can trust to do the work.
Leaking oil is not a symptom of a failure of the entire diff. Replacing the seal is straight forward. Find a dealer you can trust to do the work.
Last edited by Wayne Smith; Sep 14, 2020 at 03:22 PM.
Drifting
Joined: Jul 2019
Posts: 2,015
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From: Southern California
Sounds like complete BS. I've seen a few front diffs with the undercover removed (mine included with 58k miles) and every single one had an oil film on the front of the front diff from minor seepage at the axle seals. How much grease/oil was built up on the top side of the undercover? This will give you a good feel for exactly how much is leaking. If there's not much there then it's just a small amount of seal seepage which is not uncommon at these mileages and doesn't mean anything.
If you are worried that the diff is now underfilled you can replace the gear oil as it's due at 120k miles/12 years. (This is simple to do, do not pay this dealership to do it.) You don't even need to go that far, just pull the level check plug and stick in an "L" shaped piece of wire so you can see how low it is. It would have been to the bottom of the fill plug from the factory.
These dealerships have no shame. COVID must really be hurting their sales quotas. What exactly does "a little bit of oil" mean? Did they provide photos or otherwise document it?
If you are worried that the diff is now underfilled you can replace the gear oil as it's due at 120k miles/12 years. (This is simple to do, do not pay this dealership to do it.) You don't even need to go that far, just pull the level check plug and stick in an "L" shaped piece of wire so you can see how low it is. It would have been to the bottom of the fill plug from the factory.
These dealerships have no shame. COVID must really be hurting their sales quotas. What exactly does "a little bit of oil" mean? Did they provide photos or otherwise document it?
Last edited by PV997; Sep 14, 2020 at 03:49 PM.
Drifting
Joined: Jul 2019
Posts: 2,015
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From: Southern California
Following up, as Wayne points out a seal replacement is not difficult if there truly is a leak that's more from a little seepage (far from certain). For them to suggest you need a new diff from a little bit of oil leaking is absurd. Remember that a Porsche dealership "service advisor" is a commissioned salesman as they receive a percentage of all repairs. The successful ones make more in commission than their base salary.
Drifting
Joined: May 2009
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From: Toronto
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Drifting
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Thread Starter
Track Day
Joined: May 2012
Posts: 17
Likes: 2
Thanks everyone for all the advice. Service advisor didn’t provide photos, documentation or details. Btw, there is no noise or other noticeable symptom of imminent failure. After researching more on Rennlist (and sixspeed), I might have the dealer check for metal in the fluid, replace seals and fluid, and see how that goes. Or should I first try to check and replace fluid myself? I’m not really set up for such work under the car (I used to work on my cars 30 to 40 years ago when everything seemed more straightforward!). ... I do get the feeling that the dealer service dept is just pushing the “cha-ching”. My car just failed inspection due to leaking RR strut, corrosion of RF brake line at connector where it screws into caliper, 2mm and 1mm front brake pads. So they are ordering parts to replace front brake pads + rotors, RF brake line, both rear struts. Est price $7800. They said they additionally “might have to replace FR caliper if they can’t get the brake line disconnected cleanly, due to the corrosion”.
Instructor
Joined: Jun 2020
Posts: 225
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From: Northern NJ
I think there comes a time as a 911 ages that you need to seek out an honest indy mechanic for long term care of the car. Not all indy's are honest, but you can get a sense of who's fair through Google reviews.
I just did a quick Google search in the Portland, ME area, and there are a few prospects to choose from.
Not only is it cheaper, but the honest guys make their money by being a partner in the care of your car over time and are used to dealing with informed owners (guys like you who are on RL and SS looking for knowledge). They don't immediately see a sucker and try to do a smash-and-grab of your cash like many dealers do every time you pull into their service bay.
I would take this front diff business as a lesson that either your dealer's techs are inexperienced, or the dealership is trying to steal $10k from you. Either way, I don't think I'd go back.
I just did a quick Google search in the Portland, ME area, and there are a few prospects to choose from.
Not only is it cheaper, but the honest guys make their money by being a partner in the care of your car over time and are used to dealing with informed owners (guys like you who are on RL and SS looking for knowledge). They don't immediately see a sucker and try to do a smash-and-grab of your cash like many dealers do every time you pull into their service bay.
I would take this front diff business as a lesson that either your dealer's techs are inexperienced, or the dealership is trying to steal $10k from you. Either way, I don't think I'd go back.
Drifting
Joined: Feb 2012
Posts: 2,612
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From: Raleigh, North Carolina
So, brake pads in front, struts in rear and a brake line replacement for $7,800? And they're setting the stage for charging you for a new caliper if the tech is too ham-fisted to get the old hose fitting out without breaking the fitting off?
That sounds high even for a Porsche dealer. I humbly suggest you get a second opinion.
That sounds high even for a Porsche dealer. I humbly suggest you get a second opinion.
Drifting
Joined: Jul 2019
Posts: 2,015
Likes: 2,082
From: Southern California
Thanks everyone for all the advice. Service advisor didn’t provide photos, documentation or details. Btw, there is no noise or other noticeable symptom of imminent failure. After researching more on Rennlist (and sixspeed), I might have the dealer check for metal in the fluid, replace seals and fluid, and see how that goes. Or should I first try to check and replace fluid myself? I’m not really set up for such work under the car (I used to work on my cars 30 to 40 years ago when everything seemed more straightforward!). ... I do get the feeling that the dealer service dept is just pushing the “cha-ching”. My car just failed inspection due to leaking RR strut, corrosion of RF brake line at connector where it screws into caliper, 2mm and 1mm front brake pads. So they are ordering parts to replace front brake pads + rotors, RF brake line, both rear struts. Est price $7800. They said they additionally “might have to replace FR caliper if they can’t get the brake line disconnected cleanly, due to the corrosion”.
The $7800 quoted for two struts and a brake job is way too high assuming all that stuff is even required. If the brake pads truly are that thin then you do need new pads. However, you don't necessarily need new rotors if they have not not reached the wear limits. The brake line corrosion things sounds flaky to me but I'm in California so probably not the right person to ask. Were there any signs of shock issues? Not saying it's the case here but some shops have been known to fake leaking struts by splashing a little oil on them. After claiming you should spend $10k on a new front diff that works perfectly fine for "peace of mind" (lol) I would not trust a word these guys say. Even if you do need new struts, OEM are only ~$400 each and several hours labor per corner. Assuming all this work actually needs to be done, I'd ballpark it at $3k parts and labor done by a good Indy.
Edit: just noticed based on Iceter's comment it's only the front brakes as I thought it was all the way around. It just gets worse.
Last edited by PV997; Sep 15, 2020 at 02:57 PM.
Three Wheelin'
Joined: Apr 2014
Posts: 1,519
Likes: 330
From: NoVa
Simply amazing. Most dealerships of all brands have gone the way of parts replacement vs actual diagnostics. Porsche just tends to be a bit more expensive. Definitely find a trusted independent or do the work yourself.