: My Differential is leaking



CoolMomMobile
03-22-13, 12:15 AM
Hey Guys, I know this a topic that has been discussed at great length over the years, so forgive me for bringing it up again. I have a 2005 CTS-V and noticed today that my differential is leaking, and judging by the spot on the garage floor, this is not something that popped up today.

From looking around on this forum, I am getting a little confused, So I was hoping someone could clear a few things up for me. 1. Does my stock 2005 have the vent that everyone is talking about. 2. Does anyone have any pictures of what to look for to determine where my leak(s) is coming from. (since most of the posts I have seen are very old, the pictures are no longer showing up)

From looking under the car tonight I see that the front of the "Pumpkin" is wet, I also see spraying on the passenger side exhaust pipe behind the pumpkin, as well as another dripping spot on the exhaust pipe in front of the pumpkin same side.

Any help would be appreciated.

D3l7a3ch0
03-22-13, 01:46 AM
subscribed~

my diff isn't leaking, but I'm getting noises from the back in sweeping turns under power (eg left through a large four-way intersection).

I think it's time to begin looking for a diff and axles, now that I notice some complaining~

so. I am subscribed to the thread.

darkman
03-22-13, 07:52 AM
There are three places the differential can leak. One is at the output seals where the half-shalfs enter the case; another is at the vent, which is on all models; and the third is at the pinion seal shaft. There was a recall on some units for the pinion seal (GM Recall No. 072040. See attached.

barrok69
03-22-13, 09:22 AM
subscribed~

my diff isn't leaking, but I'm getting noises from the back in sweeping turns under power (eg left through a large four-way intersection).

I think it's time to begin looking for a diff and axles, now that I notice some complaining~

so. I am subscribed to the thread.

It sounds like you just need to change your diff fluid. The posi is most likely what is making the noise if it's during turns only. New fluid should resolve it.

D3l7a3ch0
03-22-13, 09:36 AM
one to three clunks, from the side on the outside of the turn. still just the posi/fluid?

CoolMomMobile
03-22-13, 09:53 AM
Great! Thank you for clarifying this. I went out this morning and the paper towel I placed under the car is dry, no new drips. Without jacking the car up and getting in there I am thinking it is the vent that is the culprit.

If there was a leak at the Pinion seal or at the Output shaft, it be leaking all the time, right? Even when parked?

I have a feeling that I have been lucky to not have experienced this with the car until this point, because I don't really drive it to it's full potential. Only the other day there was a slushy wet mess of snow in the driveway and I had fun fishtailing it all over the driveway.

Thanks for the info I will keep an eye on it.

----------

[QUOTE=CoolMomMobile;3260092]

I have a feeling that I have been lucky to not have experienced this with the car until this point, because I don't really drive it to it's full potential. QUOTE]

Mainly because I know the rear end are issues in this car, and I don't want to blow my rear end up.

D3l7a3ch0
03-22-13, 10:01 AM
but that could also mean it's empty or low.....

Andringa
03-22-13, 11:14 AM
It should be fairly obvious if it is coming from the vent, as the vent leak is the only one that will cause the top of the diff to have fluid on it. If the top half of the diff is basically clean it's probably coming out of one of the seals.

This picture is from another forum member, but it is exactly what my diff looked like when my pinion seal was leaking. A trail of relatively clean fluid like you can see in this picture is a good sign that you've found the source of the leak.

http://img846.imageshack.us/img846/3066/diffg.jpg

barrok69
03-22-13, 11:16 AM
one to three clunks, from the side on the outside of the turn. still just the posi/fluid?

Worn out fluid will feel like there is resistance while turning and will make noise. The casual term is crow-hop. It will feel similar to what you get in a 4x4 in low range trying to turn on dry pavement.

My car has 32,000miles on it and needed new diff fluid. The friction modifiers in the fluid don't last forever and need to be changed as part of normal vehicle service. It's nothing to be too concerned about, but should be addressed.

To the OP. I had to replace my driverside axle seal. It is apparently a known issue on these vehicles for these to leak. The oil would blow back all the way to the back of the differential on my car, but I never had any drips on the ground though. I replaced it before it got any worse. I bought the new seals from rockauto.com

rand49er
03-22-13, 11:30 AM
No doubt about it, you just need to get under there and take a look.



(My money's on pinion seal. :stirpot:)

D3l7a3ch0
03-22-13, 11:38 AM
I~ would be quite happy if it is a matter of fluid. I will go out and get some today.

what... should... it be replaced with? (other than GM dealer stock?)

rand49er
03-22-13, 02:51 PM
I use Amsoil Severe Gear 75w-90. It's suppose to already have the anti-slip additive in it, but I put that in, too. You'll need about 42-44 fl oz total to put in the diff.

D3l7a3ch0
03-22-13, 04:09 PM
what brand is the anti-slip additive?

barrok69
03-22-13, 04:15 PM
what brand is the anti-slip additive?

amsoil
severe gear diff oil
http://www.amsoil.com/shop/by-product/gear-lube/severe-gear-75w-90/

Slip-lock gear additive
http://www.amsoil.com/shop/by-product/gear-lube/slip-lock-gear-oil-additive/

CoolMomMobile
03-22-13, 05:12 PM
No doubt about it, you just need to get under there and take a look.



(My money's on pinion seal. :stirpot:)

Yeah, I think you may be right about the pinion seal. I was really hoping it was just the vent so I can drive my car again soon. Looking at it some more there is a big mess under there.

What do repairs like these usually cost?

Andringa
03-22-13, 05:24 PM
Yeah, I think you may be right about the pinion seal. I was really hoping it was just the vent so I can drive my car again soon. Looking at it some more there is a big mess under there.

What do repairs like these usually cost?

My records show I paid my local dealer $95 for the pinion seal and $215 for labor. Note that the labor was for replacing the pinion seal and transmission output seal. I'd say a fair dealer quote would put you in the $200-$250 ballpark.

Thinking back on it, that $95 may have included some rush shipping or something as well.

As long as you keep fluid in the diff, driving around with a leaking pinion seal isn't really going to hurt anything. Just don't let it run out of fluid.

darkman
03-22-13, 05:34 PM
You can drive the car with a differential leak as along as you top it off with fluid periodically.

Replacing either the pinion seal or the vent involves 1.8 labor hours. Replacing the output seals, which involves removing the axle is 2.4 labor hours per side. Hourly labor rates vary by location and type of shop. Parts costs - seals or vent are not high.

CoolMomMobile
03-22-13, 06:16 PM
Thanks Guys really appreciate all your help.

D3l7a3ch0
03-22-13, 07:22 PM
Autozone did not carry Amsoil, so I picked Royal Purple... two bottles of it, because according to rand49er, the diff needs 42-44oz and each bottle is 32 oz(1 QT).. and also a limited slip additive.

the pump you see is a dual-action pump that sucks through one tube and pushes through the other--there was a "traditional" single-action pump for a few bucks less, but I picked this one for the length of hose, and thinking that if I can squirt into a hole in the diff, I should also be able to suck the old stuff out first, through the same hole.

should be good for periodically refilling your diff

//total cost was $20 per bottle of Royal Purple, and $8 for the additive... could add up after a while. There are other brands which are less than $10 per 1 QT bottle.

HAMSTAR
03-23-13, 02:28 PM
Looked under my car and it seems something either in the diff or in front of the diff is flinging some fluid onto the passenger side exhaust pipe. There are no drips below the car after being parked overnight, so this is something that only happens when driven. Any ideas what could be going on? From what darkman has said, it seems this could be the output shaft seal. Here's a pic of what it looks like:

http://i.imgur.com/kMErCtGl.jpg

In the meantime, I'm going to do a diff fluid change to make sure I'm topped up and get some new fluid in there. My mechanic friend is suggesting I go with a heavier weight fluid to reduce the leaking and buy me some time till I can get the parts needed, etc. Thoughts on this? Pros vs cons?

Thanks!

HAMSTAR
03-23-13, 03:44 PM
Well, since y'all had better things to do than get back to your internet friend with advice within 20 minutes, I went ahead and ordered 2 quarts of Amsoil Severe Gear 75W-140, along with Amsoil limited slip additive. Signed up for the preferred customer program, too.

rand49er
03-23-13, 03:50 PM
Looked under my car and it seems something either in the diff or in front of the diff is flinging some fluid onto the passenger side exhaust pipe. There are no drips below the car after being parked overnight, so this is something that only happens when driven. Any ideas what could be going on? From what darkman has said, it seems this could be the output shaft seal. Here's a pic of what it looks like:

http://i.imgur.com/kMErCtGl.jpg

In the meantime, I'm going to do a diff fluid change to make sure I'm topped up and get some new fluid in there. My mechanic friend is suggesting I go with a heavier weight fluid to reduce the leaking and buy me some time till I can get the parts needed, etc. Thoughts on this? Pros vs cons?

Thanks!Sure looks like the pinion seal to me. :thumbsup: Personally, I wouldn't go with the heavier weight, though some guys claim it reduces the diff whine. Just call Luke at Lindsay Cadillac for a seal. I had mine professionally installed, but I've heard it's easy enough to do yourself. A little leakage isn't going to hurt, just get that new seal in there and be done with it.




Autozone did not carry Amsoil, so I picked Royal Purple... two bottles of it, because according to rand49er, the diff needs 42-44oz and each bottle is 32 oz(1 QT).. and also a limited slip additive.

the pump you see is a dual-action pump that sucks through one tube and pushes through the other--there was a "traditional" single-action pump for a few bucks less, but I picked this one for the length of hose, and thinking that if I can squirt into a hole in the diff, I should also be able to suck the old stuff out first, through the same hole.

should be good for periodically refilling your diff

//total cost was $20 per bottle of Royal Purple, and $8 for the additive... could add up after a while. There are other brands which are less than $10 per 1 QT bottle.


Well, since y'all had better things to do than get back to your internet friend with advice within 20 minutes, I went ahead and ordered 2 quarts of Amsoil Severe Gear 75W-140, along with Amsoil limited slip additive. Signed up for the preferred customer program, too.You'll have fluid left over when you get done. Save it for your next fluid change.

HAMSTAR
03-23-13, 04:13 PM
Sure looks like the pinion seal to me. :thumbsup:

Thanks for the feedback, bud! What makes you think pinion seal vs. output shaft seal?

rand49er
03-23-13, 06:32 PM
Thanks for the feedback, bud! What makes you think pinion seal vs. output shaft seal?Uh-h, because it's flinging out of the pinion onto the exhaust pipe and being swept rearward on the underside of the exhaust pipe. That was my first clue. That, and I had one do this, too. Got a spot on the garage floor as a souvenir, too. Seems to me the local repair shop charged me <$100 to replace it after I bought the part from Luke.

Why do you think this is the output shaft seal?

CTSV_Rob
03-23-13, 08:09 PM
^^ Good question.

HAMSTAR
03-23-13, 08:27 PM
Uh-h, because it's flinging out of the pinion onto the exhaust pipe and being swept rearward on the underside of the exhaust pipe. That was my first clue. That, and I had one do this, too. Got a spot on the garage floor as a souvenir, too. Seems to me the local repair shop charged me <$100 to replace it after I bought the part from Luke.

Why do you think this is the output shaft seal?

I don't, I'm just looking to learn. How would it look different if it was the output shaft seal?

darkman
03-23-13, 08:40 PM
I don't, I'm just looking to learn. How would it look different if it was the output shaft seal?

When my output seal leaked the fluid was only of the exterior of the case around the leak and below. As general rule leaking fluids run down (gravity) and rearward of the source (wind). Leaks in the vicinity of unshrouded radiator fans, of course, can go any where. Finally, our differential almost has to leak at the pinion to get much on the exhaust.

Andringa
03-25-13, 11:33 AM
FYI, the diff has two plugs. Remove the top "fill" plug first. Nothing more frustrating than draining the diff, thinking you are almost done and then finding out the fill plug is stuck.

D3l7a3ch0
03-25-13, 11:35 AM
FYI, the diff has two plugs. Remove the top "fill" plug first. Nothing more frustrating than draining the diff, thinking you are almost done and then finding out the fill plug is stuck.

there's a drain plug? ah.

rand49er
03-25-13, 12:17 PM
I don't, I'm just looking to learn. How would it look different if it was the output shaft seal?Gotcha. Yeah, if leaking at the output shaft seal (either side of the diff where the axles are inserted), the fluid would be flinging on one side of the diff or the other, possibly missing the exhaust entirely, but probably showing up on the underside of the floor pan right above the leak. Pinion seal leak is a much more common occurrence.

Andringa
03-26-13, 12:35 PM
there's a drain plug? ah.

Yes, don't have a pic handy, but there are two plugs on the driver side.

The bottom "drain" plug is also magnetic, so it is normal to have some small amount of metal flakes accumulate on the plug, make sure you clean it off before putting it back in.[COLOR="Silver"]

darkman
03-26-13, 01:27 PM
http://www.cadillacfaq.com/faq/answers/difflube/index.html

xbladr
03-27-13, 09:42 PM
It should be fairly obvious if it is coming from the vent, as the vent leak is the only one that will cause the top of the diff to have fluid on it. If the top half of the diff is basically clean it's probably coming out of one of the seals.

This picture is from another forum member, but it is exactly what my diff looked like when my pinion seal was leaking. A trail of relatively clean fluid like you can see in this picture is a good sign that you've found the source of the leak.

http://img846.imageshack.us/img846/3066/diffg.jpg


Exactly what mine looks like. I also need to replace the SWPS I just havent gotten around to doing it. I may bring it and have both those things done.

CoolMomMobile
03-28-13, 09:59 AM
OK So it is definitely the Pinion Seal that is leaking on my car. We checked the fluid and it is still full, so I caught it early. And I can still drive it :)
Since my car is not part of the recall group, we are going to do the work our selves.

I called the dealership to order parts, and they told me there are 2 different pinion seals for my car. The one I would need is based on the stamping on the Differential.

It seems pretty tight under there. Can I find the stamping # without lowering the rear end? Is it near the Getrag (sp) label?

Also we weren't able to find the vent. I know it is on top, but it something you can only see when the differential is lowered?

Thanks Guys!

darkman
03-28-13, 10:45 AM
Well you can buy both kind of seals and ask to return the unused one.

I am not sure it is possible to get the number if it is located on the top. However, if it is possible, it would be with the car on jack stands at the rear jack-placement points (marked on the side of the car BUT inward of the rocker panel) so that the rear suspension is fully extended. With the car in this position you might be able to use a mirror to see the number.

Finally, another alternative might be to take a picture of the pinion. My recollection is that the two pinion styles look significantly different.

Andringa
03-28-13, 10:54 AM
When I had my pinion seal replaced at the dealership, they ordered both and returned the one they didn't use.

CTSV_Rob
03-29-13, 07:47 PM
Gotcha. Yeah, if leaking at the output shaft seal (either side of the diff where the axles are inserted), the fluid would be flinging on one side of the diff or the other, possibly missing the exhaust entirely, but probably showing up on the underside of the floor pan right above the leak. Pinion seal leak is a much more common occurrence.
So is "flinging" a technical term?







:D

HAMSTAR
04-04-13, 02:55 PM
Gotcha. Yeah, if leaking at the output shaft seal (either side of the diff where the axles are inserted), the fluid would be flinging on one side of the diff or the other, possibly missing the exhaust entirely, but probably showing up on the underside of the floor pan right above the leak. Pinion seal leak is a much more common occurrence.

So i got under the car today to top up the diff fluid and got in there with a flashlight and got a close look. There's no leak from the pinion seal. Instead, it seems the leak is from above the diff, and it's pooling and dripping down onto the exhaust. I think it's the vent leak. Fortunately, that means there's nothing that's failed, and I could go along merrily simply topping up the diff fluid. It actually only took 10oz, so the leak is really minimal.

Having said that, has anyone here done the TSB vent relocation fix?

D3l7a3ch0
04-04-13, 05:26 PM
what's... TSB vent relocation fix, preciousss?

PJGross
04-05-13, 12:02 AM
I'm with Randy. That picture shows a pinion seal leak.
1) I don't think a vent leak would come forward on a running car (you say no puddle on ground so the fluid is fighting the wind and going forward across the top of the diff)
2) That fluid is being slung right from the pinion seal radially outward. I don't think something dripping down onto it would leave as precise a pattern
3) Maybe I've had a few too many pops tonight and don't know what I'm looking at.

:)

-PJ

Andringa
04-05-13, 10:46 AM
So i got under the car today to top up the diff fluid and got in there with a flashlight and got a close look. There's no leak from the pinion seal. Instead, it seems the leak is from above the diff, and it's pooling and dripping down onto the exhaust. I think it's the vent leak. Fortunately, that means there's nothing that's failed, and I could go along merrily simply topping up the diff fluid. It actually only took 10oz, so the leak is really minimal.

Having said that, has anyone here done the TSB vent relocation fix?

To me 10oz would be a significant leak depending on when it was topped off last. I think the diff takes ~42oz, so you were 25% low?

I would be surprised if you lost 10oz through the vent.

People that had the TSB vent fix done reported mixed results. Some people still had fluid coming out the now relocated vent.

HAMSTAR
04-05-13, 12:03 PM
To me 10oz would be a significant leak depending on when it was topped off last. I think the diff takes ~42oz, so you were 25% low?

I would be surprised if you lost 10oz through the vent.

People that had the TSB vent fix done reported mixed results. Some people still had fluid coming out the now relocated vent.

This is the first time I've checked the diff fluid level in the year I've owned the car, so it may have been low when I bought it.

In support of it being the vent, there is no fluid on the pinion, and all the way around the pinion is dry. There is fluid, however, above the diff. The top of the exhaust (above the black area where dirt has collected in that pic) has clean-looking diff fluid on it. I park my car downhill, which I believe accounts for why it's dripping forward of the diff. In one particular place, it is dripping from the heat shield / sound deadener onto the exhaust. When I drive, it then runs backwards along the length of the exhaust.

That's my best conclusion, anyway. I open to the possibility I have this wrong, if you could tell me for something else to look for. Thanks.

Andringa
04-05-13, 01:11 PM
This is the first time I've checked the diff fluid level in the year I've owned the car, so it may have been low when I bought it.

In support of it being the vent, there is no fluid on the pinion, and all the way around the pinion is dry. There is fluid, however, above the diff. The top of the exhaust (above the black area where dirt has collected in that pic) has clean-looking diff fluid on it. I park my car downhill, which I believe accounts for why it's dripping forward of the diff. In one particular place, it is dripping from the heat shield / sound deadener onto the exhaust. When I drive, it then runs backwards along the length of the exhaust.

That's my best conclusion, anyway. I open to the possibility I have this wrong, if you could tell me for something else to look for. Thanks.

Not sure what else to look for. At this point, now that you have it full. I'd probably check it again in a couple weeks and try to figure out how fast it's leaking. If it's a slow leak it's really up to you whether it's worth fixing or not.

HAMSTAR
04-05-13, 01:23 PM
Not sure what else to look for. At this point, now that you have it full. I'd probably check it again in a couple weeks and try to figure out how fast it's leaking. If it's a slow leak it's really up to you whether it's worth fixing or not.

That's the plan. If it is indeed the pinion seal, I will probably take it down to Lindsay. If it really is a vent leak, I intend to do the fix myself and hope that takes care of it.

D3l7a3ch0
04-05-13, 05:37 PM
would the fluid escape the vent if it's not viscous enough?