Differential Oil Leak? - How and Why?

[986owner]

My parked 986 was struck broadside in the rear driver side wheel and wheel well. The wheel and suspension was shattered and the drive axle shaft pulled from the differential. The vehicle was also pushed laterally up over a curb. To picture the impact think of the rear wheels and drive shaft assembly being compressed between a moderately speeding vehicle and a concrete curb. At the site of the accident a significant amount of fluid (oil) was leaking from the underside rear. I'm not sure where, but I suspect the differential. The body incurred minimal damage (one quarter panel to be replaced) as most of the force was imparted to the rear drive mechanism. The repair estimate didn't include any mention of damage to the differential, fluid replacement or the like. However I didn't think to mention this prior to the estimate. Since the drive axles are held in with a simple clip allowing for disengagement and the differential seemed to be in tact, where could the fluid be leaking from? If it is the differential, could this be a seal that has ruptured? Something else?

My concern is there is damage somewhere else that hasn't been evaluated or estimated for insurance purposes and will become a headache down the road.

Anyone have knowledge in this area that you could share? It would be most appreciated.

Thanks!

Edited December 7, 2009 by 986owner

[Loren]

Please do not double post - your second identical post has been deleted.

Please re-read the board Guildelines/Rules that you agreed to when you registered here.

"Please post your messages in one forum only. Crossposting, double posting, triple posting, etc. are all a waste of time and valuable resources. If you post the same message in multiple times or in multiple forums, we will delete the ones we feel are inappropriate."

[986owner]

My apologies. I accidentally posted under the wrong forum initially and didn't know how to delete it myself.

[ericinboca]

My apologies. I accidentally posted under the wrong forum initially and didn't know how to delete it myself.

Can you tell where the leak is?

Can you tell if it is engine oil or gear oil? Hypoid gear oil has a very unpleasant odor; engine oil smells like, well, engine oil ;)

[986owner]

My apologies. I accidentally posted under the wrong forum initially and didn't know how to delete it myself.

Can you tell where the leak is?

Can you tell if it is engine oil or gear oil? Hypoid gear oil has a very unpleasant odor; engine oil smells like, well, engine oil ;)

Ericinboca,

Thanks for the reply.

The leak seemed to be coming from the differential area....unfortunately at the time of the accident it was dark and the plastic under cover concealed the exact location. I did touch the oil...it was light in color and didn't seem to have a noticable odor, but then again I didn't put it up to my nose. I looked again at the car in the yard where it was towed and still wasn't able to see exactly where the oil was leaking from.

My concern here is there may have been damage to the differential, the transmission, engine and/or the motor mounts due to the force of the impact imparted by the drive axle. The fluid that I saw leaking probably wasn't more than a quarter cup or so, but I didn't know how much could have been pooling somewhere else in the body and/or under cover.

Any other areas that could have leaked fluid? With such an impact would you have concerns about damage to the suspension bushings? motor mounts or other components? A couple photos included.

Thanks,

Jim

[seafeye]

My apologies. I accidentally posted under the wrong forum initially and didn't know how to delete it myself.

Can you tell where the leak is?

Can you tell if it is engine oil or gear oil? Hypoid gear oil has a very unpleasant odor; engine oil smells like, well, engine oil ;)

Ericinboca,

Thanks for the reply.

The leak seemed to be coming from the differential area....unfortunately at the time of the accident it was dark and the plastic under cover concealed the exact location. I did touch the oil...it was light in color and didn't seem to have a noticable odor, but then again I didn't put it up to my nose. I looked again at the car in the yard where it was towed and still wasn't able to see exactly where the oil was leaking from.

My concern here is there may have been damage to the differential, the transmission, engine and/or the motor mounts due to the force of the impact imparted by the drive axle. The fluid that I saw leaking probably wasn't more than a quarter cup or so, but I didn't know how much could have been pooling somewhere else in the body and/or under cover.

Any other areas that could have leaked fluid? With such an impact would you have concerns about damage to the suspension bushings? motor mounts or other components? A couple photos included.

Thanks,

Jim

Most of the accidents i have seen from the 993 and up that involved rear suspension ended up cracking the transaxel.

That hit looks hard enough for to warrent a new transmission in my opinion. At the very least the transmission should be removed and

looked over. A small leak wouldn't surprise me at all. As for the other parts...I would look at the whole rear suspension, and get

everything replaced that has a scratch on it.

[ericinboca]

My apologies. I accidentally posted under the wrong forum initially and didn't know how to delete it myself.

Can you tell where the leak is?

Can you tell if it is engine oil or gear oil? Hypoid gear oil has a very unpleasant odor; engine oil smells like, well, engine oil ;)

Ericinboca,

Thanks for the reply.

The leak seemed to be coming from the differential area....unfortunately at the time of the accident it was dark and the plastic under cover concealed the exact location. I did touch the oil...it was light in color and didn't seem to have a noticable odor, but then again I didn't put it up to my nose. I looked again at the car in the yard where it was towed and still wasn't able to see exactly where the oil was leaking from.

My concern here is there may have been damage to the differential, the transmission, engine and/or the motor mounts due to the force of the impact imparted by the drive axle. The fluid that I saw leaking probably wasn't more than a quarter cup or so, but I didn't know how much could have been pooling somewhere else in the body and/or under cover.

Any other areas that could have leaked fluid? With such an impact would you have concerns about damage to the suspension bushings? motor mounts or other components? A couple photos included.

Thanks,

Jim

Most of the accidents i have seen from the 993 and up that involved rear suspension ended up cracking the transaxel.

That hit looks hard enough for to warrent a new transmission in my opinion. At the very least the transmission should be removed and

looked over. A small leak wouldn't surprise me at all. As for the other parts...I would look at the whole rear suspension, and get

everything replaced that has a scratch on it.

I'm with Seafeye. I'd be surprised if your axle is not bent or CV joint(s) not broken. If you speared your gearbox, you would know it, but it definitely got a whack.

Suspension bushings do not have any fluid in them, but I think the front motor mount does, but it's not near the gearbox.

I'd say likely culprit though, at least the one you would press for recompense on, is the gearbox.

The mobil1 gear oil they use at the factory looks pretty much like motoroil - sort of standard oil/gold in color when clean and new. Moly gear lube is dark grey grease like stuff. Both have strong odors of sulfur.

[seafeye]

Oops...

Looking at your second picture in your first post it looks like your transaxel is ruined.

The axel was pulled right out and that is where all your fluid will leak out.

Looks like to me you will need a new transmission.

[wvicary]

The stub axle has been pulled out of the transaxle. It could be caused from the wheel carrier being separated from the control arm but it's hard to tell from your pic. Bring up your concerns with the insurance company and repair garage, I'm sure they will sort it out.