I found out that my Transmission in my 1992 SC400 is leaking from an old gasket, which I now need to replace. I got this thread from the search function:

From Pearlpower,
The differential leakage is a common issue with the SC's. What is required is a drain of fluid, pop off the cover and rebead with orange gasket maker.

Gasket maker-$4.00=Permatex red/orange
Good synthetic fluid 2 qts-$7.50
--------------
total cost -under $10.00.
Labor- under 30 minutes


- Can someone explain this more in-depth and step by step and if it is necessary to buy the lexus gasket instead of the one he explained. Thanks everyone for your help in advance!

James

 

where is it leaking? the post you mentioned refers to the differential.

 

Yes, its coming from the gasket located on the rear differential. Thanks for your help

James

 

First, something doesn't sound right. I once owned an sc400, and I'm sure the carrier for the differential is similar to the sc300.

The *only* cover on the pumpkin is the rear access plate, but it's completely blocked by the rear subframe of the carrier. Plus, the rear cover has three large threaded holes that are used to bolt the pumpkin into the subframe.

If the pumpkin is out of the car, then yes... all you have to do is drain the pumpkin, pop the cover, clean the mating surfaces and reseal. However, that job is a couple hour job at the least. (Drop the exhaust, drop the DS, remove DS from the differential companion flange, unbolt the rear axles, unbolt the rear subframe bolts, and finally remove the main carrier bolts.

Are you sure the leak is from the pumpkin?

-scott

 

SCfan,
How long since you last changed the diff oil? There is a vent hole on top of the diff, if your oil is old, the leak you see is probably oil splashing out of the vent hole. I've seen quite a few toyotas with this problem, none were leaking from the rear cover.

Regards

 

Thanks alot for the replies thus far,

Nick, I bought the car in April and have not changed the differential fluid since I bought it. Who knows when the dealership that sold it to me changed it. I had one of the techs take a look at it. It is dry on one side of the differential and completely covered with oil on the other half. Plus a little piece of orange was sticking out. He saw that and said that it was because of the gasket that was sticking out just a little.

If anyone has fixed this problem on their own in their sc400 please let me know. I have a 1992 with 108,000 miles. Than ks alot to everyone that has helped me to this point!

James

 

SCfan,
I would clean the diff and then change the oil. Drive a few weeks and check for leaks. If it's leaking, a clean diff will make it easier for you to trace exactly where. If not, it was probably the vent splashing oil, no worries.

If the previous owner had service done at a lexus dealer, you can ask for a printout of the service history. This will tell you what has and has not been done and give you an idea of what needs to be done to bring the car up to specs.

Regards

 

Thanks for the advice Nick,

I will clean it off an drive it around for a while. However, I am fairly positive it is leaking from the orange gasket. What I am looking for is anyone that has repaired the problem on their own, if it was indeed the gasket that needs replacement.

What problems would a leaky differential cause?

Thanks again

James

 

So has anyone fixed the gasket on their rear differential?

Does anyone have any experience with cold start problems?

No one really seems to know and the lexus techs are many miles away....Definitely need some help. Thanks again

James

 

SCfan, I suggest you contact one of the guys that has an SC repair manual and have them scan you the pages on the differential.

The question is "who has a repair manual"?

 

Thanks aliga,

would the cd manual work or only the actual one? Thanks alot

James

 

SCfan,

Send a pm to nextlevelcoupe, he knows a Lexus tech, he may be able to get the info you need from the repair manual.