Here are some photos of 2 leaks that I have identified on my '99 maxima. I am unsure of exactly what I am looking at on the transmission case. There is a small plate with 2 bolts located directly above the leaky area on transmission case.







The second leak is the oil cooler line but I need to know if I am looking at a radiator replacement or if new lines will suffice. Does the line clamp onto a fitting that is replaceable? I can see that a wrench can be put on the fitting but I am hesitant to un-thread it.



Any advice from someone who has been here before would be great, and as far as the other leak is concerned, I have no idea what I am looking at there.

 

The first pics looks like your transmission is leaking. Maybe from the shaft seal. Ive only had manual transmissions so i dont know if its your torque converter or the actual transmission. Somebody else can correct me.

The radiator pic looks weird. It looks like somebody put some kind of stop leak in the radiator and thats why it looks all brown and rusty but thats plastic and rubber lol.

 

The wet spot on the transmission looks like an extremely slow weep, there isn't a drip hanging. Might just cough that up to normal wear and tare.

The transmission cooling line on the radiator could be fixes. Replace the clamp, see if it stops. That's a $2 repair.

 

The first leak is most likely due to the half moon seal that is supposed to keep motor oil out of the the bell house. The new seal will cost l15$ at most, but it is an upper oil pan job.

 

What is this seal called? Part #? What is an upper oil pan? Can I fix this myself?

 

Go on rockauto.com and look up gasket upper oil pan for 99 Nissan maxima. You will need a pair of them. One is for the crank pulley seal, and the other is for the one under the rear main seal (the one you need).

An upper oil pan is exactly that, the top half of the oil pan. It's directly above the y pipe. You could do this job yourself with basic tools, but lots of things come off. The passenger side axle, axle bracket, lower oil pan, upper oil pan, y pipe, crossmember, splash guards (not exactly on that order).

Before all this, are you leaking tranny fluid or motor oil

 

There right, and honestly compared to others that's minor and normal. I've seen waayy worse. But there both simple fixes imo, good luck.

 

On RockAuto.com, the part listed under "Crankshaft Seal" is actually the Rear Main seal which, OP, I do not think you need.
FEL-PRO (LINK>>) BS40631Crankshaft Seal


I agree, the first 3 pics look like the dreaded upper pan seals leaking. I just had a shop do mine.

I bought from rockauto.com...they are labeled "oil pan gasket" with a FelPro part number of OS30696 which also came with the RTV needed for the job.
FEL-PRO (LINK>>) OS30696Oil Pan Gasket

And here is the link to the "How To" Write up. http://forums.maxima.org/4th-generat...n-removal.html

 

The first photo is the upper oil pan half moon seal leaking. I had the same experience with motor oil dripping down onto that 2 bolted flywheel cover on the AT. The rear main seals rarely leak.

 

So, in all of your expert opinions can I let this leak continue, am I damaging any internal components? If I check my oil weekly, do oil changes on reg basis and inspect it periodically am I safe. Will it get worse, do these seals suffer a catastrophic failure?

 

It will eventually get worse. As for what I see in the pics now, it is not that bad. The way I felt about mine was, as soon as I see drops on the ground, then I will fix it. I went for a little over a year and a half with a leak that looked MUCH worse than yours and had no problems. Just keep the oil topped off and you'll be fine...unless the leak gets much worse. Heres some pics of about what mine looked like but these pics are a little worse that mine was...http://forums.maxima.org/8412014-post1.html

Basically to help you understand what is going on here...this pic illustrates the view as looking at the driver side of the motor with the transmission removed. The Upper pan seals, to the best of my knowledge, will not suffer any catastrophic failure...Just keep an eye on it.

 

I told him to search oil pan seal, and one of those crescent seals goes under the crank pulley and the other under the rear main seal. . To OP, the repair is involved, but it's easy. I drove my car for years before I decided to tackle this job. Luckily I had some guidance the first time I tried.