Many track junkies have experienced this messy/smelly issue with assorted OEM & aftermarket LSD’s. I recently joined the leaking diff fluid club, so I came up with a solution. All I needed was a catch tank, some custom brackets (Thanks zillinois!), an air breather filter, an adapter fitting and 8 metric screws. Having access to Black Flag Jack’s well equipped garage made the install very easy. Thanks Jack!

I took a few pictures, and I apologize for my lack of picture posting skills. I’ll start with a why shot, then a where it goes shot, then a what the tank looks like shot.

 

The tank very is solidly mounted on the rear sub-frame to which the differential mounts. The tank is WAY up and out of the way, so I don't think even I could rip it off while landscaping! Easily accessible for checking it's level or draining.

Now for some installed views:

 

enthuZ
thanks for posting.
great set up.
my question though, wouldn't a oil cooler( same size/weight) be even more effective?
regards

 

Yes, a diff fluid cooler would be a better solution. But the few I've seen on race cars require a pump, usually driven via a belt with pulleys driven off the driveshaft. I'm not thinking I need to get that elaborate. I'm not sure if just plumbing lines on the housing to "naturally" feed the cooler would work. Maybe one of the racers could add some insight.

 

How much leakage are we talking about ? Do you have to add fluid to the differential once in a while ?

 

The install looks really clean Enthuz. Great solution to a leaky problem. :-p Glad the brackets worked out. I can make some smaller ones if you need more. Also, I found the original bracket.

 

I've only lost a tiny bit diff fluid, not enough to measure anyways. Another track junkie, Redfoot, reported loosing about 1/2 a pint at a 2 day HPDE.

zillinois, thanks for the kind words! The brackets you made worked out great. The next install I'll relocate the mounting holes though. I think we can store the unused brackets that came with the can in Jacks garage. I have some better mounting bolts on order.

 

I need to get the same setup, I started to notice an odor of diff fluid after going to the track a couple of times during the summer last year. This is with the stock LSD as well.

Let me know when you get all the kinks worked out

 

Well StaticCling, your diff air filter will be in tomorrow, and 100 new bolts & washers came in today. I'll probably be installing Jack's within a couple weeks.

 

I tried this a while back and was not able to unhook the rubber hose from the diff. I couldn't get the leverage using just jack stands. Do you have any tips for getting the hose disconnected??
A racer told me to use an extra long hose allowing the fluid to make its way back to the diff without actually entering the catch can.
Very clean installation. Mine will have more of the DIY look to it.

 

Interesting. I've experienced this problem as well and I'm getting tired of cleaning diff fluid off the front side of my muffler. I'll have to look into this as a solution. Thanks EnthuZ.

Dave- if you come up with an alternate solution let me know. I'd like to meet up and check it out.

 

NICE write up!!

my suggestion: coke can. easier to toss after it gets full. after full day of HPDE. my rear diff (even w/ nismo fin'd) smells like ***.. i will look into this!! thanks for the tip

 

I've had my pig out a few times, and the hose is just slid over a 90 degree fitting that presses into the diff cover. I'll look to see if I have any pics, if not I'll take some new ones. But, you shouldn't have to remove the hose from the diff. I removed the hose where it attaches to the frame (good luck! ), then reattach it to the 1/4" fitting on the can. Jack is talking about using some aeroquip he has lying around to connect his. But that will require tapping the diff cover.

 

We used a catch can all last season, but this year are going to an electric pump and dedicated cooler system. You need a pump.

 

I just got the new APS Carbon Disc LSD installed witha 3.9 rear gear along with a "Dougie Do" (Crawford stuff combo) for better breathing and a chip upgrade for higher revs. Have not had it out for track exercise yet.

Do you think I will have this hot slosh DIF problem with carbon disc's and higher track revs?

 

What do you guys think is causing the actual overflow of oil?? I spoke with an engineer from redline today about this problem and he highly doubts that we are boiling the fluid since the boiling point is over 500 degrees. He was the second person to suggest making a longer hose (with wider diameter) to allow the fluid to drain back into the diff when things cool off. Could it be that the fulid is just sloshing around too much and spilling out of the top? I see my fluid leaking out even after short sessions. I can't see how I could get that much heat into the diff oil after 10 minutes of lapping. I also loose about 1/2 pint in a weekend.

For those of you that are having the problem, what was your backlash set at? I know evo recommends 0 lash to keep temps down. My diff installer didn't even measure backlash so I have no idea what mine is..

thoughts?

 

David, I agree that it is doubtful that we are overheating the fluid. I'm running Redline 75W90. Maybe someone who tracks will install a thermocouple & get hard numbers for us. I think what [I]might[I] be happening is like a fluid in a blender. Spin the sucker fast enough, and the fluid fly's out. Yes, I have tested this theory many times!

Wright Engineering installed my 3.9 & Nismo LSD, so I'm sure it's backlash is set correctly.

 

Next track day, I'll get the IR temp gun out and check the diff.

 

definitly something I'm going to look into. The last thing I want to do is damage my sexy diff

 

Last week I installed a catch tank "JUST LIKE MINE" in Jacks 350Z. I moved the mounting points a bit for ease of tapping the crossmember. He decided not to go with his aeroquip fittings, and just let me do my thing. His install is 100% complete. Blue LockTited to 48 in-lbs. The OEM rubber hose is already at a perfect length. It's attachment just clears the filter. And, the filter has enough clearance to be changed without removing the tank. He is currently running his OEM muffler with it's built in air deflector, and it cleared without any issues.

Getting ready to do it again on StaticCling's Z this weekend. ALL the kinks have been worked out!

Some new pics: