Causing transfer case to leak R32 GTR?

[T.Krol]

Hi,

if had the car for around 3000km now. Since the last 750km the transfer case started to leak. I have degreased it a few times and after a drive the drips are already hanging under the case. It’s red of color so I am sure it is ATF fluid. The case or gearbox has not been removed. I did change the gearbox oil to redline to get rid of a grind in fourth, but thats it. What are the most common causes of these cases to start leaking? 
 

Also when shifting I feel the car does a hard clunk even when letting the clutch get up slowly. Its like something gets a snap due to getting power from the engine. If that makes sense.

 

Hope someone can narrow it down for me. Can’t get the car in the air to verify more. Would need to go to a shop for that. 
 

cheers! 

Edited April 27, 2023 by T.Krol
Spelling error

[joshuaho96]

1 hour ago, T.Krol said:

Hi,

if had the car for around 3000km now. Since the last 750km the transfer case started to leak. I have degreased it a few times and after a drive the drips are already hanging under the case. It’s red of color so I am sure it is ATF fluid. The case or gearbox has not been removed. I did change the gearbox oil to redline to get rid of a grind in fourth, but thats it. What are the most common causes of these cases to start leaking? 
 

Also when shifting I feel the car does a hard clunk even when letting the clutch get up slowly. Its like something gets a snap due to getting power from the engine. If that makes sense.

 

Hope someone can narrow it down for me. Can’t get the car in the air to verify more. Would need to go to a shop for that. 
 

cheers! 

Transmission or engine mounts need to be replaced if you get bad shift shock even with a lot of clutch slip. The back of the transfer case is probably leaking where the hose connects. It’s a high pressure hydraulic system so leaks are inevitable with age. To be sure you need to clean it off and then repressurize the system while under the car. 

[GTSBoy]

4 hours ago, joshuaho96 said:

Transmission or engine mounts need to be replaced if you get bad shift shock

And while that can be true, it is also possible that the clunk comes from the tailshaft centre bearing, from the diff CW&P lash, from CVs or the splines of the driveshafts into the hubs, etc. Also possible to be in the front drive stuff, but you wouldn't expect anything there to cause much noise on a normal takeoff.

[joshuaho96]

2 hours ago, GTSBoy said:

And while that can be true, it is also possible that the clunk comes from the tailshaft centre bearing, from the diff CW&P lash, from CVs or the splines of the driveshafts into the hubs, etc. Also possible to be in the front drive stuff, but you wouldn't expect anything there to cause much noise on a normal takeoff.

Good point, there’s a whole class of failures I forgot about that can also cause this. 

[T.Krol]

Thank you. I did read that the clunk noise can have many different causes. I guess the car needs to go in the air to figure that one out. I did go ahead and ordered this product: https://frenchysperformancegarage.com/collections/nissan-skyline-r32gt-r/products/fpg-bnr32-attesa-high-pressure-hose-replacement-with-optional-pressure-sensor-adapter-fpg-116?variant=42829932724402.

Since I am quit sure that the leak is coming from the Attesa hose. Also it might be leaking at the Atessa pump above the read diff, since I do get a bit of oil leaking from the right side area of the rear-diff, also red colored oil.

Is it harmful to drive every now and then with the car with this small leak?

 

[GTSBoy]

24 minutes ago, T.Krol said:

Is it harmful to drive every now and then with the car with this small leak?

Not if it is actually just a small leak. Just watch your level. But, it could also transition into a really big leak at any moment, and that could be destructive.

[Duncan]

so, as I mentioned in another thread on this leak recently, just back off the attessa line where it goes into the rear of the transfer case about 1/2 turn (or 12 turns if I can't type), then tighten it up again. Give everything a thorough degrease and see how it goes.

you can monitor the level of that fluid in the reservoir in the boot, just top it up if necessary

[T.Krol]

Thanks guys. Can you simply add fluid to the reservoir or do you need to bleed the system afterwards?

[GTSBoy]

Just put some in the top. So long as it hasn't gone to low and sucked some air, of course.

[T.Krol]

Allright. Will try that. Lets hope it all stays in one piece before I install the upgraded hose/connectors. 
 

 

[T.Krol]

Reservoir was almost at max level without ign on. Topped it off but did a lil too much. I am 8-10mm above max level. Tried to put the ign on and see what it did but it stayed at that level. Is that allright to run the car with a little over max? Havnt turned the car on yet to check the level. 

[Duncan]

A minor overfill will be no issue