Diff Breathing a ...lot of oil

[Kinkstaah]

Appreciate the comments, I should add more info

I get I shouldn't need additives for the OS Giken fluid, though its made for OS Giken riffs, not Nismo. Is there a difference that is relevant here? I surely don't know..

I haven't tried any other oil since the conversion and diff rebuild was done. Previously, all thinner oils worked amazingly (I.e normally) but would exit the diff within.. 300km of normal road driving. I don't know for sure if this behaviour persists post diff rebuild.

The tailshaft is new, so recently balanced. From what I know the uni was fine (fine enough for driveljne shop to say 'nah its fine' when asked.

The gearbox and engine mounts and diff mounts are all new. I mean I changed every piece of Nissan rubber in the car. Every bit!

The only thing I can think of is my car has a set of pineapples in 'Max grip' configuration. Given the fact this doesn't feel like tyre skipping (it feels like the subframe is going to fall out levels of clunk) then perhaps this has something to do with it.

None of the cars I've driven have had those pineapples installed. Or 'subframe alignment bushes' I think is the correct term. I did also replace the entire subframe with a non-hicas subframe, so can rule the subframe itself out as a cause.

I think based on this info I will try removing the pineapples to see if this changes anything. With less power back there now I probably don't need the level of squat I've had in the past.

[KiwiRS4T]

4 hours ago, Kinkstaah said:

Appreciate the comments, I should add more info

I get I shouldn't need additives for the OS Giken fluid, though its made for OS Giken riffs, not Nismo. Is there a difference that is relevant here? I surely don't know..

I haven't tried any other oil since the conversion and diff rebuild was done. Previously, all thinner oils worked amazingly (I.e normally) but would exit the diff within.. 300km of normal road driving. I don't know for sure if this behaviour persists post diff rebuild.

The tailshaft is new, so recently balanced. From what I know the uni was fine (fine enough for driveljne shop to say 'nah its fine' when asked.

The gearbox and engine mounts and diff mounts are all new. I mean I changed every piece of Nissan rubber in the car. Every bit!

The only thing I can think of is my car has a set of pineapples in 'Max grip' configuration. Given the fact this doesn't feel like tyre skipping (it feels like the subframe is going to fall out levels of clunk) then perhaps this has something to do with it.

None of the cars I've driven have had those pineapples installed. Or 'subframe alignment bushes' I think is the correct term. I did also replace the entire subframe with a non-hicas subframe, so can rule the subframe itself out as a cause.

I think based on this info I will try removing the pineapples to see if this changes anything. With less power back there now I probably don't need the level of squat I've had in the past.

I had "pineapples" in my diff too so doubt its the cause but easy to try I guess. Wouldn't have thought it would get that hot with normal road use. If you can get it up on a hoist you could try various things with a pry bar to see where there is excessive movement.

Here is a PDF from OS Giken warning against using added friction modifiers:

The Importance of OS250R.pdf

[Kinkstaah]

I am tempted to get a gopro under there to get and figure out what is going on!

I will adjust the pineapples to just see.. but it is good to know that that isn't the cause at least.

I don't know If the run in procedure needs to run. Given I bought it 2nd hand, couldn't possibly still need a run in? I assumed simply driving on the damn thing for thousands and thousands of km would do that right? Did buy it used back in the day...

[admS15]

I had a knock from the rear end. I replaced the diff, drive shafts, shocks and various bits and pieces to no avail. Drove me nuts for months, in the end i bought some chassis ears and found the problem in less than 5 minutes. Was a loose bolt on one of the brackets that connects to the subframe.

I still have the chassis ears, they're just microphones on alligator clips that you attach on various points you suspect. You're welcome to borrow them, im located in Springvale south, not too far from you. Pm me if you want to give them a go.

[iruvyouskyrine]

I need a diff for my track car so i'll buy your clunky one if you decide its easier to buy a whole new diff ?