What's wrong with my diff??

Engine, Transmission and related drivetrain.
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JordanTr
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Joined: 20 Feb 2013 22:27
Location: Langley, BC, Canada

What's wrong with my diff??

Postby JordanTr » 10 Oct 2016 14:41

Looking for some help diagnosing my problem diff-- 4.11 stock 2 way from a BNR32 Skyline.

Cliff notes of the diff history:
- ~ 87K km in an R32GTR
- Pulled from GTR and swapped into my S14.
- Removed CV companion flange to swap on 4 bolt flange; retorqued pinion nut with red Loctite (there is no crush sleeve)
- Refilled diff with proper amount of oil. GL5 Redline 75W90 NS with additional LSD additive.
- Drove the car a bunch this summer (nearly 5000km) and never really beat the crap out of it.
- Noticed a noise on the last part of my drive home on Friday.
- Diff still has oil in it and it doesn't look super dirty or anything.
- Took video #1 (200km/h = 100km/h in reality)
- Removed and retorqued pinion nut before taking video 2.

See 2 video links to YouTube below.
Diff video 1
Diff video 2

Needless to say, I'm choked. Would really appreciate some help troubleshooting this. Thanks guys.
Jordan | '72 2 door KA project | '94 240sx RB26DETT | '97 Silvia RB25DET | '90 Audi 90 Quattro 20V (DD)

Three B's Racing
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Joined: 03 Mar 2009 11:58
Location: New Hampshire

Re: What's wrong with my diff??

Postby Three B's Racing » 11 Oct 2016 06:26

You sure it doesn't have a crush sleeve? because as you said Removed and retorques pinion nut before taking video #2 which tells me retorquing it, has changed tolerance where you now have to much play between ring & pinion, or incorrect torquing and not enough play,,eitherway it sounds like incorrect ring & pinion meshing.
"Lastnight the wife said oh boy when your dead you can't take nothing with you but your soul oh "Think"
- John Lennon

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JordanTr
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Joined: 20 Feb 2013 22:27
Location: Langley, BC, Canada

Re: What's wrong with my diff??

Postby JordanTr » 11 Oct 2016 07:07

I'd have to agree with you on the noise, B.

There is no crush sleeve and changing a pinion seal follows the same sequence I did and is straight out of the FSM. The Z32TT R230 rear end DOES have a crush sleeve.

If I did get my torque wrong (it's only a tq wrench after all), why would it have taken 5000km to manifest itself?

Video 1 and 2 shouldn't sound any different. I just wanted to verify that the pinion nut hadn't backed off before taking video 2.
Jordan | '72 2 door KA project | '94 240sx RB26DETT | '97 Silvia RB25DET | '90 Audi 90 Quattro 20V (DD)

Chickenman
Posts: 474
Joined: 06 Sep 2010 15:10
Location: Coquitlam

Re: What's wrong with my diff??

Postby Chickenman » 15 Oct 2016 23:54

Sounds like a bearing has gone bad. It happens. Time to pull the diff apart and do a full forensic. Oil may not look dirty...YET. That's probably because the RL oil is saving things so far. But I wouldn't drive it any more till you find out what's wrong. The last thing you want is any fine metallic chips going through the gears.

Bearing's are cheap and easy to replace. Gears aren't.

The nice thing about a bearing replacement is that you don't have to change any R+P settings. Just use the old shim packs and spacers ( non Crush only of course )

datzenmike
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Re: What's wrong with my diff??

Postby datzenmike » 16 Oct 2016 09:33

It's an R-something diff. Take the cover off!!!!!!! and look! No sense guessing what it is unless there's a prize for the winner.



For the record. The whirring sounds like gear teeth meshing, bearings tend to whine or growl. (in case I win)
"Nissan 'shit the bed' when they made these, plain and simple." McShagger510 on flattop SUs

Chickenman
Posts: 474
Joined: 06 Sep 2010 15:10
Location: Coquitlam

Re: What's wrong with my diff??

Postby Chickenman » 17 Oct 2016 01:00

BTW, if the diff doesn't have a Magnetic drain plug, install one. Can give you a heads up if something is starting to wear. Or Epoxy a small magnet to the inside of the diff cover, but I prefer the Magnetic drain plug.

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JordanTr
Posts: 734
Joined: 20 Feb 2013 22:27
Location: Langley, BC, Canada

Re: What's wrong with my diff??

Postby JordanTr » 17 Oct 2016 07:12

For sure. I'm quite sure the drain plug is magnetic. I may just install a mag drain plug on the fill port as well!
Jordan | '72 2 door KA project | '94 240sx RB26DETT | '97 Silvia RB25DET | '90 Audi 90 Quattro 20V (DD)


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