Editing Forums/Z31P/z31-performance-upgrade-forums driveline-aa/30a Noises.

{{ForumImport
|op_user=DeleriousZ
|op_date=2013-10-07 23:29:43
|post_count=7
|archive_url=/Z31performance_archive/forum/z31-performance-upgrade-forums/driveline-aa/22744-30a-noises.html
}}

'''DeleriousZ:''' <small>(2013-10-07 23:29:43)</small>

So I recently replaced the clutch on the red Z, did the throwout bearing and stuff while I was in there. I had figured it was the throwout bearing making noise because whenever the clutch was engaged it'd make a whine noise (tob freewheeling) and whenever I depressed the clutch (engaged the tob onto the PP) the noise would go away.

Anyway, everything replaced, noise still there. Now I'm thinkin input shaft bearing. Can this be replaced without completely disassembling the transmission/removing the bellhousing?

There was a bit of radial play on the input shaft I noticed when the transmission was out.

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'''amreboot:''' <small>(2013-10-08 00:46:31)</small>

The input shaft bearing can be responsible for alot of noise and vibration in the 30a.

It is very common for it to fail and produce a whining or whirling noise.

To replace it, you will have to pull off the bell housing.

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'''DeleriousZ:''' <small>(2013-10-08 04:38:52)</small>

Fuckit, burning it down and collecting insurance.

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'''shromy:''' <small>(2013-10-08 12:30:37)</small>

Just fyi for next time, TOB will make noise when loaded not when unloaded. But your thinking you have internal bearing issues would be correct. Pretty common since most have had gl5 put in them over the years. In nissans case and others gl5 is not compatible even though it states it is on the bottle. It will likely make this noise for a long time before anything happens, i also recommend to overfill it as well.

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'''Spooledup300z:''' <small>(2013-10-08 14:54:23)</small>

Gl-5 shouldn't case a bearing issue, just a synchro grinding problem, a small amount of play isn't a problem. Put amsoil, redline, or royal purple gl-4 and be done with it

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'''Tempestas:''' <small>(2013-11-11 17:07:46)</small>

gl5 is thicker, you wouldn't think so, since they advertise gl4 at 75-85 or 75-90. Look at the bottle of redline mt-90 where it claims 75-90, then says it has the viscosity of 5w-40. This is true for all gl4s, they are the viscosity of motor oil.

Anywho, the gl5 can cause bearing noise and hard shifting when cold, usually goes away when warm and it's not so thick. But I know for a fact it can and will cause whirling sounds on a cold morning. I know people claim that gl-5 is corrosive to your syncros, but the real issue is that it's too slick and the wrong viscosity, different friction modifiers. gl5 is made to go where you want no friction, and is slick as possible. gl4 is made to go where you want to protect bearings but still have the friction required for syncros. when you put gl5 in, it will cause your syncros to not "grab" as well, and eventually glaze over.

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'''DeleriousZ:''' <small>(2013-11-11 17:28:15)</small>

I never said that there was gl5 in the transmission, when i drained it, the fluid was nasty, but was thicker than motor oil. I'm assuming the correct fluid was in there, just hadn't been changed in a very long time. Anyway, the car's sitting until I move once again, and then I'll tear it back down to replace the bearing.