Is the whine from the gearbox or the differential ??

JNijst · Post by **JNijst** » Sat Oct 10, 2009 5:40 am

Gents,

Like every Pinz-owner, I have this high pitched whine when driving (not too loud, but still...), however when I am rolling along and I drop it into 'zero gear / free ' approaching a red-light far ahead, the whine stops...

This makes me think that the gearbox gives the whining noise, as it is now disengaged; no gears running, but the differential is obviously still turning.

The only thing at the back of my mind is, that when you drive; the drive-train actually pushes on the differential gears and that that causes the whine, when you disengage there is no more pressure on the gears and the whine stops, so... it still could be the differential (as everyone says it is...)

Anybody that can enlighten me on this ?
Overhauling the gearbox or the differential with new gears is costly no matter what, but I'd really feel bad if it turned out to be the other that needed repair.

I read several articles on the forum about this but they only point to the differential, but could the gearbox give the same whining noise ??

Appreciate your input on this

Jules

M Wehrman · Post by **M Wehrman** » Sat Oct 10, 2009 11:26 am

Does it whine in all gears?

Thomas-E · Post by **Thomas-E** » Sat Oct 10, 2009 6:11 pm

I think that most likely you are hearing the wheel drive gearbox (portal axle). They can whine in any gear or free-wheeling. I am using Swepco oil 80-140 in mine and it seems to quiet them a little.

hrafn · Post by **hrafn** » Sat Oct 10, 2009 8:13 pm

I agree with Tom - most of the gear whine is in the wheel drives. The gears
in there are simple spur gears which will make more noise that helical cut
gears (such as those used in the transmission).

I use Red Line Heavy Shockproof Gear Oil (synthetic) in all gearboxes
except the transmission and it seems to reduce the whine a little.

Erik712m · Post by **Erik712m** » Sat Oct 10, 2009 9:45 pm

I'd watch what oil you put in the portals. I used Lucas and lost all six hub seals. Make sure it's a low foam oil! Right now I'm using a $30 for five gallon cheap oil and seems pretty good. But I'll probably switch to synthetic before it gets to cold.

hrafn · Post by **hrafn** » Sun Oct 11, 2009 12:15 pm

Five years running Red Line and no leaks.

Thomas-E · Post by **Thomas-E** » Sun Oct 11, 2009 1:33 pm

Four years with Swepco 212 80-140 and no leaks....It is a petroleum based oil not synthetic.

JNijst · Post by **JNijst** » Sun Oct 11, 2009 3:22 pm

Gents,

If it was in the wheel drives, then the whine should slowly reduce as the speed reduces, but in my case the whine stops immediatly after I drop the gearbox in the free position - or even if I push in the clutch -.
But the wheel drives are still rolling, but the whine has stopped....

Any idea how this could happen ??

Also the original Pinzgauer booklet says to use HypoidGetriebeÖl GÖ-Pz-90 - translated: Hypoid Gear Oil GO-Pz-90... But I have not found any reference to this, probably a Gear oil used in the 80's...

Thanks

Jules

Erik712m · Post by **Erik712m** » Sun Oct 11, 2009 3:51 pm

JNijst wrote:Gents,

Also the original Pinzgauer booklet says to use HypoidGetriebeÖl GÖ-Pz-90 - translated: Hypoid Gear Oil GO-Pz-90... But I have not found any reference to this, probably a Gear oil used in the 80's...

Thanks

Jules

Hypoid
Hypoid gear sets are a form of bevel gear, but offer improved efficiency and higher ratios over traditional straight bevel gears. Commonly found in axle differentials and used as the ring and pinion gears, hypoid gears are used to transmit power from the driveline to the axle shafts. Because of the spiral design and sliding action of Hypoid gears extreme pressure additives are required.

They still sell hypoid gear oil here! Most looks green in color.

hrafn · Post by **hrafn** » Sun Oct 11, 2009 3:52 pm

The whine is relative to the loading on the spur gears in the wheel drives.
More load - more whine. Helical gears where originally developed to
reduce noise in gear sets, however helical gears introduce a thrust that is
not present with spur gears, requiring bearings that can absorb said thrust.

That said, the gear whine is part of owning a Pinz - comes with the territory,
so to say. Modern lubricants can slightly reduce the whine, but will not
eliminate it. I chose the Red Line Heavy Shockproof Gear Oil because it
provides a viscosity rating of 75W250, somewhat quieting the gear whine
without increasing the actual viscosity.

Thomas-E · Post by **Thomas-E** » Sun Oct 11, 2009 4:23 pm

Questions;

Does this whine continue at all speeds under power?

Does the whine seem to change loudness when you let up on the gas pedal?

Is it MUCH louder at high speeds?

You said that it goes away when you press the clutch pedal in, do you also reduce engine speed when you do that?

Are you sure that it is not the FAN?

Perhaps Jim or Dennis could add their thoughts......[/b]

JNijst · Post by **JNijst** » Sun Oct 11, 2009 4:46 pm

All good questions Thomas, but it is 11:30 at night, no time to drive anymore and the wife keeps calling to come to bed...

I'll try tomorrow and see what i can find out about these interesting questions.

I do know that the whine comes with all Pinzes. A long time ago Dennis wrote a lenghty piece about gear-oil and the differentials, pointing in that direction. It was apiece about reducing sound... Tried to look it up, but just cannot find it right now, his suggestion was also to try different oil before taking differentials apart..

Thanks for all your time and answers

Jules - 710M

JNijst · Post by **JNijst** » Mon Oct 12, 2009 12:57 pm

Thomas and other interested.

The whine is pretty much only in the 4th and more so in the 5th gear. In the other gears there is really no whine.

When I let the gas up; the whine reduces as the rpm reduces from the reducing speed.

The whine gets progressively louder & whinier after reaching 40 mph and worst at 50 - 70 mph (in 5th gear). At certain speeds, it seems to gets its sweet spot and really whines...

Again, the moment I push in the clutch , the rpm drops and the whine disappears completely.

I reved the engine to hear if it was the fan, but no whine from reving the engine, only when driving.

Well Pinz-doctors, It was interesting to really get to know the engine and the whining, when and how much...
I am still not sure what it could be, just not enough engine- and mechanical-experience to really pin-point it. Looking forward to interesting answers

Regards,

Jules

landy · Post by **landy** » Mon Oct 12, 2009 10:11 pm

characteristic of the Pinz drivetrain design.

JNijst · Post by **JNijst** » Wed Oct 14, 2009 3:08 am

Hi Landy,

Drivetrain is pretty general, I know it is a Pinzgauer thing, but by this you mean it is not the transmission / gear-box ?

With the drivetrain you have the differentials that many people point to, or the individual four wheel drives.
Dennis mentioned how gears in the differentials could cause whine and possibly reduce with a different oil.
The wheel-drive is actually new to me, I wonder if the whine could be reduced with new gears ?

Regards,
Jules

THE PORTAL HUB - Pinzgauers, Haflingers, Volvo 303s and more!

Is the whine from the gearbox or the differential ??

Is the whine from the gearbox or the differential ??

Whine?

Whine

Yeah, mine does the same thing, I think it's just