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How critical is it Gents?

Adam Davis

Cruisin' Guzzisti
GT Famiglia
Joined
Apr 12, 2018
Messages
193
Location
Ft. Myers, Florida. USA
Questions for tranny and CARC gurus....

Is it causing harm that both my transmission and final drive gear oils that i utilize are rated GL-5? Manual calls for GL-4 in final drive unit....I am aware of different weight classifications.

I have been running this gear oil setup since i can no longer find the ENI products.

80W-90 Final Drive (CARC) GL-5
85W-90 Trans GL-5
 
GL-5 is only an issue with brass components. I'm not aware of any brass components in either the Gearbox or CARC where there is heavy contact such as observed in a syncromesh gearbox (Guzzi uses constant mesh). There is a GL-5 oil that claims to be compatible with brass components and that is made by Royal Purple.
 
GL-5 is only an issue with brass components. I'm not aware of any brass components in either the Gearbox or CARC where there is heavy contact such as observed in a syncromesh gearbox (Guzzi uses constant mesh). There is a GL-5 oil that claims to be compatible with brass components and that is made by Royal Purple.
Awesome John! Thats great info and that helps explain why it shifts better now at 57,000 miles than it did when it was new.

Thank you sir.
 
I run Redline Shockproof Heavy in all my Guzzi CARCs. Because it's full synthetic, the intervals between renewing the lubricant can be extended.

Yes, another oil thread. >:)
 
Considering that it just uses a liter to do both , why bother extending change intervals . It's not
like it's a commercial vehicle ( is it ? ) . Peter
 
I started changing CARC and Tranny gear oils to once for every 2 oil changes at which is roughly every 10,000 miles. The lubes always looked new. However, I did have to route a snorkel hose from breather on CARC to up under tank. I used the extra front Spiegler brake line when I bought a F,B, Brake and Clutch set from Toddy. It works perfectly with no water intrusion at breather point on CARC any more. Had to tap threads in housing to match banjo bolt. Looks tits and matches color of all other lines. I thought of that myself but then I saw someone else beat me to it prior. Back to work i guess....lol

Keep her lubed boys.
 
The specified Weights aren't super critical either.
Anything around the 80W mark will do, 70W-80 ~ 80W-90 ~ 75W~90 etc.

No idea what weight my Gearbox or CARC Oil is, I've been using Mobil Jet II in both for over 18,000 miles now. :wasntme:
 
The specified Weights aren't super critical either.
Anything around the 80W mark will do, 70W-80 ~ 80W-90 ~ 75W~90 etc.

No idea what weight my Gearbox or CARC Oil is, I've been using Mobil Jet II in both for over 18,000 miles now. :wasntme:
Sorry, but if it really didn’t matter there would only be one oil :p
will it survive sure, will it really be as happy :nerd:
 
Sorry, but if it really didn’t matter there would only be one oil :p
will it survive sure, will it really be as happy :nerd:
John Warner is probably correct for the CARC, Tonti, and Loop frame bikes. The Small Blocks and the newer V7 to V9 range do need the 140 weight in the rear drive due to the lower volume and resulting heat build up.
 
Oil logic is often times the most confusing of things.

Case in point, in my Stelvio, it calls for GL5 in the Gearbox and GL4 in the Transmission (Final Drive).

Now the difference between GL4 and GL5 is the additive package, specifically the EP (Extreme Pressure) additives, (usually sulfur & phosphorus).

Funny thing is, in the automotive world, GL4 is normally ok in transmissions, but GL5 is normally not unless the manufacturer calls for it. (GL5 is usually relegated to front and/or rear differentials).

This is due to the additional EP package, which is basically DOUBLE strength in GL5 vs GL4 and supposedly not recommended for gearboxes as GL5 can react aggressively towards bronze and copper. (This can be disastrous for the synchromesh rings of a gearbox.)

However, in Moto Guzzi Land, at least on my Stelvio and other CARC bikes, it’s the other way around!

GL5 in the gearbox and GL4 in the transmission (Final Drive).

Go figure.

Now…

The specified Weights aren't super critical either.
Anything around the 80W mark will do, 70W-80 ~ 80W-90 ~ 75W~90 etc.

No idea what weight my Gearbox or CARC Oil is, I've been using Mobil Jet II in both for over 18,000 miles now. :wasntme:

This knocked me back in my chair John!

The dissonance between the “Anything…will do” and “I’ve been using Mobil Jet II…” is staggering to me!

MJ II costs more than $25 a quart at the FBO!

It’s an amazing aviation product that I never would consider for the GB and FD in a Moto Guzzi.

You’ve peaked my curiosity for sure!
 
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I've got Motul Gear 300 75W90 synthetic arriving tomorrow for my Norge. It claims to be GL5 and GL4 compliant. At $36 CAD a litre I'm expecting great things.

I've got my narrow pathway melted through the 6 inches of ice on my long driveway out to the road and just waiting for a warmish day for the first ride of the year. Hoping to do a couple of ski/ride days again this year. My PMS is really bad! (parked motorcycle syndrome)
 
I've got my narrow pathway melted through the 6 inches of ice on my long driveway out to the road and just waiting for a warmish day for the first ride of the year. Hoping to do a couple of ski/ride days again this year. My PMS is really bad! (parked motorcycle syndrome)
The driveway and streets are Snowfree, down here in the “South”
Thursday last week was over 60, but I was Stuck working nearly an All Nighter :mad:
 
I've run both the Motul you have and Pennzoil 80W90 (mineral oil) in my 2018 Eldorado .
I'm going to suggest that you moderate "expecting great things" . Peter from Burnaby .
 
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