75W-90 or 75W-140 ???

[kballowe]

While reviewing maintenance logs for the last six or eight Moto Guzzi's - it appears that the transmission/rear pumpkin lubrication recommendations are different.

The most recent comparison is that our 2020 Eldorado 1400 specs 75W-90 for both. 
This new V7 850 specs 75W-140 for both.

Past rear drive pumpkin specs were for 80-90 GL4.

[Guzzistajohn]

That Kevin, always trying to start a fight! 

[bad Chad]

I would stick with spec, there must be a reason for it.   And on the off chance something went south in the pumpkin, and you had non spec fluid, well, that might not work out so well.

[Old Jock]

I'm not familiar with the latest Guzzis, my knowledge stop pre carc

In general though I don't think the difference in viscosities on the multigrades is as critical as an engine oil.

The gearbox and transmission run way cooler than the engine, so although there will be a difference in the viscosities at running temp between the 2 different specs mentioned, it's probably not as much as most people think.

[twowheeladdict]

Mussent be good ridin weather today.

[kballowe]

How about this one ?

Ya'all just drop by.  We'll just change ya out.  I have a 50 year supply.

[Chatmanx]

Let me know if I have this wrong.

They are the same base 75 weight. They differ in modifiers that keep them from breaking down at higher temperatures. So, if the temperatures are the same in a V9 or Eldorado then both will behave as if they are 75-90. However, if there is something different about the V bikes and the V bikes operate at much higher temperatures, then it will be helpful for them to behave as if they were heavier weights up to 140.
 

[pressureangle]

I just did a deep dive into gear oils, found a couple things;
Sulphur and Molybdenum Disulphide (Moly) create acids under high heat, which deteriorates the base oil, and perhaps the metals in use. Boron based EP additives have no such issue. I'll be using Chevron Delo ESI 80w90, after a lot of navel-gazing. They have a 85w140, but Chevron says follow the manufacturer's recommendation for viscosity. Delo ESI meets the harshest manufacturer's criteria, including Meritor and Mack 500,000 mile service intervals.

I did not try to discover if the usual suspects were Sulphur or Boron. IIRC Bel-Ray also uses boron EP additives. I've used Redline in the past and been happy with it; don't know that the Chevron is any easier to source.

https://www.chevronlubricants.com/en_us/home/products/delo-gear-esi-80w-90.html

[kballowe]

A friend of mine bought a case of this Genuine Honda shaft drive oil - and then decided on a different product.  It's been sitting on the shelf here for a couple of years.  It says that it is recommended for Gold Wings.

A little shaft drive oil goes a long way.

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[lucian]

Oil thread with no WARNING .  moderator , we need a ruling.

[Chatmanx]

Before we are canceled, fun fact is that 80 weight differential oil is really 40 weight. 75 is 30 weight. They used a much higher number to discourage people from confusing the two.

[twowheeladdict]

Before we are canceled, fun fact is that 80 weight differential oil is really 40 weight. 75 is 30 weight. They used a much higher number to discourage people from confusing the two.

Fortnine says the W means Winter, not weight.  As in 75W(inter) - 90. 

[jrt]

A little shaft drive oil goes a long way.

Hey! Watch your language- I have kids!

[Huzo]

Hey! Watch your language- I have kids!

Well, you didn’t need telling then...

[kballowe]

 

Oil thread with no WARNING .  moderator , we need a ruling.

It's only a matter of 

 

[chuck peterson]

BB vs SB difference

[kballowe]

BB vs SB difference

You may have something there......

[Vagrant]

They put an oil pump in the V7Iii tranny and cut the quantities in 1/2. V85 doesn't have one. Don't know about the V7-850. How much does the tranny hold?

[kballowe]

They put an oil pump in the V7Iii tranny and cut the quantities in 1/2. V85 doesn't have one. Don't know about the V7-850. How much does the tranny hold?

1,750 CC engine oil
500   CC transmission lube
180   CC rear drive pumpkin

[kballowe]

[Vagrant]

I bet they put a pump in it

[chuck peterson]

You may have something there......

First difference I noticed moving to a SB is the rear “pumpkin” change in viscosity per spec

[SIR REAL ED]

A friend of mine bought a case of this Genuine Honda shaft drive oil - and then decided on a different product.  It's been sitting on the shelf here for a couple of years.  It says that it is recommended for Gold Wings.

A little shaft drive oil goes a long way.

[/img]

if it has been sitting on the shelf for a couple years, check the expiration date!!   

I recently found some stuff in the refrigerator that expired a couple years ago!