Toast Smell and gear box questions

[sebking]

When the gearbox is hot is smells of toast - very odd and quite nice, a sort of fresh baked bread smell.

Is this normal?

Also what oil should I be using it's got straight 20/50 in there at the moment.

And on the subject just how noisy should these be - small wailing banshee or big ugly wailing and screaming one?

Cheers

Seb

[stirlsilver]

No idea about your toast smell, probably the smell the rubber seals or insulation around the gearbox tunnel gives off when it is warm.

About your oil question I pulled this from http://stage1v8.org.uk/phpBB2/viewtopic.php?t=850

I use Castrol EPX 80W-90 in my gearbox no problem.

As I understood it the reason landrover specified engine oil back then was because there wasn't any good quality gearbox/diff oils around then. It is completely different today so it is suggested to use gearbox oils now.

But it seems that either option works just fine

90W is too thick for cold temparetures. I have that in mine and I can not shift the truck without effort and grinding unitl I get it warmed up.

EP90 and EPX 80W-90 are completely different. The EP 90 is the thick nasty smelling oil used in diffs and transfer boxes and series main boxes pre 2000ish.

You are right it's not suitable for Stage one main boxes as it's too thick for the oil pump to deal with.

EPX 80W-90 is a new high shear low viscosity gear oil which feels and runs more like engine oil. It's now used in axles and transfer boxes of post 2000 discovery etc. Unlike engine oil used in gearboxes it survives the bashing shearing and abuse the gears give it. It stays cleaner and holds it's original structure longer.

The only drawback is it's not cheap.

The disco 2 uses EPX 80W-90 as standard and the car has one of the quietest transmissions for a 4x4.

[disco2hse]

On the other thread you said you did a tip run. If you were carrying dough maybe that's the problem :p

Is the smell coming from the gearbox or somewhere else on the vehicle. I often get strange smells coming through when driving over country roads, especially during milking time. The smells usually seem to come from stuff stuck to the exhausts (don't know why but the tyres seems to flick a lot of rubbish in under where the exhausts, etc. are when it's wet or dusty.

About the oil, I use engine oil 'cos I'm cheap. And noise mostly goes away with ear plugs

Small banshee when oil just changed, medium banshee is acceptable and is most of the time, big angry banshee suggests something is not right.

[stirlsilver]

Small banshee when oil just changed, medium banshee is acceptable and is most of the time, big angry banshee suggests something is not right.

Umm?? What the?

[disco2hse]

Small banshee when oil just changed, medium banshee is acceptable and is most of the time, big angry banshee suggests something is not right.

Umm?? What the?

lol Just read Sebs post

A banshee is an Irish fairy of the female form. Noted for their loud sustained screaming, something like a short tempered and angry teenage girl.

[sebking]

Toast smell long gone!

And did an oil change today in both boxes (what a lot of oil!)

Much quieter now!

Seb

[disco2hse]

Till the next time of course, or after two weeks of driving

[billingtond]

EPX 80W-90 i am using this in the diffs, should I be or should I be using the EP 90

[disco2hse]

EPX is a formulation for different metals and temperature ranges to those found in your vehicle.

For info see this:
http://www.castrol.com/liveassets/bp_in ... r_Oils.pdf

and this:
http://129.35.64.91/bpglis/lubtds.nsf/t ... enDocument

I don't think it really makes a big difference in the end.

This gives some general information to compare the EP and EPX.
http://www.castrol.com/liveassets/bp_in ... ochure.pdf

[stirlsilver]

From something I have just discovered.

DO NOT USE EP or EPX oils in the gearbox or transfer case, this oil contains suphur and phosphorus and can corrode yellow metals (which the LT95 has) under high temperatures. If you are going to use a gearbox oil make sure it specifically says it doesn't contain these compounds!

[disco2hse]

Oh crap. Really?

Dammit, you get the info from these guys and you expect it to be kosher. That's what happens when the marketing/communications/PR idiots get hold of facts and 'dress them up' for the market to sell more bottles.

Oh, by the way. Who was your source Stirl?

[5988]

you sure , as EP90 can be used in the 4 and 6 cyl transmissions and they contain so called yellow metals

the only spec with them is it should be GL4 not GL5 spec (as GL5 aledgidly eats the metals - not done any research into it , i just stick with the GL4 LR said) and the stage 1 will be staying with 20w50 engine oil

[stirlsilver]

What triggered it was this:
http://www.aulro.com/afvb/technical-cha ... -wear.html

The use of EP90 , was the reason 75% of the transfercases I overhauled , blew up !!
Usually the same scenario ,
Step 1 get it serviced
Step 2 Nice and cheap at the Local K-mart , ultra-tune etc
Step 3 Put GEARBOX oil in the Gearbox (as you would !!!)
Step 4 Exactly 1232K later , bang !!!! The bastard of a thing keeps flipping the Transfer case into neutral
Step 5 Tie in High range using rope
Step 6 200 k's down the road BANG again , oops chewed throught the selector arms .
Step 7 , call for the Tow Truck !!! ($1 per Kilometer )
Yep , sulphur based extreme prerssure additives absolutely love those Phosphor Bronze Thrusts
Again , the manual clearly states the use of a ENGINE oil not a gearbox type oil !!!
Wait till you see what Gearbox oil in the main gearbox can do , very messy !!!!

AS for the No 2 biggest problem of LT95's , that of transferring oil from the main to the Transfer box , just peg the Output gear spacer to the spline , so as the output gear and its spacer can not rotate at unequal speeds .

So I looked up the EPX data sheet:
http://www.castrol.com/liveassets/bp_in ... r_Oils.pdf

"The Castrol EPX Gear Oils contain sulphur-phosphorus extreme pressure additives which enable them to withstand high rubbing speeds and tooth pressures. These additives are activated by high localised temperatures on the gear tooth surface, and chemically react with the metal to form materials (metallic sulphides and phosphides) of low shear strength between the rubbing surfaces. This prevents welding, scuffing and galling of the gear teeth at their contact points."

After some google searching:
http://books.google.com.au/books?id=z_x ... il&f=false

Starting from Pg 109

"Sulphur Corrosion
This is a general description which is applied to most forms of corrosion encountered on silver-rich or copper-rich bearing alloys. There is no doubt that sulphur compounds in lubricating oils can promote the corrosion of these particular alloys. On the other hand, both naturally occuring sulphur compounds in lubricants and sulphur-contining additives confer beneficial properties on lubricants. Etc etc...


...The corrosion problems of copper alloys are more complex because the alloys themselves are complex. On simple copper-lead alloys the copper phase may be attached by sulphur, but this is comparatively rare occurrence, the problem of sulphur corrosion being much more acute on phosphor-bronze alloys. This is because phosphor-bronze alloys which are very popular for little-end bushes in diesel engines, are expected to operate at considerably higher temperature than copper-lead bearings in use today. etc etc..."

You can keep reading if you like

Basically it seems that sulphur will attack phosphor bronze which is used in the transfer case... (and gearbox) I did read somewhere that the corrosion only starts to occur at high temperatures. I haven't checked the condition of the bushes in my transfercase yet, i'll have to have a look to see if they have been attacked or not.

[Jamie_grieve]

My tuppenceworth:
As above but another place not to use EP90 which would seem normal is in the capstan and drum winches used on androvers which use a phosphor bronze worm and wheel. I was rather under the impression that it was high pressure with the EP additives that damaged the phosphor bronze. Planetaries in tractor hubs is another no no for the same reasons on the thrust washers.

[disco2hse]

Thanks Stirl,

OK. Now that is not really definitive and reading the quote the poster was referring to the use of gearbox oil in the gearbox instead of engine oil.

You see, things get confusing because then you read this from BP's fact sheet "Compatible with all seal and metal types" http://129.35.64.91/bpglis/lubtds.nsf/b ... enDocument.

So, there is a sulphur content in the EP oils, but what gear oils do not contain sulphur compounds of one form or another?

Also, in the extract there is special mention of the use of EP oils in diesel powered engines. Diesel in many parts of the world also contain sulphur, so what part does this play in corrosion? Is it increased in places where the concentrations are higher, or is it lower in places where the concentration is lower?