polyalphaolefin (PAO) or polyalkylene glyco (PAG)

[nta16]

Hi, new member from the UK
having already made the mistake of refilling and recommending to others a GL-5 oil (Mobilube 1 shc 75w-90) for a manual synchro car geabox that requires GL-4 I thought it best to check -

would Mobilube 1 shc 75w-90 or Castrol Syntrans Multivehicle 75W-90 Fully Synthetic MTF be polyalkylene glycol (PAG)?

I ask as the gearbox is without a drain hole so the existing oil has to be sucked out leaving a lot of it in the box around 25% (0.4 litres of 1.9 litres) and already have seen -
Quote:
beware that there two kinds of synthetic gear available: polyalphaolefin (PAO) based and polyalkylene glycol (PAG) based. PAOs are basically a man made version of mineral oils (although with greatly improved properties) and can therefore be mixed with mineral oils. In fact, semi-synthetic products have mineral and synthetic base fluids in them, so obviously, they must be able to mix. PAGs, on the other hand, will not mix with PAOs or mineral oil. Utmost care must be taken when using this kind of product.

 

[Rand]

your post is confusing.

you are trying to find a PAG oil or you want to know if those are?


are you trying to replace what oil? you dont list an application/car/model/whatever.

 

[mechtech2]

Another good reason to NOT use that M1 in a manual trans is that is is not friction modified for synchros and shifting.
Go get a modern dedicated manual trans fluid.

 

[INDYMAC]

What PAG gear oil are you interested in trying? As a rule, PAG is incompatible with mineral oils. But there is an exception. Does the product your interested in mention compatibilty issues? If so, I would not use it.

 

[nta16]

Hi,
thanks for replies

Rand,
I want to know if either of these are PAG as both are in my gearbox because it doesn’t have a drain hole and I was only able to get just over a litre sucked out of it this time, so M1 and Castrol are co-habiting in my gearbox and I wanted to know if they’d mix in together or be like a bitter divorcing couple sharing the same house and not mix together at all

mechtech2,
I found out too late (totally my fault for not scrolling down to page 2 of the spec sheet) that I don’t want M1 in my g/box so I’m trying to get it out but Ford and my g/box supplier both haven’t bothered to provide a drain hole and now the box is in the car and difficult to remove or put a hole in I have to try to suck as much oil out each time as possible, I’m going for the diluting a little more each time hope

INDYMAC,
as above, I’m not really interested in using a PAG as such just confirming that either M1 or the Castrol are not PAG

 

[ac_tc]

Dont bother to much!
Change whatever you get out with a proper oil.
The GL5 may or may not be bad for your box but
after a change or two..no problem.
I would be more concerned about shift quality.

 

[SubLGT]

Originally Posted By: nta16
..............because it doesn’t have a drain hole ...........


This is the first I have heard of a manual gearbox not having a drain plug. What vehicle is this? Is the factory fill supposed to be a lifetime fill?

 

[nta16]

ac_tc,
Mobilube (on 2007 spec sheet, there are so many Mobilube spec sheets) put 'Not recommended for applications requiring API GL-4 level performance'

the g/box was a fill 'for life' item and most classic car owners over here wouldn't think of changing g/box or r/axle oils even if they weren't

I put the Mobilube in to improve shift quality and it did and then recommended it to others to later find out Mobil (no longer?) doesn't recommend it for this type of gearbox

 

[nta16]

SubLGT,
you've not lived long enough then

the g/box isn't original to the model of car it's from a penny-pinching outfit you'll know well - called Ford

yes it was a factory 'filled for life' component but then of course what does life mean and which lfe, the car, the component ? it like those lifetime guaranttes you get that never mean the lifetime you thought it meant

it's a Ford Type 9 gearbox that was fitted to the UK Sierra range of cars - http://www.type9gearbox.co.uk/type-9-history.html

 

[MolaKule]

Quote:
PAGs, on the other hand, will not mix with PAOs or mineral oil.


There are some new PAG's from DOW. They are oil soluble PAG's and are being used in some lubes as a "co-base" oil.

It is mainly the PI or additive package that is important and is found in application specific Manual Transmission Fluids. Of course having the correct viscosity of oil is important as well.

Many synthetic MTL's have a mix of base oils which may include PAO and esters, or PAO and PAG's.

 

[nta16]

Originally Posted By: MolaKule
It is mainly the PI or additive package that is important and is found in application specific Manual Transmission Fluids. Of course having the correct viscosity of oil is important as well.

Many synthetic MTL's have a mix of base oils which may include PAO and esters, or PAO and PAG's.
ok, thanks so do you know if Mobilube 1 shc 75w-90 or Castrol Syntrans Multivehicle 75W-90 Fully Synthetic MTF have PAG?

 

[tdi-rick]

Syntrans will be a PAO/ester fluid.

It's friction modified for manual 'boxes and IME with Syntrans 75W-85 is one of the premier manual trans fluids, and has been for years.

 

[nta16]

thanks

Ithought that was the case especially for the Castrol