Gear box oil additives

[nel]

Following a gear box oil change my car has developed a whining roller bearing on the shaft taking drive to the front wheels. Replacing it will be an engine out job, so would like to put this off until I have other major maintenance tasks to do. Does anyone here have experience of any of the "wonder" gearbox oil additives, e.g. Slick50 with its PTFE claims, etc?

I know the engine oil additives have been largely discredited, but with gearbox oil staying in the system for so long it does seem possible that additives could make a difference.

Thanks

[Matthew C]

More slippery oil will mean the synchros will be less effective, so you're better off sticking to the original spec, otherwise you're exchanging one problem for another. IMO.

[leorest]

It's probably not what you want to hear, and this is probably what the additive making companies are praying on, but..

Good quality oil already has a well designed additive package which is designed to be synergistic or at least compatible with the base oil. An after market additive by definition can not lay claim to either of these err claims, it can however often offer long lists of unsubstantiated endorsements from seemingly independent members of the public, who may or may not even exist, and should their words prove incorrect/misleading the additive peddling company is in the clear as they didn't make the claim.

This is of coarse an unsubstantiated and humble opinion of a seemingly unconnected member of the public aka me. I do however, exist, as it would serve no purpous for me to invent myself. Come to think of it I wouldn't know how to invent myself? Anyway… You should take what I say with an equal pinch of salt as what is written on the side of the packet of snake oil in question and make your own mind up.

If there is a gremlin in your box and you manage to hide the symptoms with an additive then it can only do more harm until you remove that gremlin.

Magic goo = No thank you
Good quality oil = Yes please

IMHO
Leo

[GavinPearson]

I have experience of evaluating oil for OEM use in transmissions.

I would stick to what the manufacturer recommends. It tends to give optimum synchro action and decent bearing life.

What you have used may just be incompatible or the wrong grade.

[nel]

GavinPearson said:

I have experience of evaluating oil for OEM use in transmissions.

I would stick to what the manufacturer recommends. It tends to give optimum synchro action and decent bearing life.

What you have used may just be incompatible or the wrong grade.

That's a good point - I trust the specialist garage where the oil change on the gearbox was carried out, but I suppose that I should confirm with them that they did put in exactly what Mr. Porsche recommends.

As for the additives, the lack of positive reaction from you lot kind of sums up what I suspected - not worth considering and capable of doing more harm than good.

[GavinPearson]

Just remember that OE oil tends to be expensive because it is very good and is guaranteed to be the right spec. "Equivalent" oil might be, but might as well not be. For example, Ford gearboxes use an oil made by Castrol known as BOT 130. Using Mobil 1 might seem to be the equivalent, but it isn't. You HAVE to use what was specified, or better still what the manufacturer specifies as the fluid that fixes gearchange issues in their technical service bulletins.

[wildoliver]

I was going to say don't add the additive just live with the whine till you can afford to do the job, as although you may hide the whine you won't hide the problem and you will most likely cause more.

But you say this is a Porsche box??????? You are seriously considering driving a Porsche around with a worn whining gearbox increasing wear to other components??? Unless your talking about doing it inside a thousand miles or so I would really think again, at the moment the job isn't silly money, but by the time extra wear is caused its major rebuild time.

And I'm not even going to comment on the thought of adding an additive to a Porsche! 1987 Nova fair enough but not a Porsche lol!

See snake oil thread!

[nel]

wildoliver said:

I was going to say don't add the additive just live with the whine till you can afford to do the job, as although you may hide the whine you won't hide the problem and you will most likely cause more.

But you say this is a Porsche box??????? You are seriously considering driving a Porsche around with a worn whining gearbox increasing wear to other components??? Unless your talking about doing it inside a thousand miles or so I would really think again, at the moment the job isn't silly money, but by the time extra wear is caused its major rebuild time.

And I'm not even going to comment on the thought of adding an additive to a Porsche! 1987 Nova fair enough but not a Porsche lol!

See snake oil thread!

Yep - I understand the sentiment! But my indy expert says that's it's no big deal and can be driven like that, not to worry. My initial concern related to the risk of catastrophic failure, but he put my mind at rest. I'll get it done but I'd like to have a list of other engine out jobs to do at the same time to make it worth the effort!

He was the one who talked about gearbox additives, so I'll quiz him further on exactly what brand of serpentile lubricant he's proposing and look into it.