Gearbox oil additives/friction modifiers (1 Viewer)

[Jake Royd]

The post above would not upload yesterday but did now in response to the post above.
Strange , never had that before.
Post was in my buffer?

Anyway, to reply to that post.

I started my career as a Craft Apprentice at Longbridge in I think 1970.
Highly prized then.
I went on to get some technical qualifications, ending with an MSc , finishing up working for Land Rover at Gaydon doing transmission design and development management.
Had a wonderful time.

Yes , the cars were what they were but there were many great engineers there.

I don't live too far away but never visit the At Modwen developed site , it's too sad for me.

 

[jezport]

Thought about using ATF in your manual box ?

Please explain why you suggest it?
I know Auto transmissions create a lot of heat and the transmission fluid helps to cool as well as lubricate, but is the lubricating properties of Dextron better than normal oil? Also which version of Dextron is best?

 

[Geo]

At the garage we removed many many gearboxes for various and numerous faults
Whilst fully capable of repairing some of them we were never familier enough with the vast array of gearboxes to make in house repairs a viable option cost wise.
As a result we very often used the services of a local specialist.
Who without exception sent them back having been lubed during re build with ATF and with instructions to use standard ATF to re fill.
I too asked the very same question as you only many years earlier.
I was told in no uncertain terms the ony difference between auto and manual is the way the gears are changed, Cogs, syncro, and bearings are all the same.
ATF is a far superior lubricant.
Whilst thick oil may have a better quieting properties, correctly assembled gearboxes dont need quieting.
Bring one back with oil in and your warranty is out the window.
Inever argued with that and never had to return a repaied box either in over 20+ years.

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[jezport]

At the garage we removed many many gearboxes for various and numerous faults
Whilst fully capable of repairing some of them we were never familier enough with the vast array of gearboxes to make in house repairs a viable option cost wise.
As a result we very often used the services of a local specialist.
Who without exception sent them back having been lubed during re build with ATF and with instructions to use standard ATF to re fill.
I too asked the very same question as you only many years earlier.
I was told in no uncertain terms the ony difference between auto and manual is the way the gears are changed, Cogs, syncro, and bearings are all the same.
ATF is a far superior lubricant.
Whilst thick oil may have a better quieting properties, correctly assembled gearboxes dont need quieting.
Bring one back with oil in and your warranty is out the window.
Inever argued with that and never had to return a repaied box either in over 20+ years.

So Dextron 3 or 4?

 

[Geo]

As none of the Dextron range of ATFs are specified for Manual gear boxes
the question is mute
We used whatever was to hand and in stock at the time
when we first started using ATF there was ATF and that was your choice take it or leave it
If you are at all concerned or want sound proven advise use what is specified for your vehicle

 

[Jake Royd]

I'm no oil technologist but I would observe two things about ATF that might be of concern or of difference.
1) ATF will be used hydraulically in a standard slushbox auto, to operate the brake bands and to be used under pressure in the hydraulic logic circuits. This is not the case in a manual gearbox. In otherwords are there any synchros in an auto box. Not 100% sure but I think not. Therefore different friction conditions may required in auto and manual. Note , this is not the same thing as viscosity.
2) Does ATF degrade over time?. If fully synthetic possibly not?

Just thinking.

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[donkey]

Gearbox manufacturers spend £.............. on R & D. So why would they not get the lubricant right. If ATF was the best lubricant, then that is what they would recommend.
Have you seen inside a modern gearbox? They are a work of art and quite staggering in the quality of the engineering.
Go away from their recommendations at your peril.

Geoff

 

[jezport]

Ive read on some American car forums that ATF it recommended for some manuals in the USA

 

[Lagotto]

I must agree with those that believe the manufacturers are the experts. Those that spend decades designing, building and testing their products, they should be taken seriously. I believe there is a great deal of the "placebo" effect in operation. Having checked out a product, read the wonderful properties on the label, handed over the cash and got the tool box out, it has definitely made it better

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