Oil for Transmission Gearbox

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A Collaud
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Oil for Transmission Gearbox

#1 Post by A Collaud » Wed Jun 12, 2019 11:03 am

Hello,
I'm sorry to ask for a question which has been already discussed many times, but I'm still confused
I need to refill my 741 Gearbox (BT6 transmission) and looking on forum the only brand mentionned is the Swepco 201 which is not distributed in France ... In the workshop manual it is written "SAE 90 HD Hypoid", and looking for such on the web available in France, could you confirm if one or the other will be OK :

- Castrol EP90 (Mineral, SAE 90, API GL4) : Castrol EP 90 is recommended for the lubrication of conventional spiral bevel final drives and mild hypoid axles where API GL-4 oils are recommended. It may also be used to lubricate spur and helical gears and for other applications where the manufacturer specifies the use of an oil meeting API GL-4. It should not be used in high off-set hypoid axles where API GL-5 oils are typically recommended or in axles with limited slip differentials

- MOTUL ALLGEAR EPL 90 (SAE 90, API GL4 – MIL-L 2105) "Mineral lubricant for mechanical transmission, synchronised or not synchronised gearboxes, gearbox/differential, transfer gearbox and hypoid differentials without limited slip system operating where a SAE 90 grade is recommended by the manufacturer."

- MOTUL GEARBOX 80W-90 (Mineral, 80W90, API GL-4/GL-5) : "Mineral lubricant reinforced with Molybdenum bisulphide to handle heavy loads and reduce transmission noise. All mechanical transmission, synchronised or not synchronised gearboxes, gearbox/differential, transfer gearbox and hypoid differentials without limited slip system operating under shocks, heavy loads and low revolution speed or moderate loads and high revolution speed. Very high lubricating power decreases friction and wear. SAE 90 grade at hot temperature to provide outstanding oil film resistance at hot temperature."

Thank you for your advises

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Doug McDonnell
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Re: Oil for Transmission Gearbox

#2 Post by Doug McDonnell » Wed Jun 12, 2019 12:43 pm

Vic Skirmants says that any name brand 80/90 is fine here in the states. I would assume the same is true in Europe. A quick call to Mike @PRS in the UK or Marco @elevenparts could result in a confirmation for you. Some here in the States complain about leaks using Swepco. I use it in my transmission rebuilt by Vic without any leaks.
1965 356C There is never enough time to do it right, but always enough time to do it over.

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David Lawrence
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Re: Oil for Transmission Gearbox

#3 Post by David Lawrence » Thu Jun 13, 2019 4:38 am

I put Swepco into my 64C 5 years ago. At that time the transmission was 50 years old and all original. Well that was a mistake, the transmission started leaking the Swepco out of every seal except the axle tubes at the wheels. It is probably alright to use it after a rebuild but not before.
Growing Old is Mandatory - Growing Up Is Optional

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neilbardsley
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Re: Oil for Transmission Gearbox

#4 Post by neilbardsley » Thu Jun 13, 2019 5:06 am

I think any quality 75/90 oil will work for you. If it hasn't been changed for a well I would consider a short change. Maybe within 1k. Worked on my non porsche car. I changed the gearbox and noticed a lot of fur on the magnetic and it ran better for a bit so I changed it again after 1k (still lots of fur on the magnetic). It has been running better since.

I use this

https://www.ebay.co.uk/i/250606606374?chn=ps

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Al Zim
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Re: Oil for Transmission Gearbox

#5 Post by Al Zim » Thu Jun 13, 2019 3:07 pm

Use the Motul all gear EPL 90. This will be more than adequate. The Porsche synchronizes require more friction than the Borg-Warner synchronizes do. al zim
 

A Collaud
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Re: Oil for Transmission Gearbox

#6 Post by A Collaud » Fri Jun 14, 2019 3:34 am

I will do, thank you !
Alexis

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