Thread: Gearbox Oil

Sorry Admin,
Just thought it was just a link.

whitehillbilly

I've just been going through the same investigation, and also found the Richard Widman document shown above. Richard runs an oil company, so presumably he knows what he's talking about.

Though I no longer own any old tractors and therefore cannot comment on the current situation, it can't be more than 5 years ago that the oil company's agricultural reps were selling and recommending oils specifically for "yellow metal" compatibility. Whilst it is possible that the formulations have changed and the modern oils are indeed safe with yellow metals, it is of course equally possible that providing the correct products to a small "classic" market is not profitable, and the risks associated with recommending the wrong product (especially to low use classic cars) are outweighed by the costs saved in not carrying low turnover products. In any case, most gear oils on the shelf in my local stores are GL5 products.

Roamerdrive (previously Roverdrive) recommend a synthetic GL4 oil (Castrol Syntrans 75W/90 Multivehicle) in their installation manual, but it's not available in Australia. We do have Syntrans 75W/85, which is also a GL4, and a couple of companies import and sell Redline MTL, which is also a Roamerdrive recommendation, and Redline MT-90. I contacted Roamerdrive directly and (contrary to their installation guide) they recommended against using synthetic oils in high ambient temperatures because "they tend to weep out and are a bit thin so makes things noisy". They recommended Penrite Mild EP as the best choice in Australia.

Castrol sell Syntrans 75W/85 as a GL4 synthetic, and their technical rep. suggested it would be OK. They also sell a heavy transport product, Syntrans 75W/90 Heavy Duty which is synthetic GL4 but on paper it has significantly higher viscosity than the normal "high street" products. In the UK Castrol still sell EP-90 in old style tins for classic cars, and it can be bought on eBay and shipped over, though the freight cost is high.

Penrite's product selector recommends "Mild EP" from their classic vehicle range, but as an EP-90 replacement for the gearbox and Fairey overdrive their technical staff suggested Trans Gear 75W/90 which is a GL5 product. They stated that the additives would not attack yellow metal, but if the Richard Widman document is to be believed then direct chemical attack is not actually the issue. They also produce Trans Gear 75W/80, which is GL4, but they didn't mention it as a recommendation.

HiTec oils list a 75w/90 GL4 Gear Oil on their web page, but I have no idea how good it is or where to buy it.

At present I have not 100% decided on a product, but based on The Richard Widman explanation I have decided to stick with a GL4 oil. I'm leaning towards Penrite's Mild EP but I've not completely ruled out Redline MT90.

I should perhaps comment that the wear to synchromesh problems described above can be entirely avoided by simply driving so as to not use the synchromesh - i.e double declutch every change. This should prove no hardship to drivers of Series 1 & 2, who are used to doing this anyway for the first two gears.

John

G'day All,

I can give you some positive feedback on Castrol Syntrans 75w/85 GL4 manual transmission oil. Have been using this oil since 2012 in a S2a 1966 SWB transfer and gearbox. Before I fitted a roamadrive did my research as you are doing. Ray at roamadrive gave me good advice. They have an excellent article on the use of synthetic GL4 oil in the roamadrive.
When changing over to this thinner oil I replaced all the external oil seals on transfer and gearbox. Used Viton seals.
Most important is the transfer rear output seal. Used speedie sleeve and viton here. The roamdrive needs the oil level increased in the transfer box and you use about 3.25 lts and 0.5 ltrs in the O/D. So this seal is flooded with oil. Oil is available from Burson and bought 20 ltrs.(the Ford Focus uses it as well).Thinner oil means you have to slow down the gear changes slightly when oil hot and slightly more gear noise noticed however, that's included with a LandRover. Don't park on very steep slopes with bonnet facing down. Miss the smell of EP oil in the cabin on a hot day!!!!!. No known issues with this oil and long drain times make up for the extra cost.
Fit a magnetic drain plug to the gearbox.
Chris

its a series.

go to kmart.

buy the cheapest brand gear oil they have that says 80/90 on it.

thats what the series wants. just give it to it regularly

if you cant find it at kmart goto supercheap anything that has the exact numbers 80/90 on the front of it will do

I found about 10 products that are suitable from searching the online website. if you widen the range to include the 75-90 ranges you get even more choices.

I would advise to avoid the single weight oils. but more because I just couldnt be bothered opening up and researching any more product SDS's

before you ask...

Penrite Gear Oil - 80W-90, 2.5 Litre - Supercheap Auto Australia
or
Nulon Gearbox & Differential Oil - 80W-90, 4 Litre - Supercheap Auto Australia

IF I had to pick 2

Well, I headed into Super Cheap Auto and cam home with the stuff Hillbilly first posted which is the Nulon Smooth Shift GL4 75W-80. I am stunned at how runny it is, very easy to fill the gearbox and transfer case and no gear oil smell. Still haven't tried my rebuilt gearbox though, so no idea how it will go noise wise. I have also changed both diff oils, these also got same. What came out was like honey, what went in was more like water! I am thinking this stuff is just too runny for the front swivel joints though, I am thinking of a 140 weight for these but any suggestions are welcome.

Originally Posted by Blknight.aus

I found about 10 products that are suitable from searching the online website. if you widen the range to include the 75-90 ranges you get even more choices.

If you'd spent $2K+ on an overdrive whose manufacturer specifically states NEVER to use a GL5 oil, you'd put a GL5 oil in it?

Originally Posted by Warb

If you'd spent $2K+ on an overdrive whose manufacturer specifically states NEVER to use a GL5 oil, you'd put a GL5 oil in it?

I wouldn't fit an overdrive. Its a series