LCGB Forums

Anyone know if you can use EP90 gear oil with an LTH clutch?

I've been sent 5 litres by mistake.

Isn't the problem with EP oils related to the phosphor bronze bushes rather than the clutch itself?

EP90 oil would be great for the gearbox, but Extra Pressure oils prevent the clutch plates from gripping properly leading to clutch slip.
ST90 is therefore specified as a satisfactory compromise.

Oiltek told me to use 85wt oil.

rossclark wrote:Isn't the problem with EP oils related to the phosphor bronze bushes rather than the clutch itself?

The problem with bronze/copper/brass components and EP90 oils is that if the oil is to GL5 spec, the additives can attack the metal. EP oIls to GL4 spec are fine with bronze/copper/brass parts.

Have used Rock Oil ST 90 in my engines that use LTH clutches and NEVER had an issue. Many many miles covered, no excessive component wear, clutch plates/ steels etc all great. I’ve carried a spare set of LTH clutch plates for 4 years and never had to use them !!!!
Great clutch, best out there IMO.

soullad wrote:Have used Rock Oil ST 90 in my engines that use LTH clutches and NEVER had an issue. Many many miles covered, no excessive component wear, clutch plates/ steels etc all great. I’ve carried a spare set of LTH clutch plates for 4 years and never had to use them !!!!
Great clutch, best out there IMO.

Got to agree with that. I have one in the sidecar some time without any problems.