EP90, with just a cheeky hint of engine oil

[daverclasper]

Hi. I topped up engine and tranny and by mistake (well it is the same colour) added about a small cup of left over 20/50 into my EP 90 supply can (about 4.75 litre's).  I would think this is ok to still use (as tranny oil😃), though thought I'd better check.

Thanks, Dave

[Clive]

Should be fine, certainly for the gearbox (which some people insist on using engine oil anyway) and the diff should be OK, only a small dilution. No warranty implied or given.....

in fact I saw that most diesel engine oils meet GL4 spec anyway. However, that won't include EP which is required for the diff. (but as above very small dilution)

[NonMember]

6 hours ago, clive said:

the gearbox (which some people insist on using engine oil anyway)

Including the factory on some later models, though not the Vitesse. The EP additives do benefit the gearbox a bit, in that the maximum torque you can put through it is higher with EP oil. But as you say, it's a tiny amount of dilution so nothing to worry about.

[Clive]

12 hours ago, NonMember said:

Including the factory on some later models, though not the Vitesse. The EP additives do benefit the gearbox a bit, in that the maximum torque you can put through it is higher with EP oil. But as you say, it's a tiny amount of dilution so nothing to worry about.

Please elaborate? I thought all te small chassis stuff was ep80 fresh fill/90 top up?

I think the LT77 boxes were an oddball, didn't they go to ATF or something?

[NonMember]

2 hours ago, clive said:

Please elaborate? I thought all te small chassis stuff was ep80 fresh fill/90 top up?

I think the LT77 boxes were an oddball, didn't they go to ATF or something?

I think it was probably only the LT77, rather than any version of the SC box. Yes, at one point they did go ATF, which is crazy, but before that they specified engine oil, as the EP80 made the shift too heavy. Ultimately the LT77 is so overrated for a TR7 engine that it matters very little how poor the oil, but most of the later SC applications were pushing it a little so the extra torque handling was needed. I think Rover changed the PG1 spec from engine oil to EP90 to cope with the M/T series turbo applications.

[daverclasper]

Thanks a lot for that your info. Has put my mind at rest.

Dave