Postby Hasbeen » 06 Feb 2015 12:42
I filled my box with Penrite manual transmission fluid about a year or so ago. It was slightly more noisy immediately after putting it in, but that disappeared in about 50 Km. It does give great gear changing.
When I bought the car I used Penrite EP 80 & STP in the diff. That was 14 years & 70,000Km ago. Yes I know I'm slack & should have changed it, but I hate pulling the back cover off an oil tight diff, & sucking the oil out of a diff is worse than leaving it there, it just stirs up the muck on the bottom. Besides my magic STP will keep it fine.
Now sit down folks, & I'll tell you a tail.
When I bought my Lotus 20, it was close to the Bathurst easter meeting. While checking everything we magnafluxed the crown wheels & pinions of the Hewland transaxle, & found cracks in the root of 2 teeth of the high ratio crown wheel. I could not get one from the UK in time for Bathurst, & nothing was going to make me miss Bathurst with my new, [to me] open wheeler, so we stuck it together & crossed our fingers it would hold together.
As it was a crash box, with the diff in there, I added STP as usual. DON"T EVER USE STP IN A SYNCHRO BOX, IT DESTROYS THE SYNCHROS BY ELIMINATING THE FRICTION THEY REQUIRE.
I got through Bathurst, & changed to the low ratio crown wheel & pinion. Out the back of the shed was a damp area, with very long grass, 4 Ft or so, fenced off from the rest. It was my dump, & I threw the old crown wheel & pinion out into that grass.
9 months later, with the next Bathurst easter approaching, a very good mate rang me. He had raced an MG A when I was racing my Morgan, & then we both moved to Lotus 20s at the same time. We often helped each other out loaning bits. He wanted to know if I had a spare high ratio diff available. His was shot, & without one he could not go to Bathurst.
I told him of the one in my soggy long grass, but thought it would be rusted away by now. He was desperate. He came over on Saturday, & took well over an hour to find both bits, half buried out there.
To our amazement there was no rust anywhere. The STP had totally protected that metal all that time.
To prove how we are often overcautious with parts, he did Bathurst & another meeting on that diff, & it was still going strong.
So, if you want to stop your car rusting, forget that that wax oil & other stuff, just smear it with a mixture of EP80 gear oil, & STP. Not only will it not rust, it will probably look so dreadful, you could forget insurance, no one will pinch it, I'll bet.
Hasbeen