Gearbox Oil - Penrite pro gear 70w-75.

Has anyone here tried Penrite Progear 70w75 in their gearboxes?

The gearbox is stiff and the mechanic recommends the above but it seems a bit light for the main box?

Penrite recommend PRO GEAR 75W-85. Maybe your mechanic knows special conditions where you are. You have not done an intro so are you in a very hot or very cold area or somthing that could change the base recommendation?

Ah the intro, sorry new to this. Yeah in tassie mate.

Not overly cold here. I'm thinking it's too light. I noticed the Penrite recommendation as well so I might go with that I think.

The car has only done 80000 so it shouldn't be knackered. It's just stiff mainly from 2nd to 3rd. I noticed a lot of people use VMX 80 or VMX 75w-85. I tried the later but it made it worse. It even started to hit the gears so that's being dropped out. I've got the 70w80 but I might change it for the 75-85. The big thing I think is going to the full synthetic.

The 70w75 worries me as it refers to being uses in boxes that use ATF. The patrol doesn't as far as I know, only in the transfer if using auto hubs?

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Not overly cold here.

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Lots of hills though. I'm only thinking that he may have some local experience that the lighter works a bit better. I am assuming he is a good mechanic. I'm a long way from Tas, both in k's and in terrain type, but have used Penrite in everything I have ever owned and gone by their recommendations and never had a problem. Maybe @taslucas might like to jump in here if he is back from WA?:biggrin:

Yes he's a good mechanic and well regarded. He suggested full synthetic and the lowest viscosity due to the stiffness in the box. I got this and showed him and he said that was a good one to go with.

Now I'm wondering if it's too light mainly due to Penrites own recommendation that's all and wondered if anyone else has tried it in a patrol.

I wouldn't know the first thing about oils. I just know I don't want to keep swapping them and tossing $ away :)

I have found that in my gq GL-5 oil tends to be sticky in and out of 2nd when the box is cold. tried caltex and penrite, wont touch castrol as it was worse in other gearboxes i've had. now running nulon as i could get it in a GL-4 think its 75-85 ish. nicer gear change.
when it goes in it looks really thin for a diff oil though.

Well I changed the gearbox oil today and I went with the Penrite Pro Gear 75w85 which is a full synthetic. Just came back from a 60km run with plenty of gear changes.

The differences without a word of a lie truly amazing. The gear stick nearly flies out of my hand doing the changes now. From the moment I drove out the driveway it was very noticeable. That was a cold start and it's was as smooth as silk.

It all started with changing the oil to VMX-M 75w-85 and that felt worse than the dirty oil. So I dropped it a day later and put this Penrite full synthetic in and it's better than ever.

Still an occasional slight crunch shift from 2nd to 3rd but I suspect that's a syncro issue. Strangely the shifts going from 5th all the way back to 1st are perfect all the time. Hopefully over the next week once the oil get right into the gears the 2nd to 3rd issue disappears.

I am honestly amazed by the difference in the feel of the box. I was told it would improve it and I thought that was bullshit. It appears I was wrong. :)

Edit: these were both GL4 oils.