Thread: Will thicker oils make for a quieter gearbox/drivetrain?

Originally Posted by pfillery

The old trick of thickening the oil with sawdust to quieten a noisy transmission springs to mind.

Any thoughts?

Banana peel was the go in my neck of the woods. Not sure that I would recommend it though......

You can get 140 grade oil for the transfercase makes a big difference to the noise but it adds to the drag abit. I have used it in both diffs and the transfer case and swivel joints and it does slow the leaks too

Originally Posted by pfillery

I was contemplating gearbox, transfer, diff and overdrive oils. Will the use of a thicker/heavier grade of oil, if such a thing exists, or alternatively oil additives that thicken your oil, make the drivetrain better and quieter? The old trick of thickening the oil with sawdust to quieten a noisy transmission springs to mind. There are several additives that make the oil thicker to reduce oil consumption in an engine and I wondered if something similar might reduce noise and wear in drivetrain components or if there is a better thicker oil that will still do the same job as the 90 grade recommended but may leak out less, not heat up as much and not vapourise out of an overdrive. Any thoughts?

I have a bottle of LUCAS HD Oil Stabilizer sitting in front of me now.
"(cools & quiets engines & gear boxes)"
I bought it to oil my motor bike chain, coz it is sticky stuff.
Will it do the job 4 U - NFI, (google it).

Originally Posted by THE BOOGER

You can get 140 grade oil for the transfercase makes a big difference to the noise but it adds to the drag abit. I have used it in both diffs and the transfer case and swivel joints and it does slow the leaks too

When you say it adds to the drag, is this noticeable? When you are pulling 2.5 tonnes of land rover behind a holden 6 there would presumably be things giving more drag than this?

I'm about to put a fairey on so would like to look at all this at the same time.

Is it bad at all to put more oil than the "level" in the gearbox and transfer? Some say extra oil in the 186 when using in a landy helps reduce the pressure drops when using off road, maybe the same applies to the gearbox and transfer as well as the fairey? Pity the fairey doesn't share oil with the transfer the same as the roverdrive does. Might be a possible mod idea there?

I havnt found it noticable but I still have a rover 6 in mine but some people on here have said it is Over filling a little cant hurt but if you put to much in the oil can foam and doesnt work as well

I know we are discussing series boxes, but you need to be careful which type of box you use a thicker oil. e.g. 90 EP will kill an LT95 box.

Originally Posted by Lotz-A-Landies

I know we are discussing series boxes, but you need to be careful which type of box you use a thicker oil. e.g. 90 EP will kill an LT95 box.

But a 75W-90 would be fine as it's the same viscosity as a 15W-40 engine oil

Depending on the chemistry, some of the bronze components may not be ok, however.

pfillery, whatever you do, don't use something like Lucas oil stabiliser to 'boost' and existing fluid as you will dilute the balanced additive package inherent in an existing oil.

If you really want to use heavier fluids (and FWIW I use an 80W-140 in my Sals rear diff and a mix of 75w-90 and 80W-140 in an LT230 t/case as 75W-110 lubricants aren't readily available in Australia. They are from the same blender so their additive chemistry is compatible)

I overfill the rear diff deliberately, overfilling (within reason) isn't likely to cause a problem.
Have a look at any high pinion diff, the filler is high so the pinion can get lubricated properly and the majority of the crownwheel is immersed in oil. (Patrol front diffs take something like 5 litres as the axle tubes become flooded too)