Ferret Scout Car Mk2 gearbox questions

[keithh]

Greetings from sunny Perth in Western Australia

 

I have a few questions on the Ferret scout car gearbox and transfer case that I am hoping someone can help me with.

 

After five hundred miles of driving the Ferret I have noticed that the gearbox oil level has gone up slightly and the transfer case oil level has gone down.

It looks and smells like the SAE 90 gear oil is making its way into the gearbox very slowly.

 

When I had the gearbox out of the Ferret I drained the transfer case and then lifted the gearbox up on its end and let it sit for a week.

No gearbox oil made its way into the empty transfer case so I thought that the seal between the gearbox and transfer case was OK.

While the gearbox was out I changed the output shaft seals, gaskets etc refilled the gearbox with SAE 30 engine oil and the transfer case with SAE 90 gear oil and sat it in the workshop for 12 months with no major leaks.

 

Apart from the shaft seal seperating the gearbox and transfer case is there any other way the SAE 90 gear oil can be moving from the transfer case into the gearbox?

 

I have checked the dipstick for both boxes and the breathers are not blocked

 

Does anyone know the long term affects of the SAE90 gear oil contaminating the gearbox?

I am thinking that the gearbox brake bands and top gear clutch pack might not like it to much and it may cause slippage.

 

From the posts of others I have seen comments about using SAE 30 engine oil in both the gearbox and transfer case.

It is quite a reduction in oil viscosity and type.

You would think that there might be a big increase in wear in the transfer case gears and components?

Has anyone tried this and seen the results over a long period and a lot of miles?

 

The gearbox is currently working perfectly and the Ferret is a pleasure to drive, I had not planned on removing the gearbox unless absolutely necessary.

Having said that I don't want to be sitting on the side of the road far from home with a Ferret that won't drive.

 

Would appreciate the experience of others with these questions.

 

Regards,

 

Keith

[robin craig]

I cant say I know for sure the effects of cross fluid contamination but I do know where it is coming from and that is this section here in the pictures.

 

I rebuilt mine over the winter but the vehicle is a ways from being running.

 

R

[Richard Farrant]

Some Ferrets I came across in service had a common oil throughout, namely engine oil, there was little to distinguish them apart from something painted on. I have no doubt there would a number strike on the Mod. plate to show this. The Fox was also common oil throughout and a similar box, so there should really be no issues using engine oil in the transfer box. If you change both oils and fill with new SAE30 engine oil, you just have to keep a check on levels, but don't worry about cross pollenation

Edited October 15, 2012 by Richard Farrant

[keithh]

Yes I am thinking that changing the transfer case to SAE30 may be the simpler way to go.

I will do some more research on the Fox Box and go from there.

 

Thanks

 

 

Regards,

 

Keith

[Richard Farrant]

Yes I am thinking that changing the transfer case to SAE30 may be the simpler way to go.

I will do some more research on the Fox Box and go from there.

 

 

 

Keith,

I am thinking of where you live, and the temperature. The Fox gearbox is only really different in that the oil runs through a heat exchanger, which must mean that it was thought neccessary to cool the oil as using engine oil in the transfer area proably thinned it out too much. The choice is yours really. The seal renewal meaning box strip down or use engine oil in both boxes. Depends on the amount of use it will get.

 

regards, Richard