Oil for transfer box

[Jules59]

Can someone please confirm what oil is recommended for the transfer box on the 4WD Bongo.
I know its EP90 GL5 for front diff and standard rear diff (EP90 GL6 for rear diff with LSD), but I cant find the transfer box oil specifically mentioned on the info sheets etc.

[scanner]

I don't think it uses oil, seem to have read somewhere on here that it is "filled for life" with a special gel/lubricant stuff.

Or maybe that's the centre diff??

[rita]

Hi Jules,
If memory serves me correctly I think it is GL5 1.6 Litres

[Rhod]

According to the Service Manual (Pg177): "Pure long life gear oil (SAE 75W-90) - to refill the transmission oil, transfer oil". It doesn't seem to give an amount however.

[Jules59]

I don't think it uses oil, seem to have read somewhere on here that it is "filled for life" with a special gel/lubricant stuff.

Or maybe that's the centre diff??

Unlike some other 4WD card (eg Freelander), the Bongo's viscous coupling unit is located inside the transfer case on the end of the front prop shaft drive (as far as I can tell from the Lush Projects diagrams). The viscous unit does away with the need for a centre mechanical diff locker and you are correct in that (AFAIK) is filled with a gel which allows slip at low prop shaft rotation differences to prevent "transmission wind up" but locks up when rotation differences increase when a wheel is spinning to maintain torque through to the other axle. However the drive to the front prop shaft is transferred sideways from the gearbox output shaft via a chain which requires lubrication inside the transfer case. The question what is this lubricant?

[Jules59]

hmmm, 3 different answers so far . Im none the wiser really.
I had already put EP90 GL5 in my transfer case before i realised it wasnt specially mentioned on the Bongo Fact Sheets. Im just a little worried that Ive done something bad.

[waycar8]

if you are talking about the atf oil then its, dextron III
or for the manual transmission its SAE 7.5W-90 (GL4)

[Jules59]

if you are talking about the atf oil then its, dextron III
or for the manual transmission its SAE 7.5W-90 (GL4)

No, Im not talking about the ATF.
I am talking only about the Transfer box (aka transfer case) on a 4WD with automatic gearbox.

Im also NOT talking about the lubricant for axle diffs, manual or auto gearboxes, LSDs, CV joints or anything else on a bongo that requires something slippy.

Has anyone ever drained and refilled their transfer box ? If so with what ?

[waycar8]

I was under the impression that its a sealed unit ie the viscous coupling, that is the transfer case/box? isnt it? as someone has stated already that its filled with gel?, not sure myself but thats why I mentioned what oils for the ATF ect so if anything woudnt any oil be the same through the autobox?

[Jules59]

I was under the impression that its a sealed unit ie the viscous coupling, that is the transfer case/box? isnt it? as someone has stated already that its filled with gel?, not sure myself but thats why I mentioned what oils for the ATF ect so if anything woudnt any oil be the same through the autobox?

Hi
I agree, all the viscous couplings that Ive seen are sealed units (Freelanders). But the Bongo transfer box does appear to have very obvious drain and filler plugs.
When I drained it - dirty looking oil ran out - certainly not a gel and definitely not ATF. In my experience (which I admit is entirely Landrover based) the transfer box doesnt share the same oil with the attached gearbox be it manual or auto.

Im rather confused right now.

[missfixit70]

My Sierra 4x4 had a separate transfer box, fuctifican remember what went in there though.

[Jules59]

Further to this; on the Fact Sheet "Service Schedule" it says change Transfer Case Lubricant every 50,000 km. But unfortunately it doesnt say with what though.
Logically it cant be any weird silicone gel stuff becuase you simply cant buy it, so it must be something readily available like EP90.

[missfixit70]

Quick search on transfer & oil revealed -
http://www.igmaynard.co.uk/bongo/forum/ ... il#p366241
http://www.igmaynard.co.uk/bongo/forum/ ... ansfer+oil

Question asked & answered many times before, the search function is your friend

[Jules59]

Quick search on transfer & oil revealed -
http://www.igmaynard.co.uk/bongo/forum/ ... il#p366241
http://www.igmaynard.co.uk/bongo/forum/ ... ansfer+oil

Question asked & answered many times before, the search function is your friend

The fact that the questions get asked so many times indicates there is a lack of "sticky threads" and /or inadequate info in the Fact Sheets.
Searches are a variable feast and work best if you know the answer in the first place.
If I type in "transfer box oil", your thread comes in at number 14 which is not great for information so fundamental to Bongos.
Clearly the Fact Sheets need updating, and it would have saved all this fannying around if they were more informative. How do we get the Fact Sheets updated ?
Other forums have "sticky threads" which do they same as Fact Sheets but get updated more frequently. How about starting some "Sticky Threads" ? See how its done on Briskoda.net (one of the best autoomtive websites in the UK - IMO ofcourse). What do the moderators think?

[Jules59]

Oh bye the way Kirsty.
THANKS for your help