Second hand auto box checks?

[Stevehall]

Hi all, I have a 95 N reg 2.5D bongo camper. I've recently noticed my automatic gearbox is making a burning rubber smell, and smelling the dipstick is a burnt smell. I'm presuming the box is worn out, so I'm going to buy another cheap bongo (as i need quite a few other parts too) subject to driving and the dipstick not smelling burnt.

Are there any other checks I can do to ensure the box is good at this time?

Thank you for any comments/guidance
Steve

[Stevehall]

A further thing I should add, is the vehicle hasn't been used for about 3 years, so I changed the oil and cleaned the filter beforehand.

[g8dhe]

Have you drained and replaced the ATF from the gearbox as well ? Remember there is a lot of oil held in the Torque convertor as well.

[Stevehall]

Hi, I sucked out 3.5 litres through the dipstick. Removed the sump and filter which gave me another 1.5 litre. Then I connected a hose into the oil pick up, and ran it, sucking up 3.5 litres of new oil, whilst also despencing 3.5 litres. My figures may not be exact, but should be close, as I did measure it. So that's a total of 8.5 litres. I then cleaned out the filter with brake cleaner, blew it off with high pressure compressed air, refitted all parts, and topped up with oil.
I used dextron 3 plus atf.

I didn't know if being stood for a few years would have something to do with the smell, and using it may improve things? It doesn't seem like it's slipping, and changes gears ok? It's just starts to smell when under heavy load in 3rd or top gear (not 100% sure of the gear at the time)

Thank you Steve