Hot gearbox and smell

Hi all,

Am looking for some help please. I recently changed the oils in gearbox and transfer box, and took it on a drive today. Gearbox is running hot, yes I normally get the warm transmission tunnel, but this seems really a lot worse and it started after an hour. Even the handbrake handle is over warm. Can also smell the gear oil quite strong.

I used Motul 300 gear oil in both.
Not sure what’s wrong?

Puma 2012.

thanks.

Did you measure the volume of oil that you put in the transfer box? and not use the filler hole as a level plug. If you used it as a level plug there will be too much oil in there. Inspect the area around the transmission where the dpf on the exhaust is clamped to the transmission, it gets very hot there and excess oil might be venting if there has been overfilling.

Is it the correct oil for that gearbox ?

Don' know which Motul oil the op has used (there may be several types). For the one I looked at on Motul's website, it appears to meet the spec for the transfer box. The spec sheet for it (oil) makes no mention of the Ford / Land Rover spec for the gear box (WSD M2C200-C). But it is the same viscosity and GL rating as the oil I would have chosen for the gear box which does meet the specifications. It is also fully synthetic. So I don't see that as the cause of the problem the op has.

Wimblowdriver said:

Did you measure the volume of oil that you put in the transfer box? and not use the filler hole as a level plug. If you used it as a level plug there will be too much oil in there. Inspect the area around the transmission where the dpf on the exhaust is clamped to the transmission, it gets very hot there and excess oil might be venting if there has been overfilling.

Click to expand...

2.3 in the transfer CSW and 2.4 in the gearbox - which I read from the specs. I can see the transfer case is a bit wet, and a drip forming on the lowest point. The 2.3 I put into the transfer box did actually fill it to the inlet hole. That doesn’t explain the excess heat tho.

2.4 litres in the gear box is for the initial fill when new. 2.2 litres is the service fill, as there will always be a bit in there after draining. (see spec sheets attached to previous post). So you might have slightly overfilled the gear box by about 10%. Don't know if that would cause your problem?

Wimblowdriver said:

Don' know which Motul oil the op has used (there may be several types). For the one I looked at on Motul's website, it appears to meet the spec for the transfer box. The spec sheet for it (oil) makes no mention of the Ford / Land Rover spec for the gear box (WSD M2C200-C). But it is the same viscosity and GL rating as the oil I would have chosen for the gear box which does meet the specifications. It is also fully synthetic. So I don't see that as the cause of the problem the op has.

Click to expand...

Sorry I should have said . Used Motul Gear 300 75W90 fully synthetic and I did research which says it’s good to use throughout the drivetrain, (used in diffs also). Really worried about the heat coming through.

DefenderAdventuresUK said:

Hi all,

Am looking for some help please. I recently changed the oils in gearbox and transfer box, and took it on a drive today. Gearbox is running hot, yes I normally get the warm transmission tunnel, but this seems really a lot worse and it started after an hour. Even the handbrake handle is over warm. Can also smell the gear oil quite strong.

I used Motul 300 gear oil in both.
Not sure what’s wrong?

Puma 2012.

thanks.

Click to expand...

Is the handbrake dragging?

Bit of a long shot here. There was a discussion on here some time ago, concerning a hot hand brake lever. If the earth strap between the transmission and the chassis is not doing its job (corrosion or disconnected) the engine and a lot of other stuff will earth through the handbrake cables. And things get hot. Worth a check.

not sure what gearbox you have but my old 110 has an LT77S and that uses dextron 3 auto transmission fluid, may be worth checking that your gearbox my be the same

OP says it is a puma so it will have the MT82 6 speed cog box.

Wimblowdriver said:

Bit of a long shot here. There was a discussion on here some time ago, concerning a hot hand brake lever. If the earth strap between the transmission and the chassis is not doing its job (corrosion or disconnected) the engine and a lot of other stuff will earth through the handbrake cables. And things get hot. Worth a check.

Click to expand...

100% the heat is being transferred through the floor and onto the handbrake lever. I drove back home yesterday from my holiday and the metal behind the driver's seat, kinda where the bulkhead would have been, is hot - too hot to leave a finger on there for more than 10 seconds.

Wimblowdriver said:

2.4 litres in the gear box is for the initial fill when new. 2.2 litres is the service fill, as there will always be a bit in there after draining. (see spec sheets attached to previous post). So you might have slightly overfilled the gear box by about 10%. Don't know if that would cause your problem?

Click to expand...

So I'm not sure if its the transfer box giving off the heat or the gearbox, but I am going to drain both and add the oil back in and double check my measures. Another guy in another group suggests that overfill could cause oil foaming, which can increase heat, so it could be that, but geez, we only talking about 10% overfill. And real bad heat.

@DefenderAdventuresUK , I'd be very surprised if a slight overfill would cause increase in gearbox temperature to this extent. I've known of others have this problem where local/gearbox earth wire is lose and/or broken...the electrical earth is routing its way back through the handbrake. Have you replaced the earth wire with new? Earth wires are critical and rarely maintained/checked for properly good condition.

Really, you should complete an oil change to both gear and transfer boxes [+ check gearbox breather operation whilst there], remove gearbox earth cable, clean, inspect and check for continuity and re-install. Then, drop handbrake prop end and check for free play with handbrake off.

Then take for a thorough test drive...

eta: gear oil foaming from overfill is nonsense, it is the reverse, any viscous fluid may foam a little when under filled - when overfilled the additional oil will act as a heat transfer enabling the gear box to run cooler...but internal 'box pressure will increase.

v8250 said:

eta: gear oil foaming from overfill is nonsense, it is the reverse, any viscous fluid may foam a little when under filled - when overfilled the additional oil will act as a heat transfer enabling the gear box to run cooler...but internal 'box pressure will increase.

Click to expand...

Not according to this ...
https://www.machinerylubrication.co...d6qMXhZtJ_Yqnft_QZNoiBhJVyf9JjymAwxvHvsfR9qKg

Specifically:
The causes of foaming are many. The most common include - Overfilling of the sump with splash- and bath-lubricated compartments
Foam is an efficient thermal insulator, so the temperature of the oil can become difficult to control.

I'm no expert, but it seems a legit source.

Have you checked the earths as suggested? Do not dismiss this as it could well be the cause of your problems.

Never known any foaming problems with either series or 230 transfer box's. On series gearbox oil would migrate to the transfer if seal failed. Transfer overfilled Only problem over time is lack of oil in main box.
I also say check that earth, on series it is usualy the speedo cable that carry's current when earth fail but on defenders it is the direct to drum hand brake cable that becomes the carrier.