Grease melted after Porlock Hill!

[Arripay]

Parked up in a Porlock campsite immediately after coming down the "Hill", could feel the front wheels giving off a fair amount of heat.
Few minutes later, some steam started emanating from the speedo drive on the grease cap, then grease started dripping out the hole, clucking bell
Guess temps carried on going up, suppose should have carried on driving for a bit to let everything cool down.

Time to refill the cap with some maybe more expensive high melt grease

[itchyfeet]

Sounds to me like water got in your grease cap through the speedo cable hole, it should have a blob of sealant on it but most no longer have.

The disk is the hub so gets very hot with prolonged heavy braking and water in there will turn to steam and push out some grease.

The grease may not have melted but I would remove hubs and re grease bearings as a minimum.

[itchyfeet]

Also the fact you saw it implies you have no hub caps so you really need to seal up the speedo cable hole after inspecting and regreasing.

[937carrera]

Molybdenum disulphide grease should be more than sufficient for the job

[Mr Bean]

In my early days of camper van use I ran a what we figured as hot Frod Thames with a three speed column change and a zephyr Six diff. The high first gear required Porlock Hill to be addressed in reverse gear.

These days I don't have the bottle for Porlock hill or the Great Orme for that manner due to a possibly irrational fear of brake failure. So glad to have found alternative routes.

[bigherb]

Molybdenum disulphide grease should be more than sufficient for the job

Moly grease is meant for sliding surfaces, not wheel bearings, lithium-based greases should be used.

[937carrera]

Ooooh , a grease thread

This is what I was thinking of Bigherb. It is a lithium base grease to NLGI grade 2, rather than an NLGI grade 1 grease which I understand some moly are and consequently too thin for automotive bearings. It is good for CV's too

[bigherb]

Just use the correct grease. Moly grease can cause roller bearings to skid, it is used in CV joints because they are not true rolling they slide as well.

[ZsZ]

Seal the speedo drive with some RTV sealant as factory manual says, then grease cannot drip out