I have a pretty new wheel and whilst transferring the cassette to a different wheel, I noticed a massive build up of grease on the free hub bodyat the back of the cassette. where did this grease come from? I'm assuming from inside the freehub body, but how did it get onto the outside?

Whoever put the cassette on the wheel put grease on the splines of the freehub body; seems like a good mechanic to me, although s/he might have been a bit lazy and put a whole bunch on.

Step 1: clean.

why would you want grease on the splines of the FHB?
chain lube manages to work itself onto the splines no matter how meticulous a cleaner you are.

Is this grease that oozed out of the inside of the freehub? I'm guessing you just need to wipe it off.

Prevents corrosion between metal-metal contact. Keeps moisture out between metal-metal area (this might not apply for people riding in either dry areas or fair-weather riders).

As to the second part your statement, this is not true--for example, people using SRAM Red cassettes.

Later.

Almost forgot, it's also important to grease the threads of the lockring before putting it on.

ah, good old one-piece red cassettes.

all my FHB splines and lockring threads are covered in some mixture of chain lube and grease.

Wow, how much chain lube are you using? It's supposed to go on the chain, not the cassette right?

I usually put a drop on each link end. Nothing more, nothing less. I run it in then wipe it off. The only cog with any lube on it is the one that the chain is running on when I lube it, and only a little. I'm sure some gets on the cogs and hub eventually, but only a little.

A friend of mine though thinks the stuff is gear lube and liberally coats his entire cassette. I think he's a few cards short of a full deck...

It's just really wet here.

whatever you do, don't put grease inside the freehub.

i really think it is oozing out from the inside. I am the excellent mechanic who put grease on the outside and the grease i used was wldtite teflon grease which is red. the oozing big slops of grease is white/snot colour. not bogey green but the sloppy stuff you blow out of your nose when you have a runny nose but thicker and gloopier.

with aluminum freehubs, i stick a bunch of phil wood grease on on the splines before i stick the cassete back on. it keeps it quiet, even if the freehub is notched