MGB Register Forum

I am in the process of fitting new discs to my 71 GT. When I look for information about cleaning the wheel bearings there are so many conflicting pieces of advice. Use paraffin (which is very hard to obtain now), use petrol, don't use petrol. just wipe old grease off etc. the list goes on. What is the best and most effective solution?
Thanks
David

Hi David,
if the grease in the bearings looks reasonable - i.e. not full of grit or burnt/black then I can't see why you would wash it all out. However, if the grease was like that described above I would suggest new bearings would be a good plan! In other words if the grease needs replacing then the bearings probably need replacing also.
If you want to remove the grease just to check the bearings for wear, roughness and any discoloration due to overheating etc., then petrol or paraffin would suffice. I still use petrol for cleaning - out in the open air, away from anything electrical, and wearing nitrile gloves. It evaporates really quickly which paraffin does not do. Paraffin can usually be bought in DIY stores in small containers should you wish to use that.
Hope this helps,

Ian F.

White spirit also works well and is easy to get from anywhere that sells household paint. Buy some cheap paint brushes at the same time!Brake/carb cleaner is very effective and the aerosol jet effect really penetrates. Bit expensive from local shops but cheaper if bought from wholesalers or on-line.
If you change the bearings, and don't want to do the job again in a year or so, make sure you use OEM quality bearings (side set is part No. GHK1005) and not the cheap aftermarket ones (with the same part no. but with a Z suffix). The car would probably have been fitted with bearings made by RHP, Timken or SKF when new, so ask to make sure. The bearing set comes with a sachet of the correct grease.

Be aware that paraffin is also abrasive. You may be able to get your paraffin from a garden centre as it is quite commonly used in green house and cold frame heaters, though it does contain some mollasas (I have no idea of the reason why).

Many years ago we used to clean wheel bearings using diesel. Diesel cleans it all out o/k but is very prone to giving you diesel rash or dermatitis as we now know it. Blowing the diesel out afterwards with an air line was also done back then but not really a good idea as we now know as-well.

What would I do?

clean off as much as possible with rag and then use a good degreaser and wash it out and repack with new wheel bearing grease, there is though an art to repacking a taper bearing by hand, keep pushing it through with your fingers until it starts to come out the other side, do this all the way round.

Paraffin is pretty easy to find in the garden centres as it is used in greenhouse heaters. It does however now usually have some molasses in it I haven't a clue why it is. Remember though that paraffin is slightly abrasive.
Many years ago we used to use diesel to clean bearings that not being abrasive, but as we now know is not a good idea as it can cause all sorts of health problems the old diesel rash as it was called being one of them.

If you do use paraffin then perhaps use some degreaser after that and rinse it away with clean water. You will of course need to then dry it and then repack with fresh clean wheel bearing grease.