8 replies to this topic

[HarrysMini]

I'm after some advice with regards to cleaning an assembled gearbox. As you can see from the pictures, there is lots of sludgy, dirty stuff at the bottom of the case. I want this to be cleaned out as thoroughly as possible.

I'm guessing it would be unwise to spray the whole thing (including gears etc.) with Gunk and rinse off. Could I just gunk the bottom of the case and drain it out of the sump plug? Leaving the gears in the dirty oil.

 

 

Also, while I'm here, what checks can I do with a fully assembled gearbox to see what the condition is like?

 

Thanks in advance.

 

 

[Craig89]

I'm pretty sure you can clean as assembled gearbox with paraffin, probably best sprayed using a compressor. This is what I plan to do when I get round to it

[HarrysMini]

But do I really want to dry out all the bearings etc.? 

 

Nothing comes up with searching, it seems nobody has ever cleaned an assembled gearbox.

[Craig89]

Paraffin is oil based, its not "dry" as such. It will clean all the grime out and coat everything in a filmy to oil. But like I said I have not done this myself, it is something I read somewhere and seams to make sense to me

[tiger99]

Please do not use paraffin, which contains free water and will leave a film of rust. Instead, I would suggest diesel, which also has some lubricating properties.

 

But I am not sure about washing it with the bearings etc in situ, and think that a full stripdown would be better, as you will not want to wash dirt into the bearings.

[The Matt]

Make a start on it with a load of cloth/rags.  Soak the rags in derv (as above) or maybe thinners?  Just be careful with your skin if using thinners, so wear gloves if possible.

 

Don't spray it, wipe it/brush it.  Spraying the dirt around the box will just make it harder to get it all out.  Wipe/brush/soak up with kitchen roll

[Guess-Works.com]

If you do insist on 'washing it out' while still built, remove the speedo cover so that there's a big hole for all the crap to come out of... and wash down so the gearbox is standing on its end speedo end down.

 

As has been mentioned above... avoid ANY cleaning products which involve water, this includes water soluble parts washer fluids. I use a petroleum distillate solution in my parts washer, and I would steer clear of fluids which evaporate off, thinners, clutch brake cleaner etc... You need the internals to stay 'wet'

 

Tho' for peace of mind, I'd strip it.

[HarrysMini]

Thanks for the comments guys. I'd love to strip it, but I don't have the time, the tools, or the knowledge. 

The reason I wanted to clean it as much as possible is because when I removed the bearings from the engine, it was obvious that it hadn't had many oil changes and there was a lot of debris in the oil. 

 

Maybe I'll just clean out the bottom of the sump and leave the gears etc. as they are.

 

What checks can I do to an assembled gearbox to try and determine what condition it's in?

[A-Cell]

Send it to Guessworks if you want it done properly and peace of mind.