Cleansing a gear box.

[ukracer]

I say cleansing as it's the inside of a gearbox already off a car not the outside.. Old oil seemed to have impurities in it so what process and fluid do you recommend to flush it thoroughly?

 

[Kram]

Are you stripping it or just flushing and refill?
I'd probably use diesel, drain it out then put some cheap oil to get the diesel out before good oil.

 

[ukracer]

Are you stripping it or just flushing and refill?
I'd probably use diesel, drain it out then put some cheap oil to get the diesel out before good oil.

Not stripping the engine has cost way more than enough...

 

[mr haynes]

Used to use thinners when stripped boxes.
It cleans all the oil and gunk off then evaporates

 

[minimutly]

If you have everything to hand to rebuild and connect it to a running engine then the thing to do is to gunk it, then steam clean it, wd49, oil, then put it back together aand run it. If you can't run it with hours - dont do this!

 

[Matchless]

diesel, then engine oil, then the correct oil..........

 

[frank horton]

depends on mileage.....
often the bit's o metal, crunching gears and brass from the syncro ring form a semi solid in the nook n cranies of the casting.....
by using Diesel or v/thin flushing oils it could disterb them but not enough to free them prop....
u dont need this carp to get in the bearings.....
so for me would be drain the old oil out, put some new g/box oil back in, if it's the old fashioned gearbox say Transit style behind the engine 25% would be enough, if it's the trans axle type u need 50%.....drive a few miles 20) or till warm and drain again...
refilling the proper amount of the correct oil....

 

[CompoSimmonite]

diesel, then engine oil, then the correct oil..........

This is how I was told years ago, when I had a secondhand Saab 95 gearbox for my car, to ensure the needle rollers were clean of debris.

 

[jsf55]

I take it it's a manual box ? if it's not i would just change the filter and add fresh oil too a automatic

 

[Mikes]

Brake cleaner is excellent at removing oil. Either from an aerosol can or a hand spray. Old muck runs out nicely and just leave it a while to evaporate. I normally buy the aerosols that Toolstation sell as it's not too expensive.

 

[Matchless]

best value for this sort of job is the gallon cans, I do like aerosol cans, especially for cleaning all the deposited oil from my ancient motorcycles, usually just before returning from a run at a rally, that way everyone thinks my bikes are oil tight! they are not as most are total loss, no oil is returned to the tank!

 

[gaz_moose]

this on an RB box?
I tend to just pull the housings off and blast everything with a can of brake cleaner.
its worth checking the selector forks aren't cracked when its in bits. and I like putting an additional magnetic drain plug in them.

 

[ukracer]

this on an RB box?
I tend to just pull the housings off and blast everything with a can of brake cleaner.
its worth checking the selector forks aren't cracked when its in bits. and I like putting an additional magnetic drain plug in them.

Yes mate you guessed it.

I will pass that onto him.