Gearbox flush

[igotta40]

I have a 4 speed that has been stored (indoors) a long time. Before I put it into service, I want to flush out the old lubricant and get the insides good and clean before I introduce the new oil. Any suggestions what to use? Kerosene? Mineral spirits?

 

[charliemeyer007]

Yea those would work so will diesel. You could drain and flush it now while out of the rig. But nothing will power wash the inside like driving. What is it like 4 quarts of syncro oil. Valvoline is like $11 a quart. Put in 2 qts top off with solvent and go for a good drive, then drain and refill with the syncro gear oil.

 

[Pighead]

Any suggestions what to use?

I like the Marvel Mystery Oil for almost everything. It probably wont hurt and it just might help.

 

[Paul_A]

While your at it, get a magnetic drain plug to collect the shavings.

 

[SteveH]

If using diesel, I would only add a small amount - several ounces. You want gear and bearing protection on your test/cleanout drive, and too much diesel/kero will compromise that. Or, just make the 'test drive' short and easy. Sitting inside, the trans shouldn't be full of water and sludge, so don't overdo the cleanout.

 

[CloudForestCruise]

Be careful. The gear oil is there for a reason. I would change with the cheapest oil you can get. Run it for 100 miles. Then change it again with good oil. Heat and agitation will do the cleaning that is necessary.

 

[brian]

i would open it and take a look in inside before going crazy.....you might be surprised.... a drain a fill might be all it needs.
This one sat idle for 50 years.

 

[igotta40]

Yes it will not be run with solvent inside, just a quick flush & drain, refill, dump again and fill for good. Good responses!