Manual trans flush

[ftpiercecracker1]

Hey guys, I'm finally getting around to changing the fluid I'm my ax-15. I have 4qts of Redline MT on order, but before put the good stuff in I am going to flush it first.

 

Can I use motor oil to flush the trans? If so does it matter what kind?

 

If not, what can I use to flush it?

 

Thanks

FPC

[ParadiseMJ]

You can use oil, thin oil or oil mixed with MMO, Seafoam, etc..  Put it in, drive around the block a couple times (as opposed to out on the highway) and then drain it.  Then I'd let it drain for awhile.  My father used to use kerosene to flush everything petroleum related.  He'd make sure it had all drained out  up on a ramp 

[Megadan]

Cheap clean oil should work just fine to help flush out metal particulates.  I drove my truck around until the trans was hot, and opened the fill and drain holes and let it drain up on ramps for a while to let as much flow out as possible.  I put the drain plug back in and filled it with a couple quarts of cheap motor oil I had laying around and then drained it again to push out as much of the fine metal filings as I could (Brand new transmission break in, so I had plenty).  I then filled it up with MT-90.  Done.

[ftpiercecracker1]

Thanks a lot fellas. My current trans fluid looks and smells like diarrhea, so it needs to be flushed multiple times. I just hope the redline stuff will get third gear to quit grinding.

[91Pioneer]

I did a drain and refill with my BA10 with horrible nasty (possibly original) fluid in it, I didn't bother flushing it. It felt a lot smoother after it was done. Flushing it probably is not necessary but if you are going to do it, if I was you, I'd just refill with cheap stuff, drive it for a week, then drain it and put the good stuff in there.

[A-man930]

^this. Be careful what you dump in that Trans. The synchros are soft (brass.) I run a synthetic engine oil in mine.

[Megadan]

^this. Be careful what you dump in that Trans. The synchros are soft (brass.) I run a synthetic engine oil in mine.

He is filling it with MT-90, but 10w-40 is the oil recommended by the factory for the ax-15, so there shouldn't be any issues using it as a flush.  Doing a flush with MT-90 would be a silly expensive way to do it lol

[88mjblue]

What about a few ounces of ATF as a flush? Good detergents in there. Anybody ever do this?

[Megadan]

What about a few ounces of ATF as a flush? Good detergents in there. Anybody ever do this?

ATF is awfully thin stuff.  I would just stick with a good synthetic 10w-40.  Synthetic motor oils tend to have a high detergent level as well, and it would be more appropriate for this given application.  If you have ever seen the inside of a high mile engine that ran synthetic oil most of it's life with regular changes, you would be amazed at how clean the inside of that engine will be.