Why wash automatic gear box with automatic gear oil?

[W L Ow]

Could any body explain why the workshop where I send my car to for automatic gear oil change needs to hook up the gear box to a machine that according to the mechanic washes the gear box. Some other workshops do not do that. Is washing really necessary? How often must automatic gear oil be changed.

Thanks

 

[R2D2]

washed out inside you mean?

 

[W L Ow]

Yes, Mr. R2D2

Thanks

 

[R2D2]

Yes its a good idea because when draining gearbox fluid it is really hard to get it all out and with it all the gunk! Flushing the gear box gets the gunk out before putting nice clean fluid in.

 

[MB250D]

The torque converter in an autobox holds a fairly large amount of the old oil, which won't come out when you drain it normally. If you want to TOTALLY replace the old oil with new, they'd need to flush this oil out as well......

 

[silverarrow]

reason to power flush is the same as for using engine oil flush the particles that stay in the gearbox will soon block and stick to the inside and cause all sorts of electrical problems.
are you aware that you can test the gearbox fluid to check it is with in spec the obc will monitor the condition of the oil and gives a value which indicates if a change is needed mbz donot want every body to know this due to the reduction in profit from servicing them and selling recon boxes .

 

[W L Ow]

Dear all,

Thank you for the very technical and informative replies. Cheers