First,

How do they change the filter in the transmission with their push pull machine?

I think their machine is just to save them time and the trouble of removing the transmission pan and has no advantages to you or your transmission.

Jiffy Lube doesn't charge much for their services so they have to make up for it in little time expended per vehicle, high volume and low pay for their so called mechaincs.

You might ask them what is the torque spec on the MB transmission bolts and if they don't know, if they can look it up. If the bolts are torqued too tight, the rubber gasket can be damaged.

P E H