Chrysler Repair: Transmission oil pan install: 10 T & C

Question
I've 2010 Chrysler TC limited 4.0L with 103 K km on it. Gone 4a mechanic 4 maintenance from about 2 weeks. He did transmission oil change, but the pan started leaking. I went back, he did it again last week, but it is leaking. On this second time he told that he is using silicon mastic on the cover before fixing it  with the bolts. When I asked him why he does use a gasket he told me there is no gasket 4  this, at the dealer they have a special cementitious material that he can't get it which he is replacing with the mastic. Now failing twice I got worried if he is doing good job or he has done a problem with the cover or the bolts. Please advice. Thanks in advance.

Answer
Hi Nabil,
I checked both the 4- and 6-speed automatic transmission oil pan remove/replace information.
Both use a 1/8" bead of Mopar ATF-RTV (MS-GF-41) around the edge of the pan and under the heads of the bolts. The 4-speed bolts are tightened to 165 inch-pounds, but the 6-speed bolts to only 53 inch-pounds.
I would believe that the parts counter at the dealer would sell the ATF-RTV silicon rubber sealant. My manual covers the 2009 model year but I believe it would apply to you 2010.
Please read the PS below and respond to it.
Thanks,
Roland