My Yota with a 22r was worked on about 3 weeks ago to have bearings put in it as well as seals. It wasn't a week and I noticed the new rear main seal was leaking. They put a new one in it at no charge. I picked it up today and noticed after driving that the rear main seal was leaking again. Why would this happen?
Some possibilities - To much end play in the crankshaft. The crankshaft has shims,and if they got back in the wrong spot,or the end play was not checked,this could cause a leak. Was the same crankshaft used?? If a different crankshaft was used,it should have been line bored. The bore on the end of the crankshaft where the seal rides could be wore or have a burr in it causing premature seal failure. Check for a oil pan gasket leak,rocker arm cover leak. There is a plate assembly around the rear main seal,the bolts need to be torqued and sealer used. there is also a gasket around the assembly that could be leaking.