Greetings,
just did rear seal on 94 850 turbo, about $ 700-800 approx from independant, came back from long drive about 600 miles in 2 days, found pool of oil under vehicle every day, oil is around where engine meets transmission.
i also have used mobil1 approx every 2 months and volvo filters. I wonder if the synthetic oil effects seals im pretty sure im going to use regular oil or blended. i had a 77 240 andabout 20 years ago,began using the first teflon additive "tuffoil"
and had to replace the oil pump within a year, good luck
frankd
south florida

If the oil is leaking from the weep hole between the engine block & transmissiom, then you have a bad seal! If this is your first seal leak, I think you are lucky since my seal went at 61K on my 95 Turbo. What I understand from the the mechanic that did my seal repair, the problem is a poor original seal design from Volvo. The new seal is slightly modified from the original and I hope is better but I plan on selling my Turbo before it happens again! I won't be buying another Volvo! Try to find a good independent mechanic to repair to reduce the cost. I got my seal replaced for $650 vs the dealer quote of $950.