Is it safe to use an Oil additive in the STR to stop a leaking rear main seal?
 

Lets try this one more time,..alright, I wish some of you all wise ones on here, would please care to chime in and give me some insight on whether its advisable or not to use an oil stop leak product, in my case "BARS REAR Main SEal stop leak" http://www.barsproducts.com/tech/1050_tech.pdf. In addition to the additive I was going to use HIgh Milage MObile 1 10W 40 Full Synthetic, instead of what I have been using which was 5w30 Full Synth. I'm guessing since I have 90K miles on the STR, 5W30 has become way to thin for the seals to hold up :icon_emm:,

Thanks to all for there suggestions,

I am not a fan of using any type of additives to seal anything in my engine. If its made to seal the leak how does it know whats the leak and whats just normal. How bad is the leak?? Do you have any pics of the leak?? If its just sweating out I would not even worry about it for the time being and just check the oil at fillups. If its bad your better off just getting it replaced. Its probably alot cheaper then if the bars leak swells all your gaskets and makes you end up needing all the gaskets and an engine rebuild. I would actually do that job myself but it is pretty in there since you have to pull the trans back to get to it. In the military we classified leaks and if its just sweating we dont touch it.

..Thanks Vance for your quick response back, When I took it to the JAg mechanic, he removed the cap on the bellhousing, and swipe inside with his finger, there was oil, most likely engine oil, it wasn't tranny fluid because the zF fluid has a horrid smell to it,lolz, but yeah I noticed it was seeping out moderately, I'm like 3qts of oil low right now. The plastic pan is a bit soaked with the engine oil, plus I have the A/C compressor oil leaking slight as well, which is a common problem on these Jags :icon_doh:. About using the stop leak oil, I totally agree with you about it swelling up the seals and gaskets, not just the REAR Main seal, but other stuff as well and in the long run I might encounter more problems, thats another reason I want to avoid it, I might as well just use a 10W40 synthetic Oil thats for High Mileage by MObile 1. Heard it has extra conditioners etc..... which might help slow it down or who knows cause a temp bandage from leaking oil :icon_shrug:.

Cheers!

Wow if you are that low I would definitly try and get that fixed asap. Too bad you arent closer I would help you out and do it. The seal cant be more then 20 bucks its the labor that sucks. I would definitly not risk the bars leak. Running the 10W40 I'm not really knowledgable about oil additives and such as I just run what the manual says. I think since its a heavier weight I have heard that helps when you burn oil not sure about leaks though.