Since my tans fluid leaks may now be mastered, I am getting optimistic about the last leak that bothers be quite badly and that is rear main seal leak… I had a new 2 pieces RMS installed 2 years ago (by expert mechanic) and it made absolutely no difference… leak leak leak… that diminishes somewhat during the season when I drive the car often, but always a trace left here and there…
Anyone has an opinion about RMS repair polymer products, such as this one:
http://barsleaks.com/product/concentrated-rear-main-seal-repair/
Sorry if that was discussed already but I looked through the forum and did not see anything,
Thanks in advance.
This is a mechanic in a can. More often than not something like this won’t work. But you know what? Always do the cheapest and or easiest thing first. So go ahead and try it. It’s either going to work or it’s not. Seems to me the product will try to swell the rear main seal along with every other seal the oil comes in contact with. You’d only be out the cost of the product.
While standing in front of the product, I had just about the same thinking as you… I should try and see, if not work then I only loose a few $$… well unless it rapidly & irreversibly destroys/eats the seals/gaskets … hence this thread for second opinions.
The add claims the rms repair will not only swell seals/gaskets but will build polymer around them including in the groove worn in crankshaft by the rms, and that makes a lot of sense to me so I am really tempted to try it, even if it was only once…
Yeah… and if it works and I like it, what if the polymer agglomerates in other areas where it is not desired and/or forms chunks with time??
I will sleep on that a few nights I guess.
Or you could just replace the main seal. it’s a task you can do at home and not that difficult. You have to drop the steering linkage down. Then remove the oil pan. Unbolt the rear main cap and use a small punch to start driving the upper seal out. When the other end is exposed grab it with pliers and pull it out. To install the new upper seal put some grease on it and slide it back in. MAKE SURS THE SEAL IS FACING THE CORRECT DIRECTION AND ISN"T BACKWARDS. Clock it at about 2:00 so it’s not even with the main cap. CHECK THE BOTTOM GROOVE ON THE MAIN CAP. THERE IS A LITTLE NUB THAT WAS USED FOR HOLDING THE ORIGINAL ROPE SEAL. THAT NOB NEEDS REMOVED SO IT DOESN"T CRUSH THE NEW SEAL. A little silicone on the ends of the seals and reinstall the main cap and torque to spec. New oil pan gasket and reinstall the steering linkage and your done. About a two hour job.
The mechanic that replace the seal should have removed the nub for the new seal. If he didn’t then that would be the source of the leak and miracle goop isn’t going to fix it. Think of all the places that oil goes in your motor. Do you really want to risk that just for a rear main seal leak? I’m sure their is u tube videos on how to do it as well. The two piece seal can be a pain to get to seal and don’t be surprise if it takes a couple of attempts before you are successful.
Thanks Brian for taking the time to write this procedure, actually does not seem too bad written this way… before the last sentence of course.
Regardless, I searched HowTo’s on Utube & found enough to better visualize the task and it sure is doable.
However, I would be the 3rd attempt, if I count my expert mechanic (knows his stuff inside out) who replaced an already replacement 2 piece seal… so I am far from the rope and I would be astonished if that knob was still there! (But of course mistake is always possible).
Also, my guy kind of told me that there was metal wear where the seal rubs… so the “miracle goop” would take care of that if the claim is true.
At the same time your’e so right, the oil touches so many parts in there Ahhhh!
And to wrap things up, I realized, while searching the net on this subject, that I am most probably using a wrong engine oil that does not contain enough ZDDP…
OK small headache for now, so I guess I’ll sleep a few more nights on that!
I would replace the rear main and either use an oil with the ZDDp, or use the Zinc Additive. You can also use Rotella as it still has a high amount of ZDDP, as does Harley oil. Rotella being the cheaper of the two. The 400 in my old LTD used to leak if it sat for extended periods of time, but if driven regularly, would quit.
Over 20 years I’ve had the rear seal on a 390 changed 4 times. Usually good for awhile but then the leaks start again. The first three times I had different people change it and the last time I did. The nub is gone and I’ve follow the offset and silicon at the tips. What I wanted to mention is all times on this engine two more main caps had to be loosened to get a little play on the crank to drive out the top of the seal. The last time the leak started I put in a quart of Lucas Oil Leak Fix and after two oil changes no more leak. Two summers now and still dry.
The hole left behind after removing the little “nub” should be filled with a dab of black silicone.
Actually it’s a sharpened pin.
And there is no “miracle goop” that will repair physically damaged engine parts. Companies have made $millions on so-called “overhaul-in-a-can” products for years.
Would you mind saying which engine oil you use? ZDDP content? Mineral or synthetic?
10W40, conventional, high zinc. Usually get Brad Penn, Lucas, or Joe Gibbs whatever Summit has on sale.
Thanks.
I’ve got this same project on the books for my '70. Started leaking when I switched to synthetic and started driving it in a month more than the PO did in a decade. Not a big deal.
UPDATE: testing showed dripping was solely occurring between and/or behind the 2 thin block plates (linking engine & transmission). Some wetness/dirt near rear intake and below heads on the front (behind alternator and close to/on fuel pump), but no dripping at all. So RMS and/or flexplate bolts for sure. Oil dripping caused a spot (in plastic container) of roughly 2” after few days. Not a major leak I think, but still too much (a car is a self contained unit that should remain so, at least IMO).
From PO info, it is believed that this engine has never been rebuilt nor opened, so flexplate bolts would be surprising.
New 2 piece RMS was installed (for at least the 2nd time) 2 years ago by an expert mechanic with no change i.e. same amount of leakage before and after. He had showed me wear in a part that he removed while installing, that must have been the bearing case. So not sure at all I could do better if I tried myself.
For these reasons, I decided to give a try to the RMS Repair that is claimed to swell RMS (and other seals and gaskets) as well as build polymer in the worn bearing case and/or crank shaft. Drove the car twice (20 & 30 miles) since then and significant improvement: dirtied the trans pan during the 1st ride but then only one drop formed under the bellhousing (did’nt fall for the next 2 days) AND no spill on the trans pan during the 2nd ride, however still one drop formed under bellhousing (not fallen yet after 8 hours). Looks like it’s going to work! I’m using mineral oil for now, synthetic later only.