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Rear main seal installation
#11
On a 93 gm 350 1 piece rear seal, does the gasket btwn the block and the seal housing need permatex #2? The original did not apear to have any sealant.
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#12
The gasket and the surfaces it seals should not have any sealant applied to them. You will need to apply sealant to the joints where the RMB cap meets the block above the oil pan.
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#13
On my crank there is a groove worn from the old style seal that has the internal spring on the inside _ the groove is not deep, but it's there none the less.
The new PTFE seal is right on top of the worn groove, will that affect the proper sealing of the PTFE seal, or should I use a repair sleeve ?
The sleeve is only 10 thou thick, so I don't think it will over-stretch the new PTFE seal _ what do you think ?
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#14
(08-26-2017, 07:42 PM)Guest Wrote: On my crank there is a groove worn from the old style seal that has the internal spring on the inside _ the groove is not deep, but it's there none the less.
The new PTFE seal is right on top of the worn groove, will that affect the proper sealing of the PTFE seal, or should I use a repair sleeve ?
The sleeve is only 10 thou thick, so I don't think it will over-stretch the new PTFE seal _ what do you think ?

Hi,

The new PTFE seal needs a smooth surface to ride on, so a repair sleeve will have to be used. Our seals will accommodate a repair sleeve, but if a repair sleeve is too rough it may not be ideal to use with a PTFE seal. The sleeve itself should be a high-quality sleeve with a very smooth surface finish.

Make sure the repair sleeve surface is completely clean and dry when you go to install the new seal. Do not apply any oil or anything else to the sealing lip, crank, or sleeve. You can use a tiny bit of oil on the outside of the seal to help it slide into the bore but it's critical that the crank and sealing lip are 100% clean and dry.
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#15
Thanks for the reply, it's an SKF stainless steel Speedi-Sleeve. It has a flange on it and comes with a tool that goes up against the flange for installation.
Would it be a good idea to leave the flange in place to keep the crank case oil off the seal ? For an area that has so much oil involved, what stops the crank case oil from penetrating the Teflon "seal" once it's in place ? Or once the Teflon has worked it's way into the sealing surfaces, the oil doesn't penetrate the seal ???
I've come across a umber of articles that say to rotate the crank 2 full revolutions and then leave it sit for 4 hours after that so the Teflon can penetrate the crank (or sleeve). I will be doing that at any rate.
As far as installation goes, the oil pan is off, I can simply place the seal in position and tighten up the big end bearing. With this procedure I can make sure it goes in square with out damaging the seal. I'll put a small smear of oil on the outside to make sure it "seats" properly.
I suppose a very thin smear of black RTV would work too, as long as I leave it sit for 24 hours to cure ???
It's on a 1999 Mazda (Ford) B3000, 3 litre Vulcan V6.
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#16
(08-28-2017, 03:42 PM)Guest Wrote: Thanks for the reply, it's an SKF stainless steel Speedi-Sleeve. It has a flange on it and comes with a tool that goes up against the flange for installation.
Would it be a good idea to leave the flange in place to keep the crank case oil off the seal ? For an area that has so much oil involved, what stops the crank case oil from penetrating the Teflon "seal" once it's in place ? Or once the Teflon has worked it's way into the sealing surfaces, the oil doesn't penetrate the seal ???
I've come across a umber of articles that say to rotate the crank 2 full revolutions and then leave it sit for 4 hours after that so the Teflon can penetrate the crank (or sleeve). I will be doing that at any rate.
As far as installation goes, the oil pan is off, I can simply place the seal in position and tighten up the big end bearing. With this procedure I can make sure it goes in square with out damaging the seal. I'll put a small smear of oil on the outside to make sure it "seats" properly.
I suppose a very thin smear of black RTV would work too, as long as I leave it sit for 24 hours to cure ???
It's on a 1999 Mazda (Ford) B3000, 3 litre Vulcan V6.

As long as the flange from the sleeve does not contact any engine parts, it should not hurt to leave it in place.

The PTFE sealing lip does transfer some of its’ material to the crank flange. The seal has a certain amount of “grip” to seal against the crank flange. Rubber lip seals do this with a garter spring. The PTFE seal when installed stretches a bit to fit over the crank. Usually, the seal has some sort of plastic sleeve to keep the seal in proper shape. This sleeve may be slightly larger than the crank flange. The PTFE lip needs time to “relax” and get back to its’ proper shape to seal the crank. It's important that oil is not applied to the sealing lip or the sealing surface as it will prevent the proper "break-in" of the sealing lip and sealing surface.

Since you already have the pan removed & it sounds like the RMB cap removed, there’s no need to apply oil or RTV to the outside of the seal since you are not driving the seal in. The oil is used to help the RMB seal slide into the engine bore. RTV should not be used on the outside of the RMB seal at all. Install the seal onto the crank flange with the RMB cap loose, make sure the seal is flush with the engine & RMB cap so it is square. Tighten the RMB cap to specs.
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#17
Thanks for all the info, it's much appreciated.
I had a standard seal on there on a freshly rebuilt engine and 3 days after driving the truck, the Garter spring came off the seal. I found it hanging on the crank when I removed the oil pan. What could have cause the spring to come off ? My machinist chalked it up to installation error, but I did the procedure of removing the main bearing cap and made sure that it was done properly. It was definitely on there before I put the oil pan back on. At the time the engine was up side down, so I could clearly see that the seal and the garter spring was in place.

My theory is that because the upper intake manifold was not connected to the PCV valve, that any crank pressure at that RPM could not have been vented properly, causing the seal to blow. The seal hasn't been damaged in anyway with a visual inspection and the garter spring snaps back in to place as it should.

It started leaking oil only after I revved the engine up to 4000/4200 rpm, could there have been too much crank pressure to blow off the spring ? The PCV valve was not in place at the time, it was removed and any crank case pressure simply vented out into the atmosphere. Normally the PCV valve would have been there and the other end connected to the upper intake manifold. On the other valve cover the vent simply is connected to the side of the oil filler port and is directed into the air intake tube just after the air cleaner element and before the throttle body.
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#18
(08-30-2017, 04:10 PM)Guest Wrote: Thanks for all the info, it's much appreciated.
I had a standard seal on there on a freshly rebuilt engine and 3 days after driving the truck, the Garter spring came off the seal. I found it hanging on the crank when I removed the oil pan. What could have cause the spring to come off ? My machinist chalked it up to installation error, but I did the procedure of removing the main bearing cap and made sure that it was done properly. It was definitely on there before I put the oil pan back on. At the time the engine was up side down, so I could clearly see that the seal and the garter spring was in place.

My theory is that because the upper intake manifold was not connected to the PCV valve, that any crank pressure at that RPM could not have been vented properly, causing the seal to blow. The seal hasn't been damaged in anyway with a visual inspection and the garter spring snaps back in to place as it should.

It started leaking oil only after I revved the engine up to 4000/4200 rpm, could there have been too much crank pressure to blow off the spring ? The PCV valve was not in place at the time, it was removed and any crank case pressure simply vented out into the atmosphere. Normally the PCV valve would have been there and the other end connected to the upper intake manifold. On the other valve cover the vent simply is connected to the side of the oil filler port and is directed into the air intake tube just after the air cleaner element and before the throttle body.

It is possible that too much crankcase pressure caused the seal lip to move and the garter spring to come off. The rings should seal from the beginning if all is correct but if there is some more blowby due to the rings not being seated and no PCV hooked up (why?), there could have been enough pressure to move the seal.

We would also recommend checking the crankshaft end play to make sure the crank did not walk the seal lip and cause the spring to come out.
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#19
Thank you ! That makes sense, it's nice to have an explanation, and I'm sure now that is what happened. When ever I rebuilt engines in the past, I've never connected the PCV valve up until the engine gets broken in to some degree. This prevents excessive fowling of the intake manifold. Keep in mind that all the engines that I've done were old engines with no PCV valve, they simply vented the crank case gasses out into the atmosphere with the exception of my 68 Jaguar, it was vented into the intake manifold just after the air cleaner and before the carbs _ no PCV valve.
It's highly unlikely excessive crank shaft endplay would be to blame, that would have been checked at the machine shop and dealt with accordingly. I've known my machinist for 30 years and that would have been checked.
Again, thanks for the explanation, I didn't want to install the seal back in, not knowing why the garter spring came off.
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#20
(09-08-2017, 07:43 AM)Guest Wrote: Thank you ! That makes sense, it's nice to have an explanation, and I'm sure now that is what happened. When ever I rebuilt engines in the past, I've never connected the PCV valve up until the engine gets broken in to some degree. This prevents excessive fowling of the intake manifold. Keep in mind that all the engines that I've done were old engines with no PCV valve, they simply vented the crank case gasses out into the atmosphere with the exception of my 68 Jaguar, it was vented into the intake manifold just after the air cleaner and before the carbs _ no PCV valve.
It's highly unlikely excessive crank shaft endplay would be to blame, that would have been checked at the machine shop and dealt with accordingly. I've known my machinist for 30 years and that would have been checked.
Again, thanks for the explanation, I didn't want to install the seal back in, not knowing why the garter spring came off.

You're welcome, good luck with your project and let us know if you have any other questions!
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