The tale of a front teflon seal that was not?

In a prior thread about Broadsport 5 speed install, wrote about leaking new Teflon front seal.
Many years ago converted to Teflon, replacing distance piece and O-ring and removing oil slinger.
Leak-free for all these years, thought I had ordered a new teflon seal recently but now realize the seal I ordered was the original stock one. This must be why it is leaking so much oil, so much so I installed a catch can. Went to order from the usuals a new teflon seal NLA? XKs shows the seal in a kit but none available. Will call them tomorrow, can not find the teflon version elsewhere?
Glenn

I have a NOS one if you need it, just the seal not the race.

You have to be super careful installing them. If they try to spin it tears up the corners. I’ve found this to happen if it sits for too long because the oil film dries out. Last time I put one in I also smeared a thin layer of silicone around the periphery to encourage it to stay put.

When I got my old ‘67, the front seal was leaking like crazy. I removed it, and found out it was the later, Teflon seal. I carefully replaced it with another Teflon seal, and immediately had another nasty leak.

I replaced it with a conventional rubber lip seal, making sure to do any fettling necessary to make sure it was not being distorted by the clamp load between the timing cover and oil pan…it never leaked another drop the whole time I owned it.

Now, it did have the later distance piece with the internal o-ring, but I had MUCH better experience with a rubber lip seal…the same type of seal that about a billion other cars have used successfully.

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Are you running the rubber one now without the slinger or was the slinger left on with the Teflon seal? If the latter, then it will burn out because it will be too dry.

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I don’t currently have an E-type, but I’m still working on that :wink: It’s been a long time since I dealt with this on my old car, but I remember reading countless threads on the topic, and following conventional wisdom. The replacement Teflon seal I first installed didn’t even have time to burn out…it leaked terribly on first start-up, and yes, I used the installation tool, and did everything necessary to give it the best chance at a long happy life.

I work in the high-speed rotating equipment business, so oil leaks are one of our biggest challenges. I seem to get involved in a challenging oil leak issue about once every 12-18 months, so you could say I’ve lived several lifetimes when it comes to oil leaks.

I don’t claim to be a seal expert, but I’ve spent many, many hours working alongside people who are, and I’ve become convinced that the SIII teflon seal was a misguided (at best) attempt for couple of reasons.

  1. This is not an application that requires an exotic, stiff, and unforgiving seal. In the world of spinning shafts it’s pretty benign…relatively low-temp, and very low speed.

  2. If you’re going to use a stiff, unforgiving seal, you better control its position VERY tightly. Embedding it in a ring of soft material, and clamping it between two halves of a clam-shell arrangement violates just about every best practice with a seal of this type.

It was my thinking that with such a poorly located seal (relative to crank snout centerline), a very forgiving rubber lip seal would be the most effective, and that matched my personal experience.

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I wonder if this was the issue. There is a tragic flaw in the packaging of these things. The instructions show an image of offering the part up and pushing the plastic collar off in the process. The collar only comes off one way. Every one I’ve unpacked, including the two on my shelf right now had the collar pushed on from the wrong side for this, so if you followed that instruction literally it would be installed backwards. That would be the only logical reason for it leaking out of the gate.

It’s a pointless tool anyway because most people place the seal first and the then push in the steel spacer. So long as the seal is set correctly, then the lip points inward and an oil lubed collar slips naturally through it and can’t damage the seal edge. Those instructions are likely a big reason so many people have had problems with them.

Totally agree there, terrible design, too many variables. Unless you have the luxury of examining it without the crank in place you can’t even easily test for a ovular condition so you can calculate the best sump gasket to bring it as close to circular as possible.

It’s been a lot of years since I didn’t this, but I’m confident (sure) I wouldn’t have just blindly shoved the seal over a tool that would compromise the seal. I was well aware of it’s stiffness and fragility at the time.

I’ve also installed more than a few early-Mini rear main seals, so I have a good appreciation for this type of exercise. If you’ve never seen that done, it’s something to put on your bucket list, as there are factory pushing tools and protective sleeves involved…it gives quite a sense of satisfaction :wink:

Funny you mention the oval condition. When I finally settled on the rubber lip seal, I pulled my pan and timing cover off, and did a full mock-up with a gasket, and everything. I measured, and found that the aperture created by the pan and timing cover was very ovalized…like a football…even with a very thick gasket.

What I also found was that the rubber lip seal supplied for this application these days had an OD that was too big for the aperture, which put the seal into a heavily “clamped” condition, and deformed it on the vertical axis. I actually took maybe .025”or so off the OD of the seal, so that it was just lightly clamped in the vertical direction…this arrangement still centered the seal side-to-side, but I ran a small bead of sealant down the sides of the seal to take up any small gaps that might have been created down the sides.

As I mentioned, it worked beautifully, and the guy who bought the car from me contacted me a few years later an mentioned it was one of the most leak free English cars he’d ever owned.

Erica
Yes the new rubber seal is being used without oil slinger. As I said earlier I thought I was ordering a teflon seal to replace the same installed many years ago. When I installed this new seal I thought I remembered sliding it off plastic piece to crank. The OE. does not work that way, plastic piece just holds it in the correct shape. The outer ring is fairly soft material and should not be a problem. Replacing the seal will be a PITA, A/C compressor and bracket will have to be removed as will water pump alternator and radiator. Cooling fans also to come out to make room to pull off damper. Front cover comes off and I hope I can just lower oil pan a bit to clear lip. I thought I remember that earlier cars did not have the lip and seals were easier to replace? Or grinding off lip an option? would not do that.
Glenn
70 E

Glenn, you shouldn’t have to remove any of that stuff. You only need to remove a couple things to replace the front seal, the sump, the damper, and the front seal spacer. You may need to remove the down pipes to remove the sump. It depends how much clearance there is with your pipes. I’ve always just removed mine because it’s one less thing to impede progress.

Not sure why your fans have to come off. Do you have a fluid damper or something so you have to use a puller?

Once the sump is off, you need to extract the spacer. It’s a little tedious but totally do-able. I use a 5 in 1 scraper tool because they’re sturdy so you can tap on it, and they have a nice thick tapered blade. Place it between the spacer bevel and the part behind it, in your case the oil pump gear since your slinger is gone. Tap it until the blade slips in. Then just start working it from both sides until the gap opens enough to use something more substantial to tap with like a small brass rod. I’ve done this several times with the engine in the car.

Once the spacer is out, the seal can drop free and by tipping it, it will pass by the timing cover easily. A '70 should have the later cover where the outer lip on the timing cover that holds the seal is pared back at the bottom which allows the seal to slip out.

Insert the new seal with some silicone on the edge. Install the pan. Oil up the spacer and slip it into the seal. I’ve done one on mine in a little as 2 hours. Like I said, I have two of the Teflon ones in Jag boxes if you want to use one. I bought them from Dick Vs estate so they’re old stock, likely predating some of the quality issues that set in in the mid 2000s.

The plastic collar is completely superfluous to the process. As you say, I suspect its main purpose is to preserve the seal shape.