I'm replacing the three front seals and timing belt and tensioner on my 1981 242. I have the timing belt and all three sprockets off and am looking straight at the seals. I don't want to scratch any sealing surfaces digging out the seals. A couple guys suggested removing the piece that houses the crank and intermediate seals. It sounds like a good idea because it looks like seal removal and installation would be much easier with the seal housing on the bench, but I'm not sure I can do this without wrecking the oil pan gasket because the housing seal sits against it.

How hard is replacing the oil pan gasket if I do wreck it?

How do you get the seal housing piece off without damaging the housing, the pan gasket, or anything else? The housing sits on two pins that position it, so there is little wiggle room. Any ideas would be appreciated.

Should I forget this idea and just pry them out in the conventional way?

Also, I ended up with Scan Tech seals, but after I see the work involved I'm wondering if I should have bought better seals if there is such a thing. Are OEM seals any better, or are Scan Tech as good as any?
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Thanks to everyone for the help, Doug C. 81 242 Brick On Blocks, stock; 86 240, 129K

The seal carrier came off just as Don described. No damage to anything. Thank you.

The sealing surface on the intermediate is smooth with a few small spots of discoloration. The outer 3/8 inch of the crank sealing area is polished steel and the inner 7/16 inch is not polished and is kind of a brownish color. Where the shiny section joins the brown section is a ridge and a shallow groove.

Is this ridge a result of original machining and polishing?

Or, was the whole end of the crank equally polished to begin with, meaning the ridge and color difference are results of where the seal rode for so long?

What can be used to clean up the sealing surfaces?

Should I seat the new crank seal a little deeper into the carrier?


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Thanks to everyone for the help, Doug C. 81 242 Brick On Blocks, stock; 86 240, 129K

The little groove is wear caused by where the oil seal contacts the shaft. I think I remember on my BMW 320i the book called for not seating the seal quite as deep, maybe a few thousandths so that the seal lip will ride on a "virgin" portion of the shaft (hmmm, that almost sounds kinky... ;-P). The browning color and rifge may just be varnish/crud buildup, try scrubbing it off with a lacquer thinner soaked rag and see what you have.

Justin B.

The front main seal housing is secured with (I think) four bolts through the front, into the block, and two bolts up from the pan into the housing. You won't have to touch the pan gasket.

The difficult part is that the housing also sits tightly on two alignment pins (that fit into the block). So starting the housing outward, away from the block, is sometimes a chore because the pins get rusty and/or varnished, "gluing" the housing in place. I've successfully used a thin knife blade to pry the housing out, one side at a time, a few thousandths of an inch until I could get a putty knife (gasket scraper) under it. Be sure to pry evenly, left-right-left-right, a bit at a time.

Be prepared with a new housing gasket, although in a pinch you can make a new one from a glossy magazine cover (done it).

The cam seal pops out very easily if you first remove the valve cover and the front cam bearing cap.

Be very sure to clean all surfaces, and remember to prelube the seal lips. If you start the engine with dry seals, they'll last about 5 seconds.

I've had good luck with Scan Tech products.

Be sure that your crankcase ventilation system ("flame trap" and associated plumbing) is free and clear and that you have crankcase vacuum at idle. Positive pressure can make otherwise good seals weep a bit.
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Don Foster (near Cape Cod, MA)

I'll be doing the front seals this Spring and I plan to pull the front seal carrier to do those seals. I'm wondering how hard it is to get the carrier, with the new seals in place, back onto the crankshaft and intermediate shaft. I know to oil the seals but how about getting them started on the shafts?

With all this advice I'm ready to go at it. I'll post how it goes.
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Thanks to everyone for the help, Doug C. 81 242 Brick On Blocks, stock; 86 240, 129K

It's easy. With the new seal in the housing, lube the seal lip and shaft, and fit the seal over the shaft. Be ultra careful that the lip does not "roll" as you push the seal over the shaft.

When you examine a new seal, you'll see that the lip is angled and has a small spring wound around it to increase its tension against the spinning shaft. You need only to push the seal slightly more open, increasing its ID (against the spring force) so it'll fit. Once it's over the shaft, the shaft keeps the lip in the right position -- unless, that is, you inadvertently "hook" the lip as you slide it on the shaft. This would roll the seal lip outward.
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Don Foster (near Cape Cod, MA)

Thanks, it sounds doable (word?)

That word's doable.
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Don Foster (near Cape Cod, MA)

Thank you for the responses from everyone. So the bottom edge of the seal carrier where it contacts the pan gasket is not typically glued to the pan gasket with gasket sealer or something? The carrier will typically slide off the pan gasket without any damage if a person is careful? I suppose if I were to ding up that front section of the pan gasket accidentally, I could probably use some kind of Form-A-Gasket product to repair it. Am I understanding correctly? Again, I really appreciate everyone's help. I'm getting lots done on this car with the Board's help.
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Thanks to everyone for the help, Doug C. 81 242 Brick On Blocks, stock; 86 240, 129K

"...the bottom edge of the seal carrier where it contacts the pan gasket is not typically glued to the pan gasket with gasket sealer or something?"

Not that I've seen. It might be stuck with varnish buildup, but I've never seen it tear the pan gasket.

"The carrier will typically slide off the pan gasket without any damage if a person is careful?"

It should.

"...if I were to ding up that front section of the pan gasket accidentally, I could probably use some kind of Form-A-Gasket product to repair it..."

Yep. In fact, I routinely use the red RTV to help reseal the gasket. I use a very thin coating -- not even enough to "smush" out and leave the tell-tale bead of silicone.
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Don Foster (near Cape Cod, MA)

"Yep. In fact, I routinely use the red RTV to help reseal the gasket. I use a very thin coating -- not even enough to "smush" out and leave the tell-tale bead of silicone."

I like to clean the surface with lacquer thinner and use a little Hylomar gasket sealer. I avoid the silicone sealers.

I think you need to remove the two oil pan screws at the front. I don't recall having any particular trouble removing the housing otherwise. It makes the job easier and you get to see what's behind there.

I think I would just pry them off. If you have to replace an oil pan (??) gasket, I suppose you'd have to pull the entire engine. Just try a small awl or flat blade screwdriver. I lucked out and had the machine shop do the front cam seal.

As far as ScanTech v OEM seals.. Nick of FCP Groton fame told me that he believes that the ScanTech are of a higher quality than the Elring (OEM) seals. The seals are cheap either way.. and since you don't really need to worry about damaging them on the way out.. and they don't usually fail catastrophically you have little to loose by trying cheapie seals.

- alex

'85 244 Turbo
'84 245 Turbo