Don G 1947 Posted September 18, 2009 Report Share Posted September 18, 2009 I am rebuilding a 218 and am having 2 problems with the rear main seals. 1. The rubber "h" seal seems to be too thick. It is seated properly in the cap groove, but the cap does not contact the block because of the seal. I'm sure this is not correct. Is the "h" incorrect or does it need to be shaved down? 2. In the picture you will see the metal rear main seal holders and the new seals I was sent. Do I pry the sheet metal apart and force the seals in? Is the new seal incorrect for this application? First time rebuilding, and the engine was in pieces when I got it. Thanks, Don Quote Link to comment Share on other sites More sharing options...
Arthur1947 Posted September 18, 2009 Report Share Posted September 18, 2009 That's a good question Don, I to have the same seal. I'm guessing here but the rope seal you have have pictured above might be for an earlier model and cannot be mounted to the plate. I think this plate comes with the seal pressed onto it. Hopefully someone can clarify this and also if it is possible to get the plate type seal on without too much disassembly? Best. ARTHUR Quote Link to comment Share on other sites More sharing options...
Jim Saraceno Posted September 18, 2009 Report Share Posted September 18, 2009 There are two types of seals. The newer one is a plastic seal that slips into a grove, the older seal uses the rope and looks like the one you have pictured and bolts onto the back. I'm not sure what your question is. It sounds like you are trying to use both seals. According to my manual they changed from the old seal to the new in 1953. Quote Link to comment Share on other sites More sharing options...
grey beard Posted September 18, 2009 Report Share Posted September 18, 2009 Don, The seal you have pictured is for the earlier flatheads through about 1950. To install the top half, the flywheel of course must be removed. The newer seal is a neoprene type that fits into a machined recess in the block. The two cannot be interchanged because the block is made differently in this area. When I rebuilt my 218, I found it to be the earlier style. I also had a 1953 engine spare in the shop at the time and could compare the designs. The latter of the two is by far the best arrangement of the two, because the top half can be rolled into place with the crank and flywheel in place - might need to loosen the mains to do this, but it's possible, while the type you pictured is held in place with cap screws. Hope this helps. Good Luck Quote Link to comment Share on other sites More sharing options...
rolliejoe Posted September 18, 2009 Report Share Posted September 18, 2009 I'm dealing with the rear seal also. So which is better, neoprene or the rope type for sealing? If I go with the rope, is there any secret on getting the rope inserted in to the plates? Quote Link to comment Share on other sites More sharing options...
rolliejoe Posted September 18, 2009 Report Share Posted September 18, 2009 (edited) The secret to the rope seal is not to work on it when it's getting late while not wearing gloves. When I was trying to push the rope in the plate the rope would only get fatter and my hands just got greasier. Today I flattened the rope seals with my fist, then they went in to place. Mocked it up and those rope seals are dang tight, can't even turn the crank. I think I'm going to go with the neoprene plate type. Edited September 18, 2009 by rolliejoe Quote Link to comment Share on other sites More sharing options...
jim leman Posted September 18, 2009 Report Share Posted September 18, 2009 Don -- Been a couple years since I replaced the main bearing seals in a 218. I have used both types, rope and the new neophrene types. Been satisfied with both, though it seems the latter is less prone to leaking. I know the neophrene type is designed for latter year engines, but if I recall when you use the neophene type you don't need the rope seal u-shaped hardware...but from the photo it appears you have the traditional rope type. Pull-push the old seal out of the metal retainer, clean the groove well, and then lightly lubricate the new seal and slip it into the retainer. Is the crank in or out of the engine? If out, put the rope seal into the metal holder and then bolt to the cap (I think there is one as well for the block-side) and I was advised to use a length of PVC about the diameter of the crank journal and then roll it along the bearing saddle (bearing not installed) to push the rope seal fully into the retainer. Then, using a very sharp razor blade, trim off the rope seal just a little bit more than flush with the top of the retainer. Doing the same with the other half will then provide a good crush of the bearing ends when the two are mated and torqued down tight. Don't bother with the seals until you have the bearings all installed and their proper clearance obtained...the seal step should be the final one once you've gotten that all taken care of and then dropped the crank into their saddles for the last time. The Plymouth Service manual provides some help on this step. An Old Motors or Chiltons should give some guidance -- and when you but the rope seals they used to back instructions with them. Hope this helps -- running on memory and a few glances at the manuals...does this sound right to others? Quote Link to comment Share on other sites More sharing options...
james curl Posted September 18, 2009 Report Share Posted September 18, 2009 If my memory serves me right J.C.Whitney used to sell a tool that had a strap with teeth in it that you pushed over the crankshaft in the empty grove and then set the teeth into the new rope seal and pulled the "T" handle back over the crank pulling the new rope seal into place. Looks simple in the ad. Quote Link to comment Share on other sites More sharing options...
Don G 1947 Posted September 18, 2009 Author Report Share Posted September 18, 2009 The Plymouth Service manual provides some help on this step. An Old Motors or Chiltons should give some guidance -- and when you but the rope seals they used to back instructions with them. Hope this helps -- running on memory and a few glances at the manuals...does this sound right to others? Jim, The application in this case is for a truck. I do have the truck manual, but it doesn't give and information except, "Install new seals." Your instructions on how to install the ropes in the retainers and working them to fit is great. I will try it. Thanks. Anybody have any input on the rubber "h" shaped seals that go into the cap? When I install them (without the main seals to interfere) there is a .030" gap between the cap and the block. Don't seem like they want to compress enough. Any thoughts? Don Quote Link to comment Share on other sites More sharing options...
jim leman Posted September 18, 2009 Report Share Posted September 18, 2009 (edited) Don -- Let me dig around a little on this matter. Not sure these rubber H seals, as you define them, must necessarily have a good fit until you mate the two halves, the rear main cap and the block. Seems to me they are there to deflect runoff oil from the rear crank journal main slinger away from the seal. Are you saying that after you torque down the rear main bearing cap -- don't these pieces fit into notches in the cap? -- that you have a space between the cap and block once all is torqued to spec? OK -- looked in my '42 manual...are we talking here about the rubber cap gaskets that go into the recesse or notches in the cap (rear main) itself...I do think they will be above flush with the cap when inserted into the cap but will crush when you torque the cap to the block. You do have the flat paper gasket that goes between the cap/block faces and the two oil rope seal halves, right? Am I understanding the matter? Edited September 18, 2009 by jim leman Quote Link to comment Share on other sites More sharing options...
Don G 1947 Posted September 19, 2009 Author Report Share Posted September 19, 2009 Jim, You got it. The rubber cap gaskets that look sort of like an "h" fit into the cap, but don't compress enough to let the cap mate with the block. When torqued to 85 lbs their is a .030 to .035 " gap between the cap and block this is WITHOUT the rope seals in place. By the way I got the rope seals into the metal retainers and am now soaking them in oil. Amazing how easy things can be when you get good advice! Thanks, Don Quote Link to comment Share on other sites More sharing options...
jim leman Posted September 19, 2009 Report Share Posted September 19, 2009 Don -- Just a guess now....do you think the seals don't fit flush with the cap then is because they don't sit into the cap recess far enough? Trying to remember how deep the seal is our how much of it fits into the recess...could it be that these repos (they are reproductions, right?) were from poor moulds and too "thick" or deep for the actual recess? Is there part of it you can trim so they fit more flush level with the bottom of the cap...If the seal does not then fill the depths of the recess, is there some reason that would be a problem...I mean, what is in the bottom of the recess that would need a complete seal there....Don't do anything about this yet...I'll go back to my manuals and see what else I come up with... Quote Link to comment Share on other sites More sharing options...
rolliejoe Posted September 19, 2009 Report Share Posted September 19, 2009 Don, I have .013 clearance between the cap and block whether the h pieces are installed or not. On my cap the groove ramps up as it goes towards the bearing, is you h-piece too far in? Here are the instructions from the Felpro master set (somewhat confusing): Quote Link to comment Share on other sites More sharing options...
Don G 1947 Posted September 19, 2009 Author Report Share Posted September 19, 2009 One problem solved, but another one created! This shouldn't be so frustrating! Checked the grooves on the cap against other caps I had to see if it had been ground down and line bored. All the groves were the same. Took the cap off and upon close inspection of the rubber parts I noticed some irregularities so I trimmed the parts (ever so gently). Before I installed them I used plastigage to determine the clearance in that bearing (.0015"). I then reinstalled the rubber parts and rechecked the clearance with plastigage and it remained AT .0015". The gap between the cap and the block shrunk to .015". That problem solved----SORT OF. Pulled the crank out so I could put in the upper seal (engine stand made it hard with the crank in.) Got it installed and put the crank back in. Won't turn now, but I assume that will loosen up when the seal wears in. The rubber seals have a thin tab that wraps around to the outer face of the cap where the metal seal retainer attaches. That tab interferes with the seating of the retainer. Any ideas? Thanks much, Don Quote Link to comment Share on other sites More sharing options...
jim leman Posted September 20, 2009 Report Share Posted September 20, 2009 Don -- Is the seal that is interferring the H seals we have been talking about? If you were to trim off this part that is causing the interference, what would you lose -- I mean, what do you think the hanging piece of the seal is sealing? Did you end up installing the rope seal? Did you lube both the upper and lower halves? The crank should be harder to turn with the rope seal in place -- but not impossible to turn. Can you grab the front part of the crank where the crank gear will be attached and turn it? If you feel it is way too tight -- requires a wrench and muscle to turn, you might have a bearing binding against a crank journal. I live in Grayslake, IL, so if you feel you'd like to talk by phone, get back to me and we can see if we can set that up. It's Sunday about 3:30, so if you're not watching the Bears and want to chat, able to. Send a number for me to call you Quote Link to comment Share on other sites More sharing options...
Don G 1947 Posted September 21, 2009 Author Report Share Posted September 21, 2009 Jim, Well, I don't know what I would lose by cutting off the piece (of the 'h" seal) that goes on the face of the bearing cap. Have been thinking about that and using a generous amount of permatex in that area or maybe "Gasket Maker" (RTV). That piece was obviously molded into the part and also exists on some of the old bearings I have around. The issue here seems to be that everything about this seal is thicker than what was used originally. Before I installed the rope upper seal the crank turned fine with all the bearings torqued to specs. With the one seal in, it is VERY difficult to turn. I assume the seal just needs to crush a bit and seat into the crank. My number is 630-584-3089. Good to have someone in the area. Don Quote Link to comment Share on other sites More sharing options...
jim leman Posted September 21, 2009 Report Share Posted September 21, 2009 Jim,Well, I don't know what I would lose by cutting off the piece (of the 'h" seal) that goes on the face of the bearing cap. Have been thinking about that and using a generous amount of permatex in that area or maybe "Gasket Maker" (RTV). That piece was obviously molded into the part and also exists on some of the old bearings I have around. The issue here seems to be that everything about this seal is thicker than what was used originally. Before I installed the rope upper seal the crank turned fine with all the bearings torqued to specs. With the one seal in, it is VERY difficult to turn. I assume the seal just needs to crush a bit and seat into the crank. My number is 630-584-3089. Good to have someone in the area. Don Don -- I'll try to give you a call today...are you home during the day or at the job? Jim Quote Link to comment Share on other sites More sharing options...
Don G 1947 Posted October 4, 2009 Author Report Share Posted October 4, 2009 Well, after way too much time fooling around with the rope style rear main seals I ordered a neoprene one from VPW.. What a breeze to install!! The "h" seals were not as fat and went in beautifully. Highly recommend the neoprene seals to anyone contemplating installing new ones. Thanks for all the help. Don Quote Link to comment Share on other sites More sharing options...
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