Airy Cat Posted August 15, 2012 Share Posted August 15, 2012 The rear main seal in my 1955 Buick Special is leaking and I want to replace it without removing the engine.Has anyone done this and could you tell us how you did it?Steve Link to comment Share on other sites More sharing options...
Bhigdog Posted August 15, 2012 Share Posted August 15, 2012 Chilton manuals describe the process of removing the top half of the seal (the bottom half is easy) and threading a new seal half into place. There are several variations on the process. The success rate is iffy but it's worth a try. Just don't be too disappointed if it's less than a complete success................Bob Link to comment Share on other sites More sharing options...
packick Posted August 16, 2012 Share Posted August 16, 2012 (edited) Willie ("Old Tank") gave me this method of replacing the rear main seal on my 1955 Century a couple of months ago and so far this method has stopped my rear main seal leak. It was a pretty straight-forward method. The only minor problem we had was getting the oil pan off. But if you lower the pan a bit you can see the crank and if its in the way, move the flywheel so the pan will clear the crank. Here is what Willie suggested:I have worked with early 322 Nailheads and one 1947 straight-8, so yours should be similar. Some of this can also apply to other engines with rope seals.Some assumptions: You know how to get to the rear main bearing cap and remove it and you know what a rope seal is. The engine is in the car and the crankshaft is installed.Do not remove the upper seal. If it is not now absolutely flush take a portion of the used lower seal and stuff in the gap with a suitable tool. It is OK if it protrudes some. Take a 12-inch length of heater control wire, sharpen one end and install it into the groove that the upper seals sits in using a 6-inch length of brake line to keep it from kinking. Using vise grips push 1/4 inches at a time until it shows up on the other side. Install 2 pieces. Cut the wires flush with the block.For the lower seal that goes in the cap take the piece that is supplied for that engine, bunch it together and flatten it and place it in the groove in the cap. Bunch it some more to make it fit while pressing it into the cap with a piece of exhaust pipe about the same diameter as the crankshaft journal. Never cut or trim a seal to make it fit. It is OK and desirable if some seal protrudes from the cap. (For situations where the crankshaft is out of the engine, remove this seal from the groove in the cap and place it in the groove in the block; repeat for the lower seal.) Fold any stray strands of the seal to the center so they will not get caught between the clamping surfaces. Install the cap and torque to specs. Remove the cap and trim any stray strands that got clamped. Put some gasket sealer on the clamping surface of the cap. I use an anaerobic sealer. Dribble some engine oil on the seal only until it is saturated. Install and torque to specs.To seal the groove in the sides of the cap I take some cotton twine coated with some No. 2 Permatex and hammer it to stuff it tightly in the groove using a large flattened nail until it is level with the top.Willie Edited August 16, 2012 by packick (see edit history) Link to comment Share on other sites More sharing options...
Ben Bruce aka First Born Posted August 16, 2012 Share Posted August 16, 2012 (edited) The rear main seal in my 1955 Buick Special is leaking and I want to replace it without removing the engine.Has anyone done this and could you tell us how you did it?SteveCheck Willies[ old tank] web page he describes a good method he has used. Ben OOPS, looks like I was posting same time as packick. He spelled out Willies method. Edited August 16, 2012 by First Born (see edit history) Link to comment Share on other sites More sharing options...
Airy Cat Posted August 16, 2012 Author Share Posted August 16, 2012 Thanks for the info. As soon as the weather cools down I'll get to it. Link to comment Share on other sites More sharing options...
buick man Posted August 18, 2012 Share Posted August 18, 2012 Airy Cat: If you choose to change the rear main seal make sure you loosen the adjoining main bearings first and then shim the distance between the bearing and the cap on those forward bearings so as to properly support the crank shaft as you go to work on the last rear main cap removal and seal replacement. I would also chose to use the newer "Best Gasket" setup for the nailhead they sell over the rope unless you have mastered working with rope technique. Rope, also by it's nature leaks somewhat even on the best day. I believe the Buick Shop Manual goes into detail on this procedure if not mistaken. If you drop the transmission it is a world easier to do. The hardest part is feeding the upper section of seal over the journal and also correctly allowing for the proper amount of "seal tab" overage so when you install the lower cap/seal it sandwiches together properly. Just some thoughts. Link to comment Share on other sites More sharing options...
old-tank Posted August 18, 2012 Share Posted August 18, 2012 Airy Cat: If you choose to change the rear main seal make sure you loosen the adjoining main bearings first and then shim the distance between the bearing and the cap on those forward bearings so as to properly support the crank shaft as you go to work on the last rear main cap removal and seal replacement. I would also chose to use the newer "Best Gasket" setup for the nailhead they sell over the rope unless you have mastered working with rope technique. Rope, also by it's nature leaks somewhat even on the best day. I believe the Buick Shop Manual goes into detail on this procedure if not mistaken. If you drop the transmission it is a world easier to do. The hardest part is feeding the upper section of seal over the journal and also correctly allowing for the proper amount of "seal tab" overage so when you install the lower cap/seal it sandwiches together properly. Just some thoughts.DavidWhen you used the "Best Gasket" setup, did you use sealer around the outside of the seal; and how did you clean the upper seal groove so that sealer would work? When I installed one, it leaked 2 quarts in 10 miles. I then pulled a rope seal through the upper groove and it did not totally seal (2" puddles). It wasn't until I took it apart again and installed the heater control wires that it has been dry for 60,000 miles.Willie Link to comment Share on other sites More sharing options...
buick man Posted August 19, 2012 Share Posted August 19, 2012 When you use Best Gaskets, they are so well engineered and use the upmost materials, one does not have to use dopes. You lube the upper with petroleum jelly and seal the ends with just a touch dab of silicone. That is all. Best Gaskets are engineered properly using the proper materials so they "are" the sealer. This then by definition, relegates the use of gasket sealers/dopes to only light contact gluing duty to hold the gasket temporarily in place if needed. Link to comment Share on other sites More sharing options...
old-tank Posted August 20, 2012 Share Posted August 20, 2012 (edited) When you use Best Gaskets, they are so well engineered and use the upmost materials, one does not have to use dopes. You lube the upper with petroleum jelly and seal the ends with just a touch dab of silicone. That is all. Best Gaskets are engineered properly using the proper materials so they "are" the sealer. This then by definition, relegates the use of gasket sealers/dopes to only light contact gluing duty to hold the gasket temporarily in place if needed.David, Is that an infomercial or you own personal experience? Edited August 20, 2012 by old-tank (see edit history) Link to comment Share on other sites More sharing options...
1957buickjim Posted August 21, 2012 Share Posted August 21, 2012 Willie,Is there a rope seal on the heater control wire, i.e., does the heater control wire penetrate or go through the upper seal? Link to comment Share on other sites More sharing options...
old-tank Posted August 21, 2012 Share Posted August 21, 2012 Willie,Is there a rope seal on the heater control wire, i.e., does the heater control wire penetrate or go through the upper seal?JimThe wire goes between the seal and the groove in the block where the seat sits. It just serves to expand the existing seal. I did not take pictures mainly because it is a dirty procedure with oil dripping...also I cannot draw.Willie Link to comment Share on other sites More sharing options...
buick man Posted August 21, 2012 Share Posted August 21, 2012 That's funny. No commercial just quoting from my own endeavors. But with all this said, why funk out with rope seal engineering which is a hand-me-down from when they were using rope as wheel bearing packing and seals on Calistoga Wagons, when these modern superior seals are available today? Link to comment Share on other sites More sharing options...
old-tank Posted August 21, 2012 Share Posted August 21, 2012 Ok, Best Gasket does not make the seal for the early nailhead (322, 264). The Felpro has lots of problem according to other forums. Suggestions to use Buick 3.8 V-6 also have failures. For now I will stick with my ancient method.No seal will work if the sealing surface is not concentric with the main journals for if there is too much crank end play. This even affects the dynaflow seals...one old dynaflow rebuilder said that they always replaced the rear main bearing shell in the lower cap before installing the rebuilt dynaflow.Willie Link to comment Share on other sites More sharing options...
buick man Posted August 22, 2012 Share Posted August 22, 2012 Some really good points Willie. Use a dial indicator for run out determination while you are in there, but most likely will not find any if at all on a Buick. I have always heard this was a common problem with Fords and Chevys but not the well balanced buick cranks as a rule. Wait..... News Flash..... just in..... Folks you've no doubt have tried Soap on a Rope. Well now there's "Dope on a Rope" for all you shade tree padres out there. This new product is taking the country by storm. An old idea with a new twist. Available where fine hardware items are sold. Link to comment Share on other sites More sharing options...
Bhigdog Posted August 22, 2012 Share Posted August 22, 2012 I tried an after market lip seal in my 55. Not sure of the make. Complete failure........................Bob Link to comment Share on other sites More sharing options...
buick man Posted August 22, 2012 Share Posted August 22, 2012 These seals are not simple slap-ons. Once put on, they have to be trimmed properly, with the proper extension usually an 1/8 inch, lubed properly with vasoline and the main cap/bearing surfaces sealed at the right locations. Just can't slap and go. If you have destructive and detectable run out on the end of the crank, no replacement bearing is going to cure the problem for long. It will just roto-hammer itself back out of round. You have to deal with the crank problem, then reinstall then the seal will do it's job. . . . just my humble thoughts. Link to comment Share on other sites More sharing options...
old-tank Posted August 22, 2012 Share Posted August 22, 2012 I tried an after market lip seal in my 55. Not sure of the make. Complete failure........................BobMy money is on Bob knowing what he is doing and not on an infallible seal.... Link to comment Share on other sites More sharing options...
buick man Posted August 23, 2012 Share Posted August 23, 2012 Glad not to be gambling. Just have fun that is what this hobby if for. Link to comment Share on other sites More sharing options...
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