The Stovebolt Site Forums The Shop Area Engine Shop installing a new rear main seal help needed

If anyone has tip tricks or otherwise useful help please post away.

Buy a seal from Best Gaskets.

What engine are you working on?

I got a rope 2 piece seal from autozone. Installed it and fingers crossed.

Buy a seal from Best Gasket Company, no other seal material being sold now will work as good or easy. They include the tools and directions with each kit. http://www.bestgasket.com/distributors.asp

Joe

I highly recommend you take the rope seal out and go to your local parts store and get a rubber one. The rope seals have a much higher chance of failure. I was given a rope seal in my gasket overhaul kit for my 235 and went to a local parts shop and they had a rubber one.

The above post is why I suggest Best Gasket. It is a rope seal but a different material them in the sets or what is sold over the counters.

Joe

I should have checked back to this post sooner. It is saturday and Patrick's is closed probably until wednesday. I am going to have to try another rope seal this time from napa. I need to get to work wednesday and cannot be without transportation for the second week in a row. Live and learn right.


The first seal that my neighbor installed must not have seated correctly and the crank will not turn. I dropped the oil pan and unloosened the main caps enough to get the engine to turn. Snugged back down the bolts and the crank would not spin. Now i am pulling the engine out again redoing the seal this time myself so i can blame myself not my neighbor.

Is there anything to watch for when installing it? I did not line up the seal with the block and cap i had a little sticking into the cap from the top and a little sticking up into the top from the cap so it would not leak at the seam.

I am planning to remove the crank completely to gain access to the seal.
Previously i unbolted the three rear caps and unloosened the front to allow the crank to sag.

If you didn't have the seal parting ends aligned with the cap, I don't know how you put the cap on. That technique is used with the neoprene seal, not with the rope type. My guess is that it mushed into the bearing area and caused a lot of friction.

I recall when i took the old one out it was lined up with the cap and block. On the package to the new seal it clearly states to line it up and trim off excess. Me being the influential and sometimes easy going natured type of person figured my neighbor knew what he was talking about so i listened to him. Never again.

One of the best hints on here was to buy the seal made by Best gsakets. It is made differently than the others and has a woven appearance.

What year is your 235? Somewhere around 1956 the blocks had a groove that would take the nroprene seal. There was a posting a while back where someone claimed that the groove wasn't large enough for the rope seal and they used a neoprene seal with good results.

I have a 216 so it must be the rope. Is it possible to install without completely removing the crank?


I have off the three main caps. The front one still on because i dont have a pulley puller to get off the front cap. I loosened the bolts inside the oil pan though. I thought if i removed the rod caps also that i may get enough clearance. Getting frustrating because it probably would have been fine with tge old seal

I put mine in without removing the crank. You just need a little clearance. I used a piece of picture hanging wire to pull the seal in. Initially I had to guide the start of the seal into the groove and then with a steady force, pulled it around. They do create some drag when newly installed but you should be able to turn it over.

If it were my truck I'd check the clearance for the main bearings before I install the seal. If you decide to check the clearance watch so the shims don't fall out on you when you take the cap off.

I have the main caps and shims off and in order. I have went as far as removing the harmonic balancer and destroyed the auto zone made in china tool i just bought today. I removed and kept the rod caps in order. The crank will not come out because the oil pump tube will not come off.

The 4 screws are tighter than anything i have ever come accross. I go.t the tube loosened but it will not come off the engine because there is no where for it to go

So the crank is stuck in the engine by the oil pump tube. I am so close. I will prevail.


On a side note its good that i am tearing it down this far to clean tge bearings and retorque everything.

A little bit of heat can go pretty far. I disconnected the oil pump dropped the crank out of the way and am installing the top of the seal as soon as i put my phone down. Then starts reassembly. Thanks to all that helped me

Do a search for the "Sneaky Pete" tool here. I bought one and had no problem putting the rope seal in place on a 216. All I did was loosen the first 2 bearing caps a little. Afterwards it was a little stiff while turning but has since loosened up.

I just installed the Best rope seal on my '52 216 and the seal will make the crank very diffilcult to turn by hand. It should loosen up fairly quickly. Because of this, it is critical that the bearing caps are adjusted with plastigage or with the seal removed.

Just so you know how good this seal (Best Seal) material is, I installed one in a 455 Pontiac and didn't follow the direction 100%. I though a little packing would be better then the press fit. After the engine ran for 25 minutes on a test stand during a break in, I shut it off for a cool down and clean up of the area. I went back to the engine to start it and it was locked solid, even with a four foot bar on the front, it locked dead solid. The next day it was free, so I ran it again for a short time while checking things out. A heat gun showed the rear of the crank getting hot, thats when I figured out the mistake. Before installed the second seal, I read all the directions and followed them to a T. This time it worked as it should and hasn't leaked yet!

The Best Seal is really good material.

Joe

if you have it torn down that far, just go ahead and have the block machined for a full circle seal, I have the part number somewhere if you are interested. That would be the absolutely best way to go. I was under the impression you were trying to do this in the truck. You don't really need to pull the engine for this.

I pulled the engine from a donor truck i bought because my current engine has a cracked water jacket behind the generator and it is starting to smoke pretty bad from oil leaks and being tired. The only reason i was changing the rear main is because my neighbor talked me into it by saying i will hate myself down the road if i dont do it now while the engine is out. Now i hate him. My 1947 is my daily driver so i dont have time to machine for a full seal or have a way to get it to the machine shop. I was hoping this was an easy job but not with the felpro seal i bought twice. Next time i will sell the truck before changing the seal.

If a NOS GM seal is used or a seal from Best Gasket and properly installed along with proper bearing clearance set you will have no problems. As mentioned you can have the block machined to update a full circle seal, this can get expensive.
Sometimes just stick to the basics that have worked for years and get back on the road.

So what is it with Best Gaskets? Do you guys get paid commission on how many times you say their name in a thread? I am almost sick of hearing the name. It has been repeated at least 6 times. I understand your trying to help but like i said i got a felpro gasket and that is what i am using. In the future if i ever do this again i will take your recommendations into account and get one from them. I might just order one to have it in the garage. Sorry for the rant but sometimes you use what you have.

The material the Best Gasket seal is made of makes it superior. No I don't get a commission but I have used their seal. I wouldn't waste my time with any other. You do what you want with your engine.

If a someone asks a question here you get the question answered. If your not interested in the experience and knowledge here don't waste peoples time and then complain about the answers.

Also, some of the people here are privy to information/experiences with several of these brands of seals - this is a common problem area.

We have to learn to just chill out: we should just state our experience(s) and let it rest (put our egos away). This type of "variety of experiences" also occurs when people ask about Pertronix ignition, or tube/tubeless radial tires, or ZDDP additives during normal oil changes, or the need for hardened valve seats, or the . . .

If you want to learn more about comparison of product information on rear seals, join the oldGMCtrucks discussion board and look of the discussion on these seals (by pros and by careful multiple-experience restorers).

I never asked what is the best seal to use. I asked how to install the seal. Pay attention to the question being asked before just responding with a brand name. Thank you all for your input the seal i used may not be the seal of your choice but it is my truck and i will repair it with what i am able to when needed. My truck is my daily driver and i usually do not have the time to wait for replacement parts to be ordered and shipped. As i stated above i will look into the Best Gasket company for future repairs. The seal is in it is not leaking case closed. Please delete this thread and lets move on.

well if you had bought a BEST SEAL seal the insructions would have come with the seal. I am assuming the felpro seal did too, there is a tech tip on this forum, the manual has instructions as well. So if you can't follow those basic instructions, (This is one of the most basic operations you will probably perform) what would make you think, you could follow any instructions given by any of us. Sometimes a person could do well by having a little humility. A used honda or a toyota would be a good dependable daily driver, these trucks make better toys than daily drivers. Although many people use them as such, most have another vehicle they can use. The reason people were mentioning the BEST SEAL seal is because although this is a basic operation, it is time consuming. And since you can get the BEST SEAL seal in no more than 2 or 3 days from any number of vendors and a little oil leaking from one of these engines is as common as cars on the freeway, there would be no reason to NOT wait until you can get one. I am quite sure this post will be deleted, but hopefully not before YOU get to see it. You have wasted 3 pages of comments and several peoples time who were trying to help. For example I should have been in bed 1/2 an hour ago, You were told how to install it, along with some very good advice, sometimes the CORRECT answer to a question isn't what you want to hear. And for that matter "unloosened" isn't even a word, but if it was, it would mean "tightened". The correct word would be "loosened"

Here is what you first posted:

installing a new rear main seal help needed [Re: 5/8 ton]
If anyone has tip tricks or otherwise useful help please post away.

Your first post was on the 16th.
Best Gasket was mentioned on the 16th.
The first time Fel-Pro was mentioned was on the 28th, after trying/buying it for the second time.

You got upset about hearing about Best Gasket on the 29th.

hmmmm . . . who should be upset with whom?

You can be sure I'll never respond to another of his posts.

Just to clear up why one seal is better then the others, its the material used. Years back late 80's early 90's, Felpro and all the other makers removed all the asbestos from the seal material. This left us with a flimsy rope with a little lube impregnated in it. The seals would fall apart in no time if you could even get them in in the first place. The seal from Best is still made the old fashion way and holds together. I would bet they are getting there stock from England. I bought a bunch of seal from there when working on a Stanley a few years back and it was just like the old seals we used to get from Felpro.


We are also glad you have your truck working.

Joe