VCCA Home Forums TECHNICAL - 1945 AND NEWER 1955-1957 '57 235 with engine squeak and oil leak

Hello All:

I had a mechanic friend change out the oil pan gasket, the side cover gasket, the valve cover gasket, and the front main seal. Now there is a squeak that comes and goes from the front of the engine. It is not the generator or water pump. Plus I now have a good amount of oil coming out of the clutch housing, which we suspect is from the rear main seal. This engine has 41,000 original miles on it.

Any ideas? And does anyone know if it's possible to replace the main rear bearing without pulling the engine as the shop manual indicates ("major service operations")? I read on a thread someplace (maybe here!) that it's possible to "fish" a new rope type seal up into there, but that it's tricky.

Any help is greatly appreciated!

Thanks,

Bryan (Tampa, FL)

Bryan,
The squeak is coming from the new timing gear cover oil seal (front main seal). The seal is actually doing too good of a job and is "running dry". I would spray some WD40 in behind the balancer. Use the straw extension to get between the front cover and back of balancer. This may find its way to the front lip of the seal. Other than that it will eventually disappear with some driving.
The new "rubber " type replacement rear main bearing seal can be installed in your 1957 235 engine. This seal will replace the rope type and the upper half can easily be slid in place with out removing the crankshaft. The seal is available thru a parts house that has the FelPro gasket line. Too bad that it was not done while the oil pan was removed.
The rubber seal can be used on 1955-1962 235 engines. It was not available in 1957. They were first available in the early '60's. Don't mess with a rope seal.

Thanks Gene! We will try this out and I will let you know how it goes! Does the oil pan have to come out again?

I saw these parts online at Obsolete Chevrolet Parts.

Bryan ("Green" '57 235 engine!)

Yes, The pan will need to be removed again.
All the normal vendors sell the seals but a local parts house can also order it for you and eleminate shipping charges.

Gene,

This brings up a question: I know that this rubber seal would most likey not work in engines like the 216 in my '52 because, as I have been told, the machining tolerances of the oil seal grooves in the splash-oiled 216's and 235's weren't controlled tightly enough to guarantee that the rubber seal will seat properly in this space. What I'm wondering is why this seal wouldn't work in the full-pressure '53 and '54 235's? Wouldn't the machining tolerances have been changed in these engines to something similar to at least what was found in the '55?

If in all cases the issue is one of the dimensional tolerances of the groove rather than an issue of the groove being the wrong width, depth or profile altogether, it's a shame that there's no information available on what the minimum and maximum dimension should be for this groove. If we knew what the actual spec's were for the '55 through '62 engines, it might then be possible to say that the rubber seal may work in earlier engines where the groove measures "...between .XXXX" and .YYYY"..."

Thanks,

It usually does not work in a 1953-54 either.The block had many changes in 1955.
The rubber seal is available for 1955-58 8 cylinder engines.They used a rope originally.The replacement seal is a 1959 and up rubber seal with a little spacer that adapts it to the earlier blocks.
I would like to experiment along those lines on my '50 but don't have the guts to do so.

In a previous thread I posted the incorrect info. concerning a sorce that explains why a rope seal can not be used in a pre 1955.
The correct sorce is chevytrucks.org.article by Bob Adler (VCCA Tech advisor).I belive running this article in the G&D with Bob's permission should be considered.
.....can be found at www.chevytrucks.org/tech/bobadler......

Gene,

Thanks for the reply, and the email you sent. I agree -- this article should be reprinted in the G&D if Bob and/or Chevytrucks.org would allow it. Also, I wish the G&D would reprint the tech article I remember from a number of years ago about replacing the bottom half of the rope seal while doing some judicious repacking and/or adding material to the upper seal, thereby possibly eliminating the need to yank out and tear down an otherwise good-running engine. I actually held onto that particular article, but -- I'm sure you know how the story goes -- Lord only knows where the stinkin' thing is now!

On the subject of rear seals, has anyone found a modern brand that works well? I've heard nothing but bad things about the newer non-asbestos rope seals, and the NOS or NORS ones are getting more difficult to come by every day.

Thanks,

The modern non-asbestos seals don't work well.The covering seems to tear up very easily.I picked up some NOS GM seals on ebay.Will be my first/next project to install them.The upper seal in my '50 is rather hard so I didn't try the compress method last time and replaced the lower only.Still have a minor leak.Another old trick was to drive a wire up into the top half to expand the rope.I have been thinking of that also.
I don't know if I could find Bob's compress and splice article but the instructions are in GM shop manuals.It covered in the Oldsmobile 307 engine section.That engine was used up to 1990 and used a rope seal.
Will be looking to contact Bob for permission.

Alas, Gene, I've always been told by the old timers, hard to imagine anybody older than me, that it is the upper seal that does the leaking since the crakshaft tends to ride down in the bearing cap and stay on the lower seal. Over the years, I have had good luck with using a brass rod or simply an old coat hanger sharpened to a point and driven over the top. I've also extracted the upper seal and never had much trouble getting the old seal out but always had a real struggle getting the new one in. The last time I had to give up and pull the engine to get the upper half in. So good luck on which ever method you use.

This is the way I replaced the seal back when I enjoyed getting under the car.

To remove the upper seal I've alway loosened all of the main caps until the bolts are just barely holding and then pried the crankshaft down into the loosend caps. This ain't easy to do since you are working in a restricted access area. To get the old seal out I drive a sharpened coat hanger over the top and then bend the end over so that there is sort of a hook on the end. Forgot to mention to drive the hanger in so that when you pull the hanger to extract the upper seal you will be pulling in the direction that the engine normally rotates. Next is the tricky part. I use a pair of vise grips on the wire and while I'm pulling, my wife taps the starter as I holler at her. I suspect you can guess how well this works out.(pull the coil wire before you do this) To install the new seal I wrap .320 aircraft safety wire very tightly around the end of the seal and insert it over the top of the crankshaft (lube the seal with grease)use a scribe or an awl to get the end of the seal started and then I call on the good graces of my wife again (this is hazardous to family relations allow for a few days of recovery time) to tap the starter while I pull the new seal in. Getting the new seal started in is the most difficult part. Once started it usually pulls in fairly easy. Once the seal is in I use a razor blade to trim the ends and tighten every thing back up. Years ago I also tried one of the chinese finger grip rear seal fishing tools. It didn't work. It would not grip the seal tight enough to pull it in. Once again Good Luck.

Mike,
I realize that there are ways to pull the upper seal into place but I hesitate to recommend them without knowing the mechanical abilities of the person doing the job....If you know what I mean.
Hate to see a guy get in over his head.

Or in the bad graces of his wife

Sorry, I just couldn't resist that one fellas

Mike, that was a great description :grin: and I know just where you are coming from......love this hobby !!!

Thanks, Gene, for all the help. I wanted to give an update:

The squeak went away by itself.

I had the rear main seal replaced with the rubber one. No puddles on the garage floor any more! Yay! While we had the oil pan out (again!), we replaced the oil pump (could not find a replacement screen though).

Had the transmission gaskets replaced.

Also, had the 1 bbl carb rebuilt. I highly recommend Guarantee Carburetor of Tampa/St. Pete, FL. They did it in one week for about $170 and it runs and looks like brand new.

Bryan

Always great to hear a success story...... :)