Replace rear crankshaft seal

TDS · Veteran Member

Replace rear crankshaft seal

427carl · A Poncho Legend!

Johnny Ringo wrote:
.....I only did one in a 440 '69 GTX . Not easy but it can be done. There is a special tool called a " fish " if I remember right ? , still have it someplace , but it is designed to grab and hold the rope seal and let you pull it through around and over the crank to install the top 1/2. Dropping all the main brg caps abit allowing the crank to drop some will give the extra room to remove and pull through the new rope seal. Then tighten up the caps, trim the rope and install the lower 1/2. But first I would try some additive in the oil that does work for leaky rear seals. I use it in one of my olds diesels that is famous for a leaky rope seal in back and it does work pretty good. It swells up the seal and helps stop the leak.

In used this on my Camaro worked great

427carl · A Poncho Legend!

TDS wrote:
Hi
My Laurentian is leaking at the rear crankshaft seal.
I belive its a rope seal.
Have anyone tried to replace this without pulling the engine?.
A guide would be great.

Merry Christmas to all of you.

Best
Torben

heres a reply from the internet on the same subject

Re: 235 rear main seal: rope or neoprene

Vetteman61,

I have a 216 in my 48 chev and from what I've read, almost without exception, all the chev 6 cyl. engines develop a small leak where the 2 halves of the rope seal meet. If you go to the VCCA (Vintage Chevrolet Club of America) forum, there are threads on the this very subject. What some of the gear heads have done with some success is to make sure 1 half of the rope seal is just a tad long and use a dab of silicone sealer where those 2 halves meet before assembling the oil pan to the engine. I haven't tried it myself. Those guys recommend using a rope seal. My car has a small drip, no clutch chatter though... I just live with it.

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4SPEED427 · A Poncho Legend!

I believe it was Lisle tools who used to offer a special tool to do this job.

long stroke · Canadian Poncho Superstar!

Carl Stevenson wrote:
I believe it was Lisle tools who used to offer a special tool to do this job.

I have that very tool and it is called a sneaky Pete. I used it once on a friends 55 Chev 235 over 10 years ago and it worked well, not easy but it worked. About six years ago i lent it to a friend with a 390 Ford and he said it worked well, not easy but it worked. Still the best way to do the job is to pull out the crank.......... no doubt about it. I do not for one second think that "snake oil" additives do anything other than possibly swell the gaskets to the point of permanent damage. Just my thoughts. Cheers. George.

4SPEED427 · A Poncho Legend!

Yup, Lisle 27000 is the Sneaky Pete tool. Easy enough to find online using that part number.

Pontiacanada · A Poncho Legend!

Carl Stevenson wrote:
Yup, Lisle 27000 is the Sneaky Pete tool. Easy enough to find online using that part number.

http://www.lislecorp.com/divisions/products/?product=134

GLHS60 · Poncho Master!

Neoprene replacement seals were available at one time, probably still are.
Much easier to deal with.

Thanks
Randy

Lefty · Uber Guru

on some motors there is a tiny hole you can put something in and then turn the crank to "rotate" the seal out and new one back in..
did this once a few years ago..

TDS · Veteran Member

Hi
Perfect, thanks to all of you.

Im using Castrol SAE 30 oil and its only leaking when the engine and oil is hot.

There are two issues that I have considered:
Am I using the wrong oil?

When replacing the oil, Im using more oil than the workshop manual describes for my 261 cui
It takes at least 6½ liters including oil for the external oil filter to reach the middle of the two marks on the dipstick.
Workshop manual says 4+1 qt = 4,75 liter
Im pretty sure I got the original dipstick.
Is this normal?

But Ill find a new rope seal and a sneaky Pete and try it out...
Its too cold to crawl under the car now, but its nice to have plans for the spring

TDS · Veteran Member

Ok, the 5 qt imperial is around 5,7 liters - should had figured that out by myself

.
Thanks..