The Stovebolt Site Forums The Shop Area Engine Shop Changing rear main seal on 217ci straight 6 (1951)

Hello my fellow stovebolters!

So i finally got my 1951 truck running thanks to this forums help, Now i discovered that the main rear seal leaks.

So I ordered a new rope seal from the brand everybody reccomends (Best gasket).

Now i removed the gearbox, clutch and flywheel, and i now know how the thing looks at the back of the engine:

http://imageshack.com/f/f0M4G2gXj

My question is though, How should i continue? I've seen several "tutorials" online but none discribes this engine So i dont really know.

SHould i loosen and remove the two bolts you see in the picture? And try to take out the whole thing and then change the seals? If that is the case, do i have to empty the engine from oil?

Thanks a lot for the answers i'll get, cause i know you guys will help me fix this to! As usual!

Greetings from Sweden, Raoul.

Yes, you will have to drain the oil and remove the oil pan. It helps if you can get a "sneeky pete" that is a tool to remove the old seal and help pull in the new seal. With the tansmission out and with the rear main bearing cap removed, loosen the pther main bearing caps to let the crank shaft down a bit. This will help get some space for the new seal to go around the crank shaft. There is a "Tech Tip" on this site that will help. It is a tough job, but it can be done. Important! There may be shims on the main bearing caps. Keep track of them and put them back exactly where they came from. Happy wenching. Clean every thing up and reassemble. Follow the Tech Tip and it will seal.

This might be helpful:
http://chevy.oldcarmanualproject.com/shop/1948_51truck/51ctsm0617.htm

Link to pic doesnt work. Should be : https://imagizer.imageshack.us/v2/896x672q90/540/M4G2gX.jpg

Thanks Steve, i think i understand!

(BTW, this forum is reaaaallly slow on my pc and phone for some reason, thats why i cant use the 'Edit' function...

Damnit, i forgot to ask:
When i change the oil. is 10W40 good for this engine? Buddy said it doesnt really matter with those old engines because there is so much space for lubrication everywhere, but i want to make sure.

Also. I'm going to change the cooling liquid and thermostat, because i dont have a working thermometer in the car so i dont know how hot the engine gets.. How many liters of water should i put in the radiator?

You might need to consider your climate for oil selection. Maybe a lighter 30W when temps drop to below 30 or 40 below zero. How cold does it get in Sweden anyway?

it doesnt get colder than -20 degrees celsius here, and not warmer than +35, so thats why i thaught 10w40 would be perfect1

Okay guys, removed the Lower part of the seal today, got the old one out, new one in but the rope seal is almost twice as thick as the track is. Can anyone discribe as detailed as possible how i should get it in the track? Right now it's evenly in the track and I guess that when I screw it back, it seals fine. But I'm not sure...? Dot want to do this job twice

You need to roll the seal into the groove using something like a large socket. You want to get it seated right in the bottom of the groove. For the upper half, I would put the flywheel back on because you may want to turn the crankshaft at some point.

Jesus! This is probably The hardest thing I've ever done. The lower seal is in place but I have no idea if I will ever get the upper seal in place too. Got the crankshaft down Like half an inch but it's still too tight at the sides to get the rope thru.. I don't want to damage the new seal with my screwdriver.. How much lower could I try to puh the crankshaft? I'm taking a break now

I've replaced the rear seal on two engines now, and both times I had to do the process twice. I hope you have studied the tech tip on this and even done a search in this forum. Lots of us have wrestled with a rear seal replacement, and there are plenty of good ideas to be found in earlier posts.
Are you using a "sneaky Pete" or some variation? Many of us have pressed the upper half-seal into the lower cap to press-form it before pulling it into the upper track. As Truckernix says, you will probably want to be able to turn the crankshaft while pulling the upper seal into place, I have always needed to do so.
I've gotten better at replacing these seals after failing so many times. I'd come by and lend a hand but I suspect you are a ways away from Lidkoping, and my rate of success is not the best anyways. Good luck.
Karl

I used a piece of picture hanging wire to pull it in. Using some tension I guided the start with a screwdriver. I also used some lube. Once it started to move it just took patience. Getting the old one out was a big job for me.

You don't need the crank down any further.

i now made my own sneaky pete (the same way you did truckernix) hope it will work.

Also, i took away the whole bearing cap (the one thats after the rear main seal bearing so to say.)

(i count the rear main seal as one bearing cap, then there are 2 inside the engine, of those i mean the first, and after those two there's one all the way in the front)

I am now not sure if i put it back the right way.. It looks diffrent on the right and left side where the bults go. Does it matter? Or which way is it supposed to be? The other one more to the front of the engine is symetric.

Also, when putting the bults back, can I use locktite? I really want to!

I live in Falkenberg, so not to far away. I do have friends who can help, but i want to be able to do this one myself

Wie, that went reallllly smoothly with I piece of wire! Cut I bit trough my hand though but the seal is in place and it seems to sit right, but I don't dare to crank the engine because I am not sure if that bearing cap is right.. The even side is on the right side of the engine and the "steep" side is on the left. I hope anyone understands what I mean so anyone can help me!

Raoul

Heeeeellll yeah! Found a pic on the internet and it was right! Put it all back togheter and let it run for 20 minutes and no drops or leaks for how long should i keep an eye on thr seal?

Thanks alot for alll help!

Good work on that seal. If you got it right on the first try you're a pretty talented 'bolter!
One of the important steps in preparing for this kind of a chore is to read the service manual. It is full of good pictures. You can find the service manual on the internet, scanned, but if you don't already have one you should buy a paper version. On top of all the obvious benefits, it teaches me the right words for the right parts. It doesn't help so much when talking with Swedish bildårar.
Next time I have a seal to change maybe I'll see if you can help.
Karl

One of the things the shop manual says is that in order to change the top portion of the seal, the engine has to come out and the crankshaft removed. Many of us have proved that wrong!

In my case, the first two seals leaked badly after about 200 miles. The problem was the main bearings were worn out and the seal was being pounded flat. I replaced the main bearings, adjusted them for minimum clearance and the new seal does not leak at all.