Author Topic: 78er 250 inline 6 changing crankshaft main seal  (Read 1465 times)

Offline ChrisD

  • Newbie
  • Posts: 97
  • Newbie
78er 250 inline 6 changing crankshaft main seal
« on: May 22, 2020, 12:12:45 PM »
Hi,

at the moment i'm a bit frustrated. I told in another thread, that the manual transmission was oiling everywhere, so i released it put new seals and so on init and put it back in place. I meant, that was the place where all the oil came from.

i was sooo wrong!

today, the engine runs the first time after, for more than 2-3 minutes and i can say, the oil isn't runing, but near by.
so i haft to change the two parts of the crankshaft main seal.
I already looked into the service manual, and i'm happy that i dont have to release the crankshaft.

But now i have some questions
1. Must i release the transmission again, or can i do this without that?
2. I read, that i have to release the oil pan and oil pump. Is that possible with engine in place and the car not lifted?
3. Can I change the seal while lying under the car (i've no other way)

yesterday, i tried to change the intake manifold of the BMW, and this was also not successfull, because i realized that i need two little new seals, both together not more than 5$.....

sometime when it's raining, it rains heavy (it's a german saying, don't know what you say if more than one goes wrong)

frustrated regards

Chris
1978 Chevy C10 short bed with 250i6 and manual 3speed Saginaw
German us-car/truck newbie

Offline VileZambonie

  • Global Moderator
  • Senior Member
  • *****
  • Posts: 18980
Re: 78er 250 inline 6 changing crankshaft main seal
« Reply #1 on: May 22, 2020, 01:39:57 PM »
The process is essentially the same as the V8 two-piece rear main seals. There are plenty of posts on how to do it here with tips on installation. After you drop the pan, the rear main bearing cap needs to come out. I suggest staggering the seal ends so that they are not parallel to the bearing cap and cylinder block.
,                           ___ 
                         /  _ _ _\_
              ⌠¯¯¯¯¯'   [☼===☼]
              `()_);-;()_)--o--)_)

74 GMC, 75 K5, 84 GMC, 85 K20, 86 k20, 79 K10

Offline ChrisD

  • Newbie
  • Posts: 97
  • Newbie
Re: 78er 250 inline 6 changing crankshaft main seal
« Reply #2 on: May 22, 2020, 02:47:14 PM »
Hi,

okay, i hadn't thought that i6 and v8 are so similar.
Thanks for the enlightment, i'll search through the forum

regards
Chris
1978 Chevy C10 short bed with 250i6 and manual 3speed Saginaw
German us-car/truck newbie

Offline bigben5054

  • Registered Users
  • *
  • Posts: 148
  • Newbie
Re: 78er 250 inline 6 changing crankshaft main seal
« Reply #3 on: May 24, 2020, 08:52:39 AM »
Chris, here is a picture I took out of my 1979 service manual.  The section starts on the previous page, but I did not attach that page - it just says remove oil pan, oil pump and rear main bearing cap.  I don't know whether you can get the pan off with the motor in the truck, but I would have to think you can.  You might want to invest in a service manual for your truck.  There is a lot of useful information in these manuals.  Used ones can be found pretty cheap on eBay.  I think I found mine for $15.  Good luck!

Offline bigben5054

  • Registered Users
  • *
  • Posts: 148
  • Newbie
Re: 78er 250 inline 6 changing crankshaft main seal
« Reply #4 on: May 24, 2020, 09:00:32 AM »
Here is the page on oil pan removal/install.  Looks like you might have to raise up the engine a little bit.  That's "by the book" anyways. 

Offline bigben5054

  • Registered Users
  • *
  • Posts: 148
  • Newbie
Re: 78er 250 inline 6 changing crankshaft main seal
« Reply #5 on: May 24, 2020, 09:04:32 AM »
Here is the page that is right before the first page I posted.  It talks about the special tool, or using a cotter pin, etc. 

Offline ChrisD

  • Newbie
  • Posts: 97
  • Newbie
Re: 78er 250 inline 6 changing crankshaft main seal
« Reply #6 on: May 24, 2020, 02:07:16 PM »
Hi BigBen,
Thank you so much, for the pictures!
Really cool!
Unfortunatly, I have to wait a bit now because
- the parts need some days till they are in Germany
- yesterday while cooking, i choped coleslaw and also a bit of my finger...

But i‘ll tell, if it‘s finished!

Regards
Chris
1978 Chevy C10 short bed with 250i6 and manual 3speed Saginaw
German us-car/truck newbie

Offline Mike81K10

  • Site Supporters
  • Junior Member
  • ******
  • Posts: 878
Re: 78er 250 inline 6 changing crankshaft main seal
« Reply #7 on: May 24, 2020, 05:59:27 PM »
Is it true that you have to lern english in school? Someone told me that some time ago when I visited Germany. I hope your finger is OK and your seal job goes smoothly.
"Tell me and I forget. Teach me and I remember. Involve me and I learn." -Benjamin Franklin

Offline ChrisD

  • Newbie
  • Posts: 97
  • Newbie
Re: 78er 250 inline 6 changing crankshaft main seal
« Reply #8 on: May 24, 2020, 11:20:49 PM »
Is it true that you have to lern english in school? Someone told me that some time ago when I visited Germany. I hope your finger is OK and your seal job goes smoothly.
Hi Mike,
yes, that‘s true. In the 5th class we start learning our first foreign language.
Most start with english, but depending from the school, you also can choose other languages.
I started with french, and english at the 7th class.
But i should say, at school i never really learned english, i hadn‘t a real contact with this language.
French was easy, i had a friend in Paris so i was 2-3 times per year in france.

I really started „learning„ english at work in 2002 as an Oracle dba, because i had to understand all the technical documentation. But for me it‘s more a feeling, on which place i have to put the words, because i never learned the English grammar:D

When do you learn foreign languages? I think with Mexico and the rest of south america, most starts with spanish, right?
 
My finger is okay, the coleslaw has become bit to small because i haven‘t found the part i shopped in it :D . So now it needs some days till it‘s enough healed, to grab onto the oily and dirty engine again.

Regards
Chris
« Last Edit: May 24, 2020, 11:22:37 PM by ChrisD »
1978 Chevy C10 short bed with 250i6 and manual 3speed Saginaw
German us-car/truck newbie