How to replace rear seal on a 340?

[Glennster]

 It's beginning to look like my rear seal is leaking. I understand this can be replaced easily once you remove the oil pan. One guy said he thought there was a special tool for this job.
  I just replaced the oil pan gasket, I sure wish I'd have done the rear seal while I was in there.

 Does anyone have some pictures or info on this job???

THANKS!

[Moparal]

I really admire your calm collectivness. Your engine was just on a stand like 3 weeks ago, you installed it, then pulled the pan and put it back on, now you are gonna pull it again and change the rear main seal.  And there isnt even a trace of bewilderment in your post.  You are the man

Rope seal is a special tool. You most likely have a rubber seal.  Pan off, rear main cap off, that will hold a bearing shell half and a half seal, the other top seal is a bit more tricky. It will be kinda stuck tight. The end of a small punch or nail can get it started out pretty easy enough. You may have to loosen up the other main bearing caps and allow a little movement. You wont get much though with the timing chain on. But enough to give you a little more clearance. I only have trouble when someone else has installed one pryor and they stuck gobs of silocone all over the inside and it makes it so it wont slip out as easy.  Do not nick anything on the crank surface. Take notice the seal goes on one way to work right. The wide end faces the engine. Some will chime in and say install it on an angle somewhat, but when done right, you wont really have any issues. Keep it clean tho.


Um, take a good look again at your freeze plugs   Since it could be your next subject post

[Alaskan_TA]

See these links;

http://www.hamtramck-historical.com/images/TSBs/1970/D70-9-3%20page1.jpg

http://www.hamtramck-historical.com/images/TSBs/1970/D70-9-3%20page2.jpg

http://www.hamtramck-historical.com/images/TSBs/1970/D70-9-3%20page3.jpg

http://www.hamtramck-historical.com/images/TSBs/1970/D70-9-3%20page4.jpg

http://www.hamtramck-historical.com/images/TSBs/1970/D70-9-3%20page5.jpg

[Glennster]

Moparal,
  I bought this engine from a guy that should have had all these things in order when I bolted it in the car. So I am pretty unhappy about these problems. BUT, things happen and we all make mistakes. You're giving me more credit than I deserve, but THANK YOU anyway....

  This is the first time I've ever done a motor change in a car, I've worked on motorcycles and other engines for darn near 40 years. I really love turning wrenches. I've tried to take the attitude through this build that I was going to enjoy every nut and bolt. I wanted this to be a fun journey, and for the most part it has been a blast. For 35 years I've wanted a car like this, now my dream is a reality.
  The guy that's really made it possible is my friend Jim Stewart, he's allowed me to use his building, his tools, his invaluable experience and his time. He's also been generous to the point where he's GIVEN me almost $300 worth of parts. He would not accept cash for the parts......He's got quite a stash of MOPAR goodies.

  With this kind of a blessing, I should certainly keep my temper in check and I should keep a good attitude. Heck, I never removed an oil pan from a motor until last week, there are millions of poor saps out there that will never know the pleasure of dropping a MOPAR oil pan, let alone the satisfaction of getting her back together dry.

Looks like I'll soon have the pleasure of repairing a real seal. How many guys can say they did that???
YUP, I'm CRAZY!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Alaskan_TA,
 THANKS for the info!

[Chryco Psycho]

I did one abotu 6 weeks ago , & I have done them often without removing the engine , not fun but you get it done

[Glennster]

 I was looking at seals on the net, the guys a Dvorak seem to tell a great story. Is the Dvorak seal better than the rest?
I used Fel Pro for my oil pan gasket with Permatex Ultra Black. Maybe they have a good seal too......

Does the rear seal require a sealer like RTV ?

[Chryco Psycho]

I have used the Fel Pro seal , I offset the ends of the seal a little so the parting line is not the same as the steel cap & use a small drop of silicone on the ends of the seal to help them seal up

[Bullitt-]

I'll throw this out just because... Years ago I started using oil in my 340 loosing about a quart every two tanks of gas, I had just put on a set of "Race" prepped heads that had no valve seals.....Had to have the tranny rebuilt & was told that I had a rear main seal leak, AHH that's where the oil is going. Tranny guy & another professional mechanic quoted $ I did not have to spend so I determined to repair myself. Bought the seal & pan gasket, pulled the car up on ramps but before I removed anything decided I wanted to SEE it leak.  Sooo I started the motor & laid underneath waiting, finally after several minutes a drop but it did not come from the center but rather off the left side of the block. Followed the trail up to the back of the intake... When I replaced the heads months before I had not gotten the rear intake seal on straight.

[Chryco Psycho]

I was not so smart , I changed the rear seal twice before I found the cracked fitting on the oil pressure line 

[Got JOB]

How much are you going to drive the car? A piece of foam 1"x6" will squeeze between the pan and transmission and catch the leak for many miles. Drive the car for a while to see if you have any more issues that need to be taken care of. Just my

[Glennster]

  We got the car back on the lift, blasted everything with starter fluid and wiped it all down till it's clean and dry. We started it up, let her get good and hot....Then we started to see the oil seep out. At first we thought it was coming out of the right rear corner of the oil pan. But, it seems to be coming from the oil filter plate..........The rear seal is dry so far. That's good!

[The Cuda Guy]

The rear seal is dry so far. That's good!

You got luck bro!

Don