318 rear main seal replacement

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R2D100
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318 rear main seal replacement

Post by R2D100 »

Im about to gather the parts necessary to change my rear main seal, oil pan gasket and oil pump. Was curious if i can change the rear main seal without removing the transmission? Ive seen write-ups for this job on other 318s and it was possible. I can not fit a engine hoist in my garage at the time and would like to be able to do the job on my own if possible. If anyone has a link to a write up for a d100 318 with manual tranny or any tips, that would be much appreciated.

Also, how do i post pics on this forum? Id like to share pics of the olde polished turd to share!!!

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Re: 318 rear main seal replacement

Post by PwrWgnDrvr »

It can be done, but you'll enjoy the oil dripping in your face the whole time.

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Re: 318 rear main seal replacement

Post by R2D100 »

Excellent! I anticipated that.. am going to drop the pan, remove the oil pump and let it drip for a day, start workin on it after it drips out.

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Re: 318 rear main seal replacement

Post by Txas2step »

A little "oil of LA" is better than a facial. :lol: :joker
61 shorty 170/ 3spd 3:91(sold)
66 lwb 318 poly/727/4:10 (sold)
67 shorty 318poly/4spd 3:55
68 ute 318/3 spd/3:55(sold)
70 318/727/3:23
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Re: 318 rear main seal replacement

Post by stumblinhorse »

If it is rope, you should get a sneaky pete tool in advance. If rubber then it should/might/hopefully slide out...
1969 D100 LWB 318 np435
2001 2500 SWB 5.9 Cummins nv5600
2016 3500 SWB 6.7 Cummins 68RFE

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Re: 318 rear main seal replacement

Post by Hobcobble »

Txas2step wrote:A little "oil of LA" is better than a facial. :lol: :joker
:lol: :lol: :clap :clap :Thumbsup

[Still though.... don't quit your day job... :shame ]
John

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Re: 318 rear main seal replacement

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:dance
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Re: 318 rear main seal replacement

Post by R2D100 »

Was hoping they stopped using this "rope material", that i was reading about, by 71'??
Does the oil pan clear without exhaust removal? I was under there the other day, doing a mass clean up of the old oil build up and the pan looked to have plenty of clearance.

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Re: 318 rear main seal replacement

Post by MadMC63 »

You could probably find a rope seal if you looked hard enough, it was replaced by the two piece rubber. If your taking the time to drop the pan use the Melling M72HV pump. Once your pan is down and you are in the proccess of cleaning take note of any small chunks of brownish or yellowish plastic. If you see alot of this plastic in the pan plan on replaing your timing chain and gears. The original gears are aluminun coated with ( I think) teflon and the plastic pieces are reminantes of that coating. You'll need to clean or replace the pickup tube if the chucks are prevalent. When you remove the rear main cap be sure to pay close attention the bearing half and the extent of wear. Unless you have some kind of crazy exhaust you should be able to drop the pan without difficulty.
Alot of poeple use a third party web site for sharing photos I use MS Piant, resize and change the pixel setting to 310. There small but it works.
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Re: 318 rear main seal replacement

Post by earlymopar »

Several good pointers from MadMc63 for doing this job. If you need a Melling M72HV oil pump, PM me here. I have a brand new one I will make a great deal on.

- EM

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Re: 318 rear main seal replacement

Post by stumblinhorse »

R2D100 wrote:Was hoping they stopped using this "rope material", that i was reading about, by 71'??
Does the oil pan clear without exhaust removal? I was under there the other day, doing a mass clean up of the old oil build up and the pan looked to have plenty of clearance.
Not sure they stopped using rope by 71...

Once you finish yours, I am about 1 hours south of you, and you can help me do mine!
1969 D100 LWB 318 np435
2001 2500 SWB 5.9 Cummins nv5600
2016 3500 SWB 6.7 Cummins 68RFE

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Re: 318 rear main seal replacement

Post by MadMC63 »

Get him to help while it's all still fresh in his mind, good idea Ha Ha.
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Re: 318 rear main seal replacement

Post by R2D100 »

Wrastlin the old tar pit tub from the under the truck.. looks like the only way to remove the pan without lifting the motor, im gonna need to remove the oil pump first. Seems as though, the pick up tube gets in the way of getting the deep part of the pan over the axle i beam. There was only one bolt on the pan that was any trouble. A bolt very close to the exhaust crossover.. otherwise, fairly simple. Will post an update if the pan removes after dropping the oil pump.

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Re: 318 rear main seal replacement

Post by MadMC63 »

Jack the truck up and support the frame with jack stands allowing the front axle to drop.
1971 Dodge D100
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Re: 318 rear main seal replacement

Post by R2D100 »

Yea, i havent had tha jackstands around since ding some work on a buddys jeep. Thought it looked doable without jacking up the front. I had some free time wanted to get the ball rolling. Was only going to drain and take the pan bolts out today. Wanna let oil drip as much as possible befor i remove pan completely

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Re: 318 rear main seal replacement

Post by Kaegi »

you probably checked this but the oil pressure sending unit or the line for gauge can leak at back of engine and drain down the back. I have seen this get miss diagnosed as rear main seal. or the back of intake is knows to leak as well.

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Re: 318 rear main seal replacement

Post by 69PowerWagon »

I just did this same repair on the 318 in my 76 D200. The 76 had a rope seal rear main too, it was so far gone that the oil was leaking into the bell housing and shortening the life of the clutch. I already had the timing chain off so I put a jack under the bell housing and pulled the 4spd trans back just enough to clear the clutch. I removed the rear main cap and loosened the rest enough to give enough clearance to get the upper rope seal out. It fought me all the way, needle-nose pliers just pulled little pieces off of the seal, what got it out was a real long and skinny screwdriver. Just jammed it up into one end of the seal and the other end popped down enough to get the pliers on it. The Felpro gasket set came with a molded rubber lip seal so it just slid right in. The 76 has an independent front suspension but I was able to get the pan off without jacking up the engine at all. The oil pump pickup was full of valve stem seal chunks so those were replaced also. If you replace the oil pump please make sure you prime it first before installing it. I hope some of this is of use to you
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1976 D200 318 4spd

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Re: 318 rear main seal replacement

Post by R2D100 »

Well, after a bout of holidays and cold weather, i finally got around to doing some work on the rear main. I was able to get the rear main out and replaced, the new pump installed, all the old sealant scraped off and the pan nice and clean. Opened the box for the fel pro oil pan gasket then realized that its a 4 piece cork gasket thing. I just dont trust using that gasket with the way it overlaps where the cork gasket meets the seals. Not to mention, i couldnt get the tabs of the seals into the holes of the oil pan, even after hitting the seals with a heat gun. Anyone have a good recommendation for a solid one piece gasket? I hesitate to use this felpro garbage.

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Re: 318 rear main seal replacement

Post by 69PowerWagon »

I used the Felpro gaskets on the 318 and haven't had any leaks yet. It's odd how the cork overlaps the little plastic tabs of the rear main seal. If your oil pan is like mine then the rear rubber seal is a little larger than the front seal, also the little pegs on each side of the rubber seals are different size. I just put a bit of ultra black RTV in each corner of the pan gasket.
1952 B3GA truck
1971 D200 440 727
1976 D200 318 4spd

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Re: 318 rear main seal replacement

Post by R2D100 »

I noticed that the lil pegs were different sizes. Its possible that theyre a lil too large for the holes in my pan. I debated snipping them off but thought id try looking for a better gasket before i go through with it. Im pretty sure id have to alter them in some way if i were gonna get them to fit in the holes.

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