1997 Ram 1500 5.9 Rear Main Leak

[zfasts03]

Rear main on 1997 Dodge Ram 1500 started leaking. Leaving a 2" mark on concrete driveway after sitting for about a week. 76,000 miles on the truck. A good amount of rust on body and frame.

This engine has been leak free for its' 20 year life. About 2-3 months ago I changed the oil to Castrol Edge 10w-30 Syn. w/Fram Ultra and a leak developed.

This is my first time using this oil. Ran Mobil 1 for the first 14 years or so then some Amsoil, Valvoline, Pennzoil and Kendall. Always synthetic, once or twice a blend.

Do you think this leak is related to Castrol Edge or is it just coincidental, being the truck is 20 years old.

I have some Quaker State HM blend 10w-30 I may try next if the leak gets much worse. I also have Valvoline Max-Life on hand.

I am trying to keep this truck going for many more years as the new ones are big bucks (for the amount of use I need it for) and have way more technology/complexity than I need in a truck.

 

[3800Series]

Seems like it was just odd luck to me. Since you said you've been using Mobil One for many years I'm assuming your referring to their synthetic line of oils and not the Mobil Clean.. or was it Mobil 5000 now? Anyways I digress.

Seals leak its just a common fact it happens to a all vehicles (or at least most) with age. There is a few products that say they can help rejuvenate the seals without causing them to soften and swell.

The one that comes to mind is ATP 205 I've tried it in the past and while I did not have much luck with it the stuff has a good following for the most part here.

You cab try high mileage oil in the future and see if that helps any. It can slow down oil leaks and in a few cases completely stop the leak for the time being. I've only every used Maxlife as a high mileage oil and it stopped the leak i n my old car 8-10 years ago after a handful of changes but the rear main can be a pain and in most cases the only real way to fix it is to replace the seal but that's not always economical.

 

[zfasts03]

Yep Mobil 1 Synthetic for most of its' life in the 1997 Ram. Few other syn's. Always kept up with maintenance over the years.

I hate leaving drips in the driveway and other peoples driveway.

At first I thought it was transmission fluid as it was dripping off the trans. pan. But further/closer investigation, it is clearly clean motor oil.

Just odd how it started after the change to Castrol Edge.

I had the same thing happen to my 1980 Chrysler Lebaron when Castrol introduced their 5w-50 Synthetic back in the 90's. But in the Lebaron with the 318 V8, It was the front crank seal that went. It was the first time using synthetic in the Lebaron and that I kinda understood as seals weren't up to the task of handling synthetics.

 

[Chris142]

Switch it to Maxlife. See if that helps.

 

[zfasts03]

Yeah, that is what I am debating. I don't want to pull out oil with 900 miles on it if that is not the cause.

 

[CT8]

The easiest and cheapest thing to do would be to try a high mile oil. Check for loose oil pan bolts valve cover leak? Put some cardboard or a drip pan inter the leak.

 

[JC1]

Originally Posted By: zfasts03
Yeah, that is what I am debating. I don't want to pull out oil with 900 miles on it if that is not the cause.


Drain the current oil into a clean pan and store in the empty jug of Maxlife once you refill with Maxlife.

 

[tomcat27]

I had that problem with my 98 dodge 5.2 @ an early age (almost new). it leaked from the rear main seal with Amsoil but nothing else. I tried it 2x with the same result. easy: I don't use Amsoil in the truck.

 

[fdcg27]

I'd give Maxlife a try.
Just run this current OCI out to some reasonable length before you drain it and let it leak a bit.
Are you sure it's a RMS leak?
A sump gasket leak is also a possibility and might be fixed with as little as retorqueing all of the little bolts.
You'd have to be really ambitious to drop the tranny just to replace a five buck seal. I'd do that only in the course of a clutch job myself.
If there is a lot of body and frame rust, which in PA is certainly the norm, then I suspect that this problem may solve itself in that you'll be shopping for a new to you truck before many more years have passed.

 

[SatinSilver]

Originally Posted By: fdcg27
If there is a lot of body and frame rust, which in PA is certainly the norm,


Please see below:

Originally Posted By: zfasts03
A good amount of rust on body and frame.

 

[zfasts03]

Rust includes the normal rust above and around the wheel wells.

There are holes in the frame in front of front sway bar mounting brackets.

These pics are from a few years ago. Rust is a lot worse now. I knocked out the loose rust on the frame and used a lot of rust treatment products from Eastwood.

I will run this truck as long as I can keep getting through PA inspection or something REAL expensive fails.

 

[zfasts03]

The truck has really gone down hill in the past 3 years after these pics were taken in 2014. Dashboard is cracked and caving in and the rust is taking over. BUT IT RUNS LIKE NEW!

 

[bigt61]

Run your normal OCI w the Castrol, just top off with cheap dino - SuperTech is fine. Then switch to MaxLife and let it eat. If the leak gets worse or bothers you, put a drain pan under held in place with a heavy weight. (so it doesn't blow away) RMS not worth fixing on a 20 year old truck w rust.

 

[fdcg27]

You have to wonder whether a drain hole at the lowest point where the rust Swiss cheesing occurred might have prevented it.
Others who own these trucks should maybe consider drilling or blowing a hole at that point.

 

[zfasts03]

I thought the same thing. A drain hole at the lowest point about 3/16" diameter and spray inside/outside frame and hole with rustproofing.

Too late now.