Rear Main Seal Question

[PPeters]

Hey guys, little help. My rear main failed and it's being replaced as we speak. Mechanic explained to me that the seal was sucked in He seemed to think it was odd. Anyone have one fail like this? Does this type of failure tell me something else is awry? TIA



Pat

 

[paccool]

Any evidence of something hitting the seal? Maybe it was installed that way or has the flex plate failed sometime?

I can't say I've ever heard of this happening before.



Stan

 

[PPeters]

It just gets worse. Talked with the pastor yesterday, we booted some things around, like the flex plate (it's OK). The puzzling thing is you would expect the seal to blow out if caused by pressure in the block, not suck in. I can't even see how you could pull a vacuum.



Bob spoke with Piers and said to check the end play on the crank. So we did. . 018:{ The 92 shop manual gives a spec of . 005 to . 012. Bob gave me a set of figures that range from . 004 to . 017. Either way, I'm out. The seal that failed was original, metal frame sealed with lock tite. New seal is rubber coated. I'm wondering if when the seal let go it could spin with the crank and wind it's way in



So now I've got a real problem. I don't like to take chances and say,"... well, I'ts only out . 001 to . 006, just run it. It'll be OK", because about the time I do it will throw a rod and I'll be looking at a new motor. Pull the motor and repair? Might as well rebuild if you're pulling it out. On top of all this, the auto is limping and I was intending on getting a DTT done this spring. Start adding up the dollars to get all this done, and I'm well above what I could get trying to sell it in the used market, and well above what the insurance company is going to give me if it was totalled. New truck time? God, I don't want the payments, but the money toward repair is getting closer and closer. Sorry about the rant.



So, how about some advice. If I were to take the rebuild route, anybody have a suggestion for who to go to in the W. PA. , OH, NY area? Pull and rebuild mine, or get a crate motor? Or just call it quits, get it running, keep it for a beater and buy new? Thanks for listening everybody



Pat

 

[paccool]

Pat, did Piers have any suggestions or comments? My gut feel is to run it as is. Heck, it could have been like this since it was built if someone didn't Q/A it properly. How is the oil pressure holding up? Low pressure would indicate wear in the bearings and if the pressure is ok then the bearings should still be in good shape.



This worries me a little as my truck also has 180K on it.



I am going to replace the rear seal when the flex plate is replaced and just recieved the rear seal from cummins in the mail this morning. Holy crap, it is huge! The inside of the seal is about 5" across. I hope it's the right one. I'm sure it is because the 8 bolts in the flex plate that go into the rear of the crank have a pretty big diameter. I have not had the pleasure of working on the lower end of one of these engines, I'm learning why they are so heavy.



Stan

 

[SRadke]

Yea, 5" across is about right. I'd say you got the right one.



As for you Pat, I'm not sure. I can't think of a way that the cam can wear to gain endplay unless it has also worn severly in ..... (what is it they call the other direction?). Axial=endplay and from the side is... ? I've lost my mind! Anyhow, If you can't get advise from people like Piers I would run it. It's always good to watch for other used rigs I wouldn't be too scared of this one.



-Scott

 

[PPeters]

Thanks for the response, guys. Yeah, that seal is a big one. I'm of the mind to run it for a while and see if it starts leaking again. Spoke with Bob again this am, and the feeling I get is it's a coin toss. Oil pressure has been reading normal on the factory gauge, so I have not seen a decline through all this. Checked into a rebuild, probably facing $5500. transmission will be $4500. Sigh. Gotta think this over.



Pat

 

[BushWakr - RIP]

:-laf :-laf... . Pat, I can feel ya weakening all the way from here.....



I'm just worried that you could pooch the crank if it happens again and next time it's worse... tuff call bud... I'll help any way I can. .



bob.

 

[PPeters]

04, Molten red, HO, 6spd, limited slip, SLT, 4x4, Quad Cab, LWB... . 0%, $2000 rebate.....



oh, oh, oh, somebody make it stop!



If I replace it I could still keep the old beast, pull the motor myself, and... . Yeah, that would work, just gotta get it past the wife... .



Pat

 

[BushWakr - RIP]

Egads... ... . calling all members of the "intervention team" ... . on deck.....



Pastor Bob... breaking out the holy diesel fuel and incence filled/smoking piston...

 

[paccool]

I don't know Pastor, it may be too late! He already went and sinned by looking at one and he probably drove it as well. You and some other 1st gen guys stopped me short of that a few years back when I started having those same thoughts. You brought me back and I've been a believer ever since.



We need to get him back and then work with him to bomb his truck. Once he gets the power above the new ones and sees what they are capable of then he may straighten out.



Do you have a bigger stick laying around you could use?



Stan

 

[PPeters]

She whom must be obeyed has weighed in on this debate and it looks like an '04 is in the works. Not gonna get rid of the beast, however. It's worth more to me than giving it to the dealer. It may be possible to run a black operation to rebuild the 92, then I'd have the best of both worlds. Just keep it quiet. "... why yes dear, that charge on the card is for the new truck, maintenance stuff, you know, oil, belts, filters... (cough, cough, PDR head for the 92, cough)".



Pat

 

[sparks57]

HOLY SACRELIGE BATMAN!!!



Thou dust not speaketh such ungodly thingesths as converting to the dark side!

 

[sparks57]

By that, I mean pull the thing and fix it... and don't forget to BOMB while you're in there! :-laf



In case you haven't noticed, I get excited when something breaks are starts going out on my engine... because that means I have an excuse to BOMB another area of my engine!



For example, my head gasket is leaking... do I cry to mama and think about an 04??? NO!!!! I say: "AWESOME, now I get to pull the thing and port and o-ring the head!!!!"



And my timing case is cracked... am I crying to mama on that one to??? NO! I just made the excuse: "well, it's a good time to put a PDR cam in!!!"



Oo.

 

[1stgen4evr]

Getting an 04 or fixin'

I vote for fixin'. I sat in a new truck. Bumped my head getting in and took one smell of the money melting away as the new wore off and just told the owner how nice I thought it was. Got out and ran with my hand over my wallet.



But back to the truck you have. Seriously, the crank will move a lot more than that before it causes trouble. If you want to repair that particular problem, take the truck to a mechanic that knows how to roll in a new bearing. If he acts like he doesn't know what you are talking about, go to a different shop.



We have pulled engines down that had more like an eighth of an inch of end play and they were running strong. You are only one thousandth over the upper limit. A new bearing will put you back in spec. Save the big bucks for other mods.



The only way that end play can harm you is if it allows the crank to move more than the allowed side motion on the wrist pin. The first gens have had some history of rear seal problem but the new seals are better and you should get complete satisfaction with just a new seal.



Your first gen will never be a new truck (thank goodness). If you go at it right it can be better.



1stgen4evr

James

 

[JohnBrooks]

sounds like hydraulic pressure from automatic trans. pushing foreward on torque conv. wearing thrust bearing sorry cant type

 

[1stgen4evr]

bad seal

The seal being pushed to the outside may have been that way since new. Don't rule out the possibility that some how it was folded when the engine was built.



1stgen4evr

James

 

[JVanvuren]

Alright guys... sorry to bring up an old thread again, but I need some clarification. I'm working on a buddy's truck (we're swapping in a 6 speed) and it's obvious someone was in here not too long ago (clutch is new, flywheel surface was just turned, etc).



Anyways, it looks like they may have replaced the rear main seal, as it's got orange rubber around the outside of it. However, the white teflon part that rubs on the crank is towards the rear of the truck, not towards the inside of the engine. Is this right or wrong? I would say wrong, but the first post in this thread sounds like his is the other way and his mechanic was all concerned about it.



The seal is not leaking, the area is bone dry. However, the rear cam plug is leaking, any suggestions on that? I read where the newer blocks are machined for an o-ring behind this plug, but what's the right way to seal these older ones?



Thanks in advance for any help



John

 

[JVanvuren]

Here's a photo of the seal. It's hard to tell, but the white teflon is curving back towards the camera:



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[bgilbert]

And since this is brought back ttt, what has Pat done? Maybe I wasnt reading at the time of this thread. Did he run with it, rebuild, or go in debt for the high dollar payment 14mpg new truck? Bill

 

[PPeters]

John:



I did not see the seal when they pulled the transmission, but his description to me was the metal portion of the seal was pushed inboard. I can't comment on the teflon section.



Bill:



Well, I repaired the seal, and am running the truck. Not pushing it too hard though, because of the end play issue.



Several things have happened recently which have led to me ordering a new 04. 5 3500 4x4 SLT quad cab, SRW, LWB, 3. 73 anti spin, 6sp, patriot blue, fold flat storage, Jacobs exhaust brake, with some other goodies. It's a deal I could not pass up. Got an EP number from another member here, which put the price to me about $9K under MSRP.



Now, before someone (CB, Greenleaf) calls down the rath of the pastor on me, I have already called him and confessed my sins, and for my penance I am keeping the 92. I have too much into it to pedal it, and I still like it a lot. Gonna take it easy on it until I can pull the motor and reshim the crank. After that, I figure I get the best of both worlds, and I never have to drive the gasser car again



Flame suit on



Pat