Re: Rear main STILL leaking!
[Re: Ledman_70]
#1050392
08/10/11 05:07 PM
08/10/11 05:07 PM
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Joined: Jan 2003
Posts: 75,094 A Banana Republic near you.
JohnRR
I Win
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I Win
Joined: Jan 2003
Posts: 75,094
A Banana Republic near you.
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Quote:
The rear main seal in the 426 wedge in my 64 Polara has pretty much leaked from day 1. I have replaced the seal several times.... last time I put in the Mancini billet saddle and seal, and a new Milodon pan, but it still leaks. It occurred to me last week that I had installed a high pressure oil pump when I built the motor, which carries 75lbs going down the road. I thought.. That's it! So I went to Jegs and got a high VOLUME pump and installed it. STILL has 75lbs on the road and still leaking. I have no idea where to go from here. Am I overlooking something obvious?
the oil pressure has little to do with it , it's not directly oil by a pressure passage.
What type of crank do you have, stock or an aftermarket replacement .
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Re: Rear main STILL leaking!
[Re: Ledman_70]
#1050393
08/10/11 07:51 PM
08/10/11 07:51 PM
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Joined: Sep 2006
Posts: 420 Central Ohio
Ledman_70
OP
mopar
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OP
mopar
Joined: Sep 2006
Posts: 420
Central Ohio
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I have no idea if it's been line bored... I was told the block was a race block for a 65 Satellite named Alias Smith in the 70's, so I guess it's possible. The oil is leaking right out between the pan and inspection cover on the bellhousing. I'm pretty sure it's not coming from the oil pressure fitting and the crank is a stock crank from a 413 I have. I never considered taking some material off the main cap. I suppose that would need to be done by a machine shop, but how would you measure how much to remove?
Jeff Adams
64 426 Polara
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Re: Rear main STILL leaking!
[Re: Ledman_70]
#1050394
08/10/11 08:13 PM
08/10/11 08:13 PM
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Joined: Jun 2004
Posts: 893 Tustin, CA
pishta
super stock
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super stock
Joined: Jun 2004
Posts: 893
Tustin, CA
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Well, if it has been line bores, then you can't take anything off the cap, as it will already be sunk into the block centerline, just as a timing chain comes in undersized models. Youll have to add some RTV or even a second strip of gasket material to the top of the rear cap to compensate for the uneven surface. Does Someome make that spiral beveled bearing that pushes the oil away from the seal or is that a smll block thing? Dont rule out the cam freezeplug or the oil galley plugs behind the trans, or even a leak that finds its way to the lowest point of the motor. Get yourself some fluorescent dye and a black light penlight and start hunting after hours or in a very dark garage.
12 Grand Caravan 06 T&C 02 T&C 96 Breeze 65 Barracuda "S"
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Re: Rear main STILL leaking!
[Re: pishta]
#1050395
08/10/11 09:18 PM
08/10/11 09:18 PM
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Joined: Nov 2003
Posts: 36,041 Lincoln Nebraska
RapidRobert
Circle Track
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Circle Track
Joined: Nov 2003
Posts: 36,041
Lincoln Nebraska
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What Pishta said w this many tries I'd get a dye kit & pinpoint the loc exactly then a good visual during dissassembly to ID the prob
live every 24 hour block of time like it's your last day on earth
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Re: Rear main STILL leaking!
[Re: scratchnfotraction]
#1050399
08/11/11 09:30 AM
08/11/11 09:30 AM
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Joined: Sep 2006
Posts: 420 Central Ohio
Ledman_70
OP
mopar
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OP
mopar
Joined: Sep 2006
Posts: 420
Central Ohio
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The seal is rubber and the crank is smooth. I never even thought to check the back of the motor last summer when I installed a new clutch.
Jeff Adams
64 426 Polara
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Re: Rear main STILL leaking!
[Re: Ledman_70]
#1050403
08/11/11 05:40 PM
08/11/11 05:40 PM
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Joined: Nov 2004
Posts: 3,544 Syracuse,NY
CompWedgeEngines
master
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master
Joined: Nov 2004
Posts: 3,544
Syracuse,NY
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This has several " options" as to what could be wrong. Its never clear without seeing it in person, but that being said, here are the common mistakes: 1) Seal in backwards 2) Seal retainer wasnt lined up with seal grroves and/or checked 3) Rough crank surface 4) Side seals not all the way down in the slots, OR , protruding from top of seal retainer. Overall mis-installation of side seals. 5) Spot facing needed where the bolt heads rest inside the cap, Errosion etc often leave the caps cockd because of wear there.Spot facing of bolt bosses does help. 6) Seal retainer ends need to be cut in a cap grinder to be squared and add a slight bit of tension to seal 7) Oil pan bolts too long and tighttned too far, cracking open the " wells" in the seal retainer, and oil leaks out the threads. 8) As mentioned, two different " planes" between seal retainer and pan rail where the retainer and block meet. Oftn a good gasket seals this up. Many times a seal is to blame, but it can also be the side seals, the oil pan bolt threads, a misfitting retainer and also sometimes simply filling the groove ont he OUTSIDE of the seal retainer to the block will stop what is believe to be a bad rear main. I only use Superformance and Fel Pro 2904 seals. Stock ones will work fine, but never as good in my opinion as the Viton style. You also can have problems when a seal surface has been polished too much, or is too rough. Sometimes a slight polish helps, but its a good idea to cut the retainer to add some pressure afterwards. The old anti leak rear main bearings did work, but you really shouldnt need one if everything is correct. You can also switch to a rope seal, and often times it will resolve a problem, or at least band aid it. Again, if you know what to look for, and how to do it, rear mains dont and shouldnt be a troubling leak. Long shot,there were some cranks, typically marine cranks that ran reverse rotation and had the seal serrations backwards! Doubt thats the case here, just saying. Good luck.
RIP Monte Smith
Your work is a reflection of yourself, autograph it with quality.
WD for Diamond Pistons,Sidewinder cylinder heads, Wiseco, K1 rods and cranks,BAM lifters, Morel lifters, Molnar Technologies, Harland Sharp, Pro Gear, Cometic, King Engine Bearings and many others.
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Re: Rear main STILL leaking!
[Re: pishta]
#1050405
08/12/11 12:44 AM
08/12/11 12:44 AM
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Joined: Jan 2003
Posts: 75,094 A Banana Republic near you.
JohnRR
I Win
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I Win
Joined: Jan 2003
Posts: 75,094
A Banana Republic near you.
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Quote:
Quote:
Line boring only affects the crank main bores , the cap mounting face does not get machined .
Could you elabotrate? I cant picture this. Seeing it done looks like you expand the entire "bore" of the crank bearings. Does this neccesitate oversized OD bearings? Why do they sell undersized timing chains? Thought the crank was actually higher in the block now (installed)
the only part that is machined is the hole the crank sits if , some material is taken off the face of the CAP to make the hole egg shaped the the hole is rebored round . The surface the caps sit on in the block does not get machined so the rear main is not in same exact place as the main bores , it gets very expensive and labor intensive to machine the seal bore , never seen it done .
Normally you don't need a shorter chain when a block is relined bored for main studs , it's when you spin a bearing or so other major issue that one would need a shorter chain.
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Re: Rear main STILL leaking!
[Re: pishta]
#1050406
08/12/11 12:45 AM
08/12/11 12:45 AM
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Joined: Nov 2004
Posts: 3,544 Syracuse,NY
CompWedgeEngines
master
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master
Joined: Nov 2004
Posts: 3,544
Syracuse,NY
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You dont make the bores any bigger than the required specs, which have a low and high limit. The reason the bores arent " expanded" is because tyhe first thing you do is cut a few thousands of an inch off the feet of the main caps. The makes the bore " smaller" to start with, then you bore or hone ( two completely different things) back to the spec size. I prefer to hone to the low limit, which gives the maximum " crush" on the bearing shells. The bearings shells ( outer) dont change, they are all the same size. If a shop does the job RIGHT, they take minimal material off of the block sides ( saddles if you will)of the mains, so as to not change the crank to cam centerline very much. If someone doesnt do it this way, they then change that dimension, and if its been done several times wrong, thats where your " minus" timing chains come into play.
RIP Monte Smith
Your work is a reflection of yourself, autograph it with quality.
WD for Diamond Pistons,Sidewinder cylinder heads, Wiseco, K1 rods and cranks,BAM lifters, Morel lifters, Molnar Technologies, Harland Sharp, Pro Gear, Cometic, King Engine Bearings and many others.
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Re: Rear main STILL leaking!
[Re: Ledman_70]
#1050407
08/12/11 02:05 AM
08/12/11 02:05 AM
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Joined: Dec 2007
Posts: 18,159 Mass
DAYCLONA
I Live Here
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I Live Here
Joined: Dec 2007
Posts: 18,159
Mass
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Quote:
The seal is rubber and the crank is smooth. I never even thought to check the back of the motor last summer when I installed a new clutch.
That's the correct finish for a rubber 2 pc seal, I'll assume you've installed the main seal with the "lips" facing inward towards the motor,...but are you installing the seal dry?...if so, your burning the lip on start up,...if this is the case lube the mating surface of the seal and crank on the NEXT seal install with some moly lube, plus you should clock the seal offset in it's installation regarding the mating line, you shouldn't make it flush with the split in the seal retainer, basically hide the seam of the mated halves in the grooved journal way, not at the parting line
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Re: Rear main STILL leaking!
[Re: DAYCLONA]
#1050408
08/12/11 12:44 PM
08/12/11 12:44 PM
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Joined: Mar 2003
Posts: 4,848 Memphis
HemiRick
master
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master
Joined: Mar 2003
Posts: 4,848
Memphis
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The crank should have the diagonal hash marks where the seal rides. If it's an old marine crank they are going the wrong way and this is the problem.
Take care, Rick 68 Coronet R/T 440 & 68 Charger 528 Hemi,and 5 Challengers! 6 cyl, 318, 360, 383, 451
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