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Discussion Starter #1
After going through numerous threads I have seen several opinions and theories, but no consensus, to one in particular problem.

My question: Is it true that a rear main seal leak will not cause the clutch to slip, but a front main seal leak will??? :confused013: It was mentioned that the centrifugal force of the flywheel will sling any oil from the rear main away and drain out the bottom of the bell housing.

Also, if the problem is due to the front main and I replace it, will I still have to replace the clutch, or will the oil eventually burn off of it?

We just recently aquired this truck ('97 3500, 128,xxx miles) and although I know there are oil leaks, I haven't had a chance to chase them all down.

About a month ago I hauled three loads of round bales (21,000 lbs + trailer) and had absolutely no problems with it. Now, this week I drive it with no trailer or load and it slips on fairly hard acceleration.

TIA for your input.
 

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I think the front seal you are refering to is the one in the transmission on the input shaft. It will leak into the pressure plate and foul the disk. When mine did it. It would make a squalk if I let the clutch out really hard. Leak or no leak, If yours is slipping, Its gonna have to come out.
 

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Since you need a clutch anyway, pulling the trans will be the time to find which seal is leaking. The theory of the rear main is just that, a theory. In real life the oil can and will make it's way to the clutch face and ruin it. However, when mine got wet it grabbed and chattered, it didn't slip.
 

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Discussion Starter #4
Still confused:

Drove the truck today for the first time in about a week. Early on in the trip to town it was slipping, but didn't seem as bad. After the trip town (about 7 miles) it stopped slipping. In other words, after everything warmed up, it didn't do it. It then sat for about 3 hours. Drove it again and it still didn't slip.

Still haven't smelled anything that smells like clutch...........
 

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Discussion Starter #5
Since you need a clutch anyway, pulling the trans will be the time to find which seal is leaking. The theory of the rear main is just that, a theory. In real life the oil can and will make it's way to the clutch face and ruin it. However, when mine got wet it grabbed and chattered, it didn't slip.
Not grabbing or chattering. Smooth as silk during initial take-off and shifting. It was just slipping during high-torque (high boost) conditions.

Still confused.......................
 

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my "clutch was slipping" for a while and same story never smell it and sometimes it would go away once it warmed up and it was a bad slave cylinder. and a rear main seal in the motor will not cause a clutch to slip the oil cant beat syntrifical force to reach the other side of the flywheel a front tranny seal on the other hand will. and if it is the slave for the love of god dont listen to anyone who says you cant bleed the system and you have to buy the whole hydro kit thats BS. hope this helps
 

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Discussion Starter #7 (Edited)
kfisher,

Thanks for sharing your experience. I will try to get this issue pinned down when I get some days off in about a week. I can't really get anything done when I'm working. I work a 12 hour shift 78 miles from the house. which puts me gone about 16 hours a day (or night). We are looking at tons of overtime for the rest of the year, and I will probably end up with about 900-1000 hours OT before it is all over with. This doesn't leave a lot of time for playing with my toys.

When I finally get a chance to chase this down , I will report back.


Thanks,
koga


PS- One of these days I will get a sig up. For now, please do a member/user search for "witegoat", he is my 15 yr old son and it is his truck that I am talking about.
 

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a rear main seal in the motor will not cause a clutch to slip the oil cant beat syntrifical force to reach the other side of the flywheel
Centrifugal force can send droplets of oil throughout the inside of the bellhousing, it doesn't all go to the botton as implied in the theory. The turbulance of the air caused by the spinning mass turns those droplets into mist. Whenever you disengage the clutch that oily mist gets on both faces of the clutch plate, the pressure plate and the flywheel face. Believe what you will, and I'm sorry I gave you bad info in the past. I can only relay my experience, I can not read your mind or guess what your specific situation is.
 
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