Rear Main Seal advice-should I replace it? | Ford Explorer Forums - Serious Explorations

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Rear Main Seal advice-should I replace it?

saewoody

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Year, Model & Trim Level
1997 XLT (RIP)
2003 XLT
I was going to replace my rear main seal tomorrow. I did a search to get some information and it seems that even new ones may leak if not done with the special tool. I was going to use a piece of pipe or tap it in going in circles around the seal.

My dilemma is that I don't think it is leaking, but I was going to do it as preventative maintenance because my engine has been out because I did the timing chains.

Should I follow the the old "If it ain't broke, don't fix it"?

My truck has just about 205,000 miles on it and we bought it with 36,000 on it and I know that it hasn't been done in the ten years we have had it.

Please let me know what you think.

Thanks for the input and help. It is always appreciated.
 



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Replace it if it's accessible. It's easy to make your own tool instead of paying a lot of money for a one time tool. They make two types of seals (rubber & teflon). Teflon will last longer, but it cost more. Check # 68 in my list of useful threads for more information.
 






Thanks for the input. That's my logic too.
 












Thanks for the visuals. Your Haynes manual gives a lot more information than mine does! The PVC is a good idea; it is was I contemplating using today as I looked around my garage to see what I might already have. Thanks.
 






more info

I should have included a link to the following post which contains more information: Replacing rear main seal

I don't recommend installing the metal sleeve unless the old seal has worn a groove on the crank.

I planned to add a step by step procedure on the replacing the rear main seal but forgot to do it - something to work on next week.
 






What do you think the purpose of the metal sleeve is then? Is it a "just in case"? Does it serve any purpose in the actual sealing?
 






metal sleeve

You can buy a rear main seal with or without the metal sleeve. It costs more with the sleeve. I bought it just in case there was a groove on the crank from the seal rubbing against it. It doesn't usually happen before 200,000 miles. To install the sleeve it must be driven onto the crank and scratches the crank so that from that point on a sleeve must be used. It is hard to drive the sleeve onto the crank but once installed it provides an unworn surface for the seal to contact. Make sure and oil the inner surface of the seal (that contacts the crankshaft) when installing it or it will prematurely wear in the few seconds the engine runs with no oil to the seal.
 






Good info. Thank you. That is first on my to do list tomorrow once I have access to the rear of the engine. Then she goes in. Thanks for all your input on my recent threads!
 






Rear main seal replacement

I just finished replacing the rear main seal on my 1995 Explr. An oil leak had developed, since I was replacing the 5-spd transmission (for the second time), so ... might as well change the seal.

I read in my Haynes/Clymer/Other book that:
"... if the shims are not installed at the lower two mounting points of the transmission bellhousing (into the oilpan) that a leak could develop from the oil pan seal." The thickness of the shim is specified after measuring the block face with a straightedge as it transects over the lower mounting points.

My application did not have the shims, someone was into the clutch before me and probably never put them back in.

My seal came with the steel sleeve, but I did not use it. There were no instructions on installation either. Did a online search and here I am!

Will let you know how it goes.
 






My 5.0 started leaking from the rear crank seal area lately too. Not lookin forward to a tranny removal for this, but o well. So I found some info on removing other transmissions but not like mine. Probably not to different though. My truck is an 01 AWD.

Do you guys use any RTV or something of the sort on the outside of the seal to seal against the block? I do not want to do this job twice, that's for sure.
 












That's true! Mine was leaking tranny fluid AND engine oil.

No leaks to date. I did not put RTV, just lubed with engine oil on the outer, grease on the inner lips. I would check for a groove in the surface of the crank before installing the new seal. The oil seal I bought came with a steel ring in case the crank has a groove, but mine didn't so I didn't use the ring.

What would keep someone from not driving in the seal all the way, to take advantage of the ungrooved surface of the crank? Just a thought - I am not advocating this advice.
 






Are you sure the leaking fluid is engine oil and not automatic transmission fluid? Both will drip from the same area of the bell housing.

I'm positive it's engine oil. My oil is clean and my trans fluid is pure red and the fluid I see is clearish-brown and smells and tastes like engine oil. I've seen it under the truck a few times. It must gather in the bellhousing and when I park on a hill it seems to run out of there. It's rather annoying.

I have seen crank surfaces that have grooves in them from the seals basically polishing a groove in it. I wonder why one couldn't just place the seal in a slightly different place as well. Oh well, I guess they have the repair piece for a reason. Seems funny that a rubber seal could wear a groove in steel though.
 






You know what engine oil tastes like?:):):)
 






Yeah, doesn't everyone taste their oil when it's removed from their engine? I find I get all of my daily iron requirements that way. Plus my taster is the ultimate in oil analysis.:D:D
 






So when I do remove my trans to replace the rear seal, what other items should I think of replacing? Do the torque converters fail? Should I consider replacing it for any reason? It works fine now and the transmission shifts fine as well. I just want to be prepared for anything I may need to do while the trans is out. I DO NOT WANT TO DO THIS JOB MORE THAN ONCE. Anyone in K.C. wanna help out? Beers can be provided.:D
 






Bump. Any suggestions folks?
 






You can buy a rear main seal with or without the metal sleeve. It costs more with the sleeve. I bought it just in case there was a groove on the crank from the seal rubbing against it. It doesn't usually happen before 200,000 miles. To install the sleeve it must be driven onto the crank and scratches the crank so that from that point on a sleeve must be used. It is hard to drive the sleeve onto the crank but once installed it provides an unworn surface for the seal to contact. Make sure and oil the inner surface of the seal (that contacts the crankshaft) when installing it or it will prematurely wear in the few seconds the engine runs with no oil to the seal.

depends on who you ask. i can tell you i have always done this, however, mercedes benz shop manuals tell you to have absolutely no grease or oil on the sealing surface and to install it dry. really depends on who you believe. the rear main seal and the front crank seal instructions both say this.

but to the OP, i definitely recommend doing the rear main. no reason to have to pull it again down the road to replace this part when you can do it now.

edit: i realize this post is old, sorry.
 



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So, I wanted to revive this to ask a silly question. My truck is an AWD 5.0. Would it make more sense to remove the engine to replace the rear crank seal and leave the tranny and transfer case in the truck rather than vice versa?
 






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