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Rear Main Seal Change Write-up, What and What Not to do (56K...I wouldn't)

162188 Views 35 Replies 24 Participants Last post by  KYBOSH
This write up is for changing the rear main oil seal. As you can see mine was leaking, not all that bad, but I had the time. This is not a project for the faint of heart, mainly because you have to remove the tranny. Mine being an E4OD it was plenty big and heavy. Yes you have to remove the tranny, I tried a trick one of my friends who is a mechanic suggested and it didn’t work, and actually caused me more work. I learned many things and made several bad mistakes, I will go over them and hopefully by reading this you will not make them.

Ah yes, the wonderful oil drip.

This is from sitting about 2 days, maybe a little bit less.

The first thing you have to do is drain all the tranny fluid. I would say you don’t HAVE to do this, but I was changing mine any way. (And the second time I took the tranny out I did NOT drain the fluid and it did not make a differance.) If you didn’t guess everything on the E4OD is metric, which is also and easy was to identify what tranny you have.

This is what the inside of the pan should look like, if you have big particles or pieces get your check book ready.

Make sure you take the magnet out and clean it before you put the pan back on, mine wasn’t too dirty since I change the fluid once a year.

The black thing with the spout is the filter it just pulls off. Be ready for more fluid to come out there is about a quart behind it.

This is one of those parts I always get from Ford. (The tranny filter that is) I also use Royal Purple synthetic tranny fluid; it’s pricy but still cheaper than a rebuild.

This is what is looks like with out the filter, now all you need do is put it back on and bolt up the pan.

Now that she’s empty with the pan back on you can drain the torque converter.

Take off the little plastic cover and rotate the engine until the drain screw is right here. I just stick a big socket on the main pulley on the front of the engine and turn the motor with a breaker bar, just make sure you only turn it the way it turns, clockwise I think.

It holds about 4 quarts and it takes a long time for all of it to drain, so have a beer.

With all the fluid out its time to start disconnecting things, like both of the tranny cooler lines. Make sure you only turn the little fitting, or you will twist the hard line. (I learned this the hard way; you can kinda see where it twisted right after the little fitting.)

They are both on the passenger side this is the one towards the front close to the exhaust.

Now unbolt the starter, you can just set it on the exhaust or something, just as long as it doesn’t hang by the wires.

Now just gently pull the kick down rod off the linkage, no need to un-bolt anything.

You can just let it hang

Next disconnect the front drive shaft. Make sure to be careful with the bearing caps if you are reusing the U-joints, I wasn’t so I didn’t care at all.

Once you take the rear drive shaft off...If your bronco suffers from the notorious “thunk” this is a good time to lube your shaft, if there is a bad time for that?!?

Next peel back your carpet, if you have it to get access to the tranny access panel. Yours prolly wont have the wiring mess mine does, which is all for my center console. If you want to see that you can go to my link on superford, there is also a write up on FSB if you search.

By taking the cover off you get access to these 2 bolts which hold the tranny to the engine. I guess you don’t have to take the cover off, but it would be a royal pain to get these off. You also get easy access to the upper tranny cooler line

Make sure you disconnect this wiring harness on the transfer case, there are 2 other plugs on the tranny, which you can take off if you want, but if you don’t take the all the way out you shouldn’t need to remove the tranny wire. I did just to be careful and because I didn’t know if I needed to or not.

At this point I was taking the tranny out for the first time using a method I DO NOT recommend, I will show it to you guys just for learning sake, and maybe some of you will make it work but this began a long chain of screw ups so watch and learn. At this point I supported the tranny with my floor jack.

A mechanic friend of mine suggested I simply by longer bolts and use them to slide the tranny back instead of removing it, so I tried it. At this point so far so good. Just take out all 6 bolts and replace them with the longer ones. Make sure you also take off the single bolt which holds the cover thingy on. It separates the tranny from the engine and keeps crap from flying up on the fly wheel and torque converter

Now it wasn’t easy to pull the tranny this far back, I ended up using a ratcheting strap, it was a big ordeal. But now you have access to the fly wheel.

Take all the bolts out accept one and then loosen it slowly until it comes off, make sure you have a good hold on the fly wheel before the bolt is all the way out, it would not be fun to have this fall on you, it’s kinda dangerous. Also be careful that the cover plate behind the fly wheel doesn’t fall and cut your head off cause it will not be held on once the fly wheel is off.

Make sure you mark it so you know which way it goes back in, you can see the black marks I made on mine in relation to the ground, you can use what ever system which works for you.

This is what your torque converter looks like, if you wondered.

OK, now you have the rear main in sight, this is where things turned for the worst. I tried to pry if off with a screw driver, couldn’t get enough leverage, so I tried drilling with my 90 degree attachment so I could put the screws in like my Haynes manual suggested. Well the drill slipped like I should have known making a small mark on the crank, BAD.

At this point I knew I needed to remove the tranny. All my friends are loosers and refused to help me so I bought this $200.00 friend, it ended up being well worth the cost, and still cheaper than having a “real” mechanic change the seal.

Ok, so now with the tranny out of the way I pried the rear main out with a screw driver easily. Be careful to not hit the crank (even though I already did.) But you can get it out with out damaging it.

I tried to get a pic of the scratch but the angle and such made it impossible. At this point I called another mechanic friend and asked him what he though I should do, he recommended a repair sleeve, made sense to me.

So I bought this cost me $50.00 I about crapped my pants because it’s basically a little piece of stainless. (got it at NAPA)

It comes with a little cup thing and you place it over the sleeve and the crank and hammer it on. The cup fits on that little lip of the sleeve. Now you notice the sleeve is a bit to long for the crank. Time for grinding, sigh.

Be VERY careful cause one slip and repair sleeve is toast, and I don’t even want to think about taking it off. You should also put a small film of curing silicone on it to sort of set it in place

OK, so now the Teflon sleeve……It said in the directions “not recommended for use with repair sleeve” I called both mechanics this time and they both said it would be fine. It comes with a little plastic thing to slip it on. With the sleeve on it was damn near impossible to get it on but finally I got it.

Now I smacked it pretty darn hard to get it on. I used the old seal turned around so I could smack it with a hammer. At this point I thought to my self it was going on A LOT harder that the original, but I guess I just thought it was because it was new. Found out later it wasn’t supposed to be that hard.

Finally got it on and got all excited to put everything back together. Tanny installation is the same as removal. It takes some time to get the tranny back in, but the easiest way is to line up the 2 stubby shaft things on either side. Once you get those on simply turn the torque converter with one finger to line it up. All that stuff is stuff which is hard to explain, you just have to do it. Once I got it all back together and started the engine, it was leaking worse that before. I was VERY mad. So I tore it down again with a few ideas as to why it was leaking.

Now for a seal comparison. This is the old seal, nasty and leaky.

These are both new seals from NAPA (I discovered the NAPA Teflon and the Felpro one from advance are the same damn seal accept the NAPA one is 4 bucks cheaper. On the left is the rubber one and the right is the Teflon, they look about the same, but they ARE NOT.

Upon a closer examination I found the rubber one is tensioned to the crank by a spring because the rubber is very pliable, good for repair sleeves since they are slightly bigger than the original crank diameter. The Teflon one is tensioned to the crank by the stiffness of the material not good for repair sleeves should have listened to the directions. Basically what happened was that the Teflon one went on so tight it spun with the crank instead of the crank spinning in it. SO….if you use a repair sleeve DO NOT USE TEFLON. I personally would say the Teflon is better just because of the nature of Teflon, but as I discovered it does not work in all cases. If you use the rubber one put a small film of non-curing silicone on it so it doesn’t start up dry.

So I did it all over again and put the rubber one on. Went on much easier. After I put it all back together after this go-round, I started it and NO LEAKS! Finally after what seemed like forever it was all good. Now learn from my mistakes!
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I belive that if you have a 302 the bolt holes in the crank for the fly wheel go all the way through, and they need to have thread sealer put on them for it to seal correctly. For a 351 the bolts holes do not go all the way through. I dont know if I would use loc-tight either way.
stangmata50l said:
Great writeup, but if you don't mind, I'd like to elaborate on this.

By taking the tranny access panel off, you actually gain access to 4 bellhousing bolts much easier than you would if you went at them from the back of the tranny.

After unbolting the TQ, support the tranny with a jack and unbolt the x-member and remove it (i didn't see this part). Next, lower the jack so that the tranny basically hangs from the the tranny just slightly with the jack.

Now there are two methods to get all the bolts out.

1) Access 4 bellhousing bolts via the access panel.

2) Get a 6-foot extension, 5/8" socket, and an impact. Sit behind the x-fer case and zip them out.

I have done it with the 6-foot extension twice, but last night I did it via the tranny access panel. Both are the same difficulty (I think), but one gets your interior dirty.

Ya, I acctually took 5 off that way, all the ones on the passenger side and the 2 top ones on the driver side. As far as the letting the tranny hang there, I just didnt comfortable(sp) with that, but if it works theres nothing wrong with it.:twotu:
Fantastic dyi info. After 2 yrs of my baby sitting neglected, rear main leak is only one of the issues I'm dealing with right now. Pertinent question is what are differences, if any, are there w/C-6? What is TQ? Has anyone rented a tranny jack/lift from Autozone? Do you just press the new seal into place? All advice is welcome. Thanks, Randy.
great writeup.

it took 4 board members only 6 hours to pull my old trans, change the rear main (I used the rubber one, no problems, unsleaved crank) and install the new trans and get it running.

I would expect for a two member team that it would take an entire weekend easy.

this was a killer writeup, brought back everything. As mentioned, place the old seal over the new, and lightly tap on the old one. this will seat the new one.

After this install, and seeing how it took 3-4 guys and a jack to wrestle that HEAVY e4od into place, I plan on buying a trans jack from harbor freight soon. WIll make my life easier for the next run.
I was wondering if when you take the access panel out under the carpet if there is easy access to the transmission vent/breather tube?
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Very easy, it is just sitting right there
Sorry for bringing the dead back alive...but I was wondering if like said, do I need to locktite the bolts on the flywheel? I am getting ready to do the rear main as well and am planning everything before I start. Its a 92 302. (E40D)

might not need loc-tight, just some type of sealant. maybe some liquid teflon tape stuff....I dont remember the technical name.
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I just recently got done with this on my truck which is why I've been offline for the week, anyhow like said draining the fluid made no change at all in weight. I had a lift and that made it much easier. But for anyone else who may be doing this, if your like me I didnt want to pull up the cover pan, and I didnt want to pull of the X case but to get to those 2 top bolts on the tranny, take off the crossmember, BE SURE TO HAVE SOMONE HOLD IT while you get a jack or jackstand on the x case to support everything, once that is down you will see those 2 bolts, get a long extension and there ya go. It went pretty smoothly for me great write up btw as well.

Do be aware this setup of the trans and x case is VERY heavy probably around 6-700 lbs. Dont even try dropping it on your chest, you'll die.
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awesome awesome write up...

question: want to try this, my skills are a moderate sunday mechanic. problem is my two year old, and that i don't have air tools nor does my truck fit in my town house garage. sounds like i should plan for the weekend, but not sure if my neighbors would like my truck sitting in the driveway...

anyway how much/long would it take to get a mechanic to do this? i guess if its like $200 i'll shed out the money, but if its like $500 rather try to break my truck.

the price depends on the shop, all the ones around me wanted like 700, and i didnt want to pay.
7 big ones huh.... not sure if i'm up for that - but also again, not sure if i have even nearly the tools, nor experience to try to do this...
For the $700 you'll save you can outfit your tool supply quite nicely and still have a chunk of change left over.

In this awesome writeup, the author used a couple of long bolts to draw the trans/bellhousing into the engine block. Great idea, however you can also benefit by cutting the heads of a couple of longish bolts, rounding the cut ends with a grinding wheel and install them into the engine block. Then when you (and a couple of buddies hopefully) lift the trans into place, you have these studs to guide it into place. This is particularly useful when you're reinstalling a manual trans and have to align the input shaft through the pressure/clutch plates. Then use the longer bolts to draw the trans into the block. Be sure to remove the studs from the block and replace with the correct bolts. Afterwards, identify the studs so you'll have them available next time. I have three sets saved from previous work on different vehicles.
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It's my turn to revive an old thread. So, for those of you who used the long bolt trick, how long were the bolts that you used? I've been ignoring my leak for years but I'm ready to take something apart and I don't feel like breaking the Volvo just to amuse myself.
Excellent write up! I just used this thread to drop the transmission and changed both the front pump seal behind the torque converter and the rear main seal. The key issues for this whole ordeal are

(1) use the access panel to get at the upper bellhousing bolts and upper transmission line.

(2) even if you have a transmission jack, buy some beer and call up a friend to help you because it's really difficult to manipulate that huge E4OD and get it back in trying to align the guide pins, bolt holes, and torque converter studs all in a line.

(3) buy or rent the transmission jack. I've seen guys drop their transmissions using a trolley jack and a piece of wood. That won't work too well here because the E4OD is WAY HEAVY. the jack + wood trick would be too dangerous.

thanks again for the thread. I was quoted $950.00 for the job. My costs:

$195 for the transmission jack
$8 for the pump seal
$13 for the rear main seal
$44 for the trans filter kit
$95 for the trans fluid some brakeclean, loctite, and rtv sealant
$14 for the 12pack of Heineken
$15 Taco Bell run

TOTAL: $384.00
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I am about to do my RMS, and I have a few questions.

1. Can the C6 be managed without a jack? i.e. how much does it weigh?
2. Online, the RMS shows up as a 2 piece unit (adv auto, o'reily, summitt, etc). is it 2 piece or 1 piece?
3. Has anyone had luck doing a C6/351W in place? with longer bolts as OP showed in the beginning?

Hey mickaila, i can't find any rental here in Las Vegas as well and i'm thinking about getting this from HF and reselling on Craigslist after.
Anyone has experience with this jack?

AWESOME writeup!
just done this the other day

bottom of the engine without basepan

2-peice seal, 1 part goes in little seam just behind the flywheel you can see the little opening there for it on each side of the crank, the other side of the seal comes out with the bearing cap

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I replaced my rear main on my 85 bronco. Those 2 peice seals suck. I had to drop the oil pan, remove the oil pump, remove the last cap on the crank and loosen the rest to get pressure off the seal.. Had to lift the engine up to get the pan off.

Wasn't too bad. It took me about a month. But I got frustrated and didn't touch it for about 3 weeks :)

Get to replace my rear main on the 94 here soon.. Oh what fun that will be.
92 rear main seal replacement, is it necessary to also drop the T-case as well.
Just trying to do it the easiest way I can.

Thanks for the help.
Probably not, but I would. You have to pull the shafts anyways. And really in the grant scheme of things, whats an extra 8 bolts?
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