Got a main seal leak. Help me out.

How much money do you wanna spend and how often do you pull your tranny? I had my fly wheel off this last week and contemplated changing the rear seal as I am at 60K. I decided not to change it because it does not leak. "Don't fix what ain't broke" is what my pop used to say.


So If you don't want to take the tranny out again, soon, I would get the flywheel machined, buy a new cluch set up and change the fluid in the tranny. That is what I would do if I were in your shoes and had the money.


CB

well those flywheels aren't cheap....

but yeah, do the t/o bearing, replace the bearing retainer w/ a steel one, resurface the flywheel if you don't do the clutch....but if there is a stocker in there...get another stocker clutch disc, and the pilot bearing.

even if i had 20k on my clutch....i'd replace it while i was in there...unless it was a hi dollar clutch disc.

I would double check you clutch while you are in there. Just look at it and make sure it isn't wearing out. It might feel ok but that doesn't mean that is it going to last. It is sometimes easier to change a good part now then change it when it goes bad. It also depends on money and how much you mind pulling the tranny.

When you replace the seal you may also want to get a sleeve to go over the crank. It helps it to seal better. They cost $10 and the tool to install it costs $10 but you can just take the tool back after you put it in. I just did it to mine and it worked great. May want to get a teflon seal too instead of the rubber one.

agreed. if you have a RMS leak, the clutch might be contaminated. i would not necessarily want a stock clutch in there were i autocrossing.

things i would inspect or replace (i will duplicate others - too lazy to keep re-reading posts):

RMS, pilot bearing, input retainer, inspect clutch fork and ball, TOB, disk, PP, resurface flywheel. there is something else but i cant remember it right now - someone else will.

good luck.

Not to hijack but I have a question. Can anything go wrong by not replacing the pilot bearing. Mine has 6k on it and I dont wanna mess with learning how to take it out.

Numbles said:

Not to hijack but I have a question. Can anything go wrong by not replacing the pilot bearing. Mine has 6k on it and I dont wanna mess with learning how to take it out.

Click to expand...

Might as well replace it. You can borrow the tool needed to remove it from Autozone or someplace like that. I had a hard time getting mine out recently and it was because I recieved the wrong puller.

If you don't drag race then don't get a aluminum flywheel. Instead, get a billet steel flywheel so you keep your your low end torque. While you are there replace your clutch, pilot bearing, throw out bearing, if not a new flywheel, get the old one resurfaced, and also consider your retainer. May be a good idea to replace your retainer with a steel one if it is chewed up. This will often cause the fingers on the presurre plate to bend and thereby cause the clutch to pre-maturely fail. Lastly, definately use a fel-pro teflon rear main seal when you do the replacement. Good luck!!

Stay away from the aluminum flywheels on a daily driver...

If your pilot bearing on has 6k on it...don't worry about it unless it feels bad or looks bad (visually)...

Here is some part numbers of common pieces needed for a clutch install on the 86-95 5.0L’s:

ARP Flywheel Bolts - ARP-100-2801
ARP Starter Bolt Kit - ARP-450-3501
ARP Thread Sealer - ARP-100-9904
Ford Pressure Plate Bolts and Flywheel Dowel Pin Set - 397-M-6397-A302
Stock Replacement Flywheel - 397-M-6375-B302
Heavy Duty Ford Racing Clutch Kit- #M7560A302
King Cobra Ford Racing Clutch Kit - #M7560C302
Ford Racing 79-95 Aluminum Driveshaft - FMS-M4602G
Napa (Fel-pro) Rear Main Seal – Teflon (BS40644), Rubber based (BS40620)
www.buyfordracing.com sells an OEM cable and clutch fork for $40 – 7553-A302
www.50resto.com or your local parts store carries your throwout bearing, pilot bearing, and rear main seal.
www.steeda.com has a chart of what correct speedo gear you will need for your application.
Transmission fluid – Dexron/Mercron III ATF fluid for the T5

Disclaimer – Do at your own risk and research.

First jack up the car safely and securely on all four corners and the more room underneath the better so you can remove and install items much easier. Proper jack and jack stand placement is key for safety. A friend or two is probably the best way to go about the install. You will find yourself needing more hands than you have pretty quickly.

Go ahead and disconnect the negative side of the battery. Go ahead and remove the shifter (or atleast the handle) so you can drop the transmission without the shifter holding it in due to rubbing. Four bolts hold it to the transmission and two bolts hold the shift lever on the shifter base. Pull up on the shifter using the handle if you choose to remove it completely. It will give you better leverage but be careful when it finally pops loose because you might go flying back or scratch interior pieces with the shifter. I put towels around the console to prevent this. Next I would go under the car and start unbolting your mid-pipe, which is held on by a total of 8 bolts (2 for each point of connection). They can be a pain to remove if they haven’t been removed in a while they can seize to the studs/bolts. Use some wd40 or Liquid Wrench to help with this process. A combination of extensions and a swivel would be a good start to getting to the manifold/h-pipe connections. Make sure before you completely drop the pipe that the 02 sensors are disconnected. You can use a flathead screwdriver to pop off the harness connection. Pull the mid-pipe from underneath the car. Now would be a good time to clean it off from all the road grime. Next I go to remove the driveshaft which is held in by 4 bolts in where you will need a 12 point 12 mm socket or wrench to fit over the bolts perfectly. The driveshaft bolts are commonly very stubborn to get off. If you can get a break-over bar on the bolts then you should be able to break them loose. I use the appropriate wrench and put a hollow bar over it and break them loose that way. It helps on the leverage. When you go to remove the bolts you will need to rotate the driveshaft to get an angle on the bolts. When you find the right angle put the car in gear (take your shifter and temporarily pop on the tranny and stick it in gear) and put on the e-brake to prevent the back tires from turning so you can break the bolts loose. Once you have removed all 4 bolts you are now ready to remove the driveshaft. When you pull the driveshaft out from it’s trans housing do not be surprised if transmission fluid comes out (normal). You can buy the driveshaft “plugs” that will be placed where the driveshaft was inputted or you can use a rubber band and ziploc baggy and rig it up to catch any of the fluid so you don’t loose to much.

Now that the driveshaft is removed you can go ahead and undo any tranny connections that are on the transmission. You need to remove the neutral safety switch (pulls off) and speedo gear (held on by one bolt). Pull them out of the way so they don’t snag on anything. Remove any other connections that you may notice like the clutch cable which is held onto the clutch fork and also held on by a clip (do not loose it). I then start to undo the transmission bellhousing bolts (I remove the tranny with the bellhousing attached). Most of them are 5/8’s bolts with a couple smaller ones near the bottom. Make sure you loosen all the bolts because some go up near the lower intake of the engine and can be accessed thru the engine bay or if you have smaller hands (that I’m not blessed with) you can reach them from the bottom. Your transmission crossmember and bellhousing alignment dowel pins are holding the transmission right now. I next remove the starter, which is held on by 2 bolts, and I don’t undo the connections and just ziptie underneath the car and out of the way. I would go ahead and start bringing a good jack underneath the car accompanied with your buddy to get ready to remove the transmission. Two bottom bolts hold it on and two studs go through the side mounted to the body of the car. Remove all 4 of these with the jack properly supporting the transmission while your doing this. Make sure the jack sits flush and has a good balancer on it to accompany the bulkiness of the transmission. With all the bolts and connections undone you can go ahead and start pulling on the tranny towards the rear of the car as to release the input shaft from the pilot bearing and clutch assembly while also letting the bellhousing coming off the dowel pins. Make sure the engine is supported because it doesn’t have the transmission’s weight to counter the tilt. Another jack would be nice. Put a board to even out the weight distribution over the oil pan. Once the input shaft is clear of the clutch assembly (as not to get damaged) and you have wiggled it loose go ahead and drop the transmission slowly while not tilting it so you don’t loose transmission fluid through the speedo gear hole. Remove the transmission out of the way of the bottom of the car. It would be a good time to clean the transmission, crossmember, and driveshaft at this point. Use some degreaser and some “elbow grease” at your local car wash to help you out. You can clean up the bottom end of the car the same way. Good time to do it right? Check your input shaft bearing retainer and shaft itself for scouring or any other kind of damage. It is a good idea to replace all your clutch assembly parts together. Now you can go ahead and remove your pressure plate/clutch disc. If you want to reuse the pressure plate and disc for some reason. Back the 6 pressure plate bolts off evenly as not to warp the plate or disc. When you loosen it watch out because it is heavier than one would think so be ready to catch it or have your friend hold on to it. Once removed you can check the disc and pressure plate for problems and wear to see what is going on with your car. You can now see the flywheel that is held on by 6 bolts as well. These bolts are on pretty tight and I personally use an impact wrench to remove the bolts. I do them evenly as well to prevent any kind of warping. The flywheel weighs 21 lbs so be ready to catch it as well. Remove the flexplate (goes between bellhousing and block). Once the flywheel is removed and out of the way inspect the teeth on it and condition of the clutch disc mating surface. You may need a new teeth ring gear or you may not. You will want to have your flywheel resurfaced (turned) at your local machine shop. They can charge anywhere from $25-$40 bucks for the resurfacing. It will provide for a nice smooth (unspotted) fresh surface for your new disc and pressure plate to work with. Well worth the money if you consider the negatives of not doing it. Since the flywheel is removed you can now see the rear main seal and pilot bearing. If the rear main seal is not leaking DO NOT touch it because it is doing it’s job. A rear main seal install can be tricky. If you see you need to remove it (leaking) you can use a flathead screwdriver to pinch the seal and remove it. You can use a slide hammer as well. You DO NOT want to scratch the crankshaft at all when removing the seal. If you do you will need to put on a sleeve to prevent it from leaking. So be very careful on the crankshaft end. Some have put a screwdriver on the block side of the seal and pryed it out CAREFULLY to remove it. Once removed (in which ever method you chose) clean up the crankshaft and block area where the seal goes into it and put some oil in there to help the seal to go in smoother. I would go ahead and clean the back of your heads and block while your at it. Simple Green and some nice clean smooth rags will be suffice. To install the new rear main seal you want to take your time with this. Put some oil on the inside ring of the seal where it rides on the crankshaft itself. Install the rear main seal EVENLY. You can use the old rear main seal to tap against it to put the seal in the housing. Tap it in a circle slightly and put it flush with the block. Don’t bottom out the seal. Some like to put silicone on the outside ring of the seal (where it meets the block) – it acts like a bridge to keep the oil away. Don’t put any high-temp silicone on the seal part where it meets the crankshaft because it needs to turn, not like it would stop it from turning.

I would go ahead and inspect the pilot bearing by rubbing your “clean” finger in the hole to see if you feel any scouring or rough edges that could effect the ability for your input shaft to function properly and smoothly. If it seems smooth and visually looks good I would go ahead and keep it in there. If your one of those people that are a “miswell while I’m down here” type person then go ahead and change it out. Put some grease in the pilot bearing hole and get a brass punch the same diameter of the hole. You then stick the punch in the hole and hammer the punch into the grease to remove the bearing hydraulically. The bearing will push out as you use the grease as a displacement. You may need to add grease a couple times as more surface area is revealed and it will eventually come out. You may also use a slide hammer on the pilot bearing as well. Most pilot bearings are pre-greased from the factory but I put some bearing grease (just a bit more) on the inside/outside to help with lubrication. Take the bearing (after taking notice of how the pilot bearing was in previously and install it the same direction). Tap it in a circular motion evenly so it doesn’t become offset. Make it flush with the block as well I believe. You are now ready to reinstall the flywheel. Take the new or used (but resurfaced) flywheel and rotate it so the bolt holes (they are offset) match with the flywheel holes and put in a couple bolts to hold the flywheel up there. Before doing this though I would clean up the crankshaft threads a bit of any oil. Just as well MAKE SURE you clean all the clutch assembly parts well before installing them with some carb or brake cleaner to take off human grease and rust inhibitors. Anyways, once the flywheel is held up there go ahead and get some loc-tite and apply them on the threads of the flywheel bolts. That is all I have needed and I have go no oil leak. Some use thread sealer for extra security from leaks. Use it at your own reasoning. Put all the bolts in with some loc-tite and go ahead and start tightening them in a “star” pattern (evenly). The flywheel bolts need to be torqued to 90ft. lbs using a torque wrench. Make sure you clean off the flywheel of any oil or grease from your hands so it doesn’t effect clutch performance and grab. Next you can go ahead and get your clutch disc ready and I’m hoping you got a clutch alignment tool (10 spline – 1/16th input shaft size) and make sure the clutch disc is facing the correct way. Most will be labeled either ENGINE SIDE or FLYWHEEL SIDE. Put the alignment tool in the clutch disc and stab it into the pilot bearing. It may support itself. Get your buddy to hold the input shaft as evenly as he can while you take the pressure plate and set it on the flywheel alignment dowel pins (you need those alignment dowel pins to align and balance the pressure plate properly). The pressure plate will sit on the pins and hold itself. Now get your 6 pressure plate bolts and start threading them in. Go ahead and tighten the pressure plate bolts in a star pattern (evenly and go thru it a few times so you don’t warp the plate). While it is being tightened have your friend have the clutch alignment tool centered for best performance. Torque the pressure plate bolts to 24 ft. lbs (most clutch manufacturer’s recommend that). It probably wouldn’t hurt to put a bit of loc-tite on those bolts but it isn’t completely necessary. You know have the clutch assembly put together. Remove the clutch alignment tool.

Go back to your transmission and check your throwout bearing (TOB) for wear but I would suggest replacing it anyways because it is fairly cheap. Pay attention to how the old one is installed on your retainer shaft. Remove it off the clips and install the new one and check to see if it rides smoothly and turns. You can do this by moving the clutch fork (natural movement) up and down the shaft. Put some high-temp grease on the throwout bearing where it mates against the pressure plate forks. A tip: The “fat-end” of the throwout bearing goes against the pressure plate teeth. You are now ready to install the transmission. Put it on the jack for support and get your buddy to help you jack it up there. Keep in mind that the input shaft on your transmission has to slide in smoothly into the input shaft (the job of the clutch alignment tool). You may need to spin the input shaft so it will “spline” into the disc. As you are getting the spline to line up you need to make sure the bellhousing alignment dowel pins are still in place and that the bellhousing slides over them which will help align everything properly. Go ahead and install the bellhousing and transmission bolts and tighten them up. Now to go back to the transmission install. If it doesn’t “pop” in you need to check for any clearance issues or objects in the way. You should not have to “pull” the transmission on with any bolts…so be mindful of that. Tighten all the bolts down tight so they won’t come loose. Start reconnecting the clutch cable with the clip and onto the clutch fork. Reinstall the speedo gear (a good time to replace it by the way if it is all chewed up) and the neutral safety switch. It would be a good idea to go ahead and put on the crossmember to hold up the transmission and then remove the jack from underneath the car. You may now get ready to install your driveshaft. Pull your fluid plug or ziploc bag away and slide the driveshaft splines into the transmission and start threading in the driveshaft bolts. Put loc-tite on them because you definitely don’t want them bolts to come loose. Torque them down to 100 ft. lbs. Go ahead and put on the mid-pipe and check for any kind of wires or connections that might melt on the exhaust pipes. Fix it (zipties work wonders). Plug in your 02 sensors. Do a quick visual check underneath the car for anything loose or not needed. Go inside your car and reinstall your shifter. Clean the shifter mounting area with a gasket scraper of the old silicone or gasket being careful not to get any in your tranny. Lay down a bead of high-temp silicone around the mounting area and bolt the shifter down (4 bolts) and reinstall the shifter lever/cover/and knob after your sure you got the stop bolts and shifter shifting properly. Just as well make sure the cover is installed around the shifter to keep dirt out of your interior and road noise down. Finally reconnect the battery and clean-up.

The install is now done but when aftermarket pieces are applied you will need to adjust where the clutch engages and disengages to your liking. There are aftermarket pieces like clutch cable firewall adjusters, adjustable clutch cables (you adjust at the clutch fork), and aftermarket quadrants from maximum motorsports, UPR, Steeda, etc. If you use a firewall clutch cable adjuster you can turn it counterclockwise and make the clutch pedal grab closer to the floor. If you turn it counterclockwise it will raise the pedal grab higher up. Replacing the stock plastic quadrant is a good idea and can soften up your pedal as well with the feel. I have seen and learned from personal experience that an OEM non-adjustable cable with a firewall adjuster is a great combo to have and keeps the pedal feel softer than what it could be.

Follow proper break-in procedure by being easy on the car for the first 400-500 miles to properly seat everything.

Here is a really good article with pics I thought I would add after I found it - http://www.badassmustangs.com/tech/idx/9/002/article/

Good Luck

Be sure to check your pcv system -- if it's not functioning properly and that's causing crankcase pressure to build, that may be the ultimate source of your leak. Many rear main seals have been replaced only to find the leak still continues because the crankcase pressure isn't being vented properly - and it's that pressure which is forcing oil out the weakest opening - which many times is the rear main seal. Hate to see you go through all the trouble (see previous post) only to find the real problem is elsewhere.