1978 f150 Custom 4x4
stock 400 engine
NP435 manual 4 speed
NP205 transfer case

Awhile back a rear main seal leak must have saturated my clutch, now it grabs/chatters pretty bad while engaging, from what I gather there is no fix other than replace. I believe the clutch is stock. I am mechanically inclined and would like to do it myself, however this would be brand new territory for me. I believe I have the basic necessary tools other than some jackstands and a transmission jack, anything else I should consider/would need for a project like this? I do have a very good old Clymer Super Shop Manual that goes into great detail which I'm sure I can follow.

I want to do it myself to 1)save money 2)make sure it gets done right - I have had way too many bad experiences with "mechanics" and have resorted to doing everything I can myself. As far as the rear main leak goes I believe I have that tamed down, I believe I had elevated crankcase pressure from blow-by enough to take the seal out over time. Long story short the blow-by is for the most part gone and I replaced the stock pcv setup with a less restrictive one to allow more airflow and it seems to have solved the crankcase pressure problem as the leak is now maybe less than half what it was, however I'm sure the damage has been done to the seal as it still drips and I would replace that at the same time I do the clutch. Anything else it would be "mandatory" to replace while I'm in there?

Sorry for all the questions, but I would sure appreciate any advice from those of you in the know. Also any advice on where to get a good clutch kit would be great. I'm open to any and all comments!

 

Make sure you have the flywheel resurfaced.
I would only buy a new Luk clutch.

Luk Clutch repSet

 

Thanks that's good advice on the flywheel. I will look into the Luk kit.

 

No matter what you buy, buy new.
If you go rebuilt there's a pretty good chance you'll do the job more than once.
I know for a long time Ford used Luk for their clutches in new cars and trucks.
I have no idea what years or models.

 

Good to know

 

Use the AllData procedure to R&R the trans
Your public library should have AllData for you to use for free
Brakleen is your friend
Locktite the flywheel bolts, torque the flywheel bolts with a torque wrench if you remove it
If the flywheel shows no hot spots, you can just scuff it up with a brillo pad on an air bizzer (small air powered angle grinder)
I am replacing a clutch right now on a 95 F350 with a 7.5 and I am not turning his flywheel
Not necessary, but mark the drivelines to the flanges with a sharpie and put them back on exactly how they came off (pro tip) similar to tire indexing for out of round point with the factory dots

 

Be prepared for very heavy parts. T-case alone is around 100lbs and not balanced in any way. Very awkward. Don't know if you plan to remove them separately or in one big piece....just be aware they are very heavy. Hope you have a good tranny jack with some kind of cradle that will support well. As for clutch kits... definitely buy new. I bought my clutch kit from Rock Auto. AMD brand. Looks like good quality and so far it's working great for me. Wish Borg Warner still offered their Brute Power clutch kit...I had one in my 79. It was installed new in 92-93 and still in the truck when I sold it in 2014.

 

manic - Thanks for the info. My old Clymer shop manual goes into great detail per removal, teardown, reassembly, torque specs etc. so I'm hoping that will help if I get stuck. I don't plan on going through the tranny, just remove and re-install. I guess I'll just have to wait and see how the flywheel looks before I decide whether to turn it or not.

 

79F150 - Yah I'll have to invest in a tranny jack - so they come with/without a cradle? I planned on splitting them, not sure how in the world you would get them out in one piece (two jacks?). Sorry I've never used one, can the tranny jack be used for the t-case too? I suppose some short ratchet straps would help secure it to the jack? As far as the clutch kit I'm just mostly concerned with made in USA oem quality that will last. Not even sure what's all out there, Luk seems to come up a lot, I've never heard of AMD.

 

It would be quite a trip for oil to slip out between the crank shaft and seal, slide down a flange, down the front side of the flywheel and not be slung off before crossing the ring gear and crawling back towards the center to get stopped as it tried to get past a clutch disc being pressed "how hard" against the flywheel only to be squished by the pressure if it started across the surface during a clutch release? I think for more likely the transmission input shaft seal leaked letting transmission lube seep out through the throwout bearing guide tube to emerge inside the clutch disk and be thrown towards disc material, waiting for the next gear change.


Wrote a reply yesterday, it's not here, maybe I didn't save it?

 

Most come with some sort of cradle but those usually won't support what your doing. I made one out of some scrap 2x4s. A transmission jack would definitely help along with some sort of homemade cradle as I mentioned above. I'm not 100% sure my AMD clutch kit is made in USA...it's been a couple years since I installed it. Some ratchet straps would help too. Trying to keep the t case stable will be your biggest concern. If your doing these alone then splitting them is the safest option. Here's another one....might be easier to remove the engine and it would be way easier to get clutch off and on. I say this because I can have the engine out of my truck in 2-3 hours and it's way easier to handle with a engine hoist because it's doing most of the work...it's not awkward and so forth.
If I had to do a clutch job...I'd probably go that route and in retrospect I should have done it that way in the past instead of risking something falling off a tranny jack. I'm just spit balling here....if you have a plan that's great I'm not trying to change your mind.

 

tbear - the only problem with that theory is my tranny fluid hasn't moved in 3 years, the engine oil now is another story. A couple months ago when the rear main was leaking pretty good (I have a small leak out the back of the intake too but that doesn't amount to much) I got home and all underneath the pickup was wet with oil. Shortly after the clutch began to chatter, hence my assumption the clutch got contaminated with oil. I may be wrong?

 

I would have no problem just pulling engine (I see your point) IF I had the experience, but that would be another learning curve. I guess instead of a tranny jack I would need an engine hoist. Just trying to keep it simple... if I had another reason for pulling the engine it would make more sense, maybe. I can't think of anything though. I'd like to re-seal my intake.

 

Either way, transmission must come out, but you might want to look there.

 

Good point tbear, it wouldn't hurt to replace while I'm in there.