Motor rebuild: WHAT WENT WRONG

[Tuff68]

I posted on here 2 weeks ago that I had installed my rebuild 302 and new clutch, and had a bad screeching noise when I pushed in the clutch.
Droped the trans/tcase and checked everything with all looking good.
Reinstalled the trans/tcase with the second new throw-out bearing only to have the same noise issues.
Started looking under the hood with the clutch ped pushed in and see that THE CRANK IS MOVING FORWARD, causing the flywheel to contact the back on the motor.
WHAT DID WE DO WRONG. The only thing not new inside the block is the crank and I had a mach shop check and polish it. They also did the block work.
I'm lost at this point.
Thanks

 

[ugly74]

sounds like the cranks thrust bearing is gone. and that would totally suck.
I bet you had a real colorful vocabulary after hearing it do that still, after getting it all back together.

 

[jn2630]

wow! It moved forward? Just.....wow!

 

[grant_71]

I too would say thrust bearing, But, be sure the caps for the mains are all the right ones and where they are supposed to be, i havent had mine apart for a while but doesnt the end ones have a lip on them? and if they got mixed up at a machine shop or something....i don't know, just a thought

Good Luck, sounds like you got a doozy there

Grant

 

[clarrance]

I have heard of a similar problem with the late 80"s early 90"s ford 302's what i was told was that there is a difference between the car cranks and the truck cranks in these years. I don't know the specific details, but a friend of mine went through 4 reman engines that would last about 100 miles the main bearings would be totally destroyed. He kept taking them back and had the reman company reps checking into it and it turned out to be a difference in the clearences between the cars and truck crank shafts. From what I was told it happened to alot of engines from the bigger reman like Jasper, Marshall, etc. I don't know if this is your problem but I thought it might be worth looking into.

 

[welndmn]

Pull the pan, look at the bearings.
Put a pry bar on the balancer and look for end play.

 

[Skiddy]

Pull the pan, look at the bearings.
Put a pry bar on the balancer and look for end play.

Me to and then I would drive it through the rebuilders doors

 

[JHD]

a friend of mine went through 4 reman engines that would last about 100 miles

Warranty or did he have to pay for 4 engines? Sorry I know jack about engines so no advice but I just had to ask.

 

[clarrance]

Warranty or did he have to pay for 4 engines? Sorry I know jack about engines so no advice but I just had to ask.

They replaced the motors for free, but not the labor. He got really good at changing that motor.

 

[Tuff68]

Motor

Thanks for the replies and info.
To say I am sick about this would be putting it lightly. The mach shop has told me to pull the motor and bring it back to him. I have had the motor out 2 times and the trans/tcase out 2 times and now will be going for 3.
Do you think that with the forward movement of the crank that it has damaged anything else like the cam, pistons, or other. I have not driven the truck and the motor has ran maby 35 min's total.
Guess I need to change my board name to " TUFFLUCK68 "

 

[Apogee]

Thanks for the replies and info.
To say I am sick about this would be putting it lightly. The mach shop has told me to pull the motor and bring it back to him. I have had the motor out 2 times and the trans/tcase out 2 times and now will be going for 3.
Do you think that with the forward movement of the crank that it has damaged anything else like the cam, pistons, or other. I have not driven the truck and the motor has ran maby 35 min's total.
Guess I need to change my board name to " TUFFLUCK68 "

If you're getting enough endplay for the flywheel to hit the back of the block, I would be concerned about the other bearings on the crank, both rods and mains. Everything should be inspected in the bottom end before putting it back together, including the timing set and camshaft, although a certain amount of float is expected so they may be fine.

Crank endplay is a standard thing to check when assembling an engine, so you want to make sure you know exactly why it was put together the way it was before putting that thing back together. That sucks, but hopefully the builder stands behind his work and makes it right.

 

[Bronco_46256]

I am in the same boat---.052 of end play and noise from the back of the Flywheel hitting the starter....looks like we'll get through this together!!!!!

 

[bax]

Uh. Endplay is one of those things you check right after you install the crank into the block. someone is not paying attention

Bax

 

[craigs67]

I am going to rebuild my 302 and have read about endplay but I never have figured out what to do if ther is too much.

 

[j.r.nice]

IIRC, the 3rd main bearing is the thrust one. It has "sides" on it that the others dont. I'd be right there when he pulled the pan and pay strict attention to the mains. I wouldnt let him slide and try to blame something/someone else, nor would I let him make light of it. I would also demand some sort of compensation for pulling the engine especially if it is his mistake.

I agree with Bax...checking the end play - ESPECIALLY for a professional - is elementary.

 

[bax]

Endplay should be from .0004 to .0008 some will say as much as .0010
Endplay is limited by a thrust/main bearing. It's easy to increase end play however making endplay less requires , well lets just say different crank. Unless the builder messed with the bearing before he installed it. you cant just leave it out or install it backwards? If you had the crank turned chances are it was messed up during this process.

Good luck with everything.

bax

 

[NoJoe]

Hi: I worked for a ca. engine builder for 2 years, cheap Cast pistons cheap bearings, cheap reground cam, If you can't cut yourself on the valves their o.k., knurl the guides, cheap gaskets, sleeve the block, repair cracks in heads by pinning,shim valve springs don't replace them, on and on, sorry but If I wanted a long block I would by a Ford crate engine or build it myself with good stuff.

 

[mr incredible]

sounds as if you have a turned down crank ,, and standard main bearings ,,
you might wannna check them also , if the crank is turned -10 ,, and the mains are standard , there is the end play ,,added with standard rod bearings, would also allow the whole mess to slide foreward with ease ,,

 

[Mherriford]

Me to and then I would drive it through the rebuilders doors

X2

 

[Mtn Gote]

Man that sucks!! I dont know much about motors so I can't give you any advice. Sorry!!!
Cory,