#4 Piston Removal
 

I have a 38 ford with a bad wrist pin in #4. Is it possible to remove the piston from the bottom so I don't have to take off the head? The engine was rebuilt about 2-years ago and runs fine with the exception of #4. Compression is good and plugs clean. Any help would be appreciated. Thanks Larry

Re: #4 Piston Removal
 

Not a very good plan. The piston will not come out the bottom.

Re: #4 Piston Removal
 

What is the concern about removing the intake and 1 head? Do it right.

Re: #4 Piston Removal
 

i drove an old 77 white truck for ten years with a knock that had been going on for years before i got in it, thought to be a wrist pin. cummins 250 diesel, probably 100k miles of knocking and still ran fine when they sold it. just a fun story, but i agree with the others-take the head off and see for sure whats going on

Re: #4 Piston Removal
 

How do you know it's a wrist pin??

Re: #4 Piston Removal
 

Pulling a head is a way lot easier than pulling a crankshaft. You can short cut some things but engine bottom end work, not so much. If the cylinder is damaged then it will get even more complicated.

Re: #4 Piston Removal
 

I'm with Ron. VERY unusual for a wrist pin to be loose, if it was ever 'right' in the first place.

Re: #4 Piston Removal
 

Even if it could come out from the bottom it won't be going in easy from the bottom.
I once reconditioned a rod for an MG or Triumph, I forget by getting the piston low enough to remove the wrist pin. Needed a special pair of snap ring pliers. There was not ebough room to get the piston past the webbing.

Re: #4 Piston Removal
 

Looks like it will come out from the top. I was just trying to look at all options. Experience tells me it is a wrist pin. It has had the noise for quite a while and never gets any worse. It does not sound like piston slap as I have had an engine with that problem. Thanks for the responses. Larry

Re: #4 Piston Removal
 

In the words of an old philosopher (me). "If it ain't broke, don't fix it".

Re: #4 Piston Removal
 

Ditto Ron. What is the basis for your diagnosis? Valve noise can be mistaken for wrist pin. Check the valve clearance on #4 before you tear it down.

Re: #4 Piston Removal
 

sdI have been using the "if it ain't broke don't fix it for a few years" and it may last a few more years. Thanks for the responses. Larry

Re: #4 Piston Removal
 

I bought a running '57 Ranchero with a 292 back in the 70's. It had a little light tap in the top end. I ran the engine for quite a while. Then one day I was driving about 65 mph and suddenly I heard "th-th-th-BANG". I mashed the clutch, looked in the rear view mirror, and saw oil in the road behind me. The rod had broken below the piston and wiped out the block. I could wiggle the rod stub on the piston pin when I tore it down. My theory was that the bushing wasn't level on the pin and was causing the rod to bend slightly with every stroke, resulting in fatigue/failure.

Re: #4 Piston Removal
 

Try shorting the spark on that cylinder while idling and hear if the noise changes.Cheers