The Stovebolt Site Forums The Shop Area Engine Shop Freeze Plug Question

I'm looking at buying a 1955 3100 2nd Series. The only thing that the owner says is wrong with it is that the freeze plug busted completely out in December due to the cold weather. It's a 235 with a 4 speed. How difficult is it to replace the freeze plug to get the motor running?

On a side note...concerning the 235/4-speed combo. Does the 4 speed option for this year allow for better highway cruising or is does it allow for lower gears for 'stump pulling'.

Thanks for the help!! I'm new to the classic truck hobby, and am trying to soak up as much information at I can.

Plan on replacing the motor

What nice response Profit. "Plan on replacing the motor"

How do you know?

How do you know it can't be as easy at installing another freeze plug and filling it back up with coolant and get it back running and check everything over?

Give the guy some usefull advice or don't give any at all......

It depends on the location of the freeze plug. If the problem really is just a freeze plug it should be already out of the block. Find the open hole. If it's accessable put a rubber temporary plug in it and fill up the cooling system and check for leaks in the block.

Like Proffit says,it probably has a busted block. Fifty year old freeze plugs have usually taken root and don't push out as designed.

Your 4-speed has a granny gear low, as you guessed for "stump pulling". In normal driving you would start in 2nd.

Tall Paul,

If you're really lucky, you might get away with replacing the freeze plug. However, I'm kind of with Proffit, I think you're more likely looking at replacing the motor. I've not known of very many that got that lucky with just the plug. There seems to be a number of 235's out there if you take the time to look. You might want to place an ad in the Swap section of the site and see what types of responses you get. I ran one looking for a 216 and probably got a half-dozen leads. I've seen several out on E-Bay that seemed pretty reasonable as well.

As far as the transmission, most of these were a Granny 4-speeds, or as you stated, a "stump-puller". My 52 cruises fairly nicely at 50-55 in 4th (with a stock tranny and a 4:10 rear-end) but it races that poor little motor at anything higher than that.

I know that's a little bit different than what you're looking at, but it might give you an idea of what you're looking at.

Good Luck with the truck purchase.

Phillip......... I wasn't being mean..... Odds are replacing the plug will not fix this truck for long

The fellow says he's buying this.
If your buying something do you figure the cost of repairs as part of the price

Sellers have been known to to tell new buyers that everything is simple to fix

It's not like he says 'It's got a flat tire"

Like the other guys here have said"Freeze plugs don't just fall out!" If it's been sitting out with water in it and allowed to freeze you can bet that it has several more problems.....

And while we are at it..... If you ever have the engine out it's a good idea to notch the bell housing and make an access panel in the firewall just so you can change the rear plug without a bunch a DRAMA

Just got an e-mail from the owner in response to the location of the freeze plug. Luckily it's located on the side of the motor. He is going to replace it next weekend so that I can give it a test drive.

He's only owned the truck for two years, and the owner before him had the 235 rebuilt just before he bought it. Since then, he says he's only put a couple hundred miles on the motor.

So, hopefully the freeze plug will be the only thing wrong with the motor. I'll keep my fingers crossed

It is unfortunate that they are now called freeze plugs because they really don't protect the motor. If that plug popped with ice, there is most likely other damage to the block. That said, if the truck is nice, 235s are not hard to come by.

Paul, If the owner is going to replace the plug, and the motor runs, be sure and get it good and warmed up before you decide that the motor's good! Watch for white smoke, since it froze, look the motor over really well while it's running. After it runs a while, pull the dipstick and see it the oil is milky looking. A 235 shouldn't be hard to find cheap, but if you're on a tight budget and counting on this to be a good motor, you don't want to get burned!

All good advice, guys. I really appreciate it!!

VERY good points, Pakrat. I'll definitely be sure to watch out for everything you described.

I'm looking for a project that I can drive and fix up as I have time, so hopefully this will work out.

Again, thanks for all the help.

Blew out a frost plug on my small block Chevy right under the exhaust manifold about 5 years ago. Could never replace it without pulling off the manifold. I put in a rubber plug, tightened it up and touch wood, never heard from it again.

I have a couple thousand miles on my 64 I bought w/bad core plugs, I pulled engine & replaced all the plugs, all is well. Knew it before I bought it, knew I could fix it. The cheap rebuilder style plugs are thin as paper. Plugs had just rusted away. Brian

The so called 'freeze plug' is a sand casting hole plug. It is the access hole that they get the sand out of the water jacket and seldom do they protect the block. I have on a few occasions moved a vehicle that has set out over the winter with no water in the engine and found anywhere from one to all the freeze plugs laying on the ground. I guess it was cold contraction theory working. Put in new plugs and good-to-go. But, if there was water with no anti-freeze, the engine is probablly cracked.

Truck Tinker

Well guys,

I have seen several scenarios, here are a couple that came to mind on freezing and "freeze plugs"

One time on a 1939 Chevrolet 2 door sedan I bought, the back plug was leaking so bad I just knew it was out or cracked. Well as we all know this just isn't a 15 minute job especially on the rear ones Much to my surprise the casting wasn't cracked or any evidence of out due to a freeze, but rather that dang thing was rusted completely through the steel. Needless to say this was a huge relief.

One other time on a old Massey Harris tractor, we once had. The engine froze on in it and just about every single plug was out of the block and head. I just knew this block for headed to the junk heap. Well believe it or not, nothing else was cracked, with the exception of the radiator it was bulged and wasn't worth the effort and money to fix. This was my own stupid fault, that summer took the radiator out to have it cleaned and repaired and put it back on the tractor and just put in water, (that was the year antifreeze, skyrocketed in price) Just planing on running it a few days to make sure it wasn't going to leak or get hot again, WELL, never drained the water and completely forgot all about it and then remembered, after the fact.

I think it's odd on why one engine will blow out the plugs and not hurt anything, where others will go and ruin a block. I don't know if it's is because of the way it freezes. Meaning a slow temp drop compared to a faster drop in temp. Then end result is it still freezes no matter how it gets to that point.

What's even more hard to believe, is why we (I) don't think about checking the antifreeze. I BUT that was when I was much younger and stupid.

Best thing I can say is to hope for the best, but expect the worst. Sounds like at least you have the opportunity to see what the outcome will be, before your make the purchase and the advice Packrat and others have given to you is the best plan of attack.

I do know that these little 235's are tuff little engines. BUT as already said, there are a lot of these engines still out and can be purchased for the money. A few weeks ago I heard an ad locally on the radio where a gentleman had a prefect running 235 that he was yanking it out for a street rod he was building, for 100 bucks, when I called it was to late, he already sold it. (just my luck )

Good luck and let us know what the outcome is.

John Niekamp

my friend had a rebuilt 216 he ask me to help him start it we got it running i never seen so many crackes he had put water in it the year before when it started it leaked water and oil everywhere i call him every year in november now just to remind him