4 degrees and transmission goes "!!!CLUNK!!!!"

[defdes]

I just completed my move from SoCal to Vermont, my truck was delivered last night, pulled off the car hauler, and my auto tranny made a horrific clunk when shifting into all gears. It's a '72 F250, I have never had issue with the gear box before. It was 4 degrees last night when we removed it but would that cause such a condition? I was really just relieved that the car even started in such temps, it being a Southern California car and being a bit of a hard starter to begin with in 40 degree temps. It's "supposed" to be 40's-50's this weekend so I'll give it another go then. Right now it's stranded in front of my barn on my freshly plowed skating rink. Driving that thing just from the hauler to my property was sketchy at best, it was like marbles on a mirror. As soon as I can move it I will take it into town and get some suitable studded snows if I can find them in 16 1/2.
Thanks for any cold weather insights.

[fordman]

did the truck move after it warmed up? i could have just been low on fluid.

[defdes]

It was topped off not long ago (I'll check it to be sure tomorrow). It warmed up long enough to keep it from stalling coming off of the truck (about 3-4 minutes) and then drove it about another 4 minutes to my house. I then let it sit idling for about 10 minutes while I juggled other cars around before I realized it would not drive under its own power on the ice that it was sitting.

[fordman]

fluid levels can drop after warm up. i would check it after it gets warmed up.

[Racer Z]

Here in LA it never gets cold so I'm of no help to you. I was thinking that fluids shrink when they get cold and that might cause it to work incorrectly while it's "low" until it warms up and the fluid expands back to normal.

Years ago I was in the Army (American) stationed in Germany. On day it was colder than cold, colder than ever, maybe 20 below. My deuce and a half (6x6 2.5 ton truck) registered 2 quarts low. The day before it had been full and I couldn't see any signs of a leak. I started it up and drove it over to the motor pool to ask somebody about it. When we checked it again it read full. The only thing we could come up with was contraction from the extreme cold and after it warmed up it expanded back to normal.

[Caseys71]

Since you said the transmission fluid was recently topped off and that you've never experienced this issue before I'd venture to say that it could just be from the cold temperatures. Not sure how to explain why it is that some automatic transmissions are a bit finicky in the cold but some of them seem to be until they get warmed up pretty well. I'm pretty sure it has something to do with lubrication though like what Racer Z had stated and when the temperature is very low the fluids contract which would leave you with the same conditions as your tranny being low on fluid.

Here in LA it never gets cold so I'm of no help to you. I was thinking that fluids shrink when they get cold and that might cause it to work incorrectly while it's "low" until it warms up and the fluid expands back to normal.

Years ago I was in the Army (American) stationed in Germany. On day it was colder than cold, colder than ever, maybe 20 below. My deuce and a half (6x6 2.5 ton truck) registered 2 quarts low. The day before it had been full and I couldn't see any signs of a leak. I started it up and drove it over to the motor pool to ask somebody about it. When we checked it again it read full. The only thing we could come up with was contraction from the extreme cold and after it warmed up it expanded back to normal.

, Sounds about right to me. I never really understood how that worked myself.

[defdes]

I was out all day and just had a chance to do a little further investigation. It seems it was a combination of the cold weather and being a bit low on fluid (just below the arrows). It was 45 today and the truck seemed to like it's familiar temp. It mostly shifted smoothly, with just one or two clunks but not nearly to the level of the other night.

[fordman]

so it never made a clunk before? not even from a stop? how about a screeching noise for a second or two. maybe a few weeks ago or a month. what are the condition of the u joints? when were they last serviced or replaced?

[defdes]

So it was 60 today in VT, I topped off the gear box and all is fine. As to the joint question, I do need them, it's the first on my list for Spring.

[Brokenarrow]

Maybe your SoCal truck was just mad at you for moving to frikkin' Vermont

[novaboy009]

U joints will go "clunk." A transmission doesn't usually clunk unless they're blown up.