Hi All,
I am the proud owner of a 1955 C3100 ½ ton I bought a few weeks ago and the warm weather for February has me thinking about getting it ready for the driving season which may begin a little early here in Michigan this year.

Anyways, the truck I bought appears to have a low mileage 235 inline 6 ( correct year) and the odometer, if I believe the seller was reset at engine rebuild shows 300 miles. I will be driving it only in good weather for trips under 100 miles and probably only put a few thousand miles on it per year. My first questions are on fluids and some brake questions. I have read all I can find on the site so far, but still have some base questions I could use some experience. The truck is a mostly OEM 235, 3 on the tree, stock one barrel carb and oil bath air filter and has the optional oil filter for that year.

While it may be low mileage, I believe it has been at least 5 years since it was rebuilt, and if this is true, it might have spent more time sitting than running if that matters to any of the answers below. Of course the alternative is that the odometer rolled over smile

So here are my first set of questions

1) What grade of engine oil do you guys think would work well? — it looks like the manual I have recommends either straight 30 or straight 20 weight, but that recommendation is 61 years old and oil technology has changed — I have found straight 30 weight in several places so I can go that route easily

2) What grade engine oil for the oil bath? — Manual says 90 weight I believe — just wondering if anyone thinks otherwise

3) I have found more than one style of oil filter canisters that list for my engine. I can certainly measure what I have, but I was wondering if anyone had some thoughts on if the thinner diameter is better/worse than the larger diameter one ( May be only one fits anyways — I have not pulled the existing one out yet)

4) What grease are you using on the fittings? — By this I am wondering if I should go with traditional petroleum based grease, or a newer synthetic? - I suspect a traditional type is in my front end

5) I am reading that the U-joints also need lubrication — what is recommended here — I can’t find much info here other than the manual saying stay away from “soap” type lubricants

6) I am going to check the tranny and rear end levels, and go with the manual here — looks like a stick your finger in the hole and it should get wet kind of check to me — suggestions?

7) The coolant looks good, although I no longer own a hydrometer ( or what ever its called ) — any special instructions in case I Decide to flush and refill? — I will test it after I borrow the correct tool and change if necessary

8) the last owner said he ran premium in it, but this confuses me a bit as I don't think the compression is even 8:1 in this motor - my bigger concern here is that he was not sure if the valve seats were hardened. so a two for one question here. What gas is everyone running and is anyone adding lead additive to keep the valve seats happy?

I have lots more questions, but this is a good start and I appreciate everyones help. Here is a link to my baby below

http://i157.photobucket.com/albums/t49/JoeStine/IMG_0676_zps79vixssw.jpg

She is starting to talk to me and let me know she is sick of sitting in the garage


Joe Finkelstine
Born and bred in Motown