oil testing

Good time to put a oil sample in the mail when you change oil the 1st time, CK. for sample kits when you buy your oil or at place like speedco lube center, most use synthetic 50 weight in trans,

 

If you just bought it, I'd change the rears, trans and engine oils now and send all of them out for samples, which could identify any issues. Probably adjust the overhead, test coolant and service the air dryer too. Unless you know for sure the service history of the truck, it's better to be safe than sorry.

 

I agree with grapeape...send them all out for sampling analysis. If the ph of the anti freeze is off or metal in the lubes, you want to know about it now! Should not be an issue with putting synthetics into rears or tranny. The engine might be a different story. I have had engines begin to use oil heavily if it was run on regular oil for years and then switched. Try to find out what type and brand of oil it was weened on if possible...I think oil sample report will tell you if it is synthetic.