1948 Ford F1 - New Owner
 

Gentlemen:

I recently acquired a restored 1948 Ford F1. The truck was recently restored by the previous owner and we purchased it from his Estate. We know the 239 Flathead V8 was recently rebuilt, however, we don't have any information regarding when the vehicle was last serviced. Therefore, I want to go thru the truck and change all fluids, etc.

Question: What oil should we run? (brand and weight) Located in South Carolina. I know there is a WIDE range of opinions on this topic. I have heard good things about Lucas Hot Rod & Classic 10w-30 with High Zinc.

Any advice?

Thanks,
Brent

Re: 1948 Ford F1 - New Owner
 

Flatheads do not require high zinc because they have low valve spring pressure on the lifters/cam. The oil to use is up to you, about any modern oil is fine. 10w-30 would be a good option. The Lubrication chart for the F1 is in the service manual.

Re: 1948 Ford F1 - New Owner
 

20w50 Kendall oil, or lots of guys use rotella diesel oil 15w40. I live in upsate SC and run the 20w50 in all my flatheads with good performance. use synthetic grease in all fitting and use 90wt trans lube--NEVER-use any gl 5 or above as it will ruin the brass in the trans, I also put a quart of lucas oil extender in the trans and then fill with 90 wt. I have used 140 with the lucas in 4 speed truck trans. location is SC?

Re: 1948 Ford F1 - New Owner
 

I run 10/30 from Dollar General and save a lot of money. ANY oil available these days (except for non-detergent) is so superior to what was available when these vehicles were new that there is no comparison. Many folks spend a lot on oil, but it's mainly for braggin' rights. As you will also see on here from a lot of folks who know, that in a a flathead, oil flow is more important that oil pressure, thus the higher viscosity oils are not required for use in them.

One thing I do not recommend is using oil with an additive package designed specifically for compression ignition engines (diesels) in conventional spark ignition engines. That is not what it was designed for. Contrary to what some people think, petroleum engineers working for those big oil companies do know what they're doing

Re: 1948 Ford F1 - New Owner
 

For years now I have used 20/50 from Family Dollar. Never had a problem, and I save $$!

Re: 1948 Ford F1 - New Owner
 

The light duty 3-speed transmissions do well with Sta-Lube GL4 in either viscosity rating depending on climatic conditions. The rear axle can use any GL5 rated gear lubricant or the same as the transmission if you want. The steering gearbox can use about any rating of gear oil with recommended viscosity to be equivalent to OEM specs for climate.

The engine called out SAE 10 for winter and SAE 20 for summer. This puts 10W/30 right in the specs for all season lubricant.

Re: 1948 Ford F1 - New Owner
 

Thank you! This is very helpful information!