Modern oils for a 1948 Studebaker Champion

[Robespierre]

I recently bought an all original 1948 Studebaker Champion. It hasn't been driven in a few decades, and I have no idea how old the oil is. I already had some Supertech GL5 80/90 and some Quaker State HD30 on the shelf. They seemed appropriate for the rear end and engine, so I've already installed them. Got any better ideas for my next oil change?

I'm undecided on what to put in the transmission. It has a Borg Warner auxiliary overdrive that uses a cone shaped clutch to engage. It shares its oil with the transmission. I found a pdf manual for the overdrive, and it calls for 40w motor oil. I'm sure that would work, but I'm thinking that a modern MTF or Synchromesh oil might be better. What do you guys think?

 

[StevieC]

to BITOG!

I will let the others answer your questions... Not an expert on the oldies...

Steve

 

[OVERKILL]

How many miles on it? Has the engine ever been apart?

We had great luck with Mobil 1 5w30 (scary, I know) in a 425HP Ford 312 Interceptor fitted in a 1932 Chris-Craft.

I've run Mobil 1 in a number of engines from the 30's and 40's with no ill results other than a LOT of cleaning, so if it lacks a filter, I'd run it for a shorter than normal interval and then change it, because the stuff it will unleash, at least in our marine engines, was rather insane.

 

[Robespierre]

The odometer shows 2400 miles, so I guess it has 102400. It's a lot of miles for a car of that vintage. I don't know if it has ever been rebuilt. It idles smoothly, doesn't smoke(at idle), and it shows 40psi on the factory oil pressure gauge. It has some oil leaks. It might smoke under a load, I don't know. It won't be drivable until I finish the brakes (using DOT 5 fluid). Regardless, it's not a real nice car and I'm probably going to use the engine the way it is. It does have the optional bypass oil filter. Napa actually had one in stock.

 

[OVERKILL]

If the engine has never been apart and the gaskets are original, putting in a synthetic may make those leaks much more evident. I've found cork gaskets do not respond well to the cleaning effects of synthetic oil.

 

[EricF]

I think synthetics would cause a lot of harm in your Studebaker.
I know a guy with a 1948 plymouth, he uses SAE 40 in the summer and SAE 30 in the winter, and uses regular dot3 brake fluid.

I think putting anything "exotic" in the motor as it is would break up a lot of sludge and whatever else is lurking.
Now if you had it rebuilt.. that'd be another story.

 

[Jim Allen]

I think you made a fine first choice with the oils you installed. They are light years better than 1948-spec oil.

In the long run, I would probably switch to a multigrade 10W30, but a good mineral oil I think, not a syn (for the reasons mentioned above). If you can find a SL rated oil it would be better (more ZDDP) than an SM, but if it were mine, I would use a diesel rated HDEO 10W30 like Rotella-T (which is the easiest to find of that ilk). The diesel rated oils have high levels of ZDDP, very good dispersants, which helps an engine with only bypass filtration. They are also very highly detergent, which is good in one sense but therin also lies a potential problem.

If the engine is heavily sludged, it may break that goo loose quickly and cause trouble. If it were mine, I would do a little checking. On flatheads, the first signs of sludge will be found behind the side covers (where you adjust the tappets). Pull one of those and see how she looks. If relatively clear, go fer it! If it's heavily sludged, clear it out (and the other) with a scraper and maybe drop the pan and clear it manually too (would give you tn opportunity to replace the rear main seal too). After than, do a couple of short interval oil changes and watch out.

Years ago I killed an old Dodge flathead by putting in an HDEO without any checking. It was tired, but ran well, and had been sitting 15 years. I neglected to check for sludge (it had likely been running a non detergent oil all it's previous life). Turns out it was massively sludged. Had I taken the time to drop the pan, remove the side covers and clean out the gunk, followed by several short interval oil changes, it would have likely been OK. As it was, the gunk broke loose all at once and plugged the oil pickup in about 1500 miles of driving. If I had even done a few short interval OC's it probably would have survived.

 

[mechtech2]

Why DOT 5 brake fluid? Are you kidding?
Don't do it.
I'd use 15-40 HD oil in the engine. Cheap and excellent. And luckily, a very good weight for that car.

 

[Robespierre]

Thanks for the replies, folks. I was considering using rotella. My brother, Onion, is a big fan of the stuff. It's good to see some details as to why it's a good choice. I was reluctant to pull a side cover simply because of laziness. The engine compartment of this car is surprisingly cramped. The story about the dodge flathead has convinced me to get on with it.

I'm quite serious about the DOT 5 brake fluid. I'm replacing all of the brake hydraulics, except for a few fittings which I've thoroughly cleaned. The master cylinder and all four brake cylinders were corroded solid, and I just don't trust rusty steel brake lines and 61 year old rubber brake lines on a single circuit system. I just have to finish bending and installing the lines, then I can install the DOT 5. A friend of mine has two old vehicles that he rarely drives, and he has to rebuild the brake cylinders every few years because of corrosion. I want to avoid that.

Does anyone have any ideas on the transmission oil? I put some valvoline 40w detergent oil in it, but I'm having second thoughts. Do y'all think a nondetergent oil or some kind of mtf would be better?

 

[Jim Allen]

RE the Trans: What viscosity does the specs in the manual call for? I looked though some of my old books but could not find the trans oil specs. Engine calls for SAE 30 from 50-90F and SAE 20 below that up to about 70F. If it calls for a light engine oil for the trans, an MTF might do,but I doubt it will. Most of those old transmission were designed for 80 or 90 grade gear oil.There are some exceptions, but I don't know if Stude is one. AFAIK, Stude used Warner Gear transmissions and many of those took 90 grade mineral oil (modern equivalent a GL4 gear oil) for warm weather and 80 grade for cold. If that's true, a 85W90 GL4 would be the one, or a dual rated GL-4/GL-5).

I was pretty alarmist with my Dodge story. I doubt you'll be as stupid as I was, but use my stupidity as a lesson not to be lazy. The thing I've learned thing is something the Brits call, "mechanical sympathy." That has stood me in good stead with a lot of old, tired cars and trucks since, including driving an original, unrestored 1940 Chrysler Windsor from Virginia to California

 

[JohnBrowning]

I would run a Rotella T Synthetic 5w40 it is a group III so it is going to behave like a dino with reguards to the seals. If that engine is going to see regualr use year round if not start with a 10W30 or 15W40 and work up or down from their based on oil pressure reading and the sound of the engine depending on when this engine was last rebuilt it might have buna and leather seals or it could have viton and neoprene seals? We just do not know what it has. Modern rebuild kits for the old Ferrari's have modern seal materials so that modern oils can be used.

I would agree that a modern MTL like Redline MT90 might be a good choice. My concern though about going with Redline would be that the seal materials in the engine and transmission might not react well to ester type synthetics. In fact Swepco,Cen-Peco and Schaffer's would all be worth contacting to see what they have for this unique today application. With high end dino products from the above sources I am sure they can find great products for that application. Because these guys all work with minning and industrial applications they have products that you would not be able to find on the shelf at Walmart especially for that transmission with external over drive and common sump.

Since Schaffer's is a site Sponor and you have easy access to him I would contact him with this post and see what he can come up with for you. Stay with dino and G-I-III products and seal compatability will not be an issue. If you wanted something custom blended for that transmission like say an SAE40Wt. with double the current HDEO additive package for instance I am almost sure Bruce could blend stuff like that for you at a good price. SInce all HDEO's are yellow metal friendly you would be getting what this unit calls for only with more of a good thing in the mix in the form of higher then normal additive levels!

With reguard to oil pressure on things this old you normal give them 60seconds to show positive oil pressure even better if you have full oil pressure with in 60 seconds. You normally want to have 25psi at idle and 5-10 psi per 1000 rpm's. Now all of this is generic info based on years of working on vintage vehicles I am not sure what the specifications for this model are. You can normally hear a distinct change in the engines sound as the oil pressure comes up they normally have some clatter that will suddenly go away as oil reach's all the parts normally this is gone with in the first 60-90 seconds of start up. Then you get another distinct drop in sound as all the parts expand as the engine heats up to normal operating temp.'s!You will hear the drop it is obvious.

Best thing to do in my mind would be to run an auto-rx treatment through everything lubricated with oil on this vehicle. It will not hurt any of the seals at all not even leather one it is made from reacted lanolin.Normaly dry rotted seals and rust on internals from well bearing to cam shaft lobes are the main sources of failure.

 

[zrxkawboy]

I would run a HDEO or a High Mileage oil.

I use DOT5 in my old vehicles and recommend it.

As for the trans, I would run the 40 wt unless you find someone who can say for sure that a modern substitute will work.

 

[mechtech2]

The DOT 5 will not absorb as much moisture in the system.
A good thing?
NO!
Now any moisture is still there, but in puddles and pools where it will do damage to metal parts more readily.
You'll need to flush it often.
It also aerates easily and is more compressible than regular fluid.
Just because it is more expensive and exotic does not mean it is good for a vehicle.
Stay with DOT3 or 4.

 

[Eddie]

Those engines made very fine inboard boat engines. Light weight and with some intake & exhaust manifolds, they put out decent power. My dad built up many of those engines. They would turn a good size prop 5,000 RPM. Brings back good memories. I remember 30 weight oil was the oil of choice. Ed

 

[zrxkawboy]

Originally Posted By: mechtech2
Now any moisture is still there, but in puddles and pools where it will do damage to metal parts more readily.
You'll need to flush it often.
It also aerates easily and is more compressible than regular fluid.


Have you used it? In other words, are these statements from personal experience? Because in my experience, over the years in different cars, the stuff works great.

 

[unDummy]

I have and don't care for dot-5 brake fluid unless it calls for it. Stick with dot3/4 brake fluid and bleed every year or 2.

Any HDEO or motorcycle oil for the engine should be fine. Since oil consumption and leakage is unknown, stick with cheap.

Any non-lsd 90wt or GL4 90wt weight should keep the gearbox happy. Synchromesh is too thin. Stalube, Coastal, and Valvoline conventional are some good choices here. You can even use a 15w40 HDEO since you'll probably want a cheap 'rinse' fluid.

Any GL5 90, 110, 140 wt in the rearend would work great.

The oil issue with full synthetic is cost. There should be no issues with common rubber/cork seals.

 

[Jim Allen]

Originally Posted By: mechtech2
The DOT 5 will not absorb as much moisture in the system.
A good thing?
NO!
Now any moisture is still there, but in puddles and pools where it will do damage to metal parts more readily.
You'll need to flush it often.
It also aerates easily and is more compressible than regular fluid.
Just because it is more expensive and exotic does not mean it is good for a vehicle.
Stay with DOT3 or 4.



Ditto! Major DITTO! I meant to say this in my earlier post. I have personally seen a car (my own MGB!) where water collected in a particular part of the brake system (master cylinder) and just ate it up. DOT3/4 and change it every few years... very easy to do in a car with a single circuit brake system.

 

[mechtech2]

I have used DOT5 on specific motorcycles and cars.
But my knowledge comes from what's on paper - the specs., and vicarious experience as well as empirical.
How would we know if a fluid is better? Fresh brake fluid will always feel good.
Unless we tear down /EACH component and inspect it internally, we won't know.

I still say stay away from DOT5 unless the mfr specs it.

 

[Robespierre]

Perhaps some of y'all didn't notice my third post. I've replaced ALL of the brake hydraulics with new components, except for a few thoroughly cleaned fittings. There will be no mixing with old brake fluid. I'm using DOT 5 to avoid the sort of corrosion that I've seen on vehicles that sit for long periods of time, as this car will. Onion mentioned a while back the fact that DOT 5 is more compressible than DOT 3/4. I don't know how much the difference is, but I doubt it'll be an issue. My tiny front drums are the limiting factor in my car's brake performance, not the compressibility of the fluid. Maybe the brake pedal will have a slightly softer feel with the newer fluid, but I'd be surprised if I could detect a difference.

I guess I'm going to stick with 40w motor oil or maybe 15w40 later on in the transmission. I don't have a manual for the transmission, so I'm assuming that the oil called for in the overdrive manual (same manufacturer) is also right for the transmission. I'm reluctant to switch to something a lot thinner or a lot thicker than 40w, since either could potentially cause problems. I also want to avoid additives that could cause problems with the wet clutch in the overdrive.

I'll switch to a 15w40 HDEO dino for my next oil change. I've read a lot of posts here which suggest that the latest motor oils are not so great for flat tappet lifters. Is this really a big issue?

 

[Jim Allen]

RE BRake Fluid: Use what you want, but the problems will not come right away, but down the road. DOT 3/4 is hygroscopic and will hold the water in suspension. DOT 5 is less so and moisture tends to pool in localized areas. Short term, there won't be any performance issue.

RE Transmission: I found a listing for Warner Gear transmissions and it listed either a T-86 or a T-90 (both 3-speeds)as being used in the Champion (depending on engine and year, I guess).In every other application I've seen, both of those gearboxes were spec'ed for a 90 grade gear oil for summer and 80 for winter. The 15W40 engine oil is about the right viscosity (remember that engine and gear grade numbers don't directly compare, but the 40 grade engine cover the lower half of the 90 grade on the viscosity chart) so it should work OK. It's just missing a lot of the anti-wear elements found in gear oils, so may not be suitable for long runs (could shear down much faster too). Short term, it should be fine. Would be interesting to see how it holds up, actually.

RE Engine oil: The low ZDDP issue in is a big deal, more so for flat tappet engine with high valve spring pressures that the weak springs used in flatheads (you can compress a lot of them partly by hand). FWIW, I think 15W40 is the incorrect choice for your engine. If you look in the specs, of the old engines were spec'ed for 40 grade oils unless they operated in the desert. My opinion (worth every penny you paid for it) is that a 10W30 HDEO is a better choice. That said, a 15W40 won't hurt you (nor would it be any "better" than a 10W30 HDEO) but expect that 6-volt battery to work harder spinning it over on a cold start.

Finally, we wanna see some pics!