positive or negative ground?

I have a dumb question guys. A friend of mine just bought a 1955 packard 400 hardtop and the battery is hooked up for positive ground. Is this correct? Or should it be negative like most other 12V 1950's cars? The guy he got it from said it "always been that way" He just got the car and hasn't gotten a shop manual yet. Thank you.

All 55 Packards were 12 volt positive ground. They changed to negative ground in 1956.

YFAM, Randy Berger

Does anyone know WHY they had positive ground? Was there any advantage or disadvantage, or was this just a "leftover" from the 6 volt days. I've heard of people switching them from positive to negative. Is there any reason to do so, and if so, what does it take to accomplish it? Can negative ground accessories like stereos be hooked up to a positive ground system?

I'm mainly interested because it might affect whether my search is for a '55 (which is kind of near and dear to my heart--especially the 400) or a '56.

Switching from pos to neg ground on a 1955 is straight forward. I recall that there have been several threads on this.

Personally, I switched my 55 Pat to neg ground right after I bought it so that I could fit modern electronic ignition (MSD) and modern stereo and I've had it that way for six years. The electric motors (starter, T-L, windows, antenna) don't care about polarity. The original vacuum tube radio didn't seem to care about polarity either. Only the charging system is critical, but you can repolarize the generator easily (see service manual). The regulator might give up once switched (mine did). Then switch the wires on the ignition coil and ammeter (if so equipped) and that's it.

Thanks, Craig.

Thanks. Another question. The car in question has very old 235/75/15 inch biased ply tires on it. This car will be a driver, not a show car. Is there room under the fenders for radial tires? It seems like a pretty tight fit with the biased ply tires that are on it now. Also, upon inspecting the car closer, we noticed on the drivers side front of the engine a metal chamber between the hoses connecting the waterpump and the radiator. Is this an oil cooler?

That part between the hose's is your trans cooler...As far as your tires you can put the same size radial tires on there without a problem IMO...G

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">That part between the hose's is your trans cooler...(snip) </div></div>

This is another topic that has several previous threads, FYI. On my 55 Pat, I replaced the stock tranny cooler with an aftermarket one mounted in front of the radiator. This is a pretty simple install and will definitely keep the trans fluid cooler than stock. With the T-U, this seems critical to long life and good performance.

Ditto on previous threads about radial tires. Virtually everyone on this forum agrees that radials are a [color:"green"] BIG improvement and well worth the $$$.

Amen, Brother Craig, on the radial tires. I run 235/15s on my 56 400. The improvement is remarkable.

Also agree on the aftermarket tranny cooler.

YFAM, Randy Berger

I guess I am the only one who does not agree on the radial tire thing. I have found just the opposite. I felt like I was riding on a fish tail and I did not notice any difference in ride, NOT ONE BIT!!!! I will offer this bit of thought. They do not call it

"radial tuned suspension" for nothing.

Packards or any other car prior to the advent of "radial tuned suspension" cannot, in my opinion, benefit from radial tires other than not having as many blow outs, because they do ot have radial tuned suspension. I have six cars and only two have radials and that is only because I could not get bias belts in that size. I can tell you for a fact that on these two cars there is ABSOLUTLEY NO NOTICABLE DIFFERENCE IN RIDE OR HANDLING. To quote Dennis Miller, "of course that's just my opinion I could be wrong".

Al, I like you and enjoy your posts and this time, as usual, I agree with you - you're wrong. <img src="http://www.aaca.org/ubbthreads/images/graemlins/wink.gif" alt="" /> You are the only TL driver that claims no difference. I have had my 56 400 up to 105 mph and felt comfortable where the bias tires gave me concern even when driving at a moderate or slow speed. <img src="http://www.aaca.org/ubbthreads/images/graemlins/confused.gif" alt="" /> There is just NO comparison. As an afterthought, which brand of bias ply tires and what size are you using? <img src="http://www.aaca.org/ubbthreads/images/graemlins/confused.gif" alt="" />

YFAM, Randy Berger

Al K: I had bias ply tires on my Chevelle for years and began to notice that the Chevelle was rding rough and not handling very good. One sunday I decided to go to Pep Boys and get new tires. I purchased a set of four steel radials for the car. This made the car ride and handle some much better, I couldn't believe the differnce. My 1953 Packard was sold to me with a brand new set of Coker WWW bias ply tire tires. I gave them to a friend of mine to put on his Packard. Niether one of my cars will ever have bia ply tires on them again.. I consider bias ply tires a rolling accident waiting to happen.

Aint' America wunnerfull. We each can have our own opinions without fear of retribution. You guys can buy all the radials you want, I'll stick to what came on the car when I can. Happy Packarding to all!!!!!!

When radials first started coming on the market US car manufacturers fought putting them on their cars and one reason was suppose to be the cost of suspension changes. Since radial tires have a harsher ride more noticeable at low speed one of the changes would be to the rate of the shocks so I guess a gas shock would be an improvement.

Another thing about radials are that they're good at covering up worn front suspension parts and giving you "better" handling so better take that into consideration when comparing. I once read that when switching to radials that you should set toe in to 0 to eliminate wandering.

Of course there is always the issue of whether or not the stock rims are strong enough or the bead height sufficient for the change to radials.

I think I'd put what I like and feel comfortable with on your car.