The Hudson starter solenoid #45997 (which is Autolite part # SS-4001) is listed by Hudson as fitting all Hudsons from 1934 through 1949 EXCEPT for 1940!
I have no idea which solenoid was used in 1940, or if one could make the SS-4001 fit the 1940.

Hudson lists the 1940-only solenoid as part number X-159935 but (unhelpfully) does not list the AutoLite part number of the solenoid. Normally the parts book (for the specific year of Hudson) gives Autolite's generator, starter, distributor, etc. part number for that item, making it easy to find an Autolite replacement. The detailed drawing of the starter (referencing individual part numbers) in the manual, does not even picture the solenoid. Leaving one to wonder if the starter solenoid was even attached to the top of the starter (as is the case in all other 1934-49 Hudsons). I wonder why they changed this for 1940 only? Maybe a fellow 1940 owner can answer this question.

[url= https://www.ebay.com/i/264514235813?chn=ps&norover=1&mkevt=1&mkrid=711-117182-37290-0&mkcid=2&itemid=264514235813&targetid=885583109988&device=c&mktype=pla&googleloc=9007592&poi=&campaignid=9423618855&mkgroupid=95235883346&rlsatarget=aud-497631946031:pla-885583109988&abcId=1141016&merchantid=118858209&gclid=EAIaIQobChMIh42ZzYa06QIVkYFaBR2plgSOEAQYASABEgJaG_D_BwE ]HERE[/url] is a current Ebay listing for what is claimed to be a 1940 solenoid. I have no idea whether that is correct.

Just FYI, here is the original SS-4001 solenoid (one of several now on sale on Ebay): [url= https://www.ebay.com/itm/174158117879 ]https://www.ebay.com/itm/174158117879[/url] There are aftermarket solenoids available; I believe this is one of them: [url= https://www.ebay.com/itm/291064268493 ]https://www.ebay.com/itm/291064268493[/url] .
What makes the origianl more desirable than an aftermarket replacement is the remote starter button sticking out the back, which hides under a screw-off cap. Makes it very easy to turn the engine over when (for example) putting in new Hudsonite.

Thanks for the help. The photos on eBay look exactly like what used to be installed. I wonder what the difference is for the ‘40.

The parts book for the car shows the following pictures and the part number for the solenoid.

[quote="Jon Battle" post=26061]The Hudson starter solenoid #45997 (which is Autolite part # SS-4001) is listed by Hudson as fitting all Hudsons from 1934 through 1949 EXCEPT for 1940!
I have no idea which solenoid was used in 1940, or if one could make the SS-4001 fit the 1940.

Hudson lists the 1940-only solenoid as part number X-159935 but (unhelpfully) does not list the AutoLite part number of the solenoid. Normally the parts book (for the specific year of Hudson) gives Autolite's generator, starter, distributor, etc. part number for that item, making it easy to find an Autolite replacement. The detailed drawing of the starter (referencing individual part numbers) in the manual, does not even picture the solenoid. Leaving one to wonder if the starter solenoid was even attached to the top of the starter (as is the case in all other 1934-49 Hudsons). I wonder why they changed this for 1940 only? Maybe a fellow 1940 owner can answer this question.

[url= https://www.ebay.com/i/264514235813?chn=ps&norover=1&mkevt=1&mkrid=711-117182-37290-0&mkcid=2&itemid=264514235813&targetid=885583109988&device=c&mktype=pla&googleloc=9007592&poi=&campaignid=9423618855&mkgroupid=95235883346&rlsatarget=aud-497631946031:pla-885583109988&abcId=1141016&merchantid=118858209&gclid=EAIaIQobChMIh42ZzYa06QIVkYFaBR2plgSOEAQYASABEgJaG_D_BwE ]HERE[/url] is a current Ebay listing for what is claimed to be a 1940 solenoid. I have no idea whether that is correct.

Just FYI, here is the original SS-4001 solenoid (one of several now on sale on Ebay): [url= https://www.ebay.com/itm/174158117879 ]https://www.ebay.com/itm/174158117879[/url] There are aftermarket solenoids available; I believe this is one of them: [url= https://www.ebay.com/itm/291064268493 ]https://www.ebay.com/itm/291064268493[/url] .
What makes the origianl more desirable than an aftermarket replacement is the remote starter button sticking out the back, which hides under a screw-off cap. Makes it very easy to turn the engine over when (for example) putting in new Hudsonite.

Jon is correct
1934 1939, 1941 - 1950 SS 4001 = Echlin ST 63. = 6v Grounded Base, Curved Bracket
1940 The solenoid on EBay = Tungsten SS301 = AL SS 4004 = Echlin ST 55 = 6v, Insulated base, curved bracket.

This means that if your car starts you have the correct solenoid. You could have the wrong starter installed. If you have the correct starter, then you have the correct solenoid so you have to adjust the linkage.

Good Luck.

Rob, Ed asks a good question: do you indeed have the correct starter for your car?

You didn't mention the model number (the first two digits of your serial number will tell).
Model 40 (Traveler, DeLuxe or Business Cars), Model 41, 43, 48: AutoLite MZ-4069
Model 44, 45, 47 (8-cylinder): AutoLite MAB-4103

Sometimes, over the years, Hudsons acquire equipment from other-year Hudsons, as your car may done. So we need to verify the starter you have, in order to know which solenoid it needs.

By the way, be aware that -- in the 1940 through 1947 Hudsons, I believe -- there's very close clearance between the hood and the battery terminals. That's why Hudson specified a special, lower battery for those years. Height is critical for these years, because if the battery terminals touch the metal hood they will short-circuit and cause a fire. Here are the battery sizes for poplar 6-volt cars. Note the height difference:
Group 1 -- 9"L x 6.75"W x 9"H
Group 2-- 10.25"L x 6.75"W x 9"H
Group 2L -- 10.25"L x 6.75"W x8" H

Serial # 4059378. I’ve been told it was a model 40. First two numbers show that?
Here’s an update on my solenoid sitcom. I bought a new one from Napa that they said cross referenced. It looked like the one that I’ve seen in old pictures so assumed it was correct. After I installed I got nothing. Lights, fan, pump, everything worked but the starter button. I was baffled. Upon much troubleshooting I discovered that the new solenoid was negative ground. Not positive ground like the car. Put the old “fried” solenoid back in and now everything works like a champ.
Which leads me to my next question. Let me know if I should start as new thread.
The car is supposed to be pos ground but the battery neg terminal runs to the block and the pos terminal runs to the starter. Shouldn’t it be the other way around? Everything runs fine so not sure.

Rob,
The starter for your model is MZ 4069 as Jon said. The solenoid for it is AutoLite SS 4004 like I said, not SS 4001. The Echlin (NAPA) # is ST 55 which the base is insulated from the starter body. The Echlin ST 63 is grounded by the starter body.. It's for the other year Hudson. They look exactly the same.

To get the correct solenoid for your starter you need the STARTER # not the car #. Echlin ST 55 probably not been available for 40+ years. The EBay Tungsten SS 301 is correct for the original 1940 starter. If someone replaced the original with a 1941-1950 one then you need an Echlin ST 63 which I think is still available

I used to have a 47 truck with a hole burnt thru the hood from the battery post :woohoo:

Rob, you asked if the battery's NEG terminal should be attached to the ground. The answer is NO.

The car is a POS ground, so your battery ground strap should run from the battery POS terminal to a ground connection on the engine or generator bracket. (Incidentally, you also need an additional strap running from the engine / bellhousing to the frame).

After you change the polarity to POS ground, you will need to polarize or "flash" the generator but, one thing at a time (it's very simple).. I suggest you start a new discussion for polarizing the generator because I have seen several different ways to do it and you need the benefit of the Great Minds of our club, to give you the straight scoop.

Here is something fairlly strange.

Ken Cates' page from the parts book for 1940-41-42, shows the AutoLite starter numbers as either MAB4100 (for the 8-cyl., one assumes), and MZ-4092 (for the six). Hudson's 1941 parts book duplicates these same starters as one would expect.

But Hudson's parts book for 1940, shows two completely different starters: MZ-4079 and MAB-4103. In fact, they should be shown just as Ken has shown then, MZ-4092 and MAB 4100. This is very weird.

I have never seen a 1940 Hudson in the flesh, but I am certain that it would be the same situation as the later Step-downs which have different starter motor numbers, and the only difference is that some have the solenoid mounted on the starter, and others it is remotely mounted. The only difference therefore will be two threaded holes in the starter motor case on which the solenoid mounts. Incidentally a solenoid does not give a monkey's toss whether it is positive or negative grounded. Some after market solenoids are not grounded through their casing ,and need a separate ground connection to work. I have used a Step-down starter motor to start a pre-war Hudson 8, and the only difference is the spacing of the pinion. You have to pack the starter out with washers to get clearance of the ring gear. All starters from 1936 onwards have the same number of pinion teeth, but the automatic transmissions have the pinion meshing form the front, not from behind. I'm sure Ken U will correct me if I am wrong! A footnote, the 232 engines have a smaller starter than the larger engines, and this is the same as used on the Jet 202. You can use a larger starter on the 323, but not on the Jet, it will not clear the engine block.

[size=5][b]OK , here goes. First since Rob never got back with his starter number I'm guessing that it is for an 8 cyl which has a 1/2" larger diameter than the 6 cyl one. This might be the reason why he said it was shorting out on the linkage.

As for the solenoid, I checked the different wiring diagrams looking to see if it was wired differently. It's not. All I know is that the 2 won't interchange for the reason I mentioned before.

' [/b][/size]