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1929 STuTZ Blackhawk Differential Lube

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I am looking for the modern lubricant to use in a 1929 Backhawk differential.

Thank you all in advance.

Dan

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HI Dan ,  This Stutz uses a worm drive , right ? If I am correct , then you must use an E.P. gear oil as in hypoids. Hypoid is in some ways a hybrid between skew spiral bevel , and worm. It is the sliding component of these types of gearing (hypoid and worm) , which necessitates E.P. lube. But I am sure you know all this. I mention it because I have been wondering about this myself. I certainly would not want to tell you to go out and buy just any E.P. for hypoids. Because : In other applications I am more familiar with , (much higher numerical ratios than automotive) , we often see Bronze used. For example , stainless worm turning a Bronze wheel. Therefore , I assume in automotive use , if there is yellow metal in any component(s) of the diff. , there must be a very special E.P. formulation avoiding the usual E.P. sulphur compounds which cause yellow metal corrosion. This train of thought has left me curious in a "back burner" level of priority. I met and spoke with the Tech Advisor for the Stutz Club at Hershey in 2013. We were talking about raising compression to 7.00:1 , or 7.50:1 in old OHV low compression engines. From his very high general level of engineering understanding , I am quite sure he knows everything you need to know regarding specific lubricants. When you get an answer , (someone here might inform us before you get to the T.A.) , please let us all know. Lubricants are an eternal source of fascination 'round these parts. Sorry I could not just give you a part number. Obviously you are quite aware that the choice of the right gear lube is critical.   - Carl

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As mentioned above, avoid lube with sulphur in it. The attached picture shows what it can do to a '29 Stutz component.

Sulfur lube.JPG

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Hello C Carl and Smile,

The 1929 STuTZ Blackhawk differential (as all STuTZ models from 1926 to 1934) is a worm drive unit with a "yellow" metal crown gear.

I have had a few replies via internal STuTZ Club email to my question.  I will share what I find out once I receive a little more data.

Lubricants are the life blood of these old machines.

Dan

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HI dan on my 29 Blackhawk I added New Holland oil for worm gear box on the drive of the bed chain on a maure spreader. Ill look at the part number. Iam checking because I need to fill the 1930 Stutz. rear end  JOHN

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CARL  Were a new Holland dealer part number 86520567ds in 1 qt . It listed as  SCL type SAE 90 W . IAM still looking if this is good for the rear end because ,what I used 10 year ago had a difference part number. Hope this will help. 

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Hi John. The extremely critical factor in a hypoid , and even more so with a worm drive , is the E.P. character of the lube. These gears with such a high sliding component are very demanding of proper lubrication. Particularly so when backdriving a worm drive. I wonder how appropriate a high quality , high viscosity steering box lube would be ? Those being a semi-fluid grease such as Penrite steering box lube , or Restoration Supply 1200 weight MIGHT do the trick. I emphasized MIGHT , because it is mere speculation on my part. Certainly worth looking into. Also : Cornhead grease ? What was used in 1926 when STuTZ went to worm drive ? What was it called ? Hypoid had just been developed by the Gleason Works at that time , (see Jour. SAE , 18, No. 6) , so the lubrication requirements must have been well known and met. As I mentioned earlier , my interest is purely academic. My purchasing ability for exotics was vaporized by a "financial advisor" who second guessed me , and cost me 35 years of work . Total loss well into 8 digits. But I am interested , obviousy , but never "shook the tree" here . Idle curiousity , now given opportunity for satisfaction. I DID have a worm drive car over 50 years ago. A Peugeot 403. Funny , those cars are starting to bring $$$ !! Who would have known ?   -  Carl

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PENRITE make an oil designed for non ferrous diffs like the Stutz these are Penrite Transoil 140 SAE140  or Transoil 250 SAE 250 The original oil used in these diffs was a camphor oil Do not use any oils with sulphur in it as it becomes rather expense to replace the diff. I use these oils in my Stutz diff Also Penrite make oils designed for pre 1930,s vintage vehicles See their web site Regards LEN

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Thanks to everyone that has replied.

It appears that there are two and maybe three lubes suitable for the worm drive rear with yellow metal used in the 1926 to 1934 STuTZ cars.

1. Penrite T140.

2. Mobil SHC 634.

3. New Holland if L6 can confirm a part number.

 

Oldcartech: I enjoyed the article on Machinery Lubrication. Thank you.  I spend my early years, many many years ago, in a hot strip mill where we rolls steel slabs into coils of thin steel. We had many large (10K HP) gear boxes.  I was not involved in the maintenance of these gear boxes since I was in the electrical group but I know that a lot of time and thought went to the selection and constant analysis of the lubrication. 

Dan

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The Stutz worm drive gears were Timken,  "FJ "profile if I correctly remember what was on the copy of the original drawing s that we managed to obtain about 40 years ago to have some  4:1, and 4.25:1gear sets made for open cars and heavy sedans appropriately.  We had to source another set of blueprints when the first samples were made; because the first ones were for L6-L8 models Blackhawk (one word).  So both were made to orders.  There was a difference in vertical height between axis centres between worm and the drive axles to the rear wheels of something like quarter or half an inch.  The road condition and cruising speeds are quite different now from when the cars were new, and the cars are happier geared accordingly.   New gear sets cost us A $500 in the mid 1970s, and I wish I had the cash then for more than one.  The highest ratio on the drawings was for 3 and five eighths to one, and that might be best for the 1928 SPECIAL prototype DV32, ( engine # 30004,  casting date June 27, 1928),  once I can contrive to set it up with camshafts, camshaft bearings, and alloy steel conrod such as it had originally.    Mike Holt in UK had new gearsets made,  but I do not know what ratios.  Ancient local advice was that some owners used castor oil  for these rear axles  (Ricinis).  This tends to crosslink with age and inactivity into a very powerful varnish. ( The engine of my Roamer Duesenberg had last been used with castor oil in the 1920s, and this was very hard to get apart. Stuart Middlehursts 6.5 litre OHC 'Hispano Suiza was even harder to dismantle for restoration.)  We are better to rely on Penrite.

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