remanufactured Differential Gears

hasktavern1

Tom, I just posted the info on the regular Forum.

Rocket

Thank you.

Jon B

When you finally get your pricing worked out, why not do a "full court press" of publicity, announcing the repro project and soliciting interest from owners of pre-StepDown Hudsons?  Announcements could be placed in the WTN, on the Facebook page, on both H.E.T. internet forums, and could be sent to chapter newsletter editors and even our affiliated Hudson clubs (Sweden, England, Australia and New Zealand).  This could be a rare opportunity to purchase gears that will allow Hudsons of the 1930s to cruise at 60 mph, at a very reasonable price.  In the past, there were sporadic announcements of gearset availability, but the gears were only turned out in production runs of 10 at a time (possibly because many people were unaware they were even being made).  If you turned out 50 or 100 at a time, instead, the price might drop wonderfully -- which in turn might convince even more people to order them.  In order to guarantee that buyers followed through on their intention, maybe a trusted H-E-T person or group could collect down payments from would-be buyers and hold them in escrow until the gears were ready.  To sum up: I think the secret of success for such a project lies in spreading the word, well in advance, throughout Hudsonland.

bob ward

I've been through the process of fitting (it was done by a pro I just paid the bills) a set of Ivan's 3.55 CWP to a 6 bolt pumpkin. With the benefit of hindsight and if the CWP had also been available in 8 bolt I would have gone with the 8 bolt. 8 bolt centres were installed from late 37 to end of 47 and are swappable with the 6 bolt centres.

Reason for that is that I dismantled 4 or 5  6 bolt centres and all the carriers had damage from having parted company with the crown wheel at some stage, the mating surfaces were scuffed and torn, not what you want to see when you are going to install expensive new gears. 

With an 8 bolt centre the odds of getting a good carrier are much higher. YMMV.

The 6 bolt diff bearings were expensive, I don't know if the 8 bolt diff bearings are different or cheaper but its something to check out.

hasktavern1

Jon and Tom,  I am willing to help get the word out, once we have more information on the actual production and cost.  Bob, ideally it would be nice to have some of each made.  I worry what i might find when I disassemble my 6 bolt, but it is presently operational, so my personal inclination is to be in line for the 6 bolt.  How available are the 8 bolt assemblies and would a person get stuck trying to find one? 

barrysweet52

They are so readily available that I cant sell mine . But then Im in Australia.

Smonica46

sign me up for two 8 bolt sets. Dave.

ken1962

Hi Barry sent you a private message... Would love to buy those gears cheers ken

bob ward

hasktavern, the back axle out of any dead 38 to 47 car will provide an 8 bolt diff centre.

Rocket

UPDATE  when Ivan was selling these sets they were 12 to 13 hundred dollars a set and to make these today they would cost the same it would not pay to make 50 to 100 sets unless you had them all sold before they were made (the more sets we have made the cheeper they are to make them) Jon B and hasktavern 1 I love the idea of spreading the word right now the sooner the better but I think I would tell every body that a set will cost 12 to 13 hundred dollars I have no idea how we can get the word out there so I will need all the help I can get we would also need a list of the people who want them and if they want 6 or 8 bolt hole sets and you must understand that if we start this next week we wll not get any gear sets for at least 6 months I beleive Ivan ran into the same time line I know for sure I have a set of gears that Ivan had made I can use as a pattern so I am ready to go if you guys are the more sets of each one we have made in the first run the cheeper they will cost per set when they are done Like I said I need all the help I can get so if you would like to talk about it just pm me and I will give you my number Tom.

Jon B

Tom, this is just a side remark about the ring & pinions (not pertinent to what's been discussed so far). 

Back when Pat McDonald was making the repro gears, I knew of a man who bought a set.  He sent them to a very respected Hudson mechanic to be installed in his late 1930's Hudson.  The mechanic subsequently told the car owner that he was unsuccessful in  installing the ring gear because it would not physically fit into the hole in the axle housing.  I mentioned this to a fellow Hudsonite at the time and he said that, indeed, they would not fit into the housing opening unless a small notch was cut in the perimeter of the opening, big enough to feed the ring gear through, sideways.

I never followed up on this story, so I don't know what the upshot was.  It set me to wondering if perhaps the reproduction ring gear was slightly larger in diameter than the original "factory" ring gear.  In the end, the repro gears worked just fine.   If the story is correct, they just needed a bit of coaxing to be inserted in the axle housing.  (In that case, had the mechanic been told of the fitting problem ahead of time, he could have successfully installed the gear.)

Or so the story goes.  Maybe I misinterpreted something and there was no installation problem --  I was getting all of this stuff second-hand.  Has anyone heard a similar story?

hasktavern1

Tom, thanks for all your work on this so far.  I will look into how we can get the info into the next available issue of the WTN.  Others on here probably know the key publication players better than I do, so please give me any pointers you may have.  I agree that its important to mention the cost.  Not cheap.  There may not be a lot of takers in a given timeframe...many owners have already addressed their RPM/road speed needs.  Over a period of 5 to 10 years the list of interested parties might slowly grow, but the problem is who is going to be the 'investor' to pay for a potential demand.  I can't.

hasktavern1

Bob, thanks!  I can put the word out for an 8 bolt center....but I haven't given up on the original 6 bolt.  It works now, although I admit that I won't know the full condition until I tear into it.
Jon, that is certainly interesting re: the fitment problem.....would be a slap in the face for sure after paying big bucks for a new gear set.  Someone on here might have an experience with this?  Also, sort of related to this, I noticed in the Mechanical Procedure Manual, section 13, page 10, there is a note that in Canadian production vehicles, the differential case and gears are different....in what way they are different, I have no idea, but someone on here may know.   May not be an issue, depending on if any "Canadian' owners want to make the gear change.

Rocket

Jon B you are right you have to put a notch in the housing to make them fit I was told this by Richard Esparza he put a set in his 36 Terraplane he is selling in the WTN and he loves them said they work great.

hasktavern1

The next available WTN is the May/June issue.  Tom, this is your baby, so I think you should have a say as to whether you want to wait for that timeframe.  In the meantime, I volunteer to reach out to the various regional clubs by email, as long as you are certain the manufacturing ducks are in a row.  I'll reach out to you thru PM, because so far we've just been typing messages.

35 Terraplane

Are both the ring & pinion included in the cost? 

Rocket

35 Terraplane yes they come as a set.

bob ward

As others have said, the notch (2 notches?) in the circular hole in the banjo that allows the CW to enter the housing needs attention. The notch is exactly the right size and shape and in the right position to suit the factory CW, it needs to be altered (hand file, die grinder) for the 3.55 CW.
Best to do that alteration early in the process, i.e. mock up the pumpkin with the new gears and remove material to enable the pumpkin to seat in the housing. You don't want to be in a situation where you are die grinding your freshly painted and scrupulously clean diff housing. DAMHIKT.

Rocket

Can some one tell me if the six hole and the eight hole crown geras are the same size  around with the eight hole haveing more holes then the six hole this could effect the cost.

Geoff

No, they are different in the profile of the  mounts.   And you cannot just drill and tap new holes, they are hardened

Rocket

Sorry what I ment to say are they the same size around with a different hole pattern if I have new ones made is the only diference is the hole pattern or is the whole thing different thanks I will be calling the company I am working on Monday so I can post the cost for a set of gears 6 or 8 hole cost

Geoff

The whole thing was re-designed in 1938 to the heavy duty model.  Parts book states only replacable as complete unit. I understand the carrier is a different shape, and the c/w is heavier profile.   

Toddh

I have one of the sets that Ivan had made up that I have not yet installed in my ‘34 Terraplane. If they are needed to measure to make another run of them, I may be willing to lend them out under the right conditions.  

todd h
winchester, va

hasktavern1

Todd, that's a generous offer and thank you.  I think Tom said that he 'had access to' one of Ivan's but he can weigh in.  He might(?) be in need of an 8 bolt, if the decision is made to reproduce both types (forgot to ask him when I was on the phone with him today).  I am helping him to get the word out and have emailed all the regional chapter/international chairpersons - as well as placing a detailed post on the Facebook site.  Geoff, in these notifications, I stated that the mechanical gurus, you being one, have indicated that the components, including crown gears, of earlier and later vehicles are not the same and have more differences than just # of bolt holes....but that the assembled differential units can be interchanged as a whole.

hasktavern1

Geoff, Bob and others in the know:  This has been asked on the Facebook site:  when exactly was the change made to the 8 bolt?  Late 37 has been mentioned but the Mechanical Proc. Manual implies that they were first used in 1939, and that even then, certain Hudson 112's didn't get them right away.  I have to ask, bc I have absolutely no idea and we will need to have answers for people who may want a gear set for a car in these transitional years.  Should we tell people that they need to know for sure by actually disassembling their pumpkin...rather than going by the date of manufacture?

bob ward

Deciding on buying a 6 bolt or 8 bolt CWP by the year and/or model is risky, pumpkin swaps upgrades/downgrades could have been carried out over the last 80 odd years. 
Geoff, is it possible to distinguish between a 6 bolt pumpkin and an 8 bolt pumpkin without removing it from the diff housing?

Geoff

Unfortunately no.  Usually one finds out when the bolts shear!

hasktavern1

That's pretty much what I've said to people who've asked so far  (best to sure what you have and what you want).  It's the same boat I'm in, as my 36 is parked indefinitely at the upholsterer's and I can't pull it apart in a timely manner.  It appears to be all original, but no guarantee.

bob ward

This is a photo of the 2 areas of the diff housing (circled) that need to be fettled for the 3.55 crown wheel. The marks on the back of the housing are historic, at some time in the past the 6 bolt crown wheel has parted company with the carrier.

hasktavern1

Excellent! Thank you Bob,,,,gotta love those old scars and that you know what caused them.  GOOD NEWS from Tom Lynch (I'm his volunteer press corps, not to mention an enthusiastic customer for a gear set):  He has finalized 'the deal' with his well-vetted CNC gear maker and he would like to move things along fairly quickly....not to be in a big hurry, rather it's a strategy to get an early feel as to whether there will be a minimum of 15 customers.  Here's the plan: secure at least 15 orders for a COMBINATION of 6 and 8 bolt crown gears (with matching pinion gears) by March 15.  They can be all one or the other or half and half - any combination.  If this is achieved, the project will get a green light and the cost per set will be 1300.00.  If this minimum is not reached, the project might be able to go ahead, but the price will jump and it will be Tom's and CNC's decision as to whether to abandon or proceed.  If on the other hand, there is an order for say 30, the price may drop.  Note that there will a lengthy turn around time (months, not weeks), so patience will be required.  Note also that this is for gears - not any bearings, gaskets or other parts.

Per Tom, he will deliver to the CNC all necessary parts and patterns, so that there will no question as to fitment.  My understanding is that these parts will include (at least) an Ivan Zaremba gear set, a 6-bolt differential carrier and an 8-bolt differential carrier.  Ask Tom, if you have any questions about this aspect of it.

We are taking orders starting now.  As an orderer, your main responsibilities will be 1) to know which set you want, based on your own research/knowledge (worst case scenario, if someone orders the wrong set, there will likely be a market to re-sell it); and 2) be committed to make a 1000.00 deposit (not long after March 15) to an account which Tom has set up; and 3) make sure you get your order/personal information in by contacting me (Jared Cooper, 716-5seven2-46five2 or email, terrahasktavern@netsync.net (drop the 'terra' when sending).

I think the important thing for all of us to remember is that performance with the 3.5 gear will be different.  My own research reveals that the vast majority of those who have installed these gears have been happy.  But you won't be able to start from a stop quite as quickly and you will need to be good to your clutch, so you aren't slipping and burning in an attempt to get up to speed the way it used to be.  The big plus side is that you won't be winding out that 80 year old engine just to barely keep up with traffic.