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Dodge high speed transmission gear set


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Hello John,

Unfortunately the highly respected Dodge Brothers man Ralph Provan who had these manufactured to his own design here in Australia sadly passed away several weeks ago. 

Both first and second gear were considerable higher making for a much more enjoyable drive. The requirement included the extra tooth (13) idler gear from the later gearbox, this is indicated by a bulge in the outer mounting flange to accommodate the extra tooth. The early ones were flat.

 

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You will also need a later 13 tooth layshaft gear set. I purchased new gears for each end of this shaft

 

89DED802-C91C-4685-B0B2-0A19A6BB9C5D.thumb.jpeg.6be4da6c86976ca1de9eead2abe79610.jpeg

 

Ralph also included a new intermediate gear with an ever so slightly under size internal square drive to help lessen the chatter in second. We also have a chap here making new square drive shafts for the clutch (not shown here) which makes a huge difference as it is the clutch drive shaft wear combined with the intermediate gear wear which causes the most noise in the DB gearbox. New bushes are recommended.

 

1076BE49-7831-44F6-B080-8ECC72DBEA5D.thumb.jpeg.d5824265e8ee6276b7ae28373a7b5c03.jpeg

 

1BD98586-490E-411C-BDFC-1F639142213A.thumb.jpeg.d118b1f5f226a9bf9add4ea444761881.jpeg

 

I understand that it is possible to change the gearbox internals without removing the gearbox but this is only whay I have been told.

 

B78D08BF-C675-43FE-A897-0CF968C52CF7.thumb.jpeg.de10a51861e4f8455507d08237353aa1.jpeg

 

Mine I did out of the car.

good luck with your search.

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Minibago, in your 3rd photo showing top gear on the square shaft (and clutch disk pack behind it), is the gear backwards?  In this trans cross section it shows the fork collar towards the clutch, not away from it.  Do you happen to have any photos with the mainshaft (and gears) installed  in the box ?   I would very much like to see  how far forward top gear moves when 2nd gear is selected. I wonder if the blue prints for those  higher 1st and 2nd gears?  I know a gear maker that could probably make them.

DB Trans.jpg

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Hi Mike,

Apologies, the picture was just a quick example to show the main points of wear.

 

68E21BDE-1AFE-4CFC-988E-0B7C799FC3CF.thumb.jpeg.9b9372f2211beffdeb54289c5d1e5532.jpeg

 

I will look tonight and try to get a photo and some measurements for you on the movement of first gear over the next few days on a cleaner gearbox.

I don’t have any drawings I just purchased the set from Ralph as shown below. The gears at each end of the idler gear set are also included and require pressing to remove / replace.

 

F92CE8DD-AB92-4D32-9B62-DCCA9B98A5C8.thumb.jpeg.946d0a5d15b2453834ed5400b57c89c9.jpeg

 

The skill and engineering expertise Ralph had was gained over many decades of research and development in partnership with foundries and machinists. I have no contact details for them.

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Funny to see “Dodge Brothers” and “high speed” in the same sentence!!  I really like the early DB’s, and have a ‘27 Fast Four (Ha!), but one has to slow down one’s world when driving one...

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Hi David,

just a misnomer really, the higher gear ratios allow for a higher speed in first to allow you get into second up a slight rise before the car stops, (important across traffic lights when turning) it also allows for better hill climbing enabling a change down to second at a higher speed and not revving its head off climbing. The top speed remains the same so still a pleasant slow drive.

😊

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Hi John,  The only parts suppliers I've dealt with are Myers Early Dodge and Romar.  Myers does have some gears but I don't see the square shafts for the clutch.  

I do know a guy who makes gears but it's Ford Model T and A stuff.  

Minibago, thanks!  I look forward to the photos.

 

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Hi Mike,

I have just taken photos as requested.

neutral.

 

9CEB4E0D-6AF5-4634-BA6D-23CAC462FEA6.thumb.jpeg.ceefca8de789aad445c6a5bcb4e635cb.jpeg

 

First selected.

 

852A4289-5E47-442D-95EB-A72634E972B1.thumb.jpeg.d458989fbfb579dc10120813fc496e97.jpeg

 

Second selected.

 

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Top selected.

 

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It was impossible to prevent the gears from sliding on the shafts as I did not have the gearbox completely level so I cannot give you accurate measurements between the gears.

I hope this helps.

 

John, sorry, I do not have the contact details for the guy making square shaft, I will try to find out. It won’t be for a week or two.

If you buy a set of gears off Cled rather than just first and second, the two drive gears on the idler shaft are included in the set. I do not know of anyone else making these. 

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  • 2 weeks later...

Hi John,

You send me private messages from a noreply email.

I am unable to respond to a noreply email.

The reason the square drive gear is too tight is because when the gear sets were made Ralph designed the inside square drive a fraction smaller to help compensate for the wear on the clutch square input shaft. These are the two points of highest wear and the cause of most gearbox noise. At that time it was unheard of to obtain a new shaft. I believe it is now back to impossible. 

If you had been able to discuss this with Ralph he would have explained that pressing the gear on will likely damage the shaft, a nice smooth sliding fit is necessary. Much gentle, time consuming work is required to smooth each flat equally until the gear slides smoothly, if the gear does not have some working room it will jam, in particular from first to second due to the slighly unequal pressure exerted by the selector forks unless they have been machined to be perfectly true. 

I have travelled in a car which has this problem because the owner wished to eliminate as much freeplay as possible and was too optimistic. If the best result is required a milling machine would offer the most accurate match.

I hope this helps.

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I am not sure about the other gears and now we are unable to ask Ralph.

Perhaps the first step is to carry out accurate measurements of each shaft and the internals of each gear. If your shafts and gears are not compatible then perhaps take them to a machine shop qualified in this work to have all parts matched accurately.

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I had a brainwave. Could the low and reverse countershaft be flipped over to engage the seldom used and perfect condition reverse pinion in place of the worn out and pitted low speed pinion? You can see in the image it is not a problem on the r/h end. The extra shaft can be parted off and the area next to the now low pinion turned down to be able to press the 2nd gear close to the low speed pinion as per the complete countershaft at the top.

The problem is when the large countershaft drive gear gets pressed on to the l/h end there will be 15mm less shaft for the drive gear after a spacer is made to place the drive gear the correct distance from the reverse pinion. I have other worn out countershaft that could have 15mm parted off one end to make up a spacer to take up the shortfall and be an area for the needle roller to run. There would still be 2/3rds of the of the original shaft being used to hold the drive gear on.

 I need opinions on whether the countershaft drive gear would still be viable with 15mm less shaft to grab.   I could taper the short end and the spacer and TIG weld the spacer on using a plug to align them perfectly and the woodruff key can be still used.

I’m getting a headache.

C34AFB6E-8FD4-4E42-9188-C2DE9EA99985.jpeg

Edited by John McEwan (see edit history)
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It's an interesting idea.  I wonder though, the reverse gear has no pointed ends on the gear teeth and 1st gear appears that it does (or is it just how it's worn?).  If they are pointed and you substitute a gear with no points, that might make it more difficult to engage 1st gear but maybe no more difficult than selecting reverse.  Maybe you could have points machined but then you may have issues with exposing non-hardened metal (assuming the parts were case hardened to a specific depth from original surface).  

Layshaft Cluster.jpg

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my apology John , the gears were apparently turned around on the main shaft where they could be pressed off and turned around

i was misleading about using the term reverse  ,not meaning the reverse gear

I withdraw my comments   

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Hi John,

if you can wait until Christmas I have a spare shaft in one of my boxes.

 

31D7DAAC-B7B7-4188-A668-315631D4B040.thumb.jpeg.6d042a0996818139780ae090ea9c2b15.jpeg

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I have moved house.

 

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The question is which box.

My new shed will be up shortly and I should be sorted out by Christmas, if you can wait that long.

 

 

 

Edited by Minibago
Mistake (see edit history)
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  • 3 months later...

I finally have the reversed countershaft back from machining. Turned out good and can’t see there being a problem. To rehash, I flipped the countershaft over to bring the very good condition reverse gear teeth into the first gear position and the pitted 1st gear will now be reverse.55DFCAC0-57BB-4B1E-9CED-2DBDB15219F7.thumb.jpeg.6f95beab417d8765be92dd01816e8fde.jpegr

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  • 1 month later...

Took my Dodge with the modified layshaft and high speed first and second gear for a good drive this afternoon.  The gearbox ratios are terrific now. No big jump from 2nd the 3rd and 1st gear being higher ratio makes crossing intersections from a stop much safer not having to change to 2nd half way across. Dropping from 3rd to 2nd is much easier. I can’t say there is more gear noise in reverse like I thought there would be after using the very worn 1st gear as reverse after flipping the layshaft. Sounds exactly the same as before. There is still some slight whirring noise in 1st and 2nd but nowhere near as bad as it was before. I think after some use these gears will wear in with one another and it will quite right down. In just this drive there was a reduction in noise from when I first took off. Overall very happy with the results.

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