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'25 Gearbox Queries


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Hi Guys,

Having finished the restoration on my '26 Essex I am now assisting my uncle with his '25 Dodge Roadster we are starting by getting it moving up its own power and then will move onto the bodywork etc.

 

I have had the engine running given it a tune up and have it running pretty sweet, I have some concerns about the gearbox however.

 

It is very noisy and after removing the top of the gearbox I have some questions for those who have Dodge experience. 

 

Firstly the input shaft seems to float back and forth with the clutch pedal free play but once loaded up ie depressing the clutch it does not move is this a normal characteristic?

 

Secondly the small gear on the input shaft which locks to the output for 3rd gear is very loose on the  input shaft and I believe the main cause of the noise, it is hard to imagine the centre of the gear being a high wearing part as it does not move very much nor very far. Again is this a normal thing or is it worn?

 

Lastly and not necessarily gearbox related I have found a Dodge Brothers mechanics instruction book online, does anyone here have it and is it worth owning? 

 

Thanks in advance, Tristan. 

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Hi Tristan,

The input shaft has a spigot fitting into a bearing at the flywheel end and a bush in the input shaft fits over the output shaft at the other, it passes through the front bearing in the gearbox on the way. Yes there would be end float but no, moving back and forth is not normal.

The intermediate gear you refer to is the main culprit for the noise with a combination of wear on the square drive input shaft combined with wear on the gear square drive.

This gear works hard in first and second, you will find the noise goes away in top as this gear fits inside the direct drive gear on the output shaft.

The correct oil for these gearboxes is very thick almost liquid grease, we use Penrite 250 here in Australia. If thin oil is used wear would be accelerated.

Yes, I would recommend the Mechanics Instruction book but it is not as detailed as a workshop manual for a modern car.

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With the old, non-standard shift transmission like your uncle has (but without the abnormal wear), you can either get used to the second-gear noise or do a complete rebuild to try to get rid of it.  I got used to it.  LUB164 is a good oil to use.

 

When the transmission was re-designed in 1927 to adopt the standard shift pattern, it was built much beefier and had no noise problems.

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Hi guys,

Thank you both for your replies. I am in Aus and familiar with the Penrite 250 gear oil I use it in both the gearbox and diff of my Essex.

 

I think for now I will leave the gearbox alone as there doesn't appear to much I can do with it there's nothing I can do with the intermediate gear and he does not have any gearbox spares and as far as the input shaft goes it is only moving approx 5mm so perhaps it is also just wear related.

 

Since talking to my uncle he has also told me last time he moved the car under its only power (25 odd years ago) the clutch was very grabby to the point he was concerned it would break spokes, any advise on this?

 

Thanks again, Tristan. 

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The multi-plate clutch is normally pretty good to use but perhaps lack of use is to blame. View through the inspection plate on the top of the bell housing to see if oil contamination has affected the plates. I understand there are several methods suggested to try to clean this off without dismantling. 
Play in various points can also be a factor, I have seen considerable wear in the universal joint at the back of the gearbox cause snatching also differential play won’t help.

Limited spares are tucked away home garages so perhaps local members can assist, ask, you may well be surprised. Each state has a solid group of enthusiastic DB owners most willing to assist where we can. 

The wheel spokes can be checked for security (looseness) and damage but unless loose and/or rotten this design has remarkable strength. The timber will shrink if allowed to dry out so a coating of paint (original) or marine varnish (a more modern preference) will help protect what you have.

The early wire spoked wheels were mostly favoured by “townies” as the general roads of the day were cart tracks badly rutted and cut up by the horse and cart traffic and the wire spokes would break much more easily than the wooden version. 
 

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