Axle ratio

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mnha440
Posts: 3
Joined: Sun Jul 29, 2018 4:27 pm
Location: Norfolk

Axle ratio

Post by mnha440 » Wed Oct 31, 2018 5:19 pm

My LA14/2 1939 model has a 5.25:1 axle fitted. I have a standard 5:1 spare, but I doubt it is worth changing for 5% difference. For modern road conditions I would like a ratio of around 4.3 or 4.5:1. I have found a gearcutter who will make me a cwp for an eye watering sum which is out of the question. I don't like re-inventing the wheel so thought that there might be some words of wisdom on the Forum! Any ideas? Mike.

classiclife
Posts: 46
Joined: Wed Sep 05, 2018 9:55 am
Location: Ridgewood - East Sussex
Contact:

Re: Axle ratio

Post by classiclife » Wed Oct 31, 2018 8:37 pm

Hello Mike,

Have you tried Guest Gear Services, or was that the company that made your eyes water ?? !!

If not, they are based in Chesham, Buckinghamshire via 01494.794.667

Best wishes.

Richard.

qantasqf1
Posts: 93
Joined: Mon Mar 07, 2016 10:13 pm

Re: Axle ratio

Post by qantasqf1 » Wed Oct 31, 2018 9:19 pm

FWIW if you go through with this to complete the job the speedo drive gear ratio will need changing too. The higher ratio rear axle implies the gearbox output shaft rotates at reduced RPM for the same road speed so the speedo drive ratio must be increased by the same factor,
In other words the speedo will indicate a lower speed than the car is actually travelling if the original speedo gear ratio remains unaltered. Just saying...!

mnha440
Posts: 3
Joined: Sun Jul 29, 2018 4:27 pm
Location: Norfolk

Re: Axle ratio

Post by mnha440 » Thu Nov 01, 2018 9:05 am

Thank you Richard you have "guest" it!

I am not too concerned by the speedo issue as an alternative pinion gear can be made relatively cheaply. I actually run with a sat nav so have an accurate read out anyway.

An overdrive is another way to go, I wonder if any one has experience of fitting one to this chassis or Daimler equivalent?

Mike.m

JT7196
Posts: 801
Joined: Sat Feb 13, 2016 7:22 am

Re: Axle ratio

Post by JT7196 » Thu Nov 01, 2018 9:55 am

Good morning Mike, I have just checked my Data Base and have been unable to find your Lanchester listed, would you be kind enough to send me the following details
Date of 1st Registration
Reg No
Chassis No
Eng No
Body type
Body / Int colours
Your contact details
Please send to:-
alan.wheatley63@gmail.com

Cheers Al ( DLOC Registrar )

JT7196
Posts: 801
Joined: Sat Feb 13, 2016 7:22 am

Re: Axle ratio

Post by JT7196 » Thu Nov 01, 2018 11:29 am

Hi Mike, yes you are quite correct, I actually have it listed twice !! so need to get my listings updated !!

Cheers Al :D

Sydsmith
Posts: 642
Joined: Sun Feb 14, 2016 11:15 pm
Location: Aberystwyth Wales

Re: Axle ratio

Post by Sydsmith » Thu Nov 01, 2018 2:25 pm

Just thinking aloud here Mike but I wonder if you will gain anything by changing the ratio.

My V8 250 manual overdrive achieves a higher speed in fourth than in overdrive. I have always presumed whilst engine rev's are reduced, the torque the engine produces is insufficient to drive the higher gear.

So if it is increased speed you want, I suspect you might not get what you want after a lot of work, if it is lower revs for a given speed, it would work of course.

I am not sure but I seem to recall some clever member of the old forum fitting an overdrive to a 30's Daimler, might be worth a search on the old forum. Syd

mnha440
Posts: 3
Joined: Sun Jul 29, 2018 4:27 pm
Location: Norfolk

Re: Axle ratio

Post by mnha440 » Thu Nov 01, 2018 2:41 pm

Thanks Syd I will check out the old forum, haven't been there yet. I'm looking for lower revs at 45/50 mph Mike.

Marcel Renshaw
Posts: 274
Joined: Fri Feb 12, 2016 8:44 pm
Location: Derbyshire

Re: Axle ratio

Post by Marcel Renshaw » Thu Nov 01, 2018 10:25 pm

I have a friend who is fitting a Laycock overdrive to his 1934 Daimler 15.

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