Thanks Bill,
I think this forum would become extremely valuable in future. Not for rodding, but sharing knowledge as to part swaps.
Gents,
I want to swap my 29 tranny for something better. We live in a very hilly area and I would like to eliminate the close ratio between 1 and 2 as well as change the huge gap between 2 and 3. I dont want to reinvent the wheel, go to a Getrag or T5, but was hoping that a slightly later model might improve the ratios or perhaps there might be a more suitable 4 speed still using a torque tube setup.
Hi Chris,
I don't know about the '29 trannys, but the only 4 speed available for the '27 and '28 is for the one ton truck. The 2nd, 3rd, and 4th gears in the 4 speed are the same as 1st, 2nd, and 3rd in the three speed.
What you get with the 4 speed is a super low 1st gear.
Maybe a transmission expert can offer you some ideas.
Keep us posted on what you find. I'm sure someone else has the same question as you.
Cheers, Dean
With the 4spd gearbox in my '28 Capitol LP 1 Ton truck,the ratio gap between 2nd & 3rd gear isn't as great as in a 3spd passenger car gearbox between 1st & 2nd gear,and there's not much difference between 3rd gear and top.The third gear in my gearbox is almost like an overtaking gear.
These are total gear reduction specs(taken from the 1928 Chevrolet Detail Specifications booklet)from the motor to the rear wheels:
1st speed: 33.47:1
2nd speed: 18.858:1
3rd speed: 9.4699:1
4th speed(or top gear):5.43:1
I don't know of any way to do this. Later transmissions won't work without a lot of changes and modifications and gear ratios are not much different anyway.
Gents, thanks for your imputs.
There seem to be quite a lot of interest in my question (over a 110 views) but no definite answer as yet.
How about a 4 speed truck gearbox and a low ratio final drive? The Model A guys seems to have great results by installing an overdrive.
Hi again Chris,
There are a number of threads that discuss overdrives and different differential gears in the 1929-1932 technical forum.
Although, in order to use the Chatter Search Function, you have to be a VCCA member.
There are many good reasons for joining the club. Being able to search previous discussions is one of them. Check this out:
List of benefits of joining VCCA All my best, Dean
TKS Dean,
I will certainly look into becoming a member, as you suggest. I am leaving for the UK for a few weeks and might join while over there. Otherwise I will make the effort as soon as I am back in South Africa.
In the mean time, still a strong interest in our discussion (163 views and counting)
How about a 4 speed truck gearbox and a low ratio final drive? The Model A guys seems to have great results by installing an overdrive.
This would require changing the bellhousing, flywheel, clutch, etc. I don't believe the u-joint is the same and not interchangeable either so the torque tube could be an issue as well as drive shaft. To use the four speed with its ultra low first ratio, custom gears would be needed to give useable gear ranges. There are no different differential gears available for the 1929. Really this is not feasible without great investment and significant changes to the car severely impacting its value and probably functionality.
Thank you Gents,
That settles it then. I will smile and live with what I’ve got. I have more than enough to keep me busy.
You inputs and suggestions are much appreciated.
Just read through the posts. Have you considered a rear end swap? I know nothing about the late 20's cars but I don't think giving up is the answer. Things that take away from the enjoyment of driving our cars are worth pursuing. Only my opinion.
