11:12:13pm, Thursday, May 16, 2024
4020 final gear ratio
|
Registered: 03/08/2016 Posts: 8 |
Have been pulling a 4020 with a stock transmission with 4010 planetaries. We have been pulling in 7th gear.
The transmission let go so we have decided to get a 3 speed. I am having trouble figuring what final ratio I have right now. How is this figured? Thanks for the help!! |
Re: 4020 final gear ratio
|
Registered: 03/08/2016 Posts: 8 |
Does 25:1 sound right???? |
Re: 4020 final gear ratio
|
Registered: 03/13/2009 Posts: 220 |
7th gear in a 4020 with 4010 planetaries would be 31.2: |
Re: 4020 final gear ratio
|
Registered: 03/08/2016 Posts: 8 |
J&R Thanks for the help.
Can you show me how to figure this? I'm doing something wrong. What would the ratio be if I put the 4020 finals back on??? I am planning on pulling in our 3000 rpm pro field class this year with 20.8x38 151's uncut. What ratio do most pullers in this type of class run? |
Re: 4020 final gear ratio
|
Registered: 03/13/2009 Posts: 220 |
The tooth counts for a 4020 in 7th gear would be as follows
high range pinion on top shaft 23 counter shaft 28 7th gear on pinion shaft 33 ring and pinion 9 and 47 ratio of 4010 planetaries 4.167:1 So to figure the ratio you need to multiply all the driven gears together and then divide by all the drive gears. The driven gears would be countershaft gear, 7th gear on pinion, ring gear and the large number in the ratio of the planetaries The drive gears would be high range pinion on top shaft , countershaft gear , pinion shaft and the small number in the ratio of the planetaries(this number is a 1 so really you can disregard this number. 28 (countershaft gear) x 33(7th on pinion) x 47(ring gear) x 4.167(large number in planetary ratio) / 23(high range pinion on top shaft) / 28(countershaft gear) / 9(pinion shaft) 28 X 33 x 47 x 4.167 / 23 / 28 / 9 = 31.22:1 ratio Now you will notice that I used the 28 tooth countershaft gear as both a drive gear and a driven gear.7th gear is the only gear that this happens. I could have disregarded this gear since we were figuring the ratio of 7th gear but 5th 0r 8th gear would require including this gear in the calculations but then it would only be used as a driven gear. Edited 6 time(s). Last edit at 03/09/2016 09:40AM by J&R Machine. |
Re: 4020 final gear ratio
|
Registered: 03/13/2009 Posts: 220 |
the ratios with 4020 planetaries would be
28 X 33 x 47 x 4.8 / 23 / 28 / 9 = 35.97:1 Notice the ratio of the 4010 planetary is 4.167:1 and the 4020 planetary is 4.8:1 |
Re: 4020 final gear ratio
|
Registered: 03/08/2016 Posts: 8 |
Thanks J&R!!!
I can see how to figure it now. I was only counting one of the two 28 tooth gears for 7th. This what was throwing me off . |
Re: 4020 final gear ratio
|
Registered: 03/13/2009 Posts: 220 |
Yes like I said in the calculation of 7th gear ratios, the 28 tooth gear could be left out of both the driven and drive gears. That gear is a driven gear when the power goes from the top shaft to the counter shaft but then it is a drive gear when it drives the gear on the pinion shaft. So basically in 7th gear it is only an idler but in the other gears it is a driven gear when the power comes from the top shaft. then the power is transferred to one of the other countershaft gears which then drives the corresponding pinion gear. |
Re: 4020 final gear ratio
|
Registered: 03/13/2009 Posts: 220 |
what do you have for a motor, turbo and pump |
Re: 4020 final gear ratio
|
Registered: 03/08/2016 Posts: 8 |
466 cid
S-366 turbo- 2.66 cam P-pump with 4-28 dual feed injectors simpson water injection |
Re: 4020 final gear ratio
|
Registered: 03/13/2009 Posts: 220 |
I would think you should be able to run almost stock road gear. With a 4020 that would be about 22:1. With your 4010 planetaries that would put it up to 19.1:1. The problem with these is that if you have enough power to run road gear, it probably wouldn't hold up. |
Re: 4020 final gear ratio
|
Registered: 03/08/2016 Posts: 8 |
We generally pull the sled @ 20 mph or just a little more according to the sled with 20.8x38. This is at 3000rpm.
With 18.4x42 we go a little faster because they are bigger around. Regardless we could use a little higher gear. I post a video tonight so you see what it runs like. |
Re: 4020 final gear ratio
|
Registered: 03/08/2016 Posts: 8 |
[youtu.be]
Last run before we broke. |
Website Statistics
Global: Topics: 38,771, Posts: 229,938, Members: 3,338.
This forum: Topics: 37,096, Posts: 226,027.
Global: Topics: 38,771, Posts: 229,938, Members: 3,338.
This forum: Topics: 37,096, Posts: 226,027.
Our newest member Jacklovik2009