SBJD trans ratio calculations??? January 02, 2011 01:37AM
I know this topic is likely covered a few times anually, but I am new to this, and was unable to find sufficient info trying a search on here.

What is the formula for calculating ratios in the trans for SBJD (4010) ? I would like to know for 7th and 8th gears as we currently use 7th, and would like to make some new gears that fall in between at the proper % split.

Also, how do you do the complete calculation (through trans to wheel) taking into account the R&P and planetaries? I do not have the axle stubs off right now, so I don't know what the # of teeth are on the planetaries, and don't recall the R&P right now either.

Any help would be appreciated,

Thanks.
Reply Quote

Re: SBJD trans ratio calculations??? January 02, 2011 02:30AM
On a stock 4010 the gear tooth counts would be as follows.

high range drive gear 23
high range driven gear 28

7th gear drive gear 28
7th gear driven gear 33

8th gear drive gear 36
8th gear driven gear 26

ring & pinion
pinion (drive) 6
ring (driven) 37

Planetary ratios are a little confusing but you take the actual tooth count of the ring gear and divide it by the tooth count of the axle stub shafts then you add 1.
57/18 +1= 4.167:1

To get your total ratio you multiply all the driven gears and divide by all the drive gears.

7th
28(high range driven) x 33(7th gear driven) x 37(ring gear) x 4.167(planetary ratio) / 23(high range pinion) / 28(7th gear drive) / 6(pinion) = 36.86:1 ratio

8th
28 x 26(8th gear driven) x 37 x 4.167 / 23 / 36(8th gear drive) / 6 = 22.59:1 ratio



Edited 1 time(s). Last edit at 01/02/2011 02:42AM by J&R Machine.
Reply Quote

Re: SBJD trans ratio calculations??? January 02, 2011 03:36AM
Wow! Thank you so much for the detailed explanation!! That helps me immensley!

Glad to see not everyone gives a smart a$$ answer on here.

This is Greatly Appreciated!
Reply Quote

Re: SBJD trans ratio calculations??? January 02, 2011 07:35AM
I just wanted to let you know that you can use the pto gears to make a cheap 7 1/4 and a 7 1/2 gear. You need two sets of the pto gears to do both speeds. These pto gears are located just in front of the transmission. You have to do quite a bit of machining to make fit on the countershaft and on the hubs of the old 5th and 8th gear driven gears. You use one of the 30 tooth pto gears to drive the 32 tooth pto gear for 7 1/4 and you use the 32 tooth gear to drive the 30 tooth gear for 7 1/2.
Reply Quote

Re: SBJD trans ratio calculations??? January 02, 2011 12:56PM
I believe the planitary rotio with your calculations should be 3.055? 37 on ring not 57?
Reply Quote

Re: SBJD trans ratio calculations??? January 02, 2011 01:27PM
I may have been misleading. The formula for figuring the planetary ratio is number of teeth on the ring gear inside the axle housing(not the ring gear on the differential) divided by the number of teeth on the stub axle +1.

57/18 +1 = 4.167
Reply Quote

Re: SBJD trans ratio calculations??? January 02, 2011 06:22AM
I am trying to find this information on a 4430 quad range trans and ring and pinion, the gears would be C3-4 and D3-4. Anyway you would have that information J&R Machine or point me in the right direction to find it. I haven't had in luck in the books I have or at my local JD dealer.
Reply Quote

Re: SBJD trans ratio calculations??? January 02, 2011 07:37AM
bclark,

I am sorry to say that I am not familiar with a quad range trans. so I really can't help you there.
Reply Quote

Re: SBJD trans ratio calculations??? January 02, 2011 08:47AM
J&R Machine,

I think we might try the PTO gear deal, although not sure we can run the 7 1/2 combo yet. Thanks again.

bclark,

I might be wrong, but a Quad Range is just a Syncro Range with a two speed unit in front of it.
Reply Quote

Re: SBJD trans ratio calculations??? January 02, 2011 08:56AM
Your not wrong. Speeds may be different but built the same. Except for two speed
Reply Quote

Re: SBJD trans ratio calculations??? January 02, 2011 12:56PM
A quick look at a parts book will tell you that the gears in a quad range and a syncrorange 4430 are not the same! For a stock quad 4430 D4 = 5.22*4.8*.925= 23.17 final C4 =5.22*4.8*1.421= 35.6 final
Reply Quote

Re: SBJD trans ratio calculations??? January 02, 2011 12:17PM
quad has 34 driver(counter shaft)26 driven(pinion)
sycro has 36driver(counter shaft)26driven (pinion)
thats the gears in the 8th position



Edited 1 time(s). Last edit at 01/02/2011 12:23PM by 4455puller.
Reply Quote

Re: SBJD trans ratio calculations??? January 02, 2011 12:22PM
rest of the gears are the same,i have a 7 5/8 gear if u need one,it is straight cut 39 driver 35 driven its around 27.1
Reply Quote

Newer Topic Older Topic

Author:

Your Email:


Subject:
Spam prevention:
Please, enter the code that you see below in the input field. This is for blocking bots that try to post this form automatically. If the code is hard to read, then just try to guess it right. If you enter the wrong code, a new image is created and you get another chance to enter it right.
Message:
Website Statistics
Global: Topics: 38,770, Posts: 229,937, Members: 3,338.
This forum: Topics: 37,096, Posts: 226,027.

Our newest member Jacklovik2009