I am doing a repower with a Cummins ISM / World Trans. and I am looking for a 4:10 ratio ring and pinion for my differential. It is a 1978 Eagle 05.
Anyone got any ideas where to look for this set of gears.
http://www.trucks.com/parts_used_tires.asp
I don't know what your Eagle rearend is but, this outfit has shops in Ohio and Florida. They have gears and whole rearends out of trucks.
HTH, Ed
Try Pinson Truck Parts in South Carolina. Large inventory of rear end parts, new and used. 864-578-0675
I thought all the eagles had a 3.36 or 3.73 rearend. Did you change something? I don't recognize that ratio.
David Anderson
1985 Eagle 10
Quote from: David Anderson on April 26, 2006, 07:07:08 PM
I thought all the eagles had a 3.36 or 3.73 rearend. Did you change something? I don't recognize that ratio.
David Anderson
1985 Eagle 10
I currently have a 3:73 and wish to go to a 4:10 or 4:11. I am learning. Apparently my reference to 4:10 was wrong in that no Eagle ever had that ratio. However, I learned today that there were some made in the seventys that had 4:11 gears.
Thanks for your info.
Bill
Quote from: Kristinsgrandpa on April 26, 2006, 05:49:52 PM
http://www.trucks.com/parts_used_tires.asp
I don't know what your Eagle rearend is but, this outfit has shops in Ohio and Florida. They have gears and whole rearends out of trucks.
HTH, Ed
Thanks, I have looked there (both places). I bought my World Trans. through the Fla. yard.
Bill
Quote from: Ericbsc on April 26, 2006, 06:22:48 PM
Try Pinson Truck Parts in South Carolina. Large inventory of rear end parts, new and used. 864-578-0675
Thanks,
Never heard of them, but I will try there.
Bill
Why would you want 4:10 or 4:11's. In my by gone street drag racing years those gears were great for the quarter mile run but bad on fuel for just cruising down the pike. My old Dodge power wagon had 5:38's in it, could pull a house down with that gearing but on the highway the flathead six screemed at 55 mph.You could hear me coming.
Quote from: scanzel on April 28, 2006, 04:24:59 AM
Why would you want 4:10 or 4:11's. In my by gone street drag racing years those gears were great for the quarter mile run but bad on fuel for just cruising down the pike. My old Dodge power wagon had 5:38's in it, could pull a house down with that gearing but on the highway the flathead six screemed at 55 mph.You could hear me coming.
I will have a World transmission with 5th / 6th gear Overdrive. The combination will give me far better accelleration from a stop, better grade performance, but it with the OD, I will have considerably better fuel economy than I have now. Further, the Cummins ISM has a huge improvement in HP and torque over the 8-71 we are swapping out. There is no comparison. I have been driving the 8-71 for almost 10 years and I sure won't claim that it has provided anything close to "good" mileage. Further, if you look at specs, some of the high line coaches are running 4:30 and 4:33 gears with the transmission we are putting in.
Thanks for you thoughts.
Bill
Bill, Does your Eagle run a dropbox? There was a guy in MO that had 4.10 w/dropbox. What the litre of the ISM? I am putting in a L10 in a 5c and wish I had bought a truck for parts. I just bought a truck with a N14 for the wheels, should have bought one sooner in the project. Goodluck Tom Y
Bill, Wayne St. Onge (sp?) had told me that he had a 4:10 (new I think). He sold a lot of his parts to Wayne Schell.
You should have both of the their phone numbers from the roster.
Quote from: Tom Y on April 28, 2006, 09:27:31 AM
Bill, Does your Eagle run a dropbox? There was a guy in MO that had 4.10 w/dropbox. What the litre of the ISM? I am putting in a L10 in a 5c and wish I had bought a truck for parts. I just bought a truck with a N14 for the wheels, should have bought one sooner in the project. Goodluck Tom Y
My Eagle does have a drop box. I believe all Eagles since the model 01 have them. The ISM is the latest evolution of the M11 and is 11 litres if I am correct.
Bill
Quote from: rv_safetyman on April 29, 2006, 03:00:28 AM
Bill, Wayne St. Onge (sp?) had told me that he had a 4:10 (new I think). He sold a lot of his parts to Wayne Schell.
You should have both of the their phone numbers from the roster.
I will call St. Onge right away.
Bill
Bill, I traded my 4.10 or 4.11 from my MCI 5C for a 3.38 from a Eagle. I can find the # if you are intrested. Not sure he still has it, as I did see it on Ebay. Let me know if you are intrested. Tom Y
Quote from: Tom Y on April 28, 2006, 09:27:31 AM
Bill, Does your Eagle run a dropbox? There was a guy in MO that had 4.10 w/dropbox. What the litre of the ISM? I am putting in a L10 in a 5c and wish I had bought a truck for parts. I just bought a truck with a N14 for the wheels, should have bought one sooner in the project. Goodluck Tom Y
Tom,
Sorry it took so long to reply. Very busy for the past few weeks. The Cummins ISM is an 11 liter later version of the M11.
Bill
Quote from: Tom Y on May 01, 2006, 09:31:28 AM
Bill, I traded my 4.10 or 4.11 from my MCI 5C for a 3.38 from a Eagle. I can find the # if you are intrested. Not sure he still has it, as I did see it on Ebay. Let me know if you are intrested. Tom Y
Tom,
Saw this after my last response. I am no longer chasing the 4:10 diff. The world trans. deal fell apart. I am no going back to plan 1 which is the HT740 I had, but replacing the 3:73 with a 3:36.
Bill
Bill,
Do you already have a 3:36 rearend? I'm pretty sure my 1985 Houston Metro 10 has a 3:36 because my speedo shows 80mph at 2100. I got these numbers as per Jim Sheppard.
I think his metro 10 has a 3:73 since he was surprised as to my numbers I'm getting on mine considering it is a bus from the same fleet as his. Of course that assumes my speedo and tach are correct.
David
3.36 with 11R-24.5 (478rpm) will give you a 1600rpm cruise of 60mph, 1873 at 70mph. If you could find a 3.08, that would be better. That would give you 1600rpm cruise of 65mph and 1840rpm at 75mph. Much better! It's to bad the HD4060 or B500 didn't work out. With the 4.11 you'd have a 75mph cruise at 1571rpm and a rocket ship off the line.. Good Luck, TomC
Tom C.
I've got a question. On any given differential, is the rpm to speed proportional when in 1 to 1 ratio, 4th gear lockup?
Ie., 1600/60mph 1873/70mph 2100/80mph
The rpms for each equation are slightly different, but are they close enough for accurate computations? They are all in the 26rpm +/- per each mph.
David
No- try 478rpm with 5.29 ratio. At 60 you'd be turning 2528 and at 50 you'd be turning 2107 for a difference of 421 or 42.1 per rpm. Each ratio will have different rpm splits between speeds. Good Luck, TomC
Thanks Tom,
I never thought about the formula, but I assume anyone can compute their gear ratio by looking at their tachometer at 60 mph and dividing by 478 (24.5" tires) then can get engine rpms for any mph by computing rpms for each mph from the above formula. I drove my bus yesterday and my rpms were just a tad off the mark at 60 mph, thus the computation below:
1606/478=3.36 1606/60=26.76 rpm per mile per hour. 26.76x70mph=1873 engine rpms at 70 mph and so on, and so on.
It's simple math, but my "light bulb" never turned on till this thread was written. That's the way it goes sometimes.
Thanks,
David