Question about rear ends??
 

I found this 04 columbia, 13 speed,14.0 engine with 2.90 rears.What do you guys think about this set upfor power,fuel mileage,speed? Most of my friends haven't heard of gears this low and their views are different.Would like to hear from whom may know about this stuff.:thumbsup:

Low??

That would be high geared. Should fly across Nebraska

A guy called Rutherfords show last week, he bought one of those and hates it..he said it gets lousy mileage and runs like crap.
kevin said with ultra low pro 22.5 and 60 mph it would do okay

Okay, 60mph wont cut it for me.I need to run at least 65 to 75 and still get decent mileage.I should mention that it has a 14.0 detroit.Just talked to one of my mechanics and said it was a good set up.But i still want to hear more from others.

TY

This little formula might help you decide:

RPM at 60 MPH = Axle ratio X Tranny ratio X Tires revs

I guess this truck has a direct drive tranny, so the "Tranny ratio" (top gear) will be 1. Regular 22.5 tires do usually 495 revs/mi; while tall rubber (24.5) do 473 revs/mi. To find out the RPM at 65 or 70 you put in all the numbers in this formula and then divide the result by 60 and multiply by whatever speed you plan to run at.

Example: tires revs=495, direct drive (1 ratio), axle ratio-2.90. The engine RPM at 60 MPH will be: 2.90 X 1 X 495 = 1435. The engine RPM at 65 MPH will be: 1435 / 60 X 65 = 1555 RPM

If you play with various tire types, you can find which setup will produce the RPM that Detroit recommends for cruising on the highway.

I have 3.55's and I do 70 at 1500 rpm. 24.5 low pro. I would get higher if I ever changed them.

The faster I go the better fuel mileage I get.

With the specs you listed I'm sure it's an old Swift truck. They have 2.93 rears with a direct 13sp. That tranny and rear end is near the exact same as an overdrive 13sp and 3.55's.
That transmission was originally a RTLC-16609E, once converted it's a RTLO-16613B, Top hole is now .85

That would put you at 1400rpms at 65 and 1600rpms at about 75.

Yes.You are correct.It is a swift truck. Right now, my t 2000 with a 10 sp,3.55 rears runs me at 1500 rpm @ 65.Over 1500 at higher speeds.The problem is that it really needs a rebuild and that would cost me over 10k.And once you put money into it,It never ends.According to my numbers from last year,i had quite some big numbers on repairs.That's why i decided to go with another truck,less expensive, since the economy is the way it is.A little protection from both sides.

But yeah, if any of you guys had any experience with this type of set up dont hesitate to post.

TY

I own an old Swift truck. One of the blue ones, just like the white ones except it has power windows. I had very bad luck with it at first, but a new engine, clutch, and rear main seal later, I'm in business. I get an average of around 6.8mpg pulling intermodal through the hills of Missouri. Heavy loads, 45,000 plus

New engine??? Man that's crazy!Let me know what issues you had with that detroit engine.I only dorve a cummings and had no problems at all but im new to detroit.Also 6.8 mpg is excellent on those trucks.

The engine had massive blow-by due to poor, if not non-existent maintenance. So it was covered under warranty. When they did the engine work they screwed up the rear main seal, so then that was replaced. After that, I was going home to find the clutch slipping like crazy bob tailing. I took it back to find out the clutch was soaked in oil. It wasn't like that when I had taken it in there. So after some intense "reasoning" with them, the clutch was replaced as well. Since then I've had no real trouble out of it. However my EGR valve needs to be replaced, but with how slow things are, I can't really afford to just throw 1200.00 at it.

I'd stay out of the mountains with those gears. Be splitting all day. Wont be able to skip gears as easily also.

A disclaimer....I'm not an o/o, but a company driver.

Upon reading your post, I became a bit curious about your logic, and I don't mean it in any disrespectful way.

On the one hand, you state that your existing truck needs a rebuilt engine at an expense of approx 10k, something which you're not keen on doing : yet, on the other hand, you're perfectly willing to spend even more money on yet another used truck, which has probably been run ragged by its previous owners, along with questionable maintenance. What is the guarantee that you won't have to spend even more money on this other truck that you're looking at ? It's not as if you're getting yourself a brand new truck. At least with the truck that you currently own, you're quite familiar with its functioning.

Don't you think that a known devil is better than an unknown one, especially in this economy ?

While I am certainly no expert I hear alot of truckdrivers prefer "Eaton rearends". As a matter of fact some of them just love Eaton rearends.

Roehl runs a setup close to that. 10 speed direct with 2.64 rears. And that is why they,

R oll
O ver
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oops
 

thought this was a question about girls, never mind:lol2:

Its a joke. Eaton rearends, get it? No?

what would you suggest....????
i thought the 13 & 18..were made for situations like mountains..heavy loads...etc.. YouTube - Shifting Jackass mountain :thumbsup:

How do you figure? It's almost dead on to an OD13sp and 3.55's. People see the 2.93's and **** themselves. They fail to realize the fact the the tranny is direct drive...

All right,
No problem at all and no offense taken

The rebuilt is around 10k or more.Radiator , air to air and all the hoses are around 2k or more, ac work would be around 1k, body work on the hood 5-6k, and things can go on and on.All these would cost me money out of pocket which i don have .This truck ate me last year around 24k in repairs.Small stuff here and there,headaches with lost loads etc.I'm just sick and tired of really dealing with it anymore. The truck that i'm looking at is around 25-35k financed for a period of no more than 30-40 months.I'm looking at a truck in the high 400's to low 500's miles.By the time the truck gets to 800-900 miles it would be paid off and i will get rid of it by buying a better one.I came to find out that there is no reason to keep a truck over a million miles, like i had this one.Stuff that starts breaking down, big or small is just too much and can add to the headaches.Trust me i have been there this past year with it and decided that it was enough.The amount of repairs almost knocked me down.

But anyways, right now i would consider a volvo too.It is a central refrigerated, cummings engine,10 sp, 355 rears.I guess these would be pretty nice too.I really like volvo but i'm kind of afraid of the electronics part.Oh well, let me know what you guys think.

I pretty much agree,if you get an old fleet truck, at least you know it has been maintained, at my last job, my truck was an ex werner it went fine for a million and a half miles ,when the engine spun a main bearing, the head mechanic said, put a bearing kit in it and trade it in, the boss said no, put a rebuilt motor in it, so then I had a truck with a nice new motor and a million and a half miles on the rest of it. it still spent every weekend in the shop for other stuff

"How do you figure? It's almost dead on to an OD13sp and 3.55's. People see the 2.93's and **** themselves. They fail to realize the fact the the tranny is direct drive..."


It is not a direct drive. I have a x-swift classic same specs they come with 9spd direct drives then when they are converted they become a 13sdp o/d not a big o/d it is a 0.86 final gear but still an OverDrive.
All eaton 9 spd conversions turn it into o/d go to there website and look for your self.

As for the specs they are ok while pulling my stepdeck around 65,000-74,000lbs I ran between 6.5 and 7.5 mpg depending on what part of the country I ran and no you don't spend a bunch of time trying to climb the hills you don't have to constantly keep spliting the gears either.I guess if you have not driven one you would not know.Now that I went back to pulling reffer @ 78,000-80,000 all over the country again
im running 6.2mpg so far.I keep my speed down to 63 and that puts me @ 1325rpm with the 22.5 lopro rubber.
I will prolly be going to 255/70-22.5 all position next go around and see what that does for the mpg.

Like I said, it's almost dead on to a 13spOD(.73) and 3.55's.

You are correct.

An easy way to figure this out is to determine the overal ratio of both combinations of trans & rears by multiplying the highest ratio of the trans x the rear axle ratio.

13 speed; .73 x 3.55 rear ratio = 2.60.

9 speed converted to 13 speed; .86 x 2.93 rear ratio = 2.52.

Converting the 9 to a 13 results in having a .86 overdrive when the stick is in 9th and the splitter button is in overdrive.

When the splitter button is in direct, all the ratios are the same as if it was still a 9 speed, therefore you still have the same amount of reduction in lo gear that you always had.

.

The final in mine is actually .85, but he was close enough.

That would put you at 1387@60mph.

Revs per mile for that tire is 557! That's insane. That's near 1620 or so for 70mph.