Has anyone changed the gears in their bus rear end. I wanted to go to 336 from 370 and have been told it can't be done. They said I would have to change the whole diff. Need some input please.
Richard
I did replace my gears, but did not change the ratio. During the investigation, I found that both those gears would fit that casting. There should be a tag on the axle rear side right side. Get that number and call ROCKWELL/MERITOR, 888-725-9355, (possibly Ext. 5, Bill or Mike in 2001). They should be able to confirm and give you ID numbers.
I bought my rebuilt gear assembly from Valley Truck in Michigan, 616-241-5431. In 2001 it cost $1350.
Ed Roelle
Flint, MI
Most T drive differentials are just truck rear ends rotated 180 degrees around. I know Meritor (old Rockwell) makes ratios to 2.65 for the 23,000lb axle. Good Luck, TomC
Richard, have you tried Sam Cayor the MCI guy in Kansas or Ed at Jefferson in OKC OK Jefferson sales parts for buses other than Eagles.I would do like ED and just get the assembly most of the time it cheaper and you have it out already to change the gears and bearings
Richard, have you had any luck on your gear change yet
Hi luvrbus,
No luck as of yet. spent all day today calling and discussing options. I found out no other gears will fit, so I can have this one repaired and have what I have, or I'll have to change to a eaton with 336 truck rear end. That gonna take a lot of cutting and welding, but I've just about decided to do it. Tomorrow I have to find the rear end and try to get it altogether by this weekend so I can go to the TEXAS ROUNDUP!!
Richard
For the novices, when Tom says "rotated 180 degrees around, he means rolled over, upside down, not side to side.
The right wheel on the truck has to stay the right wheel on the bus, only point the yoke backwards....
Otherwise, your bus will go backwards when you put it in drive!
There are a number of busnuts on here who have made modifications and rolled a truck axle over for their bus.
happy coaching!
buswarrior
buswarrior,
I knew about the flip over. I was just wondering if there was anything special I needed to do with the cutting and welding of the air suspension to the truck axle, and or the brakes. I have a mc-7 that weighs 35000 lbs fully loaded so I wanted to get an axle at least 38000 lbs. I'll start calling in about an hour so I can get it done...
Richard
Quote from: rdbishop on September 05, 2007, 05:01:32 AM
I have a mc-7 that weighs 35000 lbs fully loaded so I wanted to get an axle at least 38000 lbs.
Richard -You're going to have a real problem trying to find a 38,000 lb rated rear axle. Most are in the 20K - 25K range.
Granted, your MC-7 weighs in at nearly 35K, but remember, that's spread between three axles, not just on the drivers.
IIRC, the MCI data plate says 12K on the front, 20K on the drives, and 6K on the tags GAW, for a total GVW of 38K. Since you're at 35K, sticking to a stock axle will be fine - it still leaves you with 3K for "stuff". A 23K axle would work, too, but anything beyond that would be overkill.
It's entirely possible that MCI changed axle suppliers when they started offering the 336 ratios.
Have you checked with Caylor or Jefferson Bus? They're the closest to you. Luke might have what you're looking for, also, 1-888-262-2434.
Anyway you look at it, I'd suggest you NOT rush this project just to make the Texas Roundup. There will be another rally somewhere, there usually is. And you'd also be welcome if you took some other vehicle. But to rush the job and maybe "forget" something, only to have the repair come apart on the road, well. . . 'nuff said.
FWIW & HTH. . .
;)
On the topic of axle changing...
One of the weaknesses of our buses is getting stuck out on the lawn at a rally. All wheels are only just settled in a half inch, the soil is a little damp under the wheels, maybe the slightest of rise in the land in front of you to the roadway, then the peg-leg differential spins that one set of duals and then it's over.
Or the unexpected rain storm turns what appeared to be a solid base into a muddy quagmire.
Never mind a slight rise in a snow and ice covered parking lot for those of us with more northern operating ranges!
Yes, many of us lay boards out under the wheels as a defensive move, but we still have to negotiate the lawn between boards and the road.
The tractor trailer folks have locking differentials that make these adventures a complete non-event. Flick the air control as a matter of course, and drive out with all 4 duals turning as one.
Coupled with the tag unloading valve, a locking differential would be a very convenient functional upgrade.
So, is there a locking differential out there with the yoke centred in the housing that will withstand a busnut putting it upside down and still function and lube itself as intended?
I smell a tutorial in the making...
happy coaching!
buswarrior
Buswarrior - The scenario you have spoken of where the tires sink in just a little and there is just a little extra resistance and ypou ad a little spin from one set of wheels and you're done - that has happened to me more than once. Positraction would be a great addition!
Maybe there is a reason the manufacturers call them 'highway coaches'.
That's true, althoguh it still might help in inclement weather too. I'm sure its just a cost tradeoff issue.
I am in the process of installing a series 60 with an Atec transmission in a Mci-8. I went to a truck rear end & suspension shop in Houston. This shop repairs HD truck rearends. They cut off tubes repair & replace etc. I gave them my mci 8 banjo housing and a rearend out of a late model truck with a 2.69 ratio. They cut off the mounting flange for the center piece, welded it to the mci housing, found metric splined axle's to fit the new center chunk and modified my existing hubs to accept 8 bolt instead of 10 bolt axle flanges. So I basically have a mci housing with a meritor 2.69 center piece & axles with all the standard mci stuff, brakes, hubs etc. Looks normal & the axles are common & so is the center chunk. The mci housing is highly modified but done by pros with a warranty and was I believe around $1500. worth of machine work + the cost of the meritor rear end. Bus not complete yet but have all the drive train, wiring etc. Ray
You can get either positraction, that has the clutches inside and works automatically, but I'd suggest using a manual lockup diff with the air switch on the dash. Because of the distance from the drivers compartment to the rear axle, a electric over air solenoid could be used-much like your engine shut off, but in reverse. You want a normally closed solenoid that opens when charged. Good Luck, TomC
Hi can we get a number for the shop thanks Darren.
Thanks Ray,
This is the kind of information I've been looking for. Thanks again!!!!
Richard
Wow! in luck, I actually found the receipt for the rear end mod. I.M.E. Truck
5215 N. McCarty
Houston, Tx. 77013
713-675-1258
invoice date 3/10/2004 man time flies! If you call them you may reference the invoice # 15350. The total cost for the machine shop (IME) was $1460.54 This price included 2 used axle shafts welding supplies, gear mounting plate, studs, and machine labor. It did not include the cost of the late model rearend out of an 18 wheeler, it was the (rear) rearend, I bought the whole unit including drums, abs brake sensors etc, for $850.00 but as I discribed earlier all of my mci stuff was reused and the meritor rearend banjo housing, hubs, drums etc were discarded. Hope this answers some of your e-mails and be happy to answer any further questions. Ray
Ray,
You said the running gear was in your bus. Are you driving the bus, and how in the world did you get that 60 in there? Are you going to the Texas Round-up? I sure would like to see your set-up.
Richard
Richard, no the bus is not moving yet. Good things take time! Actually I am reskinning. Also the S-60 would have fit with no lengthing if I would have put the radiator on the side but I choose to have the radiator in the rear like a stick & glue so I extended the rear to hold the radiator & charge air cooler. I have the R&M rear kit which I am making the rear louvers functional. plus 4 long rolls of fiberglass from R&M. to put over metal skin. I'm sorry to say I will not be making the trip. I had really considered it but my job is getting in the way. Hope you all have a good time & I will definately be driving up one day. As a matter of fact I will be retiring in 4 years & we have already made up our minds to full time. Ray
Hi Ray,
I had considered a 60 when I put in the 8v92. It just looked like it would really be tight. I-d still like to see your set-up when time permits. I don't know yet if we are going to make it to the round-up. The rear end guy in houston never called me back friday so I called around s. a. and finally found a place that had done the same thing before. Anyway, they are closed for the weekend so monday morning early, I have to be there with the rear end. I will finish taking it out this morning and get it loaded on the trailer. I then have to build a wood frame for my birthday present (32" flat screen for the bus} that I had to take out of it's case so as to shorten the height. I have parts and pieces all over the kitchen counterand my BOSS says to get it out!!!! I need to get going so we'll talk to later. Hav a good weekend.
Richard
Richard, any luck on your gear change missed you at the roundup
Hi luvrbus,
I had taken the rear end to a guy in SA that said he could do what I wanted, said he'd get right on it. Icalled after a week and he hadn't done anything..said he needed more time. So I went and picked it up and took it to Houston like I should have done in the first place. These guys said it would take 15 days because of their work load. Sooo here I sit with a---in the air. I really really wanted to make the rally. I even tried to borrow my uncles Eagle, but it needed to much work to get it going. he passed away last year but my aunt said I could use it. The bus has been sitting for 6 years and needed alot. I'll make it next year even if I have to buy another Bus!!!!!!
Richard
Because I'm one of the older guys around, with homage paid to those older than me, I wonder if anyone has given much thought to ...the belt drive tag axle?
When I grew up most of the big trucks I knew were chain drive Mack's. Fortunately we outgrew that era. Then came the first tandems. Some were just tag axles to carry the weight and to be legal. But some enterprising individual came up with the idea that in the winter months, when you might need the additional traction, you could belt from the drivers to the tag and make it a marginal drive axle when needed.
In my small cynical mind, spending money of changing axle ratios for the reward would seem like chasing the wind. How about finding a way to belt the tag axle to the drive axle for the additional drive.
Changing ratios for better milage seems like poking money down a rat hole. The gains would not be offset by the cost.
FWIW
NCbob
NCbob,
This has nothing to do with milage. If I was worried about the cost I would have gotten rid of this money thirsty beast about 30,000 dollars ago. As it is, the rear end was going out and needed fixing anyway. With the setup I have, I was trying to lower my RPM's. So on it goes.
Richard.