Found a bus, need input on engine and transmission

[mmpetunia]

I found a Bluebird TC2000 bus

I was just reading in another thread that the TC2000 line of buses is light duty. It seems like that it a bad thing. Can someone tell me why?

I have also read in another thread that the Cummins engines from the late nineties to the early '00's were prone to some type of failure due to a pin. How can I know if this bus is likely to have this problem?

The ad states that it's front engine diesel bus. Is this a good thing? I have read yes. At the risk of sounding as completely ignorant as I am: what exactly does that mean??

The ad states that it is an Allison transmission. It seems that these are generally regarded as good transmissions. Are there some models that I should look out for? Ad does not specify model on transmission

The ad states that the bus has Dana axles. I don't know what that means. Is it a good thing? I haven't seen much in the posts about the type of axle.

The ad states that the bus has air brakes. Apparently this is good for a smooth ride but does it add any benefit for braking?

Lastly, I have been reading about gearing ratios and axle ratios and I want to know what is the good range for highway driving. What is good for maintaining a reasonable speed going up inclines? What ratios are not good?

I have sent the seller a message asking for more specific information about the mechanics of the bus but I am in need of parameters to evaluate the data he provides.

Thanks in advance!

[Tango]

Below is the straight skinny. It also shows one fix which is a small, screwed in place cover. Frankly, I see this as replacing one potential problem by adding two more. A simpler fix is to peen the offending pin in place which is what I had done to mine while it was being rebuilt.

It absolutely does need to be addressed as it can totally demolish an engine. I have heard of a few rare instances where other years were affected because the timing case had be replaced with one with this issue so visually verifying is the only way to be 100% certain.

Cummins Killer Dowel Pin (KDP) Information

[mmpetunia]

Thanks for the info!

[PigPen]

Light duty just means it can handle less weight than a truck/bus that is medium duty (or higher). Plenty of people have made light duty chassis work for conversions, just be aware of the amount of weight you put in via materials and such.

As far as engine options go, there are pros and cons to the 3 main different options. These are conventional/dog nose, front engine (FE) and rear engine (RE). The dog nose is the classic school bus look with an engine compartment out in front of the bus. FE is typically a flat front with the engine located beside/underneath the driver. With a FE you get the benefits of more space inside and no engine taking up conversion space in the back, but it will be louder and hotter for the driver. RE seems to be the most popular around here, as you can put the bed above the engine and avoid the noise/heat up front. There is no right or wrong option though.

Allison is a popular transmission manufacturer. There are several models available. The 545 is often looked down on for bigger trucks/buses, but is probably fine for a light duty if thats what it has.

Air brakes are safer because if they fail/stop, the default is to stop the bus. If hydraulic breaks go out, then the breaks just won't work and you get the excitement of trying to stop a giant, heavy vehicle using other means.

Sorry, ran out of time to answer more!

[mmpetunia]

Originally Posted by PigPen

Light duty just means it can handle less weight than a truck/bus that is medium duty (or higher). Plenty of people have made light duty chassis work for conversions, just be aware of the amount of weight you put in via materials and such.

As far as engine options go, there are pros and cons to the 3 main different options. These are conventional/dog nose, front engine (FE) and rear engine (RE). The dog nose is the classic school bus look with an engine compartment out in front of the bus. FE is typically a flat front with the engine located beside/underneath the driver. With a FE you get the benefits of more space inside and no engine taking up conversion space in the back, but it will be louder and hotter for the driver. RE seems to be the most popular around here, as you can put the bed above the engine and avoid the noise/heat up front. There is no right or wrong option though.

Allison is a popular transmission manufacturer. There are several models available. The 545 is often looked down on for bigger trucks/buses, but is probably fine for a light duty if thats what it has.

Air brakes are safer because if they fail/stop, the default is to stop the bus. If hydraulic breaks go out, then the breaks just won't work and you get the excitement of trying to stop a giant, heavy vehicle using other means.

Sorry, ran out of time to answer more!

With a front engine bus, I think I am ok with the noise and heat. Are FE buses harder/more expensive to work on because of the location of the engine?

For the lightweight chassis, I know that I can look on the placard to read the weight of the vehicle and I think the max capacity as well. It seems like I would have a really hard time evaluating whether I was exceeding the weight or not. Are there any rules of thumb I can keep in mind?

Thanks so much for your reply!

[cowlitzcoach]

The TC2000 was built as a price point option for those who wanted a Type 'D' bus but couldn't afford an All American. Typically, before the TC2000 the price jump from a Type 'C' conventional 11-row bus to a Type 'D' transit 13-row bus was a lot more than $20K. For the bean counters and low bid contracts the premium for two more rows of seats just wasn't worth the expense.

The TC2000 was built to narrow that price premium. In order to do that they were built with lighter duty components. Lighter duty as compared to the heavy duty Class 7/8 truck parts used in Type 'D' buses. Instead of Class 7/8 truck parts the TC2000 and Thomas MVP buses were built with Class 5/6 medium duty truck parts which were almost identical to the parts used to build most Type 'C' conventional buses. So instead of more than $20K premium you could get a bus with up to 14-rows of seats for less than $10K over a Type 'C' bus. Which made the TC2000 and MVP very popular buses.

For your purposes, lighter duty does not mean light duty. The running gear on any TC2000 or MVP is head and shoulders above the running gear on any stick and staples motorhome and will outlast your use without any problem.

Air brakes have a lot of good things going for them, some of which are really good for a bus convertor. The biggest issue for me is when the bus is parked there is nothing in the brake circuit to cause the brakes to go bad. Hydraulic brakes when they are not used tend to collect moisture in the brake system that causes rust which leads to component failure. The other big plus has already been mentioned--if the brake system fails the brakes will self apply and will stop the bus with a big spring. The spring brake also is a very positive parking brake, more positive than any hand brake can be on a hydraulic brake system.

Air brakes have nothing to do with the ride or suspension unless the bus happens to have an air ride suspension. Which some buses have in the rear and even fewer that have in the front and the rear.

Allison makes automatic transmissions to meet just about any sort of service duty. The least capable is the AT500 series. It is the least capable compared to the MT600 or HT700 series or any of the WT 1000/2000/3000 series. But when compared to the Ford E4OD or GM 4L60 it is built like a tank.

A Type 'D' FE bus means the engine is six inches away from your right foot. It does create a lot of heat and noise right next to you as you go down the road. This is compared to the same bus with the same engine in an RE configuration where the engine is in the rear of the bus with all of the noise and heat many feet away. Each have their own benefits. The biggest benefit of the FE is none of the bus body has anything in the way of building into living space since the engine is next to the driver and not blocking the back of the bus.

As far as having Dana axles, I sort of doubt that. It more likely has Meritor or Eaton axles. Regardless of which axles it has, all of the parts and pieces to keep it working properly are available at any parts house that sells medium or heavy duty truck parts.

If the bus has an AT500 or MT600 transmission it means the top gear is direct. The lower the gear ratio number is numerically the faster the bus will go at a given RPM. For your purposes, any gear ratio under 4.7 will produce a reasonable top road speed. Any gear ratio above 4.7 is going to limit your top speed to under a safe highway cruising speed. Don't be surprised if the bus won't travel very fast. The vast majority of school buses spend 90%+ of their service life at speeds less than 35 MPH.

[mmpetunia]

Originally Posted by cowlitzcoach

Air brakes have nothing to do with the ride or suspension unless the bus happens to have an air ride suspension. Which some buses have in the rear and even fewer that have in the front and the rear.

This is compared to the same bus with the same engine in an RE configuration where the engine is in the rear of the bus with all of the noise and heat many feet away. Each have their own benefits. The biggest benefit of the FE is none of the bus body has anything in the way of building into living space since the engine is next to the driver and not blocking the back of the bus.

As far as having Dana axles, I sort of doubt that.

I mixed up the air ride suspension with air brakes. What you have said makes a lot of sense

The RE configuration sounds like a win in many ways, however, I am trying to maximize living space and maneuverability in tight urban locations since I will be using the bus as both a business (tea cafe) and a living space. I want the shortest bus with the largest amount of living space I can get, which is why I have set my sights on the flat nosed bus. I will have to accept hot feet and being unable to hear music as I cruise down the highway as a compromise to get what I would like. My feet are generally cold and I often turn the floor vents on when I drive, so maybe it will turn into a benefit to have the engine so close to my feet!

The listing explicitly states that the bus has Dana axles so I will take a screen shot of that since it sounds unlikely that it is as advertised.

Overall what I'm hearing as a take away is that I have found a decent bus worthy of an offer

Thanks for your really thorough input

[EastCoastCB]

Originally Posted by mmpetunia

I mixed up the air ride suspension with air brakes. What you have said makes a lot of sense

The RE configuration sounds like a win in many ways, however, I am trying to maximize living space and maneuverability in tight urban locations since I will be using the bus as both a business (tea cafe) and a living space. I want the shortest bus with the largest amount of living space I can get, which is why I have set my sights on the flat nosed bus. I will have to accept hot feet and being unable to hear music as I cruise down the highway as a compromise to get what I would like. My feet are generally cold and I often turn the floor vents on when I drive, so maybe it will turn into a benefit to have the engine so close to my feet!

The listing explicitly states that the bus has Dana axles so I will take a screen shot of that since it sounds unlikely that it is as advertised.

Overall what I'm hearing as a take away is that I have found a decent bus worthy of an offer

Thanks for your really thorough input

I like the FE layout. ALL usable floor space behind the driver seat and very maneuverable in tight spaces.

[WIbluebird]

Originally Posted by cowlitzcoach

The TC2000 was built as a price point option for those who wanted a Type 'D' bus but couldn't afford an All American. Typically, before the TC2000 the price jump from a Type 'C' conventional 11-row bus to a Type 'D' transit 13-row bus was a lot more than $20K. For the bean counters and low bid contracts the premium for two more rows of seats just wasn't worth the expense.

The TC2000 was built to narrow that price premium. In order to do that they were built with lighter duty components. Lighter duty as compared to the heavy duty Class 7/8 truck parts used in Type 'D' buses. Instead of Class 7/8 truck parts the TC2000 and Thomas MVP buses were built with Class 5/6 medium duty truck parts which were almost identical to the parts used to build most Type 'C' conventional buses. So instead of more than $20K premium you could get a bus with up to 14-rows of seats for less than $10K over a Type 'C' bus. Which made the TC2000 and MVP very popular buses.

In its last few years (2000-2003ish) the TC2000 was very similiar, if not almost identical to the All American. At some point around 2003-2004, the TC2000 was discontinued and the All American became Bluebird's only Type D offering.