I bought 4x4 bus.

archangel.ahl · 09-02-2017, 01:45 AM

Hello, I have a question for you guys. Scored a pretty nice 4x4 bus the other day. It's a 7.3, 545 at with a Rockwell nine thousand pound front axel and t226 transfer case. Don't know to much about it beyond that. It had a terrible vibration at about 45 mph. Seems a little gutless but runs good and wasn't very an astronomical amount of money. Never seen another one. I kinda wanted to take the four wheel drive components out of it and put them into my dt466 spicer seven speed bus cause he screams along and then I would have a true expedition vehicle. And info appreciated.

cowlitzcoach · 09-02-2017, 02:42 AM

Since both buses appear to be about the same vintage swapping stuff around shouldn't be much of a problem.

All of the 4x4 buses tend to be screamers at comparatively low speeds. There is a lot of gears turning and extra weight that works against high speeds.

I would double check that the transfer case can handle the HP and torque of a DT466.

Other than that I don't see any real problems in making the swap.

archangel.ahl · 09-02-2017, 03:33 AM

One is a 96 and the other a 97, and everything will literally just unbolt and rebolt, but what I am wondering is can I have highway speeds with a 4x4 setup? It's just raised by blocks which I don't like, I can fab a link setup if I choose later on. I haven't been able to find info on the transfer case, but being that it's a Rockwell I would imagine it can handle a 210 dt466. Although I'm a big performance person so I don't know if I can leave it at just 210. Especially with a p-pump. I just have a knack it seems to find unusual busses. This is my third bus in a year.

BowserJournal · 09-02-2017, 08:27 AM

4X4 Bus? That is super cool! I hope you figure out your mechanical issues. That would be great for the woods and desert.

cowlitzcoach · 09-02-2017, 12:14 PM

Quote:

Originally Posted by archangel.ahl

One is a 96 and the other a 97, and everything will literally just unbolt and rebolt, but what I am wondering is can I have highway speeds with a 4x4 setup? It's just raised by blocks which I don't like, I can fab a link setup if I choose later on. I haven't been able to find info on the transfer case, but being that it's a Rockwell I would imagine it can handle a 210 dt466. Although I'm a big performance person so I don't know if I can leave it at just 210. Especially with a p-pump. I just have a knack it seems to find unusual busses. This is my third bus in a year.

Highway speeds are determined by final rear end gearing. I think you will find the choices for higher speed are rather limited for the front axle. And since you have to have the same gear ratio in front and in back I think you will have to be content in the slow lane.

As far as reducing the lift, I think most of the lift is required to clear the front pumpkin. IIRC, there is not a lot of clearance between the top of the pumpkin and the bottom of the engine oil pan when you factor in spring deflection. I can't imagine any school bus operator willingly opting for a bus with the first step 36" off of the ground if there was any option to have 4x4 with a lower first step. Having to deploy a two or three step RV step at every stop is just one more complication and system to maintain.

archangel.ahl · 09-02-2017, 11:16 PM

I didn't mean readucing he lift by taking out the blocks, more so that I'm not a fan of raising anything with just blocks. Seems cheap. I need to spend some time on pirate 4x4 and read up on what it is I actually have. Holy hell the transfer case in this thing is huge, I bet it ways five hundred pounds. Better start looking for a np205 if i want any real ground clearance. Also does anybody have an idea why they use so many small driveshafts? There is three going to the rear?

cowlitzcoach · 09-03-2017, 12:04 AM

The multiple short shafts eliminates whip.

It also allows things to not have any sharp corners in the driveshaft.

The output shaft of the transfer case needs to be within a few degrees of parallel with the pinion gear. If you do the whole drop with one joint at the front and the back it would mean each of those joints would have a pretty sharp corner. Add a couple of joints along the way and the corners become less sharp.

DWJoyce · 09-03-2017, 12:11 AM

Any divorced transfer case setup can whip under the right conditions. Make sure the mounts and ujoints are perfect and the angles are correct, wear can really mess things up.

archangel.ahl · 09-03-2017, 12:15 AM

I see, is it possible to get drive shafts with cv joints at the end for busses? I suppose anything is possible with enough cash. Definitely a neat piece of machinery. I just need to figure out what I want to do with it. Thank you all for the replies.

archangel.ahl · 09-03-2017, 12:40 AM

Do you suppose the vibration I felt at about 45 and up was due to a possible whip affect in the drive shafts? It wasn't a good feeling and I realize it could be a ton of things.

cowlitzcoach · 09-03-2017, 02:43 AM

Quote:

Originally Posted by archangel.ahl

Do you suppose the vibration I felt at about 45 and up was due to a possible whip affect in the drive shafts? It wasn't a good feeling and I realize it could be a ton of things.

As old as the bus is I would suggest you have several things going on.

Worn out u-joints and carrier bearings. It wouldn't take much to create a real vibration once you reach a particular speed.
Worn out tie rod ends, drag links, king pins, or steering box. A little wear in each of those parts could end up giving you a inch or more of slop which would create quite the vibration/shimmy at certain speeds.
Tires with flat spots. Tires that have been sitting can, and will, get flat spots. With radials it takes longer than with bias ply tires to go flat. The downside of taking longer to flat spot is when a radial gets a flat spot it not only will shake, rattle, and roll the bus but it can lead to the steel belts breaking and causing a catastrophic tire failure.
Driven front axles have a LOT of unsprung weight. If the tires are not balanced well what would be a small irritation from wheel bounce on a normal front axle can translate to a huge bounce on a driven front axle.

Discovering what you have and how to fix it is going to be a bit of a steep learning curve for you.

Good luck and keep us posted!

milkmania · 09-03-2017, 08:05 PM

Quote:

Originally Posted by archangel.ahl

Do you suppose the vibration I felt at about 45 and up was due to a possible whip affect in the drive shafts? It wasn't a good feeling and I realize it could be a ton of things.

Rotating my inner rears (virgin rubber) to the front made a WORLD OF DIFFERENCE!

Is it steering wheel/brake vibration or whole body vibration?
My whole damned bus vibrated so much, I couldn't tell where it was coming from! Found out the fronts were cupping pretty bad

How is the vibration when descending a steep grade?

archangel.ahl · 09-03-2017, 10:44 PM

It's not in the steering it's the body/carriage. It's hard to describe but it is a constant vibration that oscillates from softer to harder. Only starts at about 45 mph and above and then is constant.

Oldcarnut · 09-05-2017, 10:13 PM

That is one nice 4X4 you got there n two nice busses. Mind getting a shot of them back to back to see the height difference between the two?
As for the lift blocks, go to a spring companny and see about new or rearched springs to eliminate the blocks. And yes, blocks look cheap.

bansil · 09-06-2017, 05:32 AM

Very cool, I was looking for one 5 years ago, don't over look king pin wear in front axle

archangel.ahl · 09-09-2017, 04:03 AM

I will get a photo. Yeah when I saw it I kinda had to have it.

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