Contenental Trailways PD4104's pulling cargo trailers.

[roadrunnertex]

Every now and then a question comes up on the board about the GMC PD4104's being underpowerd.
This is a post that I found on a Trailways drivers Yahoo group board.
The driver is Howard Shaft who is still driving a bus he is now a Trailways/Greyhound Driver out of Wichita,Kansas.
The trailers were owned by the old Continental Trailways Central Lines-Wichita,Kansas.

The trailers were made at the Wichita shop, wheels and axle were off ACF's 1100/22 tires.
They had electric brakes that were not good. We hauled railway express from Joplin Mo to Harrison Ark with them, used 4104's to pull them on the night run Joplin to Little Rock. We dropped them in the parking lot of the post office in Harrison Ark and went on to Little Rock, the next night coming back we hooked up in Harrison with a load back to Joplin. When we left Gateway down bush hill you left it in 3rd gear and the old 671 would float the valves it wound so tight and sparks flew out of the exhaust you would have just enough brakes to make the joug at the bottom and across the White river bridge and then pull the guts out of it all the way to Eureaka Spgs. I think back and wonder how those 4104's took the beating they did.

Speaks well for GMC and the PD4104's and GMC other intercity coaches.

jlv

[Nick Badame Refrig/ACC]

Hi roadrunnertex,

Any Pics of  that trailer?

Nick-

[roadrunnertex]

I am sorry no photos if I get one I will bring up another post.
jlv

[Chaz]

Would those have the same issue with a trailer hitch as my 4108?? I just want to make sure my hitch is the best it can be. I think I have it on pretty good, but would like to know any technical stuff.

Thanx,
    Chaz

[roadrunnertex]

Chaz yes the PD-4104 has the same type structure as the later GMC coaches like yours.
I have no Idea how Continental Trailways Central Lines maintenance shop in Wichita,Kansas designed or installed the trailer hitch on the PD-4104's.
Sorry I can not add any iformation.
jlv

[Fred Mc]

How could they pull a trailer with a GMC. Everyone (on this board) knows you can't do that and the motor would fall out on the ground.

[Stan]

Fred: I know your comment was written witha bit of sarcasm but few of the older buses were designed to pull a trailer with a heavy tongue weight.  Some people pull heavy pickups which is just a four wheel trailer with an axle on each end instead of 48" or less spacing in tandem.

Since we know little about the trailers used by Continental  or the weight carried it is best not to draw too many conclusions from this thread.

Here are a couple of quotes from the original thread "They had electric brakes that were not good....... you would have just enough brakes to make the joug at the bottom and across the White river bridge "  This  statement comes from a class one driver hauling a load of passengers.

[kyle4501]

Could someone post the serial numbers of the buses most likely used for this trailer hauling service? Then we might be able to find one & inspect it to see what was done.

I suspect the bus chassis didn't tolerate the abuse well enough to survive till today.

Sure you can beat hell out of something for a little while & get away with it, but that doesn't guarantee long term success.

I still say that If you want to pull a heavy as h*** trailer, Get a kingsley type coach or be ready to replace your coach when the problems start. (Or I suppose you could add sufficient structure to the shell of the bus to handle the trailer loads, but I have seen very few who understand the complexities involved in this type of structural modification.)

YMMV

[RJ]

I still say that If you want to pull a heavy as h*** trailer, Get a kingsley type coach or be ready to replace your coach when the problems start. (Or I suppose you could add sufficient structure to the shell of the bus to handle the trailer loads, but I have seen very few who understand the complexities involved in this type of structural modification.)

Or get a Tuff-Tow unit installed on your trailer. . . www.tufftow.com

[roadrunnertex]

Kyle this is the serial numbers/VIN for the PD-4104's that went to Continental Central Lines (Trailways) Wichita,Kansas.
PD4104
1966 through 1979
3534 through3541
3451&3452
3830 through 3832
This means that Continental Central Lines has around 30 PD-4104's.
JLV

[Fred Mc]

"Fred: I know your comment was written witha bit of sarcasm but few of the older buses were designed to pull a trailer with a heavy tongue weight.  Some people pull heavy pickups which is just a four wheel trailer with an axle on each end instead of 48" or less spacing in tandem."

I would suggest that from the description of the wheel and tire size(1100/22)that these would have been pretty skookum trailers.

Having pulled a trailer with my Gm PD4106 I'm alway suprised at the comments regarding pulling a trailer with a GM coach considering most, if not all, the people responding had no actual experience doing that.

On the other hand I have a friend who had a 70's era 30 foot motor home who pulled a fairly heavy trailer and the frame of the motorhome bent due to the extra weight. When you sighted down the side of the MH the bend was very evident.

Fred Mc.

[kyle4501]

Having pulled a trailer with my Gm PD4106 I'm alway suprised at the comments regarding pulling a trailer with a GM coach considering most, if not all, the people responding had no actual experience doing that.

While I may not have direct experience jumping off the roof of my house, I know it is not a good idea due to other facts, experiences & training. A college class in vehicle dynamics will have you amazed at how they stay together as long as they do!

5 out of 6 people who play russian roulette live, but that doesn't mean it is safe to play.

There have been a few that have posted negative results from pulling heavy trailers behind buses.

The fact that most busses were not designed to pull trailers reinforces my opinion that trailer pulling with a bus is not to be taken lightly.

Mr. Vickers was kind enough to post the bus numbers that were used to pull the trailers. Let's find some of those & see for ourselves what was added (if anything) to allow trailer towing. If none survive, that should also tell you something.

Personally, I hope all those 4101's are out there & easy to find as I'd like to know what I need to do. 

If you want to pull a heavy trailer with a bus, knock yourself out. I'm just trying to give you something to consider so you can minimize the unexpected & have safe & happy travels.

[zimtok]

Here is a link that shows how a trailer hitch was added to a GMC.

http://www.thebouthilliers.com/4106/hitch.html



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[kyle4501]

Here is a link that shows how a trailer hitch was added to a GMC.

http://www.thebouthilliers.com/4106/hitch.html

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The photos show a very clean installation of the reciever hitch, but there were no structural changes to address the added loads.

All I'm trying to say is that if you are going to modify a engineered structure by adding unexpected loads, please do some homework on a routine basis & watch for signs of impending failure. The bulkheads on these busses were known to crack with out a trailer, so at least look for that.

Ignorance isn't as blissful as it used to be.

[zimtok]

I agree with you Kyle...

I think the receiver hitch added to the GMC was for pulling a car.
When pulling a car there is very little "tongue weight" the puling force is transferred to the main frame via the horizontal pieces added.



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