GMC 4104?

[Mr. Breeze]

We have been looking at 4104's and wanted to know, what engines came in these buses?
Was it one engine size in particular? or a couples of different models?
If it was more than one model, what was the best engine?

Also, what are some specific items to look for when checking out a bus?

Thanks for your help!

[luvrbus]

4104's had a inline 6-71 engines John

[Mr. Breeze]

4104's had a inline 6-71 engines John

How are they performance wise, going up hills and such?

The bus we looked at had the vin # PD-4104-4532

Thanks for your reply.

[luvrbus]

They faint at the sight of a hill most are not bad on fuel 8 to 10 mpg  a DDEC inline 6-71 makes a rocket out of the 4104 I am building a DDEC 6-71 for a friend to install in his 4104 this summer and we are shooting for 400 hp why he wants 400 hp is beyond me I guess it is one of those mine is bigger things lol me I would not spend the money he is going spend on a 50 year bus for a re power

good luck

[gusc]

That is a very late model, mt '53 s/n is 1274.

671 as originally installed works fine, third or second gear on serious hills but it gets there.

Good fuel mileage, 8-10 on mine.

Great buses. Only reason I got my 4107 was for AT and fulll-time PS, otherwise I would have kept driving it.

[Mr. Breeze]

That is a very late model, mt '53 s/n is 1274.

671 as originally installed works fine, third or second gear on serious hills but it gets there.

Good fuel mileage, 8-10 on mine.

Great buses. Only reason I got my 4107 was for AT and fulll-time PS, otherwise I would have kept driving it.

Please forgive me, but I am new to buses and the lingo.
If I may ask, what does mt '53 s/n is 1274 mean?

[siberyd]

Mr. Breeze,

I believe he's saying - he has a 1953, S/N serial number or VIN is interchangable here 1274. He has an early model of the 4104.

The rig you are looking at is a 1960.  1960 was the last model year.  They only made 5,065.

Welcome to the world of 4104's

[siberyd]

Mr. Breeze,

Is the bus already converted or a shell?  Also what state is it in?

I am the crazy bus nut trying to track down the where abouts of all 5,065 - 4104's ever made.

[RJ Long]

Mr Breeze -

Info on original owner of 4532 is posted in the other thread for you.

With the 4104, reflect for awhile about Aesop's Fable "The Tortoise and the Hare."

Drive one with that mindset and you'll be a happy camper.  Try to drive it like a car and you'll be very frustrated.

You will not find one with an automatic in it unless it's been repowered, otherwise you get your choice of 4-spd stick, 4-spd stick or a 4-spd stick.  All crash boxes w/ no synchronizers, thus double-clutching is the norm until you get several thousand miles under your belt.

All 4104s were delivered from the factory with the inline 6-71 Detroit Diesel - a virtually unbreakable engine when treated correctly (i.e.: don't lug it, don't overheat it, and use the right engine oil - NO multi-viscosity, straight 40wt only.)

If the coach still has it's rear windows, and said windows are cracked, be aware that the glass is currently being made from unobtainium, and has been for over a dozen years.

Clifford -

If your friend really wants 400hp, encourage him to buy up every 4101, 4102, 4103 and 4104 transmission he can get his hands on, because he could easily blow out the bevel gears w/ that much hp.  That's why GM moved the bevel set when they introduced the V-8 models.

FWW & HTH. . .

 

[tdh37514151]

RJ is hit the nail on the head. You can also use the PD4151 and PD3751 transmissions although the gear ratios of first, second and third are slightly different from the 7141a transmission used in the 4104. None of these transmissions will stand
400 H.P. and neither will the cooling system in the 4104. Its questionable how long the 671 would last producing 400 H.P. There were some turbo LA671T engines built from the factory used in buses that dependably produced 275H.P. and if the driver used that amount of horse power with some restraint the transmissions would probably give satisfactory performance life.     

[luvrbus]

Now guys I have installed 2 DDEC 6-71 330 hp setting in 4104's it hasn't been a problem yet set the DDEC rating right hp is not going to hurt one get the torque setting to high different story,lots of 4104 have a 6V92 upgrade at 350 hp they are doing fine the 4 I know of anyway

good luck

[tdh37514151]

Horse power multiplied by the gear ratio reduction through first, second and even third gear mean tremendous torque applied to the bevel gears as they are on the out put side of the transmission. Its not that it can,t be done and work ok but it really does depend on the driver and his or her ability to understand the weaknesses of the drive line and how their diving habits can effect them.

[Mr. Breeze]

Mr. Breeze,

I believe he's saying - he has a 1953, S/N serial number or VIN is interchangable here 1274. He has an early model of the 4104.

The rig you are looking at is a 1960.  1960 was the last model year.  They only made 5,065.

Welcome to the world of 4104's

OK, that makes sense now. Thank you!

Mr. Breeze,

Is the bus already converted or a shell?  Also what state is it in?

I am the crazy bus nut trying to track down the where abouts of all 5,065 - 4104's ever made.

This bus has been converted. It will need a good portion of the interior removed along with flooring they put in.....basically rebuild the entire inside. I have a feeling this interior was a private conversion (because of the quality of work/materials) and not done by someone with skills.

We were told it will need a new head and at this time, there is also a title issue which needs to be dealt with.....seems to have to many problems.

We have thought about getting this bus, but it is last on our list because we found another bus that is running and is somewhat converted. This one will also need the inside redone, which we have no problem doing ourselves as I have the equipment and skill to do the entire inside.

When we go back to see her, I will get the vin number for your records. I am pretty sure we will be purchasing this bus.
I really don't like buying a vehicle that doesn't run, especially one of this caliber.

Bus is located In Phoenix Arizona.

[Mr. Breeze]

Mr Breeze -

Info on original owner of 4532 is posted in the other thread for you.

With the 4104, reflect for awhile about Aesop's Fable "The Tortoise and the Hare."

Drive one with that mindset and you'll be a happy camper.  Try to drive it like a car and you'll be very frustrated.

You will not find one with an automatic in it unless it's been repowered, otherwise you get your choice of 4-spd stick, 4-spd stick or a 4-spd stick.  All crash boxes w/ no synchronizers, thus double-clutching is the norm until you get several thousand miles under your belt.

All 4104s were delivered from the factory with the inline 6-71 Detroit Diesel - a virtually unbreakable engine when treated correctly (i.e.: don't lug it, don't overheat it, and use the right engine oil - NO multi-viscosity, straight 40wt only.)

If the coach still has it's rear windows, and said windows are cracked, be aware that the glass is currently being made from unobtainium, and has been for over a dozen years.

Clifford -

If your friend really wants 400hp, encourage him to buy up every 4101, 4102, 4103 and 4104 transmission he can get his hands on, because he could easily blow out the bevel gears w/ that much hp.  That's why GM moved the bevel set when they introduced the V-8 models.

FWW & HTH. . .

 

This is so cool, thank you so much for providing this info for me. I don't think we will be purchasing this bus because it has some issues and I really don't want to deal with them, although the bus has many amenities, it is had to walk away.

I will be sure to post the VIN of the bus we think we will be purchasing.

Going slow up hills is no problem by us....all we have is time

Again, thanks for your help!

[Mr. Breeze]

Now guys I have installed 2 DDEC 6-71 330 hp setting in 4104's it hasn't been a problem yet set the DDEC rating right hp is not going to hurt one get the torque setting to high different story,lots of 4104 have a 6V92 upgrade at 350 hp they are doing fine the 4 I know of anyway

good luck

Hey luvrbus, did you get the PM I sent to you?