Automatic trans in a PD4104??

[straycatboat]

I am looking at purchasing a PD4104 and it has everything I want but an automatic transmission.
Its a 4 speed.
Can an auto be installed in this unit or should I look for a 4106?
Thanks for looking.

[chessie4905]

There was just recently an article about one that had an automatic installed. Apparently it worked ok. You will loose 2 to $ mpg though and draining even more power from the somewhat low powered, by today's standards, 4104. I wouldn't recommend doing it unless you turbo the engine, and we're talking serious bucks till you are done. You could find a 4107 or 4108 that already has one.

[DoubleEagle]

A lot depends on how much you have to spend, and how much the 4104 costs compared to all the other coaches with automatics that are for sale. Buying one with a manual, and then changing it, will cost much more. My first bus had the four speed Spicer, and I drove it all over the East and West, but my second bus has the Allison. If you think you can handle the manual, and you particularly like that coach, that will be more economical, but it will be harder to sell if you ever decide to part with it.

[straycatboat]

Whats the differences between the 4106, 07, 08?
Thanks

[DoubleEagle]

Whats the differences between the 4106, 07, 08?
Thanks

To quote a post from 2002 by R. J. Long (who knows the GMC buses quite well, an understatement) is the best I can do help you:

Posted on Friday, April 19, 2002 - 12:47 am:      


"4101 - 4103: First of the 41 passenger series, built from 1948 thru 1952. Steel spring suspension, small baggage bays, small windows. Nearly impossible to find replacement windshields.

4104: Industry workhorse for nearly 20 years. 5,065 built between 1953 - 1960, a number not surpassed until the MC-9. First highway coach with air suspension, now the industry standard. Used a pony engine to power the A/C. 6-71 inline DDA w/ 4-spd manual gearbox, virtually unbreakable when properly maintained. Top speed about 65, but will run "sittin' on the governor" all day long at that speed. Mountain terrain requires lots of shifting, figure 30 mph in 2nd gear on 6 & 7% grades. Automatics can be installed, a major project far outweighing the resale value of the coach, and best accomplished with an entire powertrain upgrade, including a rear axle swap due to different pumpkin offset. That so many have survived today is a testament to GM's engineering and construction capabilities.

4106: The "next generation", basically an updated 4104. Different front/rear caps, larger side & rear windows, V-8 power, elimination of the pony a/c engine, different (and awful) dash & controls (A cost-saving measure by GM - they borrowed heavily from the transit bus dash's parts bin. Howls of protest by industry prompted change with the 4107.) Affectionately known by long-time bus folk as "the sports car of buses" due to it's light weight, V-8 4-spd powertrain, and good handling. Decent fuel mileage, too. 3325 built from 1961 - 1965, didn't really sell in quantity like the 4104, as the industry began to shift to 40-footers.

4107: The first of the hi-deck "buffalo" buses, so named for the "hump" on the roof. GM's response to industry requests for more baggage space to handle the increasing parcel express services being offered. First three rows of seats are, to use a current term, "stadium seating", then the floor levels off. (This creates interesting challenges for converters.) Same powertrain components as the 4106, matter of fact, GM kept this layout right up until the end of highway coach production in 1980. 24v system, vs 12v on previous models. As already mentioned, HUGE baggage bins, and the first coach to use pantograph-style bin doors. Built from 1966 thru 1969, only 1265 produced, further evidence of the shift to 40-footers.

4108: Virtually identical to the '07, mostly just trim changes and a different dash, one very similar to the 4104, actually. (Industry was happy about that - the '04 has a nice industrial dash.) A few other components were relocated for better servicability, as well as interior upgrades. Built both as a PD4108 and a P8M4108A (no real difference other than the numbering nomenclature), a total of 297 were built from 1970-1978, making them the rarest of the Buffalos, and the last of the 35' GM highway (or Parlor) cars.

The 4903 and 4905 series are really the same coach as the 4107/4108, but have five feet more wheelbase and another baggage bin. Longest wheelbase of any 40-foot highway coach built, and longer than some 45-footers, yet they'll turn tighter than an MC-9! That long wheelbase contributes to one of the finest rides out there, and they're extremely comfortable to drive, too.

All of the GM buses, btw, have no frame to speak of. The exterior skin is the frame of the coach, just like an airplane. Don't even think about slide-outs, and raising the roof is a challenge, as the roof helps support the engine.

Might I make a suggestion? Before you plunk down your hard-earned $$$ on a bus, spend the money on a couple of books by Larry Plachno, the editor of National Bus Trader, an industry rag. "Modern Intercity Coaches" and "Beginner's Guide to Converted Coaches" are the two titles, both available from Amazon.com or www.busmag.com. Well worth the expense, may actually be the best money you'll spend on your bus!

HTH,

RJ
PD4106-2784
Fresno CA"

[straycatboat]

Thanks for the response. I have both those books as I was going to convert one myself , but chickened out and bought a finished mc-7 which I had for a few years before getting out of RVing.
Now looking again, but don't want a 40' bus 30-35 is perfect for us.

[harleyman_1000]

I have a 4104 with a automatic transmission and a 6v92 engine installed. It also has a T drive. I am thinking now on selling it due to my health.

[luvrbus]

I have a 4104 with a automatic transmission and a 6v92 engine installed. It also has a T drive. I am thinking now on selling it due to my health.

Most do sell for health reasons "you get sick of working on it" just kidding Scott 

[DoubleEagle]

I have a 4104 with a automatic transmission and a 6v92 engine installed. It also has a T drive. I am thinking now on selling it due to my health.

You have a well-equipped handsome 4104, if I didn't already have two Eagles.... How much are you thinking of asking for it?

[harleyman_1000]

Not sure what it's worth to be honest with you? I figured I would ask you bus folks Not sick of working on it but need to get something smaller that I can travel in more easily with a gas engine

[DoubleEagle]

You might be a candidate for a swap. There might be someone out there with a gas engine smaller RV that is looking to trade up to a bus. You have the advantage of having an automatic in yours compared to many other coaches of your era. You just have to advertise in the right places. The value of your coach is a very difficult judgement, you rarely get back what you put in to it. Compared to others for sale now, I would estimate somewhere between $10,000 to $20,000, depending on actual inspection. Newer coaches with the same engine/trans have sold for similar amounts. 4104 fans will likely jump in soon.

[straycatboat]

NC bob I tried to PM you but it did not go through

[straycatboat]

Not sure what it's worth to be honest with you? I figured I would ask you bus folks Not sick of working on it but need to get something smaller that I can travel in more easily with a gas engine

Pm sent

[harleyman_1000]

My number is three 14-755-0808

[Geoff]

Scott

You have a virus on your photo bucket page.

--Geoff