Switching from Manual to Automatic?

[Bryan]

Hey guys, I'm really just curious to know from some of you experts. What is involved in switching a manual to an automatic transmission? Is it even possible in a 4107? Do I have to purchase a used transmission? Or can I buy one new? What type of costs would be involved... parts and labor? Thanks! 

[uncle ned]

Bryan 

I think you need to call Gene Russell   at Russell diesel   in Mill Spring NC.   just east of ashville.

He would be the person to talk about that change that is close to you.

A trip up is a day well spent just talking to Gene.

uncle ned

[luvrbus]

It is going to be a lot cheaper on you to buy a 6v92TA from a V drive transit bus with the transmission than try and piece together a system IMO you will have more power and less smoke and the cooling requirements are not much different between the 350hp 6v92TA and the 270 hp 8v71

[Runcutter]

Bryan, check your PM's for one from me.

Arthur

[Bryan]

Thanks guys! I'm actually only 2 hours from MillSprings so I could run up there and talk with Gene. Do you have any ballpark idea of the costs I'm looking at for a swap?

[Runcutter]

Bryan, I'm putting a packet of information in the US mail today.  It's an article that JLV sent me when I was planning to do this to our 4107, and a list of parts that I'd purchased for the project from Luke Bonagura.

I understand that automatics were an option from GM in the later production of the 4905/4108, and that the options were a VS-2, or a V-730.  I don't know, but suspect a V-731 would also work (I don't recall the difference between a 730 and a 731.  With a sideways engine, V-drives are the only option without major surgery -- but some have installed new in-line powerplants, extending and modifying the rear of the coach for the necessary added length. 

There have been a lot of discussion on this board about the relative MPG between stick and automatic.  If I can summarize what I recall from them, think of a loss of maybe 2 MPG with an auto.

Arthur

[luvrbus]

The 731 is electronic ATEC transmission   cooling is the major problem with both the 730 and 731 doing the switch in the GM, very doable with the right parts

[TomC]

I have a transit bus-that were designed for stop and go-mainly cooling down at each stop. I had my radiator increased in size to the maximum. But since I also increased my heat load with going from 65 to 75 injectors with air to air intercooling, I still have heating problems on long pulls on over 90 degree days. Hence, I have 15 misters with 2 drilled out with 1/16" drill (really puts out the water).
I also have taken the stock oil to water trans cooler and added an auxiliary air to air cooler with thermostatically controlled fan. The trans fluid comes out of the trans and goes through the air to air first to take much of the heat out before going through the oil to water shell cooler-hence taking more heat away from the radiator. All has worked well now for 5yrs. Good Luck, TomC

[kingfa39]

 I put a 730 in my 4106, big mistake in my opinion, top speed was reduced 5-to 10 mpg, engine ran hotter, and fuel mpg reduced at least by 3, the cost was 4000.00. would never do this again and would not have done it had I known all the facts before hand. 4106 speed reduction to 76 mph, had the high speed rear end before installation, part of the bulkhead had to be cut away,if you can live with these things go for it , the plus side is it is much easyer to drive, on a long climb attn. to temp is a must, with standard 10+ mpg as opposed to 7, stand top speed not known but was still climbing at 80 when I got out of the throttle. after V-730 76 top speed. 4107 if im not mistaken has the slower rear end making these problems even worse. another thing is I never had a problem with the v-730, it did a good job, had it rebuilt before installion
Frank

[Gwaltnak]

What is the max power you can put through a v-730 / V-731?

[uncle ned]

I have 2 4104's

1 with the 6-71 and 4 speed.
1 with a 6v92 and v730

Guess which one i drive all the time.

If you are worried about the reduction in final drive use the tallest tire you can find.
I run 11r 24.5 hancooks.  Have no trouble running down the road with the trucks.
If I feel like it and want to use the fuel I can run in the fast lane and pass all of them.
listen to RJ the bus guru about gearing and tires.
If I want decent fuel milage i run the blue roads and keep the rpm's at about 1100
and get decent milage.
have no trouble keeping it there on most hills.

I have been in parks withe the 4 speed and have a hard time just getting out of some of them and this is in the eastern mountains.

With the v730 all of the worries about starting on hills and burning clutches are gone.

so I do have some heating problems but i also have big injectors and plenty of power.

love the combination.

uncle ned

[RJ]

Listen to RJ the bus guru about gearing and tires.

Thank you, Ned, for those kind words.  They are appreciated!   

RJ

[Gwaltnak]

I have heard of this document several times... Throne that has all the parts and stuff, who has copies of this? And would you be willing to share it again?

[TomC]

A V730 is a HT740 (the most rugged trans ever made-it is the basis for the M1A1's transmission) without 1st gear. My engine puts out 375hp and 1125lb/ft torque and it shifts fine. Course, I don't have to drive with my foot on the floor very often either. Good Luck, TomC

[luvrbus]

The RTS used the V730 behind the 350 hp 6v92 it never gave any problems