Transmissions

[5erFool (John)]

I am a newbie to this subject and this site so please be patient... I have been dickering with a man for a '96 Ford F-700 and '93 Kountry aire 40' 5er for the last 2+ years.We finally came to an agreement on price and although it was very difficult to determine a price for the truck when we did I was suprised how low it was..Now after that premble here is the problem..
The truck is a day cab so the seat sits bolt upright.. not good for my old back... and the fuel pedal forces my toes to get overly friendly with my shin... causing severe pain to the knee and etc...so I am convinced I need at least an extended cab..guess my pickup has me spoiled... also the transmission (10spd spicer) is a pia to use.. I learned quickly that is does not seem to be familiar with syncronizers.. I havent driven a square cut tranny since my '61 studebaker lark... double shifting is essential for any shift .. up or down.. love the air brakes etc but that tranny ssstinks...do all the larger trucks have that tranny... when I drove a beer and coke truck back in the late 70s I don't remember having any trouble with the tranny..I prefer to shift gears myself but not like that... it was a challenge... I drove it for a couple of hours and just barely became able to upshift without grinding..(85% maybe).. not my idea of fun.. I hate to go to an automatic but if that is the only choice ... ok..any comments or suggestions.??
thanks
JOhn

 

[Gary Atsma]

John my man, you're justy gonna hafta learn to "float the gears", which means shifting without a clutch. Anyone can do it. As you accelerate, when you want to shift, lift on the throttle, slip it out of gear, let the RPMs drop the right amount, thren slip 'er into the next gear. With a little practice and common sense, you'll have it down in no time. And contrary to what the truck school types may say, this is actually easier on the tranny and saves the clutch, as you are shifting with no load on the tranny as long as you're off the loud pedal. Try it, you'll like it! Gary

 

[Warpath-TC]

John -

It sounds like you had the same experience I did 2 years ago when I picked up my Freightliner. After a few weekends of practice I was able to shift 1/2 way decently. After a year of use (about 7,000 miles of which was highway so no practice there) I float all shifts, down shift great with the help of this devise www.gearmaster.com (this will make learning to shift a non-sycro trannie a snap) and have been on some brutal inclines to start from. The key is to put some seat time in.

Bill

2003 28' Show Hauler Motorhome on a 1995 FL 120 www.showhauler.com

 

[5erFool (John)]

Thanks for the info guys.. guess I shouldn't post after working all night and surfing all morning.. listed post under "for sale".. oops.
double shifting instead of double clutching?... oh well you got the point.. anyway I did not buy the truck and I am now convinced of the class 8 conversion being what I need... 20k gvw trailer... now all I have to do is wipe a few more posteriors so I can afford it... ok lots of posteriors...oh sorry to those of you who do not know I am a nurse... from what I have been studying "floating" in a big rig is akin to powershifting a drag car.. not that I ever did that in my younger years...I can learn to do that..thanks again
John

 

[onezman]

5erfool

I used to do a little drag racing myself. :0) Powershifting is keeping the throttle pedal on the floor, clutching and shifting as rapidly as possible. (if you miss the shift, you may be picking up expensive pieces).

Float shifting is a matter of RPM, road speed and timing. Float shifting is done with little or no throttle applied, and much more slowly.

Upshifting, depending on the engine, one must wait for the RPM to drop around 300 RPM. Downshifting is exactly the opposite. RPM must be increased by 300 RPM for each downshift (if road speed is constant). Generally you will be slowing during downshifting, so you'll only need to increase RPM by 100 or so.

onezman

http://onezman.tripod.com/yourrvhaulercom

 

[madbrit]

I am changing out my 9 speed Rockwell for an Allison HT 740. With the Series 60 in my Freightliner FLD 120, it will do a perfect job even pulling my 10K trailer, total truck and trailer grossing at 40K lbs.

I had Allison run a SCAAN using either the 4 speed or 5 speed (HT 750CR) and the 4 speed worked out better for highway use. I am changing the rear end from a 3.91 to a 2.80 ratio to compensate for the lack of overdrive. This was also figured into the SCAAN.

Apart from my back not liking the extra heavy clutch in my trcuk, my wife is not a happy camper with the thought of driving it. That's not to say she won't, she would prefer to drive the auto. I would have loved to instal a World but they are hard to find and very expensive when you do find one. That's not including all the electronics that have to go with it and which have to be adapted to fit my 1994 truck.

Peter.

 

[Warpath-TC]

Peter -

It sounds like are trucks are close. Mine is a 95 FLD120 with Cummins M11 Eaton 10 speed OT and 3.91 rear end.

So how much??????

I initially looked into the HT 740 and without a core my first quote was around $6,000 plus install. Since this would only get me to about 55 mph with present rear end I stopped there.

I have since found a few companies selling HT 740's, but don't recall if they had been rebuild. I think I saw somewhere that Allison was rebuilding them as well.

Any additional info would be appreciated.

Bill

2003 28' Show Hauler Motorhome on a 1995 FL 120 www.showhauler.com

 

[madbrit]

Bill,

My Freightliner has a Series 60 11.1 liter, set at 350/365hp and with the speed limiter at 65mph. When I get down there, I am going to have the Phoenix Detroit dealer run some tests and possibly reprogram it for max hp and torque, but I think it is pretty much there as far as I can find. I am purchasing a Pro-Link 9000 so I can read faults and reset any computer codes and also reset that speed limiter.

My present search is for a used transmission. They can be bought from around $1000 and up, but I am trying to find one in an old vehicle which is or at least was running recently. Will make locating some of those "also need" parts a lot easier. Wrecking yards are quoting around $2500 - $3000, or I have been offered one rebuilt for $3500 with shifter and cooler. Best to find one that has come off a Detroit to start with as I have been advised that other parts may need to be bought if it was originally on another motor.

We will install it ourselves, if it proves too heavier a job, then I will look at having only the trans installed at the local Detroit service center. They are far too busy to mess with my sort of project, too many breakdowns on the I-40 to attend to, so we would do all the connecting up of shifter and cooler, plus sorting out the modulator connection.

I had been warned off a few rebuilders, but it turns out it was more their "conversion" work that was not good and so since they are still in business, they must do a reasonable rebuild job. Still, a 740 is only a big Turbo 400 and we have rebuilt a few of them....... LOL.

The 55 mph was not a feature I wanted either and my 3.91 Rockwell rear end has the ability to be changed to a 2.80, even though I will probably have to purchase another carrier and the gears new. This was quoted at around $2,000 for the whole job including parts, but I will look for a used one first.

I did think of using the 5 speed HT 750 CR, but it was so hard to find one other than a rebuilt unit and they wanted a bunch for the core charge. The other problem was that people didn't know which 750 they had. The DR is the one with the low first and then similar ratios to the 740. The CR has the same first and top gears as the 740 but 3 intermediate gears instead of the 740's two. After looking at the SCAAN from Allison, it appeared that the 4 speed might actually have better ratios. Of course, only an actual road test will prove this one way or the other. The other thing to possibly avoid is the electronic transmissions such as the 741 and 748. They are controlled by solenoids and another computer. The guy at Allisons said he would avoid them, especially if you did not know which one was a "good" version, apparently there were some problems with early units, so best to stay with the mechanical/hydraulic 740.

I did find an old model Allison called an HT70 which is a 6 speed with overdrive, however it does not have the rating for the torque of a Series 60. That being said, I have seen it behind a 450hp 8v92. The HT70 was reckoned to be so tough that Allison discontinued it as it rarely broke.

That's where I am at the moment, if you need anymore info, feel free to ask as I may have already covered it.

Btw, how do I post pics on here? I would like to be able to post some as the conversion progresses if that is acceptible.

Peter.

 

[Warpath-TC]

Peter -

You can post your pictures in the photo gallery, it's really easy to use.

My M11 is a 11.1 liter set at 350 hp 1800 ft pounds of torque at 1600 rpms. My torque rating seems to be giving me fits when it comes to automatics. My rig also has the 65 mph limiter which I have yet to get reset.

Absolutely keep me posted as you go forward with this. I don't think I will be doing this to mine, but you never know. After getting a years worth of use on my rig, I really don't mind the 10 speed and rarely use the clutch other than starting and stopping. Also my clutch is very easy so even with my bad back I haven't had any trouble.

One thing I may look at is the Super 10 if my trannie where ever to give me problems. That would drop my shifts to 3 and that would be great.

Bill

2003 28' Show Hauler Motorhome on a 1995 FL 120 www.showhauler.com

 

[onezman]

Hi Bill,

I think 1,450 ft pounds is the max torque avaliable on Cummins M11s. Cummins can reset your ECM to owner operator specs for about 1/2 hour labor charge. this includes removing the governor, and increasing max RPM to 2,100. You can get a printout of the engine history of the at the same time.

I don't know a thing about the transmission you guys are discussing, but before installing any different tranny, make certain the tranny's torque rating meets or exceeds engine torque output.

onezman

http://onezman.tripod.com/yourrvhaulercom

 

[madbrit]

Onezman,

The trans I am using is an Allison HT 740 and is quite capable of handling the HP range of 365 and the torque of 1350 ft/lbs from my Series 60. It is found mainly in Greyhound buses and similar alrge vehicles and attached to 8v71, 8v92 and smaller diesels such as the 6v92.

I am sure that the M.11 has similar figures to my 11.1 liter Detroit, unless it has been hopped up.

Peter.

 

[onezman]

Madbrit and Bill,

Before committing to buy the auto, I would find out what, if any modifications or adaptations will be be required for this type of installation. You may have to lengthen or shorten the driveshaft as well, unless the auto is the same length as the factory tranny. Will another crossmember be required? Tractor transmissions generally weigh in excess of 600 pounds. I suspect the auto may be even heavier. A transmission jack will be required if you make the switch yourself.

onezman

http://onezman.tripod.com/yourrvhaulercom

 

[madbrit]

Onezman,

Have no fear, I have researched this transmission swap and the automatic weighs in at 900 lbs. I don't doubt that the driveline will need modifying, even the UJ may be a different spec. I have a trans jack that can support it, BUT if I feel that it could be too much of a pain, I will have a local shop do the basic install and tow it home for the final hook-ups. It is really whether I can slide it under with enough room to have it already on the trans jack. Other than that, I will have to raise the truck for the necessary clearance. It's only a big Turbo 400 anyway........LOL.

They say that the trans can quite comfortably hang on the rear of the engine without additional support, however, I will judge that for myself when it is installed. The manual does not have a seperate mount and in fact, the auto would be putting less strain on things, being that it would be a lot smoother without the clutch or shifting on/offs in the driveline.

Peter.