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#846 Cummins Swap.
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LCAC_Man
Posted 2019-05-13 11:15 AM (#6408 - in reply to #6405)
Subject: Re: #846 Cummins Swap.


Elite Veteran

5001001001002525
Location: Oceanside, CA
ricogomez - 2019-05-13 8:17 AM

I wish you could inspect our installation to help you save money on the installation,

It's a shame digital cameras and web posting images doesn't work in Texas...
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hemi354az
Posted 2019-05-13 5:17 PM (#6409 - in reply to #6408)
Subject: Re: #846 Cummins Swap.


Extreme Veteran

50025
Location: Scottsdale, Aridzona
Hey Terry,
Before you go any further with the 37" diameter Tires . . . you may want to check wheel well CLEARANCE in your FMC.
Are you planning on very smoooooooooooooooth paved roads where ever you go ? Ever travel across an unnoticed Speed Bump ?
Bounce ON ! Lou #120

Edited by hemi354az 2019-05-13 5:18 PM
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andy1canada
Posted 2019-05-13 8:17 PM (#6410 - in reply to #6404)
Subject: Re: #846 Cummins Swap.


Elite Veteran

500100100
Location: Victoria, BC. Canada
Actually don't feel 'boxed' at all Len.

Confident that if I address the torque converter and valvebody with this trans - as has been common knowledge over the years - that I will save myself a chunk-of-change on the transmission end of things.

The $1500 I'll save - not having to buy a standalone - will buy my Pacbrake.

Thanks.
Terry
#846
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andy1canada
Posted 2019-05-13 8:43 PM (#6411 - in reply to #6405)
Subject: Re: #846 Cummins Swap.


Elite Veteran

500100100
Location: Victoria, BC. Canada
I wish I could see your coach, too, Rico.

One day I will and am looking forward to it.

Thanks for the info.

Terry
#846
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ricogomez
Posted 2019-05-15 9:35 AM (#6412 - in reply to #6035)
Subject: Re: #846 Cummins Swap.


Veteran

100252525
Location: Houston, Texas
Hey Terry, we have an exhaust brake on ours and in my opinion is not that good, we can do much better with manually shifting our Allyson....
(I pressed reply while ago instead of submit)

Rico & Carmen
397
12 V & 6 Speed Allyson
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andy1canada
Posted 2019-05-18 6:51 PM (#6436 - in reply to #6035)
Subject: Re: #846 Cummins Swap.


Elite Veteran

500100100
Location: Victoria, BC. Canada
Sounds like you might have an issue with the exhaust brake set up maybe. Not sure what it could be. Can you control the lock-up manually? Apparently you have to be able to lock up the converter in almost all forward gears for it to work properly. Shame to spend all that coin and not have it work right. Is it a Pacbrake, BD or what? No warranty?

Hope you get it sorted out.

Scored me another 47RH trans locally. Will build it for a spare, regardless I won't need it - right Lenny?

http://www.fmcowners.com/mbbs22/photos/show-album.asp?albumid=191&p...

Ha-ha! Couldn't resist.

Terry
#846
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BigRabbitMan
Posted 2019-05-18 7:56 PM (#6437 - in reply to #6035)
Subject: Re: #846 Cummins Swap.



Expert

100010010025
Location: Cottage Grove, OR
Rico has a 6 spd Allison which has a tow/haul mode that locks the torque converter at all times except when shifting.
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ricogomez
Posted 2019-05-18 8:41 PM (#6438 - in reply to #6035)
Subject: Re: #846 Cummins Swap.


Veteran

100252525
Location: Houston, Texas
Hey Terry, because of lack of knowledge when ordering our Allison we consulted with CAC Diesel Conversion in Florida, and based on our rear end gears, vehicle gross wt, engine HP & Torque they recommended us to go with the medium duty lockup torque converter,
If I had known how good it was going to work and lock up, I would have saved a good chunk of mula and skipped the exhaust brake....

Rico & Carmen
397
12 V & 6 Speed Allison
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LCAC_Man
Posted 2019-05-19 8:14 AM (#6439 - in reply to #6438)
Subject: Re: #846 Cummins Swap.


Elite Veteran

5001001001002525
Location: Oceanside, CA
The exhaust brake will help Terry out more than us with the Allison...the small 47RH clutches will be overheated so quickly that downshifting won't have any effect...thankfully he'll have a spare 47RH that he can swap in while at a rest stop...of course we won't hear about that, we'll hear that he's getting 25mpg and setting Bonneville speed records.

Edited by LCAC_Man 2019-05-19 8:15 AM
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B. Sitton
Posted 2019-05-19 8:46 AM (#6440 - in reply to #6439)
Subject: Re: #846 Cummins Swap.


Extreme Veteran

100100100100
Location: Ignacio Colorado
Hmmm
My 94 Dodge 2500, no FMC but a 12 valve/47RH was purchased to haul cattle, yes bulls but not bullshit. Hard driving heavy loads no flat land crap. Top of the world. Red Mountain pass or Wolf creek pass. PAC BRAKE with the heavy “exhaust” valve springs, (don’t know why the intake springs would need changed as Rico has.
The PAC BRAKE rule is come down the hill in one gear lower than you go up. It works, good, no extra BS. No special way to keep the converter locked up. It WORKS.
Of course the ZOOM ZOOM BOOM club might not be satisfied but a real working truck has proven the cummins/47RH and PAC BRAKE for me.
Rico, do you run one gear lower on the way down than on the way up. They only work with some rpms!
Bill
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LCAC_Man
Posted 2019-05-19 8:52 AM (#6441 - in reply to #6440)
Subject: Re: #846 Cummins Swap.


Elite Veteran

5001001001002525
Location: Oceanside, CA
No argument that on a pickup with proper axle gears(the best pull with 4.10s) and tire size that set up will work really well; you won't get much use from overdrive while pulling a load (and that would simulate the FMC weight) but, put 37" tall tires on that same set up and the story is completely different.
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B. Sitton
Posted 2019-05-19 9:47 AM (#6442 - in reply to #6441)
Subject: Re: #846 Cummins Swap.


Extreme Veteran

100100100100
Location: Ignacio Colorado
Ok before we got the cummins we pulled the same loads and same hills with a 440/727. Both trucks have 4.10 gears.
The FMC with a 440/727 comes down the mountain and has fine engine braking with the 8r19.5 tires.
My apples to apples info on hauling cattle is seat of the pants. My FMC 440 info is seat of the pants. I haven’t driven a cummins powered FMC but have to rely on the seat of my pants.
My FMC Mountain driving takes time but not so much brakes. With a Chrysler transmission first gear and no brakes, Allison trans 2nd gear and no brakes. Watch the ZZB club fly by. Smell them later cause they are on a pullout with smoked brakes.
Wish I’d driven Rico’s coach in Chama.
Bill
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andy1canada
Posted 2019-05-19 9:52 AM (#6443 - in reply to #6035)
Subject: Re: #846 Cummins Swap.


Elite Veteran

500100100
Location: Victoria, BC. Canada
Ha - ha! Touche' Lenny! Had it comin' I figure.

One things' for sure, all this drive-line shite is a steep learning curve for a carpenter and I've barely twisted a wrench on my project yet. Also have to admit I'm confused some on this exhaust brake stuff after these testimonials.

It's been my understanding that because diesel engines are more so 'free-breathing' than gasser's - with their throttle-plate's to choke off air flow - henceforth you don't get the back-pressure in the cylinders to slow you when you back off the throttle. This said, I also have a Cummins/47RH pick up similar to Billy's (with no exhaust brake) and when going down moderate grades then hitting the overdrive lock out button to drop a gear, there is 'some' noticeable slowing from the lower gear, moreover, if it's a steeper hill yet and I'm not going too fast, dropping it into 2nd will slow it some more but not too much. The heavier the load, the steeper the hill, the slower I need to go - the more it becomes evident that more braking power is required. Like #4 Hwy to Tofino here on the Island. There's places on that road where you have no option but to 'stand hard' on the service brakes just to keep things safe, even after dropping the 727 down into 1st.

So, back to youse-guy's and your 'Ally's. I would like to clarify just what category of 'trans-braking' you are describing here? My understanding is that some Ally's are available with 'retarders' that are very useful for slowing down, but I'm not sure they are available on the 1000-2000 series Ally's, nor am I sure that is what you guys' are describing here.

Again, my understanding is that in order for an exhaust brake to work effectively - without damaging your engine - you need heavier exhaust springs - assumably to prevent 'floating' - and you need to control TC lock-up in as many (or all) lower gears as possible.

Goerend's take on this: "Why would someone want first gear lock-up? If you are mountain towing on steep grades under 10 mph locking the TC in first gear would keep the trans temp down."

"Do you or will you have an Exhaust Brake? With an exhaust brake, the VB needs to be capable of downshifting through the gears while the TC is locked to maintain engine braking. All Goerend VB’s are capable of downshifting 4-3 while locked, but not all are made to shift 3-2 while locked. So the Exhaust brake must be indicated so the VB can be built accordingly."

When I finally get the disc brakes on #846, an exhaust brake won't be an option, it'll be a savior for my service brake's and extend the useful life of the rotors many fold.

Any more feedback appreciated.

Terry
#846







Edited by andy1canada 2019-05-19 9:55 AM
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LCAC_Man
Posted 2019-05-19 11:31 AM (#6444 - in reply to #6443)
Subject: Re: #846 Cummins Swap.


Elite Veteran

5001001001002525
Location: Oceanside, CA
1000 series allison does not employ a "retarder" per-se it does have the tow/haul programming that changes the shift characteristics(maintains higher line pressure and firmer shifting) and allows for locked torque converter in the lower gears which makes the trans braking more effective(so the programming accomplishes some "retarder" functions) .
I personally plan to add an exhaust brake to my rig for when I'm towing(most of the time), the tow/haul is plenty for an unloaded rig, but when you're towing 5500-7000lbs a little more resistance would be helpful.
I would think that a pacbrake brake on a cummins would be very effective, you do have to ensure proper pressure relief exist but Pacbrake knows that and their most recent brakes have it built in. The limiting factor (again) will be that you'll be in probably second gear when you are using it, your torque converter won't be locked and will be working hard, you will need to spend your money on a very good torque converter..
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andy1canada
Posted 2019-05-19 1:16 PM (#6445 - in reply to #6035)
Subject: Re: #846 Cummins Swap.


Elite Veteran

500100100
Location: Victoria, BC. Canada
"All Goerend VB’s are capable of downshifting 4-3 while locked, but not all are made to shift 3-2 while locked. So the Exhaust brake must be indicated so the VB can be built accordingly."

Translation: you need to tell them (or, Revmax and/or a host of others who can build these) that you're running an exhaust brake so they can... "be built accordingly". Thus, yes, my TC will be locked and running cooler.

You are spot on though that the 'stock' 47RH did not feature a lock-up capability in 1st or 2nd gears. But it's doable.

From the Pacbrake site:

"Vehicles with 47RH/RE transmissions which have aftermarket valve bodies and aftermarket lock-up torque converters
which are able to hold lock-up during exhaust braking in 1st and 2nd gears can use the later 48RE programming.
To change the existing program within the Pacbrake control unit, simply locate the orange wire with a spade
connection approximately 6 inches from the control unit. Disconnect this connection. Turn the ignition ON. The
exhaust brake should cycle 3 times confirming the 48RE program has been loaded. The difference between the two
programs is that the 48RE transmission will allow exhaust braking in 2nd and 1st gears, where the factory 47RH/
RE transmission will not. Test drive the vehicle. If lock-up will not hold during exhaust braking in 2nd or 1st gear, reconnect
the orange wire."

Great info on that PDF!

https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=5&ved=...

Terry
#846
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LCAC_Man
Posted 2019-05-19 9:33 PM (#6446 - in reply to #6445)
Subject: Re: #846 Cummins Swap.


Elite Veteran

5001001001002525
Location: Oceanside, CA
Goerend builts excellent stuff, save your pennies, you'll be at $2500 just in a good converter, valve body and rebuild kit and that's if you do the work yourself..
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ricogomez
Posted 2019-05-20 10:12 AM (#6447 - in reply to #6035)
Subject: Re: #846 Cummins Swap.


Veteran

100252525
Location: Houston, Texas
Hey Bill, when changing the governor spring in the VE44 pump for more rpms, they recommended you to also change to 60# intake springs,
we haven't gone any higher than 24 - 2500 rpms so far.

Bill, you are welcome to drive our rig when we stop by to pickup our rear louvered door.

hey guys, I figured it out on how to load more pictures in our original album for our 397....
it was operator error and not a computer error....

Rico & Carmen
397
12 V & 6 Speed Allison
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andy1canada
Posted 2019-05-20 10:26 AM (#6448 - in reply to #6035)
Subject: Re: #846 Cummins Swap.


Elite Veteran

500100100
Location: Victoria, BC. Canada
Great news Rico! Really looking forward to seeing the pics.
Especially the part where you show us (okay me) how you stuffed a freakin' Cummins in the arse-end of an FMC!

Cheers,
Terry
#846

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andy1canada
Posted 2019-05-20 10:49 AM (#6451 - in reply to #6446)
Subject: Re: #846 Cummins Swap.


Elite Veteran

500100100
Location: Victoria, BC. Canada
LCAC_Man - 2019-05-19 7:33 PM

Goerend builts excellent stuff, save your pennies, you'll be at $2500 just in a good converter, valve body and rebuild kit and that's if you do the work yourself..


Yeah I hear you Len. Trans ain't no place to skimp.
Will also be looking around locally here on the south Island and Greater Vancouver area to what's available. BD and TCS are both based up here, too.

Terry
#846
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andy1canada
Posted 2019-06-01 12:21 PM (#6477 - in reply to #6035)
Subject: Re: #846 Cummins Swap.


Elite Veteran

500100100
Location: Victoria, BC. Canada
Check out these mo-fo's!

https://www.airbagit.com/Air-Springs-Air-Bags-p/baga-4400-triple.htm

Not sure how you'd fit em' in?

I bet Len - 'Mr. Fab-all' - could figure it out!

Terry
#846

Edited by andy1canada 2019-06-01 12:23 PM
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LCAC_Man
Posted 2019-06-02 7:32 AM (#6478 - in reply to #6035)
Subject: Re: #846 Cummins Swap.


Elite Veteran

5001001001002525
Location: Oceanside, CA
Nice heavy duty units but a bear to package...12" diameter makes locating them more of a chore (read=more fab work)
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andy1canada
Posted 2019-06-02 8:35 AM (#6479 - in reply to #6035)
Subject: Re: #846 Cummins Swap.


Elite Veteran

500100100
Location: Victoria, BC. Canada
Yeah, I hear you, but they would be - 'fab' ulous!

Jack that sucker right-up...

Terry
#846
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andy1canada
Posted 2019-06-02 9:31 AM (#6480 - in reply to #6479)
Subject: Re: #846 Cummins Swap.


Elite Veteran

500100100
Location: Victoria, BC. Canada
Was thinking about this air-bag business and thought while we're at it, maybe you (Len) and whoever else wants to contribute, that we might clarify a few things about them.

Truthfully, I don't know dick about them beyond the obvious: you use compressed air to raise/lower the attitude of the vehicle.

So, here's my question(s) stupid or otherwise:

- when a given airbag is rated to lift, say, 2500/lbs (x 2 = 5000/lbs), does that equate to being able to adequately support an additional 5000/lbs behind the rear axles, or, to put it another way, would it reduce that same weight (5000/lbs) on the rear axles (the OEM bearing-point) by transferring that weight rearward to the top of the bag-mount on the chassis?

- if, while considering the Cummins extra weight, a guy wanted to level the rear of the coach, or, actually lift the entire coach with an air-bag system to gain some ground clearance for certain driving conditions, what is the formula one would use to calculate your required bag-specs to do this? Would you simply match the front and rear GVW's with the same lifting capacity of air-bags on each axle, or, could you anticipate/calculate that a system with a lifting capacity of say, 50% of a given axles GVW would still provide 'X' amount of lift, just not as much as a matched GVW set up? This carpenter's-brain wants to understand this.

- finally, if a guy wanted to lift the entire coach, say 3" - what would be the limiting OEM suspension/driveline components?
We have a chassis-mounted diff with slip-yoke style propeller-shafts designed to allow a certain amount of lift/compression of the rear suspension; it's apparent to me that these yokes only have so much travel to full extension. What is that tolerance as it equates to raising the ass-end of these coaches? Suppose I should go out and have a look at the loose prop-shafts I have now. Would be some geometry involved and if anyone else has already figured it out - please do share.

As always, any and all input appreciated.

Terry
#846
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BigRabbitMan
Posted 2019-06-02 12:33 PM (#6481 - in reply to #6035)
Subject: Re: #846 Cummins Swap.



Expert

100010010025
Location: Cottage Grove, OR
Adding air bags behind the rear wheels transfers part of the weight of the coach from the frame at the pivot point of the torsion bars to the frame at a point behind the rear wheels. By transferring the support point rearward, the pivot/balance point of the body of the coach is shifted rearward and more of the existing weight is carried by the front axel and less at the rear.
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andy1canada
Posted 2019-06-02 2:43 PM (#6482 - in reply to #6035)
Subject: Re: #846 Cummins Swap.


Elite Veteran

500100100
Location: Victoria, BC. Canada
Well said Stephen; even I understood it.

My mind was around the axle's as the rear load point; forgot about the torsion bar tubes.
In reality, wouldn't the rear shocks take some of the load as well, therein shifting that point back some towards the axles?

Terry
#846
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