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Thread: Allison Sun coast kit?

  1. #1
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    Default Allison Sun coast kit?

    Please forgive me, if this is a dumb ? Or it has been asked more times than it needs to be. But have not find it searching.
    To start off, I have a 2005 Chevy Kodiak C5500. That had a 2000 5.9 24 valve RV motor hooked up to a 5 speed Allison 5.13 rearend on 225/70R-19.5 tires and wheels. The trans has the Sun Coast 6th gear kit added to it. Pulling 16,000 lb 41ft long 13.3" tall 5th wheel camper. It does a good job, but does not down shift until 40 MPH. When your pulling a big hill, it does pull good. But it needs to down shift at a higher speed. Or feels like it to me. As by the time your down to 40 MPH. And it drops to I sure its 4th gear rather then 5th. Is this normal or just a bad tune that has been running for 35,000 miles?
    The trans has a stand alone box for it and EFI live tune. If anyone is in West Tn Middle Tn North ms or North Al and can tune these. Please let me know and would love to get it turned where it down shifts into 5th gear to help out pulling.
    Pete

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    So guess no one here knows how these should shift? If I have to would put a different stand along controller on it to get it to work right. Do the newer 6 speed trans down shift from 6th to 5th gear when pulling hills?
    Pete

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    What RPM is the WOT downshift happening?. A 6 speed allison does grab 5th under load but they are very closely spaced ratios.
    2005 Cummins - EFILive Conversion - S474 single - 1325hp on the spray.

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    Lifetime Member IdahoRob's Avatar
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    If this conversion has a Suncoast TCM 6 speed conversion in it like your post suggests, then it is most likely locked from tuning. Contact Suncoast or the company that did the install to see if changing the TCM shift parameters is possible.

    Impossible to say if what you are feeling is normal as this conversion is not normally done or experienced.
    2013 LML, 550hp with factory emissions, stock cp4 and compound turbos.
    2002 LBZ, 4x4 (Max'd Out) 6000lbs 9.36 @ 154 mph NHRDA Champion and Record holder
    1965 El Camino, duramax 9.6 @ 149MPH

    All EFI tuned by Adrenaline Truck Performance

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    Can't say for sure on the RPM's but its round 40 MPH. So would say 1500 RPM's, but its more like its dropping to 4th and skipping 5th gear. But I agree being 0.61 for 6th and 0.71 for 5th not much difference there.
    Will have to look in the paperwork the shop that did a lot of the build is east of Nashville Tn. So if its locked may be cheaper for me to just add a different box to run it? If I can get one buy its ran by EFI tunes I do remember that.
    225/70R19.5's 5.13 rearend and 0.61 top gear is how its geared. And does a good job just needs to drop out of 6th sooner when pulling hard. Also this trans will free wheel, where the same trans but without the suncoast kit in my 2004 2500HD would not coast. And would rather have this one not coast. Exhaust brake works and keeps it from coasting. But the trans in the 2500HD would bring our 16,000 lb camper down a 6% grade with just the trans.
    Pete

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    Lifetime Member THEFERMANATOR's Avatar
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    Quote Originally Posted by wildwolfproducts View Post
    Can't say for sure on the RPM's but its round 40 MPH. So would say 1500 RPM's, but its more like its dropping to 4th and skipping 5th gear. But I agree being 0.61 for 6th and 0.71 for 5th not much difference there.
    Will have to look in the paperwork the shop that did a lot of the build is east of Nashville Tn. So if its locked may be cheaper for me to just add a different box to run it? If I can get one buy its ran by EFI tunes I do remember that.
    225/70R19.5's 5.13 rearend and 0.61 top gear is how its geared. And does a good job just needs to drop out of 6th sooner when pulling hard. Also this trans will free wheel, where the same trans but without the suncoast kit in my 2004 2500HD would not coast. And would rather have this one not coast. Exhaust brake works and keeps it from coasting. But the trans in the 2500HD would bring our 16,000 lb camper down a 6% grade with just the trans.
    Pete
    For starters it is impossible for the trans to drop from 6th to 4th, it would have to go past 5th on the way due to how the trans and valve body work. There is no way for the valve body to skip over a gear. It can go through it fairly quickly, but not skip over it. And we need ALOT more info on your setup to even BEGIN to help you. Does it use a PCS XFI as the gateway, or is it direct wired to the TCM. Does it it have tow/haul mode or not? So many questions here. And if your using the PCS XFI from DESTROKED as the gateway, join the club of people who they haven't worked correctly for. There has been MANY people who have had problems with shifting with the PCS XFI not relaying correct throttle input to the TCM. Also need to know if it uses a AL5 1st gen TCM, or does it use an A40 GEN IV TCM? If it uses the AL5, does it have a SUNCOAST, SOCAL, or killerbee 6 speed calibration in it? Does it use a 06+ 6 speed valve body, o does it have an 04-05 valve body with the 6th gear tube added in?

    This is the real problem with swaps like this as you really don't normally know what all is in it, and thus can't always get it all to work together.
    1995 GMC 2500 SUBURBAN powered by 01 DURAMAX/ALLISON, little of this, a little of that,
    DIAMONDEYE 4" exhaust, CORSA muffler, AFE stage 1 dry filter, custom tuning by me, KENNEDY single pump and pump rub kit.

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    Quote Originally Posted by THEFERMANATOR View Post
    For starters it is impossible for the trans to drop from 6th to 4th, it would have to go past 5th on the way due to how the trans and valve body work. There is no way for the valve body to skip over a gear. It can go through it fairly quickly, but not skip over it. And we need ALOT more info on your setup to even BEGIN to help you. Does it use a PCS XFI as the gateway, or is it direct wired to the TCM. Does it it have tow/haul mode or not? So many questions here. And if your using the PCS XFI from DESTROKED as the gateway, join the club of people who they haven't worked correctly for. There has been MANY people who have had problems with shifting with the PCS XFI not relaying correct throttle input to the TCM. Also need to know if it uses a AL5 1st gen TCM, or does it use an A40 GEN IV TCM? If it uses the AL5, does it have a SUNCOAST, SOCAL, or killerbee 6 speed calibration in it? Does it use a 06+ 6 speed valve body, o does it have an 04-05 valve body with the 6th gear tube added in?

    This is the real problem with swaps like this as you really don't normally know what all is in it, and thus can't always get it all to work together.
    The main reason i never did this conversion is they lock the tune. I Refuse to lock tunes or play those games. I won't have a locked tune in my truck

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    Quote Originally Posted by THEFERMANATOR View Post
    For starters it is impossible for the trans to drop from 6th to 4th, it would have to go past 5th on the way due to how the trans and valve body work. There is no way for the valve body to skip over a gear. It can go through it fairly quickly, but not skip over it. And we need ALOT more info on your setup to even BEGIN to help you. Does it use a PCS XFI as the gateway, or is it direct wired to the TCM. Does it it have tow/haul mode or not? So many questions here. And if your using the PCS XFI from DESTROKED as the gateway, join the club of people who they haven't worked correctly for. There has been MANY people who have had problems with shifting with the PCS XFI not relaying correct throttle input to the TCM. Also need to know if it uses a AL5 1st gen TCM, or does it use an A40 GEN IV TCM? If it uses the AL5, does it have a SUNCOAST, SOCAL, or killerbee 6 speed calibration in it? Does it use a 06+ 6 speed valve body, o does it have an 04-05 valve body with the 6th gear tube added in?

    This is the real problem with swaps like this as you really don't normally know what all is in it, and thus can't always get it all to work together.
    It has a stand along box for the trans that's about all I know on that part.
    It does have Tow haul mode
    Its suncoast and the box from DESTROKED.
    I do have the paper work on the total built. Every part that was used is in the folder. They did do that part when doing the build. Down to the battery's, Alt, Brakes and belts. Will look up the paper work. And get all the info I can on this. But thinking its going to come down to sell this trans and box. And put in a 2006 or above 6 speed. And new Toqurk converter and the tuning and box from a place on the coast in Fl.
    Had a few guys trying to buy the truck every time I turn around. And may just sell it, as I'm grossing 30,000 lbs and not sure if the 5.9 and Allison is up to that. Thinking on the Interstate it can handle it. But get off on the hwys and big grades it may well not handle it.
    Wife is trying to get me to sell it and just buy a semi. Turn it into a RV puller and forget about every having any issues pulling any grade that we can ever get on. And I'm about ready to agree with her.
    Pete

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    Your still not providing us much info here. For starters there is no stand alone aftermarket TCM that has proven to work with an ALLISON WORLD trans. if you're using the DESTROKED box, then it is most likely a 5 speed style TCM. Add into the mix that teh 5 speed TCM's with 6th added in can have issues even behind the DURAMAX once you throw much power to them, doing it in a swap can be a NIGHTMARE! If it was mine, I would ditch the 6 gear stuff and go back to a 5 speed valve body and stock ALLISON 1000 5 speed TCM. Seeing that you have an 05 5500 you started with, I'm going to guess thats which trans is in it. There are so many "issues" that could arise from this kind of swap with the way it has been done. I would find an ALLISON dealer you're comfortable with, and let them flash a stock TCM to a calibration compatible with that engine. You will be back to a 5 speed, but at least it will all WORK! The 2000 5.9L I'm guessing is a VP44 engine? If so theres no reason they can't find a calibration to work with it as the VP44 5.9's could have had the 1000 behind them in buses, motorhomes, FORD F-650 trucks, and MANY other box trucks and other equipment like that. The DESTROKED parts should fetch some money no problem, and I doubt you'll have ANY trouble finding somebody to buy the 6 speed stuff from you. You should be able to pick up a used TCM for $150, maybe even less(if not, PM me and I'll sell you one for $150 plus the ride), and set it up to work that way. Quit beating your head against the wall just for 6th gear. You might even be able to find a 6 speed cal that would work with the VP44 engine, then change out for a 6 speed trans, harness, and GEN IV A4X series TCM. But the 5 speed stuff would be ALOT less money, and there should be no reason you shouldn't be able to do it and come out with some money left over from selling the parts you take out.
    1995 GMC 2500 SUBURBAN powered by 01 DURAMAX/ALLISON, little of this, a little of that,
    DIAMONDEYE 4" exhaust, CORSA muffler, AFE stage 1 dry filter, custom tuning by me, KENNEDY single pump and pump rub kit.

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    Quote Originally Posted by THEFERMANATOR View Post
    Your still not providing us much info here. For starters there is no stand alone aftermarket TCM that has proven to work with an ALLISON WORLD trans. if you're using the DESTROKED box, then it is most likely a 5 speed style TCM. Add into the mix that teh 5 speed TCM's with 6th added in can have issues even behind the DURAMAX once you throw much power to them, doing it in a swap can be a NIGHTMARE! If it was mine, I would ditch the 6 gear stuff and go back to a 5 speed valve body and stock ALLISON 1000 5 speed TCM. Seeing that you have an 05 5500 you started with, I'm going to guess thats which trans is in it. There are so many "issues" that could arise from this kind of swap with the way it has been done. I would find an ALLISON dealer you're comfortable with, and let them flash a stock TCM to a calibration compatible with that engine. You will be back to a 5 speed, but at least it will all WORK! The 2000 5.9L I'm guessing is a VP44 engine? If so theres no reason they can't find a calibration to work with it as the VP44 5.9's could have had the 1000 behind them in buses, motorhomes, FORD F-650 trucks, and MANY other box trucks and other equipment like that. The DESTROKED parts should fetch some money no problem, and I doubt you'll have ANY trouble finding somebody to buy the 6 speed stuff from you. You should be able to pick up a used TCM for $150, maybe even less(if not, PM me and I'll sell you one for $150 plus the ride), and set it up to work that way. Quit beating your head against the wall just for 6th gear. You might even be able to find a 6 speed cal that would work with the VP44 engine, then change out for a 6 speed trans, harness, and GEN IV A4X series TCM. But the 5 speed stuff would be ALOT less money, and there should be no reason you shouldn't be able to do it and come out with some money left over from selling the parts you take out.
    Ok for Starters. I know you have more knowledge then me on this. But all I can do is tell you what I know.
    The stand along box for the Trans is and was built by Destroked for the Allison 1000 with the Suncoast kit 6 speed. Guy that owned the truck has more money then brains. So he had them to in 2008 build a custom Stand along box for this trans. Paper work shows the cost and when it was bought. And that its for a 6 speed trans.
    Then paper work shows Bean Diesel in Woodbury Tn did the wiring and tuning of the trans to the 2000 Cummins 5.9 24 valve 275 HP RV engine. Engine is using a 2002 wiring harness and a 1998.5 EMC for some reason? Engine came out of a Freightliner Chassis that only had 10,000 miles on it when the whole engine assy was cut out of the back.
    Trans does a perfect job shifting up on all 6 gears. And if your not pulling a big grade does a great job down shifting. I know if it had been me doing the build, I would have just looked for a engine out of a truck with a allison. Then took at the stuff and done the swap.
    Wish I had more info, but being I know nothing about these transmissions and stuff. Other then owning one the last 12 years. I'm lost on this stuff, but trying to learn.
    Guess the truck will be sold and just go get a Peterbilt and not look back. This one will be perfect if someone is not grossing 30,000 lbs +. When I pull my 33ft Tilt Gooseneck and gross around 26,000 lbs. It does great, but fear the 30,000lb + is just asking more then it can stand for the long haul.

    I will be getting in touch with Beans Diesel and see what they say about the tunes they programed into the trans. Forgot to add the tune in it and the setup has been running the last 8 years. And 50,000 miles towing.

    Pete

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