12 volt source for military 4L80E ?

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actionpaintball
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12 volt source for military 4L80E ?

Post by actionpaintball » Wed Aug 15, 2007 7:59 am

I have the military version of the 4L80E (input and output sensors on transmission body). I have been trying to track down some shift point problems I have been having and noticed the transmission computer is fed directly off the batteries, tapped in the middle using a single battery at 12 volts to feed the 12 volt GM trans computer.

Is this how it is supposed to be done? How does the upgraded HMMWV (A2) feed the 12 volts to the Transmission Computer?

Does anyone have the "More 4L80E tranny troubleshooting.(M998A2-Series and Up-armored HMMWVs" PDF letter Thomson Gale on April 1, 2006. I see Aazon is "selling" it for $6-might pick that up-but it appears to be only 10 pages.


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Post by emmado22 » Wed Aug 15, 2007 8:04 am

Thats why the A2's have the dual voltage 12/24 generator....... To feed the 12V to the tranny.....
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Post by unclesamsurplus » Wed Aug 15, 2007 11:25 am

i bought another 1992 Chevy G30 cargo van on govliq. and it has many parts missing. the 6.2 engine and trans. has 30,000 miles on it. i've been under both the van and the humvee looking at the tranny and it looks like it will fit. the tail cone on the van's 4L80 tranny is bolted on. in regards to the question asked by apb regarding the computer, will this tranny hold up in the humvee?

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Post by Mark Rozak » Wed Aug 15, 2007 6:48 pm

Anyone have experience with the transmission control unit from Painless Wiring? It's available as a separate item to provide electronic transmission controls only. Now you can economically operate a 4L60E with a carbureted engine.

http://www.painlessperformance.com/webc ... ield=66501

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Re: 12 volt source for military 4L80E ?

Post by dunsbr » Wed Aug 15, 2007 10:32 pm

actionpaintball wrote:I have the military version of the 4L80E (input and output sensors on transmission body). I have been trying to track down some shift point problems I have been having and noticed the transmission computer is fed directly off the batteries, tapped in the middle using a single battery at 12 volts to feed the 12 volt GM trans computer.

Is this how it is supposed to be done? How does the upgraded HMMWV (A2) feed the 12 volts to the Transmission Computer?

Does anyone have the "More 4L80E tranny troubleshooting.(M998A2-Series and Up-armored HMMWVs" PDF letter Thomson Gale on April 1, 2006. I see Aazon is "selling" it for $6-might pick that up-but it appears to be only 10 pages.
That's exactly how the TCM should be wired.
And as emmado has said, the 12/24V alternator supplies a regulated source of 12V too the centre tap to keep the lower battery charged.

If you send me your email address via PM I'll try and send you the manual you want. (I'm on the road at the moment so it might take a day or two.)

Cheers
Brad Dunstan
RHD '87 M1026
(with 4L80E Trans, 242 T/case, 12K hubs, CTIS, A2 wiring, Air Con, A2 ebrake, 9k Winch,
Serpentine Belt Accessory Drive & Eaton e-lockers)

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Post by Ozhumvee » Thu Aug 16, 2007 2:46 am

Mark
Can't help with the Painless Wiring but the 4L80E in my Humvee is run with a Compushift trans controller.
I wrote an article on fitting a 4L80E to a 6.2 in an older Humvee which has been posted for download on the HID on the humvee.net site. It is located in the transmission section.
Peter James
Sydney, Australia
RHD 1988 M1026
4speed, Aircon and CTIS!
Unfortunately has been sold!

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Kurt Lesser
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12 volt source

Post by Kurt Lesser » Thu Aug 16, 2007 10:23 am

For those people who don't want to change over to a dual voltage alternator there are plenty of "voltage dropping" or "voltage regulating" modules on the market that attach directly across the batteries and provide a 12 volt sources referenced to ground. This eliminates the need for a new alternator or a center tap on the batteries.

In electronics I have used modules by Vicor for both 12 volt and 15 volt equipment. I mounted a 15 volt regulator in the docking station for my Panasonic Toughbook. The spec that you will need to know is how much current the trans needs to function. Most of these voltage changing modules can provide up to about 10 amps. After that they do tend to get expensive.

Heres a link to a unit on eBay right now so you can see what you can find out there:

http://cgi.ebay.com/ebaymotors/NEW-Tran ... enameZWDVW
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Post by Ozhumvee » Fri Aug 17, 2007 1:15 am

Kurt
A better/more efficient way is to fit a Charge Equaliser, a device that sits across both batteries maintaining them as the name suggests at the same charge/voltage level.
Us Aussies use one made by www.redarc.com.au I'd imagine that you could buy one in the US as well.
Peter
Peter James
Sydney, Australia
RHD 1988 M1026
4speed, Aircon and CTIS!
Unfortunately has been sold!


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