From: Chris Brunner (cjbrunner@optonline.net)
Date: Fri Apr 22 2005 - 17:06:30 PDT
Ok, before I go and drop $3K on a gear-vendor unit or pull out my auto
to drop in another auto - has anyone ever converted their CUCV to a
manual? BTW - I don't have any acceleration or speed problems - it's my
work truck; it's all about low speed bawls and ability to haul around my
trailers - I'm not looking to go fast, just have some rpm left when I
hit 55 so I'm not running near red line. Any opinions would be appreciated.
Chris
Erik Lundquist wrote:
> Bob, good points. The 700r4 benefits from a lower first gear than
> either the th400 and the 4l80 along with a slightly lower OD gear .78
> to .75. This gives the 700 a noticeable edge in acceleration, but not
> as much for cruising speed. I also believe Bob is understating the
> parasitic drag of the th400/4l80, its probably MORE than 20hp. The
> most of the CUCV's came with a NP208 transfer case but some of them
> have the NP205. As far as rebuilding 700r4; a good rebuild, a new
> diesel torque converter, biggest tranny cooler available, and proper
> TV cable adjustment are the keys to making it last behind a diesel.
> There are lots of internal part upgrades as well. I personally used
> the 4l80 because I bought all the 4l80 parts for less than the 700r4
> conversion would have cost me.
> good discussion.
>
> Cheers, erik
>
>
> "Our country won't go on forever, if we stay as soft as we are now.
> There won't be any America - because some foreign soldiery will invade
> us and take our women and breed a hardier race." LtGen Lewis B.
> "Chesty" Puller USMC
> ----- Original Message ----- From: "Bob Ternes" <racecadet@yahoo.com>
> To: "Military Vehicles Mailing List" <mil-veh@mil-veh.org>
> Sent: Friday, April 22, 2005 12:48 PM
> Subject: Re: [MV] CUCV - Overdrive?
>
>
>> Dear List,
>>
>> Erik has some really good points, but there's
>> something that came to mind as I read and re read
>> this email. I don't know if it's especially
>> salient to the list at large but here's one
>> viewpoint on GM tranny swaps.
>>
>> The TH400 and its newer incarnations, the 4L80
>> and 4L80e, are great, strong trannies, but like
>> any "slushbox", there are parasitic losses in the
>> very nature of the technology, and the TH400
>> itself takes somewhere on the order of 20HP just
>> to spin. Simply due to size, the 4L80e is going
>> to be alot of HP to spin. This is mostly moot
>> when the coverter's locked up but until that
>> time, you're going to be slinging alot of ATF
>> around just to get up to speed. Also, 4L80's are
>> spendy trannies because of both supply and
>> demand.
>>
>> Now, a 700r4 can easily be built to take abuse,
>> and alot of abuse, and is alot more efficient
>> from an energy consumption / parasitic losses
>> standpoint. I won't delve into the finer details
>> of what generation cases you want to look for and
>> what needs to be done, but parts are cheap and a
>> good tranny builder can point you to the parts
>> you want to use... and this is definitely a
>> shadetree job (with video or manual) if you know
>> a snapring or two from a hole in the ground.
>> 700r4's are also a dime a dozen (comparatively).
>>
>> Heat is really what kills auto trannies, so make
>> sure you run a 700r4 with an external cooler.
>> Also, rebuild with the right parts, and you won't
>> run into the classic 700r4 problems, which stems
>> from the deservedly bad rap from some bad designs
>> that didn't get fixed until the 1987-88
>> timeframe. As well, go aftermarket with your
>> clutches and shells and solenoids and whatnot and
>> you can have a tranny that will outlast and
>> outgrunt your stock hydramatic 400.
>>
>> Finally, and what really pushed me over the top
>> on posting this, the 6.2 is a dog. There, I said
>> it! Anemic oil burner it is, in my opinion. You
>> CUCV guys need all the power you can conserve.
>> Mating that mill to a big slushbox, and then
>> pumping the power out to heavy, friction-bound
>> 6000ft-lb-peak axles (save for the M1009) is part
>> of the reason those aren't stellar accelerators.
>> It's for that reason that I'd be personally
>> curious to see what the benefit is to mate up to
>> the 700r4, and why I typed this up.
>>
>> Also, tcases for the 27 spline 700r4 output are a
>> dime a dozen, and there is decent enough demand
>> for a, say, 32 spline (which is the TH400 and
>> 4L80e outputs) NP205 for it to fetch $300 to the
>> right person. NP203 is slightly more expensive. I
>> honestly don't know what they stuck in the
>> CUCV's, but I want to say 205?
>>
>> Just some ideas. I'm cheap as heck and when I
>> needed a tranny to take and transfer the most out
>> of my 350ft lbs mill this fall, I went with a
>> rebuilt 700r4-type tranny. It made the most
>> sense. If you're towing a 25' gooseneck around
>> day in and day out, then you should probably
>> stick with the 1 ton stuff but for a town and
>> parts runner, a slightly built 700r4 wouldn't be
>> a bad choice.
>>
>> Just don't forget to run a TV cable (or you'll
>> cook your box within a week!), and check
>> www.700r4.com . :)
>>
>> Just brainstorming. I hope this doesn't waste
>> anyone's bandwidth. I got real familiar with the
>> 700r4 this fall so hopefully this helps someone.
>>
>> Some pages I found to explain the lineage and
>> differences:
>> http://www.chevyhiperformance.com/techarticles/46140/
>> http://www.rodandcustommagazine.com/techarticles/82558/
>>
>> Or just go to a standard gearbox. ;)
>>
>> Cheers
>> Bob Ternes
>> Proud owner of a 6'x6' pile of GM trannies and
>> transfer cases
>>
>>
>>
>> --- Erik Lundquist <Erik_lundquist@hotmail.com>
>> wrote:
>>
>>> Chris, you have a couple of options. You can
>>> get an after market over drive
>>> such as a gear vendors unit. Or replace the
>>> th400 with another GM over drive
>>> tranny such as the 700r4 or 4l80e. the 700r4 is
>>> a lighter unit and I
>>> personally don't think they are up to the task
>>> in anything but a 1/2 2wd
>>> truck or car. if you went with one of those you
>>> would have to change the
>>> transfer case to along with it. The 4l80 is
>>> basically a 4 speed
>>> electronically controlled th400. you can reuse
>>> the transfer case but you
>>> need to buy the transmission and tranny
>>> controller for it to work. With any
>>> of the 3 you will have to have new drive shafts
>>> made or your existing ones
>>> altered. I personally went with a 4l80, and
>>> kept the costs down by buying
>>> all the parts I needed on eBay and the local
>>> salvage yard. the Gear vendors
>>> are neat because you basically can overdrive
>>> all your gears making it a 6
>>> speed. If you have access to a machine shop or
>>> have a buddy that does I have
>>> seen Volvo over drive units used you just need
>>> to fab up the adaptor. If you
>>> have any questions let me know.
>>>
>>> http://www.gearvendors.com/
>>>
>>> Cheers,
>>> Erik
>>>
>>> PS. does anyone know the proper way to post,
>>> every I try to post something
>>> to ask a question I get the following message
>>>
>>> Failed to deliver to '<mil-veh@mil-veh.org>'
>>> LIST module(list mil-veh@mil-veh.org) reports:
>>> Your message cannot be posted.
>>> It has the content-type:
>>> multipart/alternative,
>>> and this list accepts text only
>>>
>>> "Our country won't go on forever, if we stay as
>>> soft as we are now. There
>>> won't be any America - because some foreign
>>> soldiery will invade us and take
>>> our women and breed a hardier race." LtGen
>>> Lewis B. "Chesty" Puller USMC
>>> ----- Original Message ----- From: "Chris Brunner"
>>> <cjbrunner@optonline.net>
>>> To: "Military Vehicles Mailing List"
>>> <mil-veh@mil-veh.org>
>>> Sent: Thursday, April 21, 2005 8:27 PM
>>> Subject: [MV] CUCV - Overdrive?
>>>
>>>
>>> > Anyone know of a company that makes overdrive
>>> units for the CUCV? I'd
>>> > like to drop my RPM's when on the highway but
>>> not sacrifice the gear
>>> > ratio's. I'm working with a M1028 but I'm
>>> sure others out there might be
>>> > interested too.
>>> >
>>> > Chris
>>> >
>>> > ===Mil-Veh is a member-supported mailing
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>>
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>
>
>
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