CK5
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'89 R3500 Crew Cab 2wd to 4wd conversion & beyond

Started out with 2wd TBI350 with SM465 to current 4wd with 454, 700r4, NP241
I think it may be. Couple of things. I watched the video about their facility and near the end they show a transmission being crated up and I can see a sticker on the bellhousing very similar to mine. On their website they talk about significance of being remanufactured and not just rebuilt. When I called the mechanic that installed the transmission he we was kinda defensive like I was questioning his work, he wouldn't tell me where the trans came from but insisted it was "new" and not just rebuilt which sounds a lot like the pitch on the website.
 
The only issue you'll have running low range is the trans won't shift right. You'll have to shift manually more than likely.
 
The only issue you'll have running low range is the trans won't shift right. You'll have to shift manually more than likely.
I thought I had read people have trouble with the trans going into limp mode because it's thinking the transmission is slipping since the RPMs are too high for the speed.

I feel like with the magnum I may end up switching between using the low range in the NP205 and the Magnum box. I like to run trails in 4Lo but there have been times I wished I had a little bit higher low range than the NP241 gives me. Those times when I'd still like to be in low but could be moving faster.

Otherwise I wouldn't worry as much about it because I could program the controller for just one of the low ranges that I'll use most of the time and not worry about the super low combo.

ask @Greg Ducato on the tone ring

I may have to because I haven't found a solid answer on the interwebs. I was also thinking maybe I could test it out with a multimeter and spinning the output. If I could spin it fast enough to generate a signal.


How does a 80 work in low range with the factory controller?

The ECM knows the transfer case low range ratio, and when the case is shifted into low a wire to the computer is grounded out by a switch on the case telling the ECM that the case is in low.
Plus the factory setup just has a single low range but I will have 3. I can program the aftermarket controller for just 1. Although I was reading that the Compushift controller has and A/B setting and if I understand properly you can program each of those with a different low range. I found at least 1 person doing that. Problem is I was hoping to use the A/B option to give me a tow-haul mode when we're hauling the camper.

I was hoping to set mine up so it just never knows I'm in low range.
 
What if you tied both speed signal inputs to the front speed sensor sender. You would loose the diagnostic function but the trans would never know you were in low range.
 
What if you tied both speed signal inputs to the front speed sensor sender. You would loose the diagnostic function but the trans would never know you were in low range.

The trans needs the rear one to shift correctly, it’d be nice if it was that simple!
 
www.usshift.com stand alone controller unit with 4 different programs on the unit . . . you set up everything for ratios and other stuff.
Nice! Just read this in the instructions for that controller:

4x4 Low Range Detection
Low range detection can be enabled if you want the controller to switch to an alternate calibration table when 4x4 low range is engaged. Configure the options in Shiftware under the “2WD/4WD Options” and “Table Select” tabs in the settings window. For example, 4x4 low range detection can be enabled so that when ground is applied to pin 5 (purple) of the vehicle harness, the controller will switch to table 2. Another option includes single-clicking the controller knob to enable 4x4 low range calibration. Up to 3 low range ratios can be used. Whenever 4x4 low-range state is changed, it will be scrolled on the controller’s display (4HI, 4Lo, 4L2, 4L3).​
 
A simple push on release off switch attached to the shifter in a way that only contacts when in low will solve all those issues.
 
Bad news. I sent a better picture to Greg and this is what he said:

That isn't the tone ring, it is the parking pawl slots in the reaction carrier. The tone ring would press onto that smooth wide band area. The factory 4x4 never uses the tone ring, I guess they saved a couple of dollars for every truck they built doing it that way.

full
 
I have thought that FMVB would be cool but I know after a while I'd wish I could just get in and drive.

After doing some more reading and video watching on the USshift.com setup, I'm thinking I could just go into manual shift mode when in double low (or any low range for that matter). That basically emulates a FMVB. So with the 4 table options I could have 2wd/4hi normal, 2wd/4hi tow mode, 4lo1 (np205 only in low), and 4lo2 (Magnum only in low). Then just turn on Manual mode when I double low. At least I think that's possible based on what I currently understand.

After watching the videos I'm realizing there's a lot of cool things you can do with the trans being electronic.
 
Full manual is cool for about 25min. Don't get me wrong I love mine, as I got it functioning and so on so forth for cheaper than any other alternative, fact remains auto is super nice.
 
That's what I'm thinking. If I wasn't going to be towing and doing a lot of road miles too I would probably just do the FMVB for cool factor and low cost.
 
how much is the fmvb kit and time to install it ?

my usshift quick 4 kit was 800 bucks basicly and its plug-n-play and 4 different programs with tons of options.

if dd use you will prob get sick of fmvb shifting a auto . there is a member here who just posted up he is going back to reg valve body on his auto as he is tired of shifting the auto .

also why not have the trans popped apart for a tone ring install and make it a 2wd style so no need for the rear sensor on the tcase system . ? ? ? i had mine popped apart and tail shaft swapped with gasket seal kit for under 200 bucks.
 
Put a tone ring in it and run it. I run a 2wd 4l80e with 3 speed case. I'm using the factory GM PCM. Shifts fine in all my ranges.
 

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