• Help Support Hardline Crawlers :

2004 Rusty Hoe

whiskeymakin

Well-Known Member
Joined
Sep 10, 2008
Messages
1,695
Location
Mid TN
I ended up with a 04 tahoe from my cousin. 5.3/4l60e/np246? 185xxx miles, looks to have a reman tranny. Bose stereo, power everything. Had a little accident in the front but it still runs and drives. I've been trying to decide what whether to part it out or throw a few dollars at it to make a budget family crawler....pics will be up later
The main issue for now is what to do about the auto np246 transfer case. Everything I've read so far points to a 241c from a 90s 1/2 ton gm. Throw a SYE on the back. Any thoughts on what could be a better option here for the t-case?
 
I agree on getting a 241. One option over getting a sye is to get an econo box and putting a Ford 205 behind it. Driveshaft would need to be adjusted.
 
That might be a good idea! Driveshafts will be redone anyways. The plan is to use 05+ super duties that I've had sitting around. Try to locate some 40-43" rubber.
I'd like to not regear the axles (3.73)

I have no experience with the econo box or any other under drives...
I'll have to research that a little
 
RustyC said:
I agree on getting a 241. One option over getting a sye is to get an econo box and putting a Ford 205 behind it. Driveshaft would need to be adjusted.

I'd do an ecobox and ford 205. That way you won't have to worry about the case.

extra gearing will help keep the 4l60 happier too ya know.

good thing is if you do get to wheeling it hard and completely hash the body, it'll still part out for decent money, or tahoe/yukons are getting dirt cheap so you could body swap it after a few years to keep it going
 
Another option is to use a NP261 out of a manual transfer case truck. I have the same tahoe, mine's also a 04. I ended up getting a 261, the shifter, and the short wiring harness that goes from the transfercase up to the underhood fuse box all from a manual tcase truck. I put it all in, removed the TCCM, and installed the little cubby hole in place of the 4x4 switch. Everything works like it came from the factory with a manual tcase the transmission even shifts correctly in 4 low. All I had to do was slightly bend the shifter to make it clear the factory Tahoe console. There is even already a dimple in the floorboard where you have to cut to install the shifter. Of course if youre going to install tons under it the NP241 might be a better choice if its got a fixed front output yoke.
 
Ok I was thinking the 261 had a 32 spline input. I think overall the best option would be blackbox and ford 205....if I want to spend that much on it. Almost kills the whole budget mindedness.

Only other drawback is how big of a tire can be stuffed in the rear fender well? I'd love to be able to sport some 43s but that might be a stretch. I've got some checking to do before this really takes shape.
 
Yeah a 261 from a GM half ton is a bolt in deal. I'd probably part out that Tahoe before I tried to go tons and 43's. There is no room to cut the rear fenders forward because of the rear door openings. You'd have to stretch it and cut the back of the rear fenders. Then you'll still have a very wide and heavy rig thats going to find every tree on the trail while being too heavy to be too impressive on climbs. I think you'd be better off to go with a winch, locker, Np261, and 35's and enjoy cruisin trails in the A/C.
 
whiskeymakin said:
I ended up with a 04 tahoe from my cousin. 5.3/4l60e/np246? 185xxx miles, looks to have a reman tranny. Bose stereo, power everything. Had a little accident in the front but it still runs and drives. I've been trying to decide what whether to part it out or throw a few dollars at it to make a budget family crawler....pics will be up later
The main issue for now is what to do about the auto np246 transfer case. Everything I've read so far points to a 241c from a 90s 1/2 ton gm. Throw a SYE on the back. Any thoughts on what could be a better option here for the t-case?

I will sell you a budget family crawler :****:
 
d_daffron said:
Yeah a 261 from a GM half ton is a bolt in deal. I'd probably part out that Tahoe before I tried to go tons and 43's. There is no room to cut the rear fenders forward because of the rear door openings. You'd have to stretch it and cut the back of the rear fenders. Then you'll still have a very wide and heavy rig thats going to find every tree on the trail while being too heavy to be too impressive on climbs. I think you'd be better off to go with a winch, locker, Np261, and 35's and enjoy cruisin trails in the A/C.

You are probably right, but something just tells me to try it... I like creature comforts. I'm going to do some measuring to see about what tire sizes will fit with trimming as much as I can without cutting into the interior cab area.

I have been emailing back and forth with nwf about the eco box. They say the np246 will work for a donor. Still waiting to see about the final verdict on the speed sensor placement. I was excited to hear the 246 would work with their eco setup. I would guess that all of the half ton 27 spline input cases have the same front planetary setup beside a few having more planetaries.
 
I would try to get the VSS on the trans output and let it think its in 2wd all the time. That will be the least headache and still let it shift correctly.

trans gets mad when the VSS pulses aren't what it should be (extra gear ratio/not using low range switch/wrong gear ratio)

I cant find any pics, but I think you can use a clamp on reluctor ring (may not even need a clamp on one?, reuse the one from the tcase?) and move the VSS to the tcase adapter.

not my pic, but I found one:
Img_4762_fixed.jpg
 
Thanks for that pic...I knew there was some odd deal with the vss placement. Guess I've never dealt with it on the past few ls motors with a th350,400 it got tuned out.

Here's the AA kit to put it in the tail of the 4l60.
https://www.advanceadapters.com/products/716073e--4l60e--vss-40-pulse-kit-for-stock-gm-output-shaft/

Looks like if you use the modified kits from nwf or ord they put the sensor in the tail of the 205....if the doubler is engaged it will not be reading the correct speed and shift points will be thrown off.
 
I used a transmission speed sensor from a 90's Mustang in a Ford 205. It has a plastic gear drive just like in the 1970's in the tailhousing of the 205. It is in the buggy behind a 5.3 th350. I needed a vss and it worked out. May work in this application too. I'm not sure the pulses per rev but I have no issues with my 5.3 stalling.
The LS / 4l60/80 4x4 tune can be changed for t case gearing down to 10-1 ratio if I remember. I've wondered how the trans would shift if the ratio was tuned to 5.3-1 in low range, and then run in low and double low. If should shift correctly in double low and off a bit in single but not sure how much.
 
RustyC said:
I used a transmission speed sensor from a 90's Mustang in a Ford 205. It has a plastic gear drive just like in the 1970's in the tailhousing of the 205. It is in the buggy behind a 5.3 th350. I needed a vss and it worked out. May work in this application too. I'm not sure the pulses per rev but I have no issues with my 5.3 stalling.
The LS / 4l60/80 4x4 tune can be changed for t case gearing down to 10-1 ratio if I remember. I've wondered how the trans would shift if the ratio was tuned to 5.3-1 in low range, and then run in low and double low. If should shift correctly in double low and off a bit in single but not sure how much.


That's my only concern is how bad off the shifting would be??
I'd say this bridge hasnt been crossed too much because anybody using a 4l60/80 in a off road rig probably has addressed the gearing in other ways than a doubler.
Leave it to me to be difficult lol.

The a.a. kit would solve the shift issue I'd say. It will be telling the computer I'm in high range all the time no matter what. I'd still like to just throw a sensor in the tail of the 205 in place of the speedo.
 
whiskeymakin said:
That's my only concern is how bad off the shifting would be??
I'd say this bridge hasnt been crossed too much because anybody using a 4l60/80 in a off road rig probably has addressed the gearing in other ways than a doubler.
Leave it to me to be difficult lol.

The a.a. kit would solve the shift issue I'd say. It will be telling the computer I'm in high range all the time no matter what. I'd still like to just throw a sensor in the tail of the 205 in place of the speedo.


-trans will go into "limp" mode and not shift at all/only shift into 2nd gear. Basically it thinks it's slipping all to hell when it sees the output speed much slower than expected.
-If you program the tcm for double low range, and wire up the low range switch, it will shift correctly in double low. If you are only using single low, but have the switch on, it will see the tailshaft speed as much faster than calculated/expected and basically think that you are going way faster than you actually are, and it will never downshift correctly/only downshift at WOT/and then only sometimes... (think coasting down a big steep hill with a trailer pushing you, that's what the computer is "seeing")

-you wouldn't need a kit to do what I posted, just drill/tap the stock tcase adapter for the vss, and put a tone ring on the shaft.


-That kit you posted a link to is for putting the vss in the back end of a 700r4/old style 4 bolt 4l60e (click on the installation PDF and it shows where it goes in the actual trans case)


OR,
if you only care about/want auto shifting in high range, you could run a manual override and switch the solenoids directly to shift gears manually.
You can build your own switch panel, or use a cool little unit from raddesigns
http://www.radesignsproducts.com/rail-controller.html

Raddesigns also sells the auto/manual selector switch kit, and a potentiometer kit to directly control line pressure on a 4l60e.


Lots of options with an electronics transmission.


But the easiest is to put your vss on the tailhousing and let it run in "2wd", ignoring the transfer case module and controls all together.



Oh and your auto tcase has 3 vss too. only 1 is for transmission control/feedback though. the other 2 are inputs for the transfer case controls/auto 4wd business. :JRich:
 

Latest posts

Top