Transfer Case Replacement Options

[Jon0249]

Update on this, for those interested.

Unfortunately, due to a busy work travel schedule, and the shop being closed on weekends, Gunny still waits on me to wrap up the TCM. But some progress, mostly in my head.

The shop told me after they did the mechanical install that they couldn't get it to shift using the Quick 4. So I downloaded the software and took the laptop to the shop. The axle ratio was set at 3.73, so that would cause a few issues. So I changed it to 2.56 and adjusted the shift points (super intuitive and very easy). No go. Worry, stress, stress for the week I'm out of town. Epiphany. Ratio is not 2.56, it's 5.12 on the ground. I would have to be going 49 mph in 1st to get it to shift with a 2.56 gear ratio. So I am stoked about getting back and correcting the ratio. Expect it to work like a champ.

Regarding Quick 4, Jake (C/S guy) is a rock star, always answers his phone, and knows his product every which way from Sunday. Couldn't ask for better help. The software comes with pre-loaded profiles, and with my experience with axle ratios, he may update the offering with a HMMWV profile because of the likelihood that little detail is missed.

On my test drive, I did shift manually, and got it into 4th gear using the software, moving the 3-4 shift point on the fly. Wow. Guessing it was going 65'ish, although the VDO Electronic speedo (yay, it works!) read 79. And I spun the rear wheels, as the 241C was in 2Hi. Weird, awesome and satisfying all at once.

More info next week, but I feel confident the fat lady is warming up.

Btw, I may have a 4L80e for sale in a few weeks in case anyone is interested.


Jon

 

[patracy]

How are you getting a tach signal? What's the total cost on things?

 

[Jon0249]

For those waffling between 700r4 and 4L80e, I personally recommend the 4L80e. It's a stronger unit, and the only add-on sensor needed is a TPS, which mounts easily where the kick-down switch is mounted. The laptop tuning option is very cool and empowering, in my opinion. If I can adjust to specific conditions, why wouldn't I? The 241C T-case is a perfect match, and you can get rid of the speedo cable once and for all. Couldn't be happier with the choices I made. Now to find a place to put a tach, since the TCM has an adjustable ratio sensor feed direct to just about any tach out there.

 

[Jon0249]

The Quick 4 takes the input signal from the sensor on the back of the block and outputs a signal to my tach. The ratio is adjustable in the Quick 4 data table (easy to modify), so you can synchronize with your GPS until you get it right. Infinitely adjustable.

 

[patracy]

Oh, ok, I've got a 6.2 so there is no sensor.

 

[Jon0249]

Quick 4 with harness was around $750. VDO speedo was $75 - you'll need one, because you'll likely lose the speedo drive cable. Don't fight it - much better and more reliable with eSpeedo. TPS was $50 roughly, can't remember. Other minor things, but those are the drivers.

 

[Jon0249]

The Quick 4 can take your TOSS signal, using drive axle ratios, and provide its own signal. Again, totally adjustable, so you don't need the on board sensor I use.

 

[Jon0249]

Update:

Quick 4 TCM is awesome. Finally set the axle ratio correctly at 4.9152 (2.56 axle x 1.92 hub reduction), and set the shift points at RPM's that were reasonable. Such a satisfying thing to feel the shift in all gears. With the T-Case in 2Hi, I actually can feel a difference, especially in a turn. Truth is, it hasn't ever felt so light. I know, hard to use those words when describing a HMMWV.

For those doing this or something similar, note that the neutral safety switch, positioned in the N position originally, is now positioned in the R position of the 4L80e. So, move the selector from its new Park position to R, where it will start, then quickly back to P. I'll probably disconnect it, but I figured it was one of those nice to know details that could get overlooked.

As expected, the overdrive tranny and T-Case with 2WD option is presenting a new issue. These wheels aren't designed to handle high speeds - and I mean relatively high, like 65-70. I've read that 10 ounces of ceramic beads/pellets helps resolve this. Can anyone validate this, and if so, the theory behind it? Seems counterintuitive to me.

Also, I will be replacing tires soon, and am considering adding in a PVC beadlock spacer instead of the runflat. Otherwise, I get to remove and reinstall the runflats. For me, the runflats don't seem worth the effort, as I'm not a hardcore offroader. Any thoughts?

Thx,
Jon

 

[Retiredwarhorses]

As long as you have a head lock your ok...these trucks were not designed to 65-70. Even my H1 at 65 exhibits issues.
just get a good balance job and install BFG's or MTR's....they ride soooo much nicer than the MT's.
IMO, the BFG's are the best...I like the RF's IJ because I don't carry a spare in most of my trucks.

 

[patracy]

So I asked them about the tach signal and this is what I got:

Thanks for contacting us. We have a handful of HMMWV guys that have made this swap successful with our Quick 4 controller.

You will need to provide a TPS signal, and it's likely our TPS KIT 1 for Holley carbs could be adapted to your linkage.

Tach input is optional. The controller harness connects to the 4L80E input shaft sensor and output shaft sensor.

Please advise if the 4L80E unit you plan to run is originally from a 4 wheel drive or 2 wheel drive vehicle and what year it was manufactured.

We'll need to know if the tone ring is installed at the output shaft sensor (factory 4 wheel drive vehicles often did not have the tone ring)

It is also possible to run the output shaft sensor in the transfer case depending upon application.

 

[Jon0249]

Yeah, that sounds about right. The 4wd 4L80e's have no tone ring, making this a challenge. The oil-pump driven transducer is readily available, which can be the feed to your TCM. For now, that's the only tach I'll get - the TCM. My "new" tach won't work without the Autometer adapter for another $100. Will keep researching.

 

[Tank007]

Tinytach is what I put on my mechanical 12v swap for a tach, it is a nifty low cost item ($95 for diesel) and is surprisingly accurate. I also had one on my 1009. It is a digital gauge real simple to hook up.

tinytach.com

 

[Jon0249]

I've seen several who've used that. It's Plan C for now. Thx.

 

[Jon0249]

If anyone in the N TX area needs an OEM TH400 from an M998, I've got one. Also have an NP242 that I replaced with an NP241C. Tell your friends!

 

[tage]

If anyone in the N TX area needs an OEM TH400 from an M998, I've got one. Also have an NP242 that I replaced with an NP241C. Tell your friends!

Post some pictures of your build!!!

 

[Banaba1971]

You won't gain anything in 2wd. There are no lockout hubs, so you will still be spinning the full front drive train by way of the wheels. I get 10mpg empty on the highway and 10mpg loaded with a fully loaded M101A3 around town. It doesn't seem to care what the load is.

Also, the truck weighs 7000lbs (I weighed mine at the dump).

IIRC the 218 has a ratio of 2.42:1 and the 242 has a ratio of 2.72:1 or something like that.

If you put in a 242 you can change one of the shift forks for a civilian one and it will allow the extra position 2wd hi.

They do have "replacement" 242's that were set up to go behind the TH400 in the A0 trucks. This was so they wouldn't have to continue to buy the 218's as spares when the new t-case was introduced.


Augi

Hello , I have 4L80e and Ls swap , I used the stock transfer case and I remember I have the old one I think it's 218np , I noticed the whinnying sounds and it's loud , is this normal ? Can I swap 242 are they the same size ? 242 is more quieter ?
pls help me - Ron

 

[Mogman]

Hello , I have 4L80e and Ls swap , I used the stock transfer case and I remember I have the old one I think it's 218np , I noticed the whinnying sounds and it's loud , is this normal ? Can I swap 242 are they the same size ? 242 is more quieter ?
pls help me - Ron

I assume you mean the stock transfer case that came with the LS.
The 242 should bolt right up to the 4L80, If you are sure you are hearing the transfer case it has a problem, there are plenty of other noises that should cover any normal transfer case sounds

 

[Banaba1971]

I assume you mean the stock transfer case that came with the LS.
The 242 should bolt right up to the 4L80, If you are sure you are hearing the transfer case it has a problem, there are plenty of other noises that should cover any normal transfer case sounds

I have stock transfer case from the old th400 , 218 as what i see , all works good , it's just loud , I'm kind of wondering that's normal from the old Humvee with 218 tc

 

[Banaba1971]

I have stock transfer case from the old th400 , 218 as what i see , all works good , it's just loud , I'm kind of wondering that's normal from the old Humvee with 218 tc

I'm kind wondering that whinning sounds is normal , it's very loud and annoying

 

[86humv]

If you put a 242 in...there's 2 types...early and late...they have different size slip yokes..
And you will need to change 2 of the 3 drive shafts and maybe rear diff yoke.