- Thread starter
- #21
No, the HF1A does not have a center differential.
FAQ Converting HF2AV Transfer Case into Part Time Transfer Case (2 Viewers)
- Thread starter OGBeno
- Start date
This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.
No, the HF1A does not have a center differential.
Look at you, you're a regular Ansel Adams with a halfway decent camera in your hands. I'd hate to see how much grease your new toy has all over it already.
I'm standing by for your care package.
I'm standing by for your care package.
Nice write up 
; looking forward to the finished product.
Really?!
; issues with Mark's low gears; now that's news to me. I am glad I asked. I thought those are bomb proof
Clear as Mud brother
; looking forward to the finished product.Really?!
; issues with Mark's low gears; now that's news to me. I am glad I asked. I thought those are bomb proofAny clearer for my fellow West Virginia
Best.
-onur
Clear as Mud brother
And it looks like you're now converted one will also not have a center diff. So your CDL switch
will become a 2wheel drive / 4wheel drive switch.
- Thread starter
- #25
Yup, that in combination with the 7pin mod to control the 2L/4L and front hubs.
Like a real part time truck!
I think you'll like it, Onur.
I wonder if you know whether the power circuit on your modified box is the same as the factory parttime boxes? In other words, will the power be driven through the box in the same sort of gears as in the p/t box? Or will it come through in another way?
Subscribed... It just so happens that I picked up a spare transfer case last week, this may be in my future!
Question for the experts...(Beno and others) So when this is done, I have a question, will you be able to hit the CDL button at any speed to shift into 4high or will you need to be at a dead stop? Will you need to shift into neutral before engaging CDL? For instance, your driving in the snow, pavement, snow. You have hubs the front manual hubs locked. Then you hit pavement for a while, hit CDL (4x4) then drivepavement for a while, hit CDL(2wheel drive) is this how it will work? Tried to explain, might seem stupid, but hope this explains.
alia176
SILVER Star
Nice pics dude!
Just a quick note: if you're doing this under the vehicle, the slippery gears will slowly try to slide down and rain on your noggin (ouch). If the gears come out, life will be VERY unpleasant when it's time to put tem back. One way to hold them all back is to use a strap of some kind around the whole T-case.
Now, back to your regularly scheduled program....
Just a quick note: if you're doing this under the vehicle, the slippery gears will slowly try to slide down and rain on your noggin (ouch). If the gears come out, life will be VERY unpleasant when it's time to put tem back. One way to hold them all back is to use a strap of some kind around the whole T-case.
Now, back to your regularly scheduled program....
Yes, your last statement is correct. This won't change the functionality of locking the CDL anymore than cruising down the road now and transitioning from AWD to 4WD by pushing the CDL switch (provided you have the pin 7 mod completed).
I'm beginning to dislike the terminology of locking the center diff for this part time mode, it implies the differential itself actually locks. It would be a more accurate statement to say the 4WD is being engaged since the engagement takes place outside of the center differential. If I am understanding the FSM correctly the engagement takes place in the front half of the transfer case. I don't Illustrator but this pic shows the location of the center diff lock actuator. If I can find a way to post a PDF I'll scan the FSM pages that show the locking mechanism.
alia176
SILVER Star
Kris,
I agree with your statement. CDL'ing is no longer an option after this mod. You're either 2x4 or 4x4, just like old times. I think you attach PDF's now here in Mud.
However, just to make everyone feel at ease about losing the ABS, it's not totally true. I've been driving around with the hubs locked the better part of three weeks due to the local weather, and I have ABS. I also fly in and out of 4x4 as needed to get through deep snow and muddy spots in our area. Of course, when I'm in 4x4 mode, ABS and CDL lights come on as usual.
Beno, while you are "in there" can you see where it may be possible to drill and tap passages for an external lube pump like the remco units? When flat towing, these built up heat in the rear housing, which can lead to failure. Remco makes all sorts of kits for auto transmissions external pumping systems, with several requiring the installer to drill and tap on the tranny. It would be nice it you could see if this is possible on our transfer case too. Thanks.
Do they make a pre-luber for the engine? There's more and more threads I am seeing on here that have to do with rod knocks. Not surprising with the way the ECM takes these things to 1500 rpm right out of the starting gate. NOT the best treatment for a cold, oil-dry engine every day. Better if the cold idle was at around 700 rpm. A preluber would cure that issue.
Since I will be dropping the tranny in my truck...mmmm this might be a good mod..miss the simple and easy t-case in my 60...
We have a 99 MBZ C 280, that starts up and idles about 900-1000 rpm when it's stone cold. No rattling going on in that engine. I hate it when I start up these gas LC's and the timing chain is rattling and the rod bearings are getting pounded dry for the first couple seconds. That is really hard on things.
I remember the old carb'd cars, they had a fast idle adjustment on the choke. I'd always set mine to idle about that when cold.
Wow!!! This thread got hi-jacked in a hurry. No offense intended but if you're interested in pre-lubing anything or discussing the merits of how other brands start when cold it ought to be in a separate thread.
Agreed. Stick to tcases here.
Great thread guys! I will be doing this and my Longfields will be forever thankful... BTW- How important is it to preheat the gears before welding? I'm just trying to wrap my head around this idea and see the importance.
That's a good question and I'm sure there are many folks asking the same question. To weld the diff case and not cause stress in the welds or base metal it is very important. I'll try and paraphrase my buddy's analogy as it relates to welding heat treated parts. This may sound a little elementary and/or childish but it paints a good picture.
Consider yourself one of the molecules in a piece of steel at standard day temperature (68* F) and you're happy as a pig in sh*t. Now all of a sudden a localized hot spot ~2,500*F and the molecules freak out and become very stressed due to the drastic temp change which causes stress in the material and weld. Now, consider the same piece of metal that has been preheated to 500*F and an arc is struck melting the metal at ~2,500*F, the temp change is not as drastic and the molecules are like "hey, whatever dude we're relaxed, it's all good" hence imparting less stress into the base material. As I mentioned this is an overly simplified analogy but you get the idea.
Those that have gone the Lincoln locker route and not preheated or overdone the welds should be able to relate easily, i.e. breakage and mass migration of parts. Part of this has to do with cast metals and/or a heat treated metals much the same as the diff carrier in the HF2A(V).
Lincoln Electric has a good synopsis of the when and why preheat may be required. Here are the key points copy/pasted from the article at the link below:
Why Preheat?
There are four primary reasons to utilize preheat:
(1) it lowers the cooling rate in the weld metal and base metal, producing a more ductile metallurgical structure with greater resistant to cracking;
(2) the slower cooling rate provides an opportunity for any hydrogen that may be present to diffuse out harmlessly without causing cracking;
(3) it reduces the shrinkage stresses in the weld and adjacent base metal, which is especially important in highly restrained joints and
(4) it raises some steels above the temperature at which brittle fracture would occur in fabrication. Additionally, preheat can be used to help ensure specific mechanical properties, such as notch toughness.
What is Preheat?
Weld Cracking
I hope this answered your question and gives a better understanding of why it is important. Ultimately, I don't wish to see anyone stuck on a trail or the side of the road with a grenaded transfer case because the welded diff let go.
Last edited:
Great thread, I wonder if I go to a part time system like this, can I get away with my stock front driveshaft instead of a dc?
I have approx 5" lift
I have approx 5" lift
