Park issue with pulling front drive shaft

[lyrikz]

I have been on this site for a bit, and was doing alot of research on disconnecting the front driveline to test for drive line vibration. There is a NASTY side effect to removing your front drive line.

PARK DOES NOT WORK. I put the vehicle in park after removing the front drive line, got out of the vehicle and walked away. I wont go into what happened after it started rolling away.

 

[slowsuki]

was this a 93 + i ask because my 91 will not move if the front drive shaft is removed, unless cdl is on, when it is on, park works, if not park will not work, hope no one was hurt.

 

[unwiredadventures]

If the front DS is removed, center diff. must be locked. Unless you have installed the part time kit.

IMHO, you should engage the parking brake when in park in most circumstances.

 

[Wrench]

Yup I knew this. Park won't work if anything is broken or missing from the driveline.

 

[lyrikz]

If the front DS is removed, center diff. must be locked. Unless you have installed the part time kit.

IMHO, you should engage the parking break when in park in most circumstances.

Ok, its a 93. So i have to drive it home without the ds installed. I need to lock the center diff? I can only do that by puttin it in low. I havent done the mod yet.

 

[NLXTACY]

Good info, didn't know this myself.

 

[Wrench]

What I really want to know is how many cars did you take out when it rolled away?

 

[lyrikz]

If the front DS is removed, center diff. must be locked. Unless you have installed the part time kit.

IMHO, you should engage the parking break when in park in most circumstances.

Im sitting here at work waiting.

I know i cant put it into park with the vehicle running and park doesnt work... so what do i have to do to drive this home?

 

[coax]

Could someone expand on or link up a description of how the t-case works? I am curious as I would expect the mechanism between the front and rear output shafts (is it a vc?) to have the ability to "slip". However would not the input shaft from the tranny have some sort of "fixed" or "non-slipable" connection to either the front output or the rear output?

And as a hypothetical question based on the original post, would removing the rear DS and leaving the front leave the vehicle able to use Park effectively?

Or does the t-case function more like a differential, where both front and rear DS's have to be connected and have tension on both to keep each other from turning? Or is is it some combination, more similar to a Limited Slip Diff within the T-case? (I've seen posts on mud both referencing the Center Diff Lock, but also a Viscous coupler lock/failure)

 

[gahi]

can you do the trick where you put it in low, than pull the diff lock fuse on the '93? I never done it, but pretty sure I saw it on here.

 

[lyrikz]

can you do the trick where you put it in low, than pull the diff lock fuse on the '93? I never done it, but pretty sure I saw it on here.

CRap, any help??????

Im doing the 7 pin mod and installing my hazard switch. I should be done in a second.. Hope that works.. Then i should be able to drive home with the center diff locked right?

 

[Wrench]

How far you have to go?

 

[coax]

the internets have answered my question

The LX 450 uses HF2AV type full–time 2–speed transfer in which a center differential is enclosed. The center differential is equipped with a viscous coupling type LSD (Limited Slip Differential). In addition, a mechanism to mechanically lock the center differential when the transfer is shifted to “L” has been provided.

Per the diagram on the 2nd page, it seems as if the Diff/VC sits between the rear output shaft and the high speed output gear. Meaning that the front axle is what is "permanently" connected to the tranny; and if you were to remove rear DS and leave in the front DS, and use park, it would work as normal.

Super interesting to me that Park will lock the front axle, and the Ebrake will lock rear, leaving both axles accounted for and somewhat redundant.

Doc here if anyone is interested, looks like courtesy raventai



Sorry for the hijack btw, I thought the OP was just relaying some info, not stuck somewhere. (As a side note, the article talks a bit about silicone oil shearing, which is interesting and probably similar to the fan clutches.)

 

[nicholas]

can you do the trick where you put it in low, than pull the diff lock fuse on the '93? I never done it, but pretty sure I saw it on here.

Yes, you can do this if you need to drive it home w/o the front Drive Line.

You can also remove your E-flasher switch and plug it into the CDL harness behind the dash and make it into a CDL switch. IIRC you may have to trim a little plastic notch on the E-flasher to make it fit, but it's easy to do.

Keep in mind that you could easily damage your viscous coupler if you drive your truck w/o a front driveline with the center diff unlocked. However, it's not a problem as long as you lock the CDL, even at highway speeds, on dry pavement, extended periods of time etc. I drive mine w/o a front driveline for a good portion of the year. You do lose your ABS feature though.

 

[lyrikz]

How far you have to go?

Well, all i was trying to do was drive it without the front driveline to see if the vibration goes away.

So, i put my hazard switch in the empty plug in the dash, i did the 7 pin mod at the relay in the left kick panel and i got nothing. The car shifts into drive just fine and moves just fine. I just dont want to break anything.

When i turn the car on, the cdl light does not illuminate on the dash. It did 3 months ago when i bought it, but i cant remember if it did anytime after that. So i could have a bad bulb im not sure...

I just need to know if i can go home. lol.

 

[lyrikz]

Now that the bulb on the dash doesnt appear to be lighting up, i cant even tell if the center diff is even locked..

What a bitch.

 

[nicholas]

CRap, any help??????

Im doing the 7 pin mod and installing my hazard switch. I should be done in a second.. Hope that works.. Then i should be able to drive home with the center diff locked right?

You don't need to do the 7-pin mod. Just plug the hazard into the CDL plug, engage the switch, make sure the ABS and CDL dash lights illuminate and then you can drive to your hearts content for any length of time or speed or road condition.

 

[nicholas]

Does the ABS light up? If it doesn't I'd guess that the CDL isn't locked. The chances of having 2 burnt out bulbs would be less likely than just the CDL.

 

[lyrikz]

You don't need to do the 7-pin mod. Just plug the hazard into the CDL plug, engage the switch, make sure the ABS and CDL dash lights illuminate and then you can drive to your hearts content for any length of time or speed or road condition.

Ok. SO the cdl bulb is out. I had the switch off, put it in drive and it felt like a car with a slipping tranny.. i moved like 2 feet. I put it in nuetral, hit the cdl switch, put it back in drive and vroom off we go. So the bulb is bad in the dash. booo... might fix it now while im here.

So i can drive hom elike this correct? I wanted to do the 7 pin mod and cdl switch mod, but didnt want to be foreced to. LOL. Also with the cdl switch on, park works.

 

[Offroads4x4]

Sorry to hear about this. It doesn't sound as though the out come was very good.

If the front DS is removed, center diff. must be locked. Unless you have installed the part time kit.

IMHO, you should engage the parking break when in park in most circumstances.

X2 With the front DS is removed the center diff must be engaged/locked for Park to work and or the rig to move forward.

I'd say you'll always pull the E-Brake when you park from now on.