Installed Center Diff Switch (Questions)

[Romer]

Productive day. I replaced my Power Antenna, installed the center diff switch and the cup holder for a bove the radio. Checked it out and everything is working fine.

Based on the search and what people have told me, this is what I think I have. Please correct me if I am wrong.

I use to have Full time 4WD in my 97 LX450. This mode was safe for all speeds and worked with the ABS brakes. In fact I could feel my ABS brakes more because of the full time 4WD.

Now I have selectable 4WD. This means that I now drive in 2WD unless I enage the Center Diff. However, it no longer works the same as before with the Full Time 4WD. Selecting 4WD is more like the FJ40. You want to use it off road but not on smooth surfaces or at highway speeds because it Locks the center diff rather than having it operate open with a power share from front to back. Because the front and rears are locked together, the ABS Brakes are disabled.

Now a few questions:
1) At what speeds is it safe to engage the center Diff while driving. i.e. road conditions get bad?
2) At what speeds is it OK to drive with the Center Diff Locked?
3) Why isn't there a switch that allows you to select the original style full time 4WD that is safe for highway speeds as an option? My GMC has an option for 2WD, 4WD or Auto4WD. The Auto 4wd is safe for pavement and is more like the full time before the switch.

I know about the pin 7 mod tha C-Dan developed. I'm not sure I need that yet. I have 2WD LO on the FJ40 and have not ever used it. However, when I start adding sliders, etc, I'll probably do that.

Appreciate any corrections and comments. I didn't see these answers in any of the searches I did.

Thanks,

Ken

 

[e9999]

uh?
selectable 4WD???? 2WD???
are we talking about the same kind of truck?

OK, I believe we may have some misconception here.
If you drive your truck around in High with the CDL button off, it's the same as before.
You are never in 2WD unless you have installed freewheeling hubs in the front.
It's a full time 4WD, always.
The CDL button allows you to engage the center diff lock which splits torque evenly back and forth, making a rigid connection if you will. The difference is that now you have control over that manually unlike original where you could not lock in Hi and when it would lock automatically in Lo.
E

 

[Romer]

I guess then I got wrong what exactly the Center Diff Switch does. Once I put it in I noticed a big difference (in the off position)in the way it handled and braked and assumed that was because I was no longer in 4WD. And the ABS system becomes disabled in the ON position by design (according to the search)

I am confused why it handles differently and the brakes no longer pulse if the switch is off. Before you could feel the traction in all 4 wheels. It did not feel that way after I took it for a drive.

Please enlighten me.

 

[Tooth Fairy]

Coincedence?

Is your ABS light on?

 

[clownmidget]

http://www.lcool.org/technical/diffs/diffs.html

this may help clear up things...

 

[Safado]

Romer,

There really is no logical explination as to why it feels different to you. Your ABS shouldn't be kicking in now anyway, maybe once the snow hits, but not now. That pulsing you feel now may just be your brakes, warped rotors, or road surface.

Think of the CDL as exactly what it is....in your 40 you have 2 differentials, in the 80 you have 3. The Center Diff acts just as the one up front and in the rear by adjusting power between the front half and the back half. You are in a Full Time 4WD, but it would be impossible to drive it on a solid surface if all 4 wheels were going at the same time....thus the reason for the 3 diffs. The only time you'll have all 4 wheels pawing with equal power is with all 3 diffs locked.

As far as when to use it...I've used mine one around town on a VERY snowy day and it made a huge difference in how the well the truck performed. Don't use it when you have traction otherwise you'll cause unnecessary wind up and torque.

As far as the speeds go, there was an old thread on this...

https://forum.ih8mud.com/showthread.php?t=9327&highlight=fast+cdl

 

[Romer]

Thanks guys. I only drove it up the street. I guess I had a wrong picture from the start. I was talking to a member of this board telling him that my wife hated the feel of the full time 4WD and he told me to get the Center Diff Switch. Thats the first I heard of it. He said that it would ride and feel more comfortable On Road.

I'll have to drive it more, the brakes would pulse slightly before when getting close to a complete stop, now (After only a mile) they did not pulse at all.

I have seen that Diff's for Dummies and even have it bookmarked. Looking back, seems like a pretty stupid question on my part. I think I'll leave the wife the impression that it does help the ride and see if she notices anything!

 

[sleeoffroad]

Ken, you need to find out why there was a difference pre and post the switch. Technically there should not be any when the switch is in the off position.

 

[landtoy80]

Ken, you need to find out why there was a difference pre and post the switch. Technically there should not be any when the switch is in the off position.

The difference between pre and post is called the PLACEBO AFFECT

Its like when you install one of those SNAKE OIL products to your motor. You sware that it drives faster and gets more MPG.


If its deep soft snow then use the CDL.
If its hard packed snow or ice, you will want to have it unlocked as you loose your ABS. Can you say sssskkkkkiiiiiiiiiddddddd thorugh the intersection

 

[Romer]

Thanks Christo. Your instructions were great. Only change was on the Lexus there is that security sensor in the top left slot. Had to move that down to below the AC controls (empty slot) to make room for the switch. The harness for the Center Diff Switch was not long enough to go down there.

C- Dan, that Power Antenna went in smooth just like you said. After I took apart the motor to remove the old Nylon (Broken) I put it back in and just fed the new Nylon down, motor grabed it and the antenna went in easy.

Sorry about the newbie question, I have only had my LX450 for a month and still figuring it out. Thats why I started this thread, I wasn't quite sure and it didn't seem right.

 

[Romer]

The difference between pre and post is called the PLACEBO AFFECT

That and probably the fact I only took it about a mile late at night to make sure it was working.

I need to figure out how to package that Placebo!

 

[landtoy80]

<I need to figure out how to package that Placebo! >

Its already been done, its called Enzyte

 

[Romer]

Discover why more men are turning to Enzyte to help support firmer, fuller-feeling, better quality erections.

I said Placebo effect, not the Woody effect!

 

[RavenTai]

Now that you have the CDL switch need to do the Pin-7 mod so you can have low range without the center differential locking automatically

 

[e9999]

I wouldn't disregard out of hand your earlier impressions. I'd look a bit more into it. The pulsation could be something having to do with warped rotors (likely) or maybe a problem with ABS (unlikely). Even the "turning easier" etc could mean something (sticky CDL?).
I'd analyze it and find out if there is anything wrong.

(Then if you don't find anything, give it 2 Enzytes in the tank and check back tomorrow. May have gotten a 6" lift... )

E

oh, btw, telling your wife it's driving much better now is a very bad idea... well, at least if you want to drive it again yourself much...

 

[landtoy80]

WHen you lock the CDL the ABS and Dif lock lights will/should come on. You will feel the difference when you trun sharp on HARD ( thanks to Enzyte) surfaces.
When unlocked, the lights will/should turn off and your sharp turning will be smooth.

 

[e9999]

snip
You will feel the difference when you trun sharp on HARD ( thanks to Enzyte) surfaces.

Is that really a sure thing? after all, there are still 2 diffs in the axles that should prevent binding if unlocked, no?

E

 

[RavenTai]

Is that really a sure thing? after all, there are still 2 diffs in the axles that should prevent binding if unlocked, no?

E

With the center locked but F/R diff's unlocked there is still wind up between the front and rear axle as the front axle travels further in a turn that the rear, it does not feel as strong as with the front locked but you can still feel it, on low traction surfaces this is no problem, on pavement stresses can build up

 

[Romer]

Drove around quite a bit. The handling really isn't changed, but the pulsation I had with the brakes is gone. Engage the center diff and the light and ABS light come on. No ABS light when off.

I had the brakes checked about 2 weeks ago in case the pulsation was a problem. They said they couldn't find anything and I had plenty of pads left, probably needed the rotors turned but could wait until the pads needed changing.

So . . . . . Let me start this thread over.

Installed the center diff switch. Bought the switch from Christo and went in easy. Everything seems to be working fine.

 

[e9999]

With the center locked but F/R diff's unlocked there is still wind up between the front and rear axle as the front axle travels further in a turn that the rear, it does not feel as strong as with the front locked but you can still feel it, on low traction surfaces this is no problem, on pavement stresses can build up

well, as usual, RT you were right on. Coincidentally, I just pulled the rig out of its cubby hole to get back to the house for me to plug the roof holes and I did it all in reverse. Well, I had left the CDL on last time I put it away (not smart) and going in reverse I didn't see the light on the dash, and sure enough when turning hard I could feel some resistance there... Sure enough there was tension in the gears...

So, yup, not good to leave the CDL on on pavement, even in High...

E