CDL on for snow??? (1 Viewer)

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I did a quick search and didn't turn up anything, and I have to leave for work in the next hour. We just got about four inches of snow so far. What I was wondering is since the 91-92 models are basically 1 wheel drive without the CDL locked should I lock the CDL for better driving.

Thanks,
Chad P.
 

Doc

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I would, especially if driving on snow covered roads. Once they get plowed, you can play with it to determine which setting is better. The feedback you recieve through the steering wheel will let you know if you're driveline isn't liking the locked c-diff.

In an AWD model I leave it up to the computer, but in my FJ60 I lock it up.
 
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I say go unlocked. The problem with locking the center diff is that when you go to turn around a corner your wheels have to slip since you no longer have the differentiating provided by the center diff. I like to minimize the slipping of wheels as much as possible in ice. As soon as a wheel begins to slip that wheel is useless. Why intentionally cause a wheel to slip?

However if it's new snow that hasen't iced over yet, then locking might be better.
 

concretejungle

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I'm not sure if the earlier model 80's are different with the CDL, but for my 95 i think it drives in the snow and ice better without the CDL locked. I like having ABS for ice. I have yet to get stuck in the snow on the roads with the CDL off. But then again the most snow we get it 5-6 inches.
 
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I prefer center diff unlocked, as stated, it prevents wheel slippage which WILL occur when you go around a corner with the CDL locked. Also I like the ABS on snow/ice covered roads, ABS is deactivated with CDL locked. 91-92 don't have ABS, so that does not neccessarily apply to the original poster's question.
 
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sc40 said:
I have searched, but cannot fine, Why is a 91-92 like a one wheel drive? thanks

p.s. should i just make this a new popic?
No need for a new topic I don't think. A 91-92 doesn't have the center diff viscous coupling, which would act like a limited slip if it had it. Also I don't think the 91-92 have limited slips in the front or rear differentials. So what this means is that the wheel with the least amount of traction will get all the torque which can be considered one wheel drive.

For instance in the 91-92 AWD, if you have one wheel on ice and it is spinning, then that wheel will get all the torque. The other 3 wheels will just sit there and do nothing. Lock up the center diff and now you have 2 wheels that have to turn at the same rate. This means that if the front wheel is spinning at least one of the rear wheels will have to spin at the same rate since the front driveshaft and the rear driveshaft are mechnically coupled.
 
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Darwood said:
No need for a new topic I don't think. A 91-92 doesn't have the center diff viscous coupling, which would act like a limited slip if it had it. Also I don't think the 91-92 have limited slips in the front or rear differentials.
As far as I know, none of the US 80s came with limited-slip F/R diffs. You're right on the viscous coupling, though- FZJs have em, FJs don't.
 
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The idea is that the 91-92 center diff is open, and can send all power to the axle that is without traction, and then to one wheel on the axle with no traction, which equals "one wheel drive", something like that. I never have been able to make complete sense of it... :)
 
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So what does AWD mean for a 91-92? I always thought power was sent to the front AND back for all US 80 series, whether viscous coupled or not. The VC, AFAIK, absorbs energy from the different rotational speeds of the front and rear axles. On the 91-91s without the VCs my understanding is energy is absorbed through clutches in the center diff. In other words no matter the year all 80 series have power distribution to front and rear axles.

In any case, I would be surprised if, say, driving in snow only one wheel gets all the power. Does this mean a 91-92 might be doing a burnout on one front wheel because there is good traction on the back? Something tells me this is not the case... the question is, what is the answer to this good question? I'd like to know...

Cheers
 
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My (limited) understanding, is that w/out VC it is like an open diff, where it is "possible" to send all power to one axle, but normally it will be evenly distributed with all wheels on equal traction surface, whereas the VC acts similar to a limited slip diff, so it prevents "all" the power from getting diverted to one axle or the other. This is all theory to me, not sure of the real life differences.
 
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Unlocked, unless your ability to move is inhibited by continuous wheelspin. As Ben notes, a locked center diff forces slippage on anything but straight ahead whether it is snow or ice. On a curve, or turn, each tire takes a completely different arc and the open center diff can handle that and still provide power to all 4 wheels.

I'll lock the center diff in high range (added switch) on a steep slippery driveway where I know I'm going to get some wheelspin and if there are not too many curves. This also means I'm able to engage the F/R lockers more quickly if needed.

The one wheel drive is more theoretical than reality, but it's worth going to a "how things work" website for a better understanding of how differentials work and their shortcomings under certain conditions.

DougM
 
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Well after driving to work and back, CDL locked is the way to go in a FJ80 (maybe not so on the FZJ80) With the CDL unlocked it was like driving a rear drive vehicle when turning a corner, the rear end just wanted to come on around, or while taking off in a straight line it would act like a front wheel drive, and the front end side shift. With the CDL locked it drove like a four wheel drive should, mostly stright forward take off, and no driveline binds because I do have open diffs front and rear. This may not hold true for you FZJ80 guys because you have the VC.
 
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You have GOT to be kidding me :eek:

FJ80/FZJ80 in this regard would be so f*$(#ing similar, its sickening.

I can't believe no-one is the wiser, better yet, that this thread exists.
 

powderpig

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they are similar but not so similar at times. By adding the VC you will not need to lock the center as quickly. At some point you will need to lock the center. By some point I mean that every person has his or hers comfort level in driveing their truck. I personally hate ABS on snow and ice. I feel that I have more control on snow and ice with the center locked( I usually keep distance, down shift and not use my brakes that much in the winter). but as others stated they have more confidence in the truck with the center unlocked. The VC makes a huge difference in driveing over the earlier years with out the VC in snotty conditions.

So Peebles24 experence of his non VC truck is different then a person who has a VC truck.
As for FJ803FE, you may need to experence what a VC will do for you, as the 100 you have does not have one as well and unless you have traction control, your experence between the two will be the same in the snow, needing to lock the center to get around. later robbie
 

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