What's all the fuss about CDL button?

[Steveindar]

I see on "other" forums that 80 owners go to great lengths to acquire said button. I have a button on my dash that says Central Differential Lock! Am I special?

 

[frank rabbets]

You have CDL in your country because Toyota thought it necessary. In UK Toyota thought it not necessary. In UK I think there are 3 reasons why not to have a CDL button.

1. Mainly good road surfaces so not really needed.
2. Added danger of trany damage due CDL being used in high ratio in a country with good road surfaces.
3. Added danger of partial loss of steering in a country with good road surfaces. The car may well under steer considerably.

There is a balance to all this but I would think there are very few drivers in UK who know what a CDL is, let alone want to use it. It is automatically used in low ratio in UK models. If you find yourself in UK in low ratio the 3 items listed above are probably absent so safe to have the CDL engaged automatically.

 

[clivehorridge]

You have CDL in your country because Toyota thought it necessary. In UK Toyota thought it not necessary.

I didn't realize that UK models didn't have the dash CDL switch Frank. Does that mean you can't select CDL in high?

Having disconnected the auto CDL in low, I now have every option available, thanks to the dash mounted switch.

Every day a school day .....

 

[chapel gate]

We dont, but its easy to retro fit, the wiring is behind the dash.one of the cheapest,easiest and most usefull mods that can be done imo.

 

[Dave2000]

Early versions as AFAIK did indeed have a CDL button, and as per Frank's comment about people not knowing what it does, funny how a couple of 80's have turned up in the workshop with the cables disconnected to the differential locks or fuses removed.

For me it was a PITA trying to reverse a trailer into a driveway slightly up hill. Low range was needed and this of course brought in the centre differential, you could here the tyres and transmission protesting as the distance being covered by the two axles differed, the transmission would wind up and the whole drivetrain sounded 'uncomfortable', the lack of CDL in LOW made reversing a whole lot easier.

The only advantage I have found thus far when using it in HIGH is when driving quickly on loose surfaces, shale, gravel and similar, bringing in the differential also deactivates the ABS, this is particularly useful as you do NOT want ABS on loose surfaces.

regards

Dave

 

[chapel gate]

I use low without cdl for trailer ops and other towing. I use high with cdl for snow driving mostly.

 

[clivehorridge]

I use low without cdl for trailer ops and other towing. I use high with cdl for snow driving mostly.

CDL in high is useful in snow and particularly that deep slush that builds up between lanes on the highway, the truck becomes much more stable.

 

[Dave2000]

I use low without cdl for trailer ops and other towing. I use high with cdl for snow driving mostly.

I agree on the non use in LOW as you would experience the same issues I did but, on snow I would be inclined to use it to 'get me going'...ooooer missus, and then switch it off once on the move to regain the ABS. I used to drive a Scorpio years ago and the ABS on the snow/ice on that was brilliant, did not get snow a lot but worth it IME.

regards

Dave

 

[chapel gate]

Ill have to disagree with you there dave. Ill comfortable drive at 40 mph on a snow covered road with cdl on constantly. i do use proper winter tyres though and the grip can be amazing. One example would be a couple of winters ago we had been logging in the woods, it began to snow,we loaded the trailer with about 2 ton plus of oak and made our way home. There is a very steep and twisting tarmac road on the way home, there was a covering of about 3inch of fresh snow.at the bottom of the hill i dropped into first and pressed the cdl, the cruiser dragged the whole lot up with out so much as a wheel spin, it surprised me and my mate couldnt believe it. Sliding backwards with a 14 foot trailer on is no fun believe me.. i also threw my abs in the bin a long time ago because I dont like how it behaves on snow..

 

[Towpack]

I originally fitted the dashboard mounted CDL switch and disabled auto CDL in low box some years ago to make boat launching/manouvering easier but I've found the LC drives better in snow with the CD unlocked due I suspect to the VC doing it's job. This is what it was designed for after all. JMO

 

[Dave2000]

I hear you Chris but, once you have the mass of the 80 on the move using centre if not all locks it is a lot to stop. I know you have no ABS and IIRC this has been debated before. So to clarify I am happy to drive on say ice/snow but I want the ABS so would switch off the CDL when on the move, not met a human being who can apply/release the brakes faster than an ABS system, JMO.

Good point about the VC Towpack, the second week of ownership had me returning through Northern Spain in snow blizzards and ice, and never even thought about any form of DL, it simply drove along the roads as if they were not there, it was much later when I fitted the CDL switch but, have not driven the 80 in any serious icy conditions since then, unfortunately we lack them in Southern Spain..........<snigger>.

regards

Dave

 

[clivehorridge]

I'm convinced I don't have a VC, I certainly don't have ABS, so my set up is as good as it can get for my truck IMO.

Does anyone know how I could check whether I have a VC or not, without dismantling the truck, that is? I would like to know...

 

[AndycruiserguyLomas]

I think the VC type transfer box is 23" from flange to flange and the non VC type is 17-18" Clive if that helps.

 

[clivehorridge]

I think the VC type transfer box is 23" from flange to flange and the non VC type is 17-18" Clive if that helps.

Thanks Andy, most helpful, I'll give it a measure.

I've never measured mine (oo err!)

 

[frank rabbets]

The centre diff is automatically locked in low range to protect the transmission from the extra torque coming from the gearbox. It spreads it between 2 axles.

High range CDL is safe enough in a country where there are scrub roads with no traffic but I would not use it in UK. There is serious possibility over going straight on at a bend when you have forgotten to turn it off after being all day on the Mway. I've done it in 1960's. That is exactly why Toyota did not fit it.

 

[Towpack]

Does anyone know how I could check whether I have a VC or not, without dismantling the truck, that is? I would like to know...

The transfer box is a HF2AV with the VC, HF2A without. It's probably stamped on the casing somewhere or maybe it will be listed in the LC's spec/paperwork? I thought it specified box type on the VIN plate but I've just looked at mine and it just gives the main gearbox type.

 

[chapel gate]

maybe i dont have a vc then. the cdl transforms how mine performs in snow. now all three locked is a different story, its like trying to control a giant snake, good fun though, and has got me out on a few occasions..

heres our drive most winters;

 

[frank rabbets]

Sorry Clive I wasn't ignoring you but Assumed you had picked up that UK models don't have the CDL switch on the dashboard as standard but the wiring is there.

 

[clivehorridge]

Sorry Clive I wasn't ignoring you but Assumed you had picked up that UK models don't have the CDL switch on the dashboard as standard but the wiring is there.

No prob Frank, it just came as a bit of a surprise to me that my Euro spec had something the UK spec didn't

As for a locked CD 'spreading the load' between 2 axles, I really can't get my head around that.

I'm not arguing with you on this Frank, I'm sure you have more mechanical knowledge than me, and I'm always ready to accept when I'm wrong, but my brain tells me the load is spread between 2 axles through the open diff in a much more "balanced" and strain relieved way than with the diff locked.

I also don't see that by locking the CD the steering would be overly affected.

Locking the front axle diff - yes, it's a nightmare to steer admittedly, and should be used with extreme caution, but I've done a lot of loose-grip off road kms with the CD locked and I've never noticed the steering become difficult. It's different, agreed and maybe a little heavier, but it's never indicated to me that it might do anything like push me straight on at a bend.

Anyway, I'm very happy to use low with an open diff, and so far I've never needed to use it on asphalt, always grass, mud or shale, so I can't see that I'm unduly straining anything, there's no wind-up, nothing.

I like this thread though, it's making us think about what we're actually doing in these trucks when we press the magic buttons

Too busy today to measure my TF box, and it's too dark now, but maybe tomorrow I'll get a tape out and have a crawl under.

Thanks all.

 

[chapel gate]

"I also dont see that by locking the CD the steering would be overly affected.

Locking the front axle diff - yes, it's a nightmare to steer admittedly, and should be used with extreme caution, but I've done a lot of loose-grip off road kms with the CD locked and I've never noticed the steering become difficult. It's different, agreed and maybe a little heavier, but it's never indicated to me that it might do anything like push me straight on at a bend."

Agreed. sometimes i reckon the theory doesnt allways pan out in practice.