Part Time 4WD 1997 Cruiser Conversion ...without differential lock switch ? (1 Viewer)

[GringoBob]

Hello people ! I am a retired gringo in Costa Rica and live off the pavement ...probably on the stone/dirt roads 25 miles (often more) a week.

I just bought a 1997 Cruiser (supposedly) with full-time 4WD. But ...it has locking front hubs ...and no center differential lock button.

Runs badly on pavement with hubs locked, and the rear slips with the hubs unlocked on unpaved hills. It's great on dirt with hubs locked, great on pavement with hubs unlocked. So evidently it's been converted to part-time 4WD.

I suspect without the differential lock button the differential must be permanently locked to function. ...Thus, when it's running with the hubs unlocked that the front tires are free-wheeling but the rest of the front drive system is still spinning. Sound right ?

Any ideas on how this modification was done ? Is there a possibility of installing a central differential lock/unlock button to quiet (unlock) the front of the system while in 2WD ?

The previous owner had the car 8 years never even thought about it ...he just locked the hubs off pavement and unlocked them on pavement.

Any feedback would be appreciated.

PS This car does get a bit better gas mileage than the full-time 4WD version ...so maybe even with the front differential locked (in 2WD) ...maybe the conversion still helps a bit on mileage.

 

[bloc]

Do you know if CR cruisers had the viscous coupler?

Does the CDL light turn on when you put the transfer case in Low?

If not it's possible they locked the center diff then pulled the fuse so it can't unlock and have been running like this indefinitely.

when on pavement with the front hubs unlocked, does it feel like the transmission is slipping? If so the CDL may be unlocked and the viscous coupler is taking a serious beating.

Truly uncoupling the front of the system requires getting into the transfer case and installing a "part time kit" along with selectable locking hubs. This replaces the center diff with a spool so that the rear output is driven constantly, and the front output is only engaged when the (formerly) CDL is locked.

Somehow I doubt this was done 8 years ago.

If you did have a part-time kit installed.. the CDL button becomes your "4wd" button.

 

[GringoBob]

Do you know if CR cruisers had the viscous coupler?

Does the CDL light turn on when you put the transfer case in Low?

If not it's possible they locked the center diff then pulled the fuse so it can't unlock and have been running like this indefinitely.

when on pavement with the front hubs unlocked, does it feel like the transmission is slipping? If so the CDL may be unlocked and the viscous coupler is taking a serious beating.

Truly uncoupling the front of the system requires getting into the transfer case and installing a "part time kit" along with selectable locking hubs. This replaces the center diff with a spool so that the rear output is driven constantly, and the front output is only engaged when the (formerly) CDL is locked.

Somehow I doubt this was done 8 years ago.

If you did have a part-time kit installed.. the CDL button becomes your "4wd" button.

Do you know if CR cruisers had the viscous coupler?

Does the CDL light turn on when you put the transfer case in Low?

If not it's possible they locked the center diff then pulled the fuse so it can't unlock and have been running like this indefinitely.

when on pavement with the front hubs unlocked, does it feel like the transmission is slipping? If so the CDL may be unlocked and the viscous coupler is taking a serious beating.

Truly uncoupling the front of the system requires getting into the transfer case and installing a "part time kit" along with selectable locking hubs. This replaces the center diff with a spool so that the rear output is driven constantly, and the front output is only engaged when the (formerly) CDL is locked.

Somehow I doubt this was done 8 years ago.

If you did have a part-time kit installed.. the CDL button becomes your "4wd" button.

Thanks SilverStar for the rapid response !

This Cruiser is a 1997 LTD Anniversary Edition from the USA (and still without several options.) I believe that the full-time 4WD in this model was equipped with a viscous coupler. No ...the tranny/motor seems solid/strong (so far) in all modes ...no slippage that I can detect. And yes ...the CDL light does come on in when in Low (just checked ...never tried it before.) And there is sometimes a whirring sound when I descend a hill with engine breaking (pedal off gas) ...notable but not very scary.

The Cruiser is in great shape, and looks/moves solid for a SUV of it's years (only about 160K miles.) The underbody is extremely clean and rust free and the body and interior shows signs of age ...but not of abuse. Some cracked plastic components as is typical (and I want to see what I can do with that.) The engine compartment is just short of immaculate.

So I want to do a partial restoration on this baby huey ...but I've got to figure out ...what it needs !!!

If there are any problems with this conversion ...I want to correct it ASAP. And get this sweet gal right again.

And after years with my Toyota 4Runner and Mitsu-Montero ...with auto-locking hubs ...in the Costa Rican rainy season and mud ...I kinda hate to get out of the car to lock hubs. But, I doubt there is any way to put an auto-hub system in this Cruiser. If you know a way (without restoring full-time 4WD) ...let me know.

And, thanks again SilverStar !!!
GringoBob

 

[-Spike-]

It probably does have a VC, and it's locked up. The previous owner put locking hubs on instead of fixing or removing the VC. This would be even more likely if the CDL light on the dash comes on when in low range. If it doesn't, see if it comes on when the key is 'on' but engine not running (all dash lights should be on momentarily, at least, as a bulb test).

EDIT- I see you responded while I was typing, and your CDL light works in low range. I'd bet money on the VC being locked up, probably after the vehicle was towed with two wheels on the ground. Remove the useless VC and leave the hubs locked all the time- or put drive flanges on it.

 

[GringoBob]

It probably does have a VC, and it's locked up. The previous owner put locking hubs on instead of fixing or removing the VC. This would be even more likely if the CDL light on the dash comes on when in low range. If it doesn't, see if it comes on when the key is 'on' but engine not running (all dash lights should be on momentarily, at least, as a bulb test).

EDIT- I see you responded while I was typing, and your CDL light works in low range. I'd bet money on the VC being locked up, probably after the vehicle was towed with two wheels on the ground. Remove the useless VC and leave the hubs locked all the time- or put drive flanges on it.

Spike -
Great name !

I am a bit confused ...I bought this car in Costa Rica for about $12,000 ...which is a bargain ...these Cruiser 80 vehicles go as high as $18-$20 K here (import costs, taxes.) My Cruiser cost about $12K ...a bargain (considering the condition). But I expected to put a couple ..to $3K more into into get it up to spec. It seems to run fine (at the moment) ...what do I need to do to make this a true part-time 4WD vehicle (or would it be better to convert it to full-time again?)

If I burn out the VC (if it still has it) ...then i need to buy a part time kit ...another $500 ? No ? ...No big loss. Or would it be better to go back to full-time 4WD (which the off-road fanatics here would abhor !)

And if the VC is locking-up (but, seems to me ...so far so good) ...what are the symptoms ??? What will happen ???

Anyhow, I'm just looking for a solution to this possible problem (if there is a problem.) Suggestions are appreciated !

Thanks,
GringoBob

 

[GringoBob]

S

Spike -
Great name !

I am a bit confused ...I bought this car in Costa Rica for about $12,000 ...which is a bargain ...these Cruiser 80 vehicles go as high as $18-$20 K here (import costs, taxes.) My Cruiser cost about $12K ...a bargain (considering the condition). But I expected to put a couple ..to $3K more into into get it up to spec. It seems to run fine (at the moment) ...what do I need to do to make this a true part-time 4WD vehicle (or would it be better to convert it to full-time again?)

If I burn out the VC (if it still has it) ...then i need to buy a part time kit ...another $500 ? No ? ...No big loss. Or would it be better to go back to full-time 4WD (which the off-road fanatics here would abhor !)

And if the VC is locking-up (but, seems to me ...so far so good) ...what are the symptoms ??? What will happen ???

Anyhow, I'm just looking for a solution to this possible problem (if there is a problem.) Suggestions are appreciated !

Thanks,
GringoBob

Spike & SilverStar-
Another confusing thing. I have been told that if you don't remove the viscous drive ...and run locking hubs in the unlocked position ...the engine power will be transferred to the front wheels (which appear to the full-time 4WD to be slipping) and the car will not move ! Well ...this car appears to move just fine with the hubs unlocked.

Sooo WHATZ UPPP with that ???

Thanks Again.
GringoBob

 

[bloc]

Normally these things are full-time 4wd with a center differential and drive flanges on the front hubs. You go anywhere, both front and rear driveline are powered and the Center Diff (CD) makes up for the speed differences between the front and rear axles when going around tight turns.

From the factory there is a center diff lock (CDL) that engages when the transfer is in LOW, which locks out the center diff, locking front and rear axles together in speed. Installing a CDL switch allows you to engage the CDL in HIGH on the xfer case.

The viscous coupler (VC) is designed to provide some resistance between the two axles when the center diff has a large speed difference. Imagine the front axle on solid ice and the rear on clean pavement. Peg the throttle and without a VC the front axle would just spin.. the CD allowing it to happen.

Now, install locking hubs on the front of a truck with the center diff and VC. As long as they stay locked it acts just like drive flanges.. everything connected, everything OK. But.. unlock those hubs.. and now the center diff is applying torque to both axles, only the front one is disconnected at the hubs. Now the VC is working its butt off trying to match the speeds (it can't.) This is the "slipping" feeling I mentioned. Basically the truck will move, but lots of torque is lost to the front axle/VC.. meanwhile the VC is in the process of turning into a solid chunk of metal.

This may have happened to the PO.. the VC couldn't handle the abuse and it locked up.

IF that happened.. you no longer have a CD and VC.. you have a full-time spool locking both the front and rear drivelines together.

Your CDL actuator and light may still work because the locking collar can still slide across.. but if the VC is locked up, even when the CDL light is off, it is probably still locked due to the VC.

So you can unlock your hubs and not notice any slipping.



To get TRUE part-time.. you'll need to order a part time conversion kit. A company out of Australia called "Lokka" makes one.. about $300 US with quick shipping over here. Pretty easy install.. can do it with the transfer still on the truck, need a press and bearing splitter. That setup Plus a CDL switch would allow you to completely disengage the front driveline so that the front driveshaft isn't spinning when the hubs are unlocked and the CDL switch isn't pressed.

 

[bloc]

Also.. to test whether your VC is locked up..
transfer case in High (NO CDL light)
jack up one rear tire,
If you have diff locks DISENGAGE them
parking brake off,
unlock the front hubs
transmission in Park.
get under the truck. if you spin the rear shaft it should spin slowly with significant resistance (but it should spin), with the front shaft spinning the opposite direction

What is happening here is the center diff carrier is stopped from turning due to the transmission being in park. Any torque applied to one driveshaft should spin the other the opposite direction due to the nature of a differential. THe VC is what provides the resistance.. but should allow movement. One rear tire in the air and one (or both) front hub unlocked allow the shafts to spin with SOME tires still on the ground.

If your CDL light is off and you can't get the rear shaft to spin at all in these conditions, your VC is likely locked up. Technically the CDL actuator could be messed up too, but your light would stay on at all times in that case.

 

[ppc]

If I burn out the VC (if it still has it) ...then i need to buy a part time kit ...another $500 ? No ? ...No big loss. Or would it be better to go back to full-time 4WD (which the off-road fanatics here would abhor !)

I don't understand the last part of this statement. Do not the off-road fanatics use 4WD? Do they like to only use 2WD until they get stuck? Seems that strategy just tears up the trails... not treadlightly for sure. Otherwise there is no difference between 4WD and AWD with the CDL locked.

 

[-Spike-]

As bloc says, the VC is supposed to transfer some of the power to the axle with traction. Without a VC, if you unlocked your hubs, the open center diff would spin only the front driveline, because there would be no resistance. With a working VC, a small amount of power would be transferred to the rear, and the truck would move sluggishly. When the VC locks up, often from the axles turning at different speeds for an extended period (such as being towed with one axle off the ground and not moving at all, and the other axle turning on the ground) the center differential no longer functions at all, and both drive shafts will turn all the time. Not good when you have traction, such as driving on pavement.

The VC is mainly intended to route some power to both axles when on icy roads. It is not necessary otherwise. A common practice here in the Arizona desert (no snow) is to remove it entirely if there's a reason to open the transfer case (such as installing lower low-range gears). In the rare instance when more traction is necessary, we hit the CDL button. Other than the CDL button, no other parts are necessary for this, just removal of the VC.

My wife's 80 had a locked VC when we got it, and she drove it that way for 5 years before we sold it. It chirped tires around corners, but otherwise wasn't a big issue. I never got around to removing it. If the one in my truck ever fails, it will get gone in a hurry.

 

[-Spike-]

Also- yes, if you want true 2wd, you would need to install a part-time kit, as explained by bloc earlier. Removing the VC and leaving the hubs locked all the time (or replacing them with drive flanges) gives you full-time 4wd again, without the bad road manners.

 

[GringoBob]

Normally these things are full-time 4wd with a center differential and drive flanges on the front hubs. You go anywhere, both front and rear driveline are powered and the Center Diff (CD) makes up for the speed differences between the front and rear axles when going around tight turns.

From the factory there is a center diff lock (CDL) that engages when the transfer is in LOW, which locks out the center diff, locking front and rear axles together in speed. Installing a CDL switch allows you to engage the CDL in HIGH on the xfer case.

The viscous coupler (VC) is designed to provide some resistance between the two axles when the center diff has a large speed difference. Imagine the front axle on solid ice and the rear on clean pavement. Peg the throttle and without a VC the front axle would just spin.. the CD allowing it to happen.

Now, install locking hubs on the front of a truck with the center diff and VC. As long as they stay locked it acts just like drive flanges.. everything connected, everything OK. But.. unlock those hubs.. and now the center diff is applying torque to both axles, only the front one is disconnected at the hubs. Now the VC is working its butt off trying to match the speeds (it can't.) This is the "slipping" feeling I mentioned. Basically the truck will move, but lots of torque is lost to the front axle/VC.. meanwhile the VC is in the process of turning into a solid chunk of metal.

This may have happened to the PO.. the VC couldn't handle the abuse and it locked up.

IF that happened.. you no longer have a CD and VC.. you have a full-time spool locking both the front and rear drivelines together.

Your CDL actuator and light may still work because the locking collar can still slide across.. but if the VC is locked up, even when the CDL light is off, it is probably still locked due to the VC.

So you can unlock your hubs and not notice any slipping.



To get TRUE part-time.. you'll need to order a part time conversion kit. A company out of Australia called "Lokka" makes one.. about $300 US with quick shipping over here. Pretty easy install.. can do it with the transfer still on the truck, need a press and bearing splitter. That setup Plus a CDL switch would allow you to completely disengage the front drive-line so that the front driveshaft isn't spinning when the hubs are unlocked and the CDL switch isn't pressed.

OK ...I understand (I think) ...but my next question ...I am off pavement frequently ...but, I am not a fanatic 4WDer that looks for challenges (I don't look for trouble though it occasionally appears.) I am a "utilitarian" 4WDer. So, am I better off completing the part-time 4WD conversion ...or should I go back to automatic hubs and find a new viscous coupler (that's to go back to full time 4WD) ???

And ...can I use the Cruiser for awhile ...as is ...without expecting a catastrophic failure ??

Note - The Aussies absolutely loathe full time 4WD ...must be a good reason !

 

[GringoBob]

I don't understand the last part of this statement. Do not the off-road fanatics use 4WD? Do they like to only use 2WD until they get stuck? Seems that strategy just tears up the trails... not treadlightly for sure. Otherwise there is no difference between 4WD and AWD with the CDL locked.

I don't understand the last part of this statement. Do not the off-road fanatics use 4WD? Do they like to only use 2WD until they get stuck? Seems that strategy just tears up the trails... not treadlightly for sure. Otherwise there is no difference between 4WD and AWD with the CDL locked.

I think I got it ! ...part-time 4WD ...is the way to go, I think so to !!!

 

[GringoBob]

OK ...If I can understand/believe the previous conversations ...I can continue to drive with a locked viscous coupling without disastrous effects. And ...rather than restore my Cruiser to full-time 4WD ...I am better off going with part-time 4WD, with a part-time kit.

...And, I can drive it awhile without disastrous effects.

So ...my current plan is to buy a part-time kit (which might take awhile to receive in Costa Rica) to continue driving the Cruiser until I am able to properly complete the part-time 4WD conversion.

Can I have some votes for/against that ? And, would the negative voters offer alternative suggestions ?

And thanks to all ...your responses have been very helpful to overwhelming !!!

 

[-Spike-]

OK ...I understand (I think) ...but my next question ...I am off pavement frequently ...but, I am not a fanatic 4WDer that looks for challenges (I don't look for trouble though it occasionally appears.) I am a "utilitarian" 4WDer. So, am I better off completing the part-time 4WD conversion ...or should I go back to automatic hubs and find a new viscous coupler (that's to go back to full time 4WD) ???

And ...can I use the Cruiser for awhile ...as is ...without expecting a catastrophic failure ??

Note - The Aussies absolutely loathe full time 4WD ...must be a good reason !

Part-time or full-time makes no difference in the capabilities of the vehicle. The only reason to go part-time is fuel economy- which is debatable. The reasons to have full-time 4wd are convenience and handling. The handling part is also debatable, but you already have part-time (except that everything is still moving), so you can decide if you prefer the handling either way. Completing the part-time conversion involves installing the kit and removing the VC. You already have the locking hubs (you probably get new ones with the kit). The original hubs are not automatic. They don't exist. What you are thinking of as hubs are just plates that lock the cv axle stub to the hub. Solidly. They do not disengage.

If you want to go full-time 4wd, you have two choices. Replace the VC, or simply remove the VC. It is not required. Leave the hubs locked all the time, or replace them with the factory drive flanges. Install a CDL switch if you want true 4wd while in high range.

If you want to drive it the way it is, you can do that forever as well. Unlock the hubs on pavement. Lock them when you need 4wd. You aren't hurting anything. If you leave them locked on pavement, you are straining the driveline all the time, but if you unlock them, no issues.

 

[bloc]

OK ...If I can understand/believe the previous conversations ...I can continue to drive with a locked viscous coupling without disastrous effects. And ...rather than restore my Cruiser to full-time 4WD ...I am better off going with part-time 4WD, with a part-time kit.
...And, I can drive it awhile without disastrous effects.
So ...my current plan is to buy a part-time kit (which might take awhile to receive in Costa Rica) to continue driving the Cruiser until I am able to properly complete the part-time 4WD conversion.
Can I have some votes for/against that ? And, would the negative voters offer alternative suggestions ?

IMO the two main reasons NOT to part-time in an area without ice/snow are cost and required work to do the install. You already having hubs make half the cost a non-issue.. and to get full-time back you'll need to get into the transfer case anyway to remove the VC, so personally I'd part-time it. The work isn't that difficult, and well documented here.. but you also don't HAVE to do it on any time-line. As you are figuring out, you are probably fine to drive your truck as is just fine for as long as you want.

The only thing I'd also do is try to figure out whether your VC is truly bad.

The only reason to go part-time is fuel economy- which is debatable. The reasons to have full-time 4wd are convenience and handling. The handling part is also debatable, but you already have part-time (except that everything is still moving), so you can decide if you prefer the handling either way.

The only other two things I'd add are reduced wear on the front driveline, (though in his case with the front hubs unlocked there is very little strain on the front driveline and very reduced wear compared to a full-time rig) and the ability to lock the front end out and still drive if something breaks.

Beyond that.. yeah.. not much benefit.

And for the record Lokka's kits can be configured with just the CD spool, or as a kit with locking hubs. Just the spool is about $300

 

[ppc]

I would vote to restore to OEM configuration or do a proper conversion to part-time by adding the spool andthe CDL dash switch. Leaving it as is could possibly cause more wear in the front driveline (spindle bushings/bearings) because it stills spins but without load. This hasn't really been proven one way or the other. If you do the PT conversion then there is no issue because in 2WD the front driveline is completely disconnected and the potiential for a small increase in MPG and lighter feel to the steering. I would remove the front driveshaft and see if you like the result. The other point is we all think the VC has failed but somewhat useable. Could it completely fail and leave you stranded? In any case the VC is an optional component in the fulltime configuration.

 

[CruiseOrlando]

Part-time or full-time makes no difference in the capabilities of the vehicle. The only reason to go part-time is fuel economy- which is debatable.

Sigh. Why to people keep trying to inject this as a reason to do PT conversion?

As a guy who's actually DONE it, I can tell you the reasons to do a PT conversion.

1) Lift. If you go into the 4" range, you're going to probably have vibration issues. PT kit fixes that.
2) Drivability in normally nice conditions. I'm in Florida. We don't have snow, ice, sleet. The truck is on pavement until the moment I go to a trail, which unfortunately isn't that often. The truck is MUCH better with PT kit - turns better, etc. But it's not a reason to do PT, it's a side benefit.
3) Fun. If you take a PT 80 on a trail, you'll know what I mean. It's a lot more fun to drive on trails, and it's amazing how often you DON'T need 4WD. Get a little slip? Rear locker. Still can't make it? 4WD. Rarely do I ever need the front locker.
4) Less use of front driveline components. Again, not a reason to do PT conversion, but a side benefit.
5) Locked up VC. If your VC goes and you don't want to pay for a new one, a PT conversion is about the same price and gives you added benefit.

Gas mileage IS NOT AFFECTED when going to PT. Trust me, I document every tankful for some stupid reason.

 

[GringoBob]

SilverStar, Spike, & ppc -

Thank-you all. In less than a day I have received so many answers to my questions ...clarifications ...options, etc. I doubt I could have found a better source of info online.

A couple more questions (not to tire you guys out):

1) Is there any configuration other than the OEM full-time 4WD that will allow the use of automatic hubs? (I assume the answer is no, since nobody addressed this option ...and, it doesn't appear possible to me.)

2) If I install a CDL switch, what wiring harness will I need ? ...Is the CD set up to accept it ?

Thanks again !!!

 

[GringoBob]

Also ...if my Spanish to English translation is correct ...the former owner of this LC said the higher gas efficiency on this car was due to a more advanced injector/intake-manifold system Toyota put on this model.

I don't know if that is true ...but it appears that the LC does get a little bit better mpg than my 1999 Mitsubishi Montero 3.5 liter SUV, which has a slightly better mpg rating than the LC.