part time vs full time

[80t0ylc]

Will still be independent until low range is selected or the center diff switch is pushed into the “on” detent.

That's right, I keep forgetting about how the 80's center diff is what actually locks the shafts together - except for a malfunctioning VC.... Anyway, the reason I asked might be appropriate for some to understand the difference between a modified full time 80 series PT transfer case and an original PT transfer case. I found that out with my '81 Mini when flat towing it behind my camper. I'll flat tow either my 80 or my Mini, depending on which one that I'm planning to use. Anyway, with the 80, I just put the transfer case in neutral and even leave the tranny in park & it tows just fine. Learned that from Cristo Slee after disco-ing both drive shafts a couple of times. Well, hell - that should work for the Mini - or so I thought...until I wore out the front drive shaft and it just self destructed on a trip from Oregon to Arizona. I just assumed that even though with the OEM TC on the Mini, you 1st shift to 4H and then neutral that the shafts would be independant - with it in neutral - being used to my 80. I figured that the front drive shaft wouldn't spin with my hubs unlocked. Wrong! So now, after finally getting another front drive shaft, it gets towed with TC in 2H & the tranny in neutral. Long story to come to a point that if you're flat towing with an original PT transfer case, leave the TC in 2H and if it's a manual tranny, shift it to neutral. If it's an auto tranny, disco rear drive shaft or trailer it. For an original, plain old part time transfer case, even in neutral, the drive shafts are locked together because the TC is still in 4WD. 2WD or 2H must be selected to unlock the drive shafts. Which brings up an important point. If you have shifted it into neutral on a hill and expect to shut off engine and leave it in gear and think it'll hold with out the parking brake, but that also applies to the 80's TC - PT or full time, if you ignore the warning light on the dash.

 

[mjosoba]

I haven’t done the part time conversion but have my front shaft out and have driven it that way for probably 2,000 miles. I hate it. It handles much less concisely, the wheel doesn’t seem to like to return by itself as well. Highway sucks. It’s wanders back and forth and the effect the road crown, or even slight ruts on black top, has is much more pronounced. The wandering and all that could be the symptom of loose bushings, but it was definitely not there when in AWD. Mpg difference is not noticeable, and handling on slick ground is awful. 10/10 would not do.

Today I got my shaft back and put on. Took the same exact route I’ve been driving with the front shaft pulled, and which I wrote the above comment about. I should mention while I was putting the shaft back on, I got a pry bar and checked all the bushings, all were good.

Result... Back to normal. Stable and confident feeling even on the badly cupped and potholed 2 lane highways that were so darty and unpredictable in RWD. One or two fingers are all that’s needed instead of the two hands needed to make sure it didn’t dart off the side. Am I 100% sure there isn’t some underlaying suspension issue that was the cause, and not the 2wd? No. But putting it back how it should be solved all the issues. Or at least covered it up... ah crap. Lol.

 

[ALX4X4]

You can pull bigger drifts in 2WD enough said !

 

[mjosoba]

Can’t argue with that!

 

[Jason Andrews]

In summary, please correct/add/subtract where neccessary (isnt that what forums are for? lol). Assuming the rig has not been heavily modified and is at or close to stock specs the following is true for the part time 4wd mod (with manual locking hubs):

positives:
less wear and tear on front end
reduced vibration and road noise
possible fuel consumption gains
more versatiliy in regards to auto-locking front diffs
more versatility on the trail in certain situations
more responsive throttle and or more torque to rear (not 100% split, 100% rear)
all wheel drive (previous, stock condition) can still be achieved with hubs free and CDL off

negatives:
will not corner as well
steering is different
have to get out and manually adjust hubs when engaging 4x
more complexity/components means more can go out (CDL, hubs)
further mods are neccessary to correct/minimize handling issues and/or castor needs adjustment if lifting or heavily modified
responsiveness and agility/handling is worse safety

Fixed it for ya. You can either have 2wd or the CDL locked for 4WD (you have to lock the hubs or you will blow them) After a PT kit is installed there is no AWD feature anymore. Like @jcardona1 said I leave my hubs locked all the time even when in 2WD. I personally don't like the 2WD since I routinely run into ice and snow patches on the highway. It's sketchy to be traveling at highway speeds in 2WD and hit snow pack. Switching into 4WD requires pulling over to engage the CDL which is not viable when traveling at highway speeds.

 

[rghouse]

10-4, TY Jason Andrews for clearing that up b/c thats a very important detail about this mod

I guess I will add the possibility of blowing out your hubs to the negatives of part time, because I dont trust myself. Half the time I have to use 4wd in my truck I am in a high stress situation and I occasionally forget to unlock/lock hubs. I'm covered in mud, my hands are numb, the family is upset, the other guy is upset, i'm mad I got stuck again...on and on, and when beverages are involved

I suppose with the fear of ruining my hubs, and with the more leisure nature of 4x'in in the cruiser it may be different. CDL light on: check, double check, and re-check hubs. My front-end geometry and driving is as such that I believe I will use 2wd. I think gears come first at this point still...

 

[Dissent]

I've not heard of the hub blowing out. What's going on there?

 

[80t0ylc]

I've not heard of the hub blowing out. What's going on there?

Not only that, but why have they made the PT conversion at all.....if they leave the hubs engaged most or all of the time? The 1st three positives in @Jason Andrews post are negated, by doing that. No disrespect intended to PT mod owners, but just askin'

 

[Dissent]

Not only that, but why have they made the PT conversion at all.....if they leave the hubs engaged most or all of the time? The 1st three positives in @Jason Andrews post are negated, by doing that. No disrespect intended to PT mod owners, but just askin'

Good points. I don't leave my hubs locked because I still get drive shaft vibes at 75-80MPH which is why I went PT in the first place.

 

[jcardona1]

Not only that, but why have they made the PT conversion at all.....if they leave the hubs engaged most or all of the time? The 1st three positives in @Jason Andrews post are negated, by doing that. No disrespect intended to PT mod owners, but just askin'

My reasoning is in post #6

 

[Jason Andrews]

I've not heard of the hub blowing out. What's going on there?

If you engage the 4WD, aka lock the CDL with the hubs in 2WD- unlocked, it will ruin the hubs.

Not only that, but why have they made the PT conversion at all.....if they leave the hubs engaged most or all of the time? The 1st three positives in @Jason Andrews post are negated, by doing that. No disrespect intended to PT mod owners, but just askin'

I basically "had to" since I went to chromoly and the hardened birfs don't last as long. Yes, they are still turning along with the diff, but they are just rotating and not having engine torque put through the front drivetrain. Less than ideal, but better than getting out to lock the hubs if you think you might need 4WD.

Good points. I don't leave my hubs locked because I still get drive shaft vibes at 75-80MPH which is why I went PT in the first place.

Leaving your hubs locked with a part-time kit does not make your front driveshaft spin. Only locking the CDL does.
Edit: actually I think this statement is incorrect. My brain isn't working

 

[thatcabledude]

Yeah, your brain isn't working.

If you engage the 4WD, aka lock the CDL with the hubs in 2WD- unlocked, it will ruin the hubs.



I basically "had to" since I went to chromoly and the hardened birfs don't last as long. Yes, they are still turning along with the diff, but they are just rotating and not having engine torque put through the front drivetrain. Less than ideal, but better than getting out to lock the hubs if you think you might need 4WD.



Leaving your hubs locked with a part-time kit does not make your front driveshaft spin. Only locking the CDL does.
Edit: actually I think this statement is incorrect. My brain isn't working

 

[80t0ylc]

..........I basically "had to" since I went to chromoly and the hardened birfs don't last as long. Yes, they are still turning along with the diff, but they are just rotating and not having engine torque put through the front drivetrain. Less than ideal, but better than getting out to lock the hubs if you think you might need 4WD...........

Maybe they didn't tell you when you installed the PT kit, but a major negative with the chromoly axle shafts is how they wear at the seal when spun continously. That is why they're suggested to be used with a PT setup. Chromoly is supposed to be superior with the torque stresses of hard off road use, but not the wear, at the axle seal, experienced with constant turning front drivetrain of a full time setup. The wear causes the seal to leak and they fail to keep your gear oil and grease separated. So leaving your hubs locked will spin the front drive train all the way to your center diff/transfer case. If it were me, with your setup, I'd lock your hubs ahead of time - before you need 4WD - like when you hit the dirt. Then unlock them before heading home on pavement. Inclimate weather being the exception. Some winters in snow country, we'll leave the hubs locked until we see bare pavement - sometimes all winter! That's how I ran all my PT rigs before I got my 80.

 

[Jason Andrews]

robbie A. mentioned a long while ago that he didnt like the handling characterisitics when he pulled his front driveshaft for long trips in 2wd. And im curious what people who have done the part time tcase kits think of the differences in handling? Does the front feel too light/ twitchy/ darty ? Or understeer/ oversteer etc?

I think we had the same sentiments. I told Robbie I hated the feel of the part time. The more your rig is lifted the more the stock rear suspension setup can create under/oversteer and this is what I didn't like about it. Robbie rebuilt my t-case and did the 2WD kit it for me in 2012.

Maybe they didn't tell you when you installed the PT kit, but a major negative with the chromoly axle shafts is how they wear at the seal when spun continously. That is why they're suggested to be used with a PT setup. Chromoly is supposed to be superior with the torque stresses of hard off road use, but not the wear, at the axle seal, experienced with constant turning front drivetrain of a full time setup. The wear causes the seal to leak and they fail to keep your gear oil and grease separated. So leaving your hubs locked will spin the front drive train all the way to your center diff/transfer case. If it were me, with your setup, I'd lock your hubs ahead of time - before you need 4WD - like when you hit the dirt. Then unlock them before heading home on pavement. Inclimate weather being the exception. Some winters in snow country, we'll leave the hubs locked until we see bare pavement - sometimes all winter! That's how I ran all my PT rigs before I got my 80.

Yep, thats why my knuckles are leaking! But the front diff is full and I'm due for a knuckle rebuild from @ajax1 anyway. If this was my DD, like I am assuming the OP is, I would not be running it with the hubs locked since it would increase the front end maintenance by a lot.

I have 2-3ft of snow to get out of my driveway and then 20 mins of very curvy and icy washboard roads to pavement. Then 20 mins of very curvy pavement with icy canyons and possible snow drifts blocking the road to reach the highway. Then its 45+ minutes of 45-65mph highway that can have snow/ice and/or 18wheelers driving 20mph out of nowhere. Keeping it in 2WD is scary so I rarely ever unlock the hubs in the winter. Also if you have a hint of wander or death wobble it will be greatly amplified as @mjosoba reported when recently pulling the front driveshaft.

IIRC if you lock the CDL in high range you lose your ABS if equipped? Is that correct? There was a huge debate years ago ~2006 about the comfortableness of driving high speeds with the CDL locked on snow/ice and no ABS. Many mudders hated it and said it was very unsafe which is not my experience. I'm just trying to let anyone who is thinking about doing this mod know that I see not having AWD as the biggest drawback especially in areas that receive snow. When you are driving on snowy roads in 4WD and pull into the Starbucks parking lot that has been plowed its not easy to park until you unlock the CDL

 

[panamacruiser]

Sorry, haven't read you all, but the things seems to be if you like full time or 2WD on a converted full time ...can't say much here, my car has manual hubs from factory, it is just great, thing is that I now leave hubs locked just not to get down when the need comes for 4WD (getting old) nothing different with or without hubs locked or unlocked, just that when locked the diff actually moves so I inspect for shortage of oil a lot more than before...I've know of some folks that have had a tough time removing front shat on a full time as the car moves very slowly, guess computer has a lot to do with it...

 

[Dissent]

I think we had the same sentiments. I told Robbie I hated the feel of the part time. The more your rig is lifted the more the stock rear suspension setup can create under/oversteer and this is what I didn't like about it. Robbie rebuilt my t-case and did the 2WD kit it for me in 2012.




Yep, thats why my knuckles are leaking! But the front diff is full and I'm due for a knuckle rebuild from @ajax1 anyway. If this was my DD, like I am assuming the OP is, I would not be running it with the hubs locked since it would increase the front end maintenance by a lot.

I have 2-3ft of snow to get out of my driveway and then 20 mins of very curvy and icy washboard roads to pavement. Then 20 mins of very curvy pavement with icy canyons and possible snow drifts blocking the road to reach the highway. Then its 45+ minutes of 45-65mph highway that can have snow/ice and/or 18wheelers driving 20mph out of nowhere. Keeping it in 2WD is scary so I rarely ever unlock the hubs in the winter. Also if you have a hint of wander or death wobble it will be greatly amplified as @mjosoba reported when recently pulling the front driveshaft.

IIRC if you lock the CDL in high range you lose your ABS if equipped? Is that correct? There was a huge debate years ago ~2006 about the comfortableness of driving high speeds with the CDL locked on snow/ice and no ABS. Many mudders hated it and said it was very unsafe which is not my experience. I'm just trying to let anyone who is thinking about doing this mod know that I see not having AWD as the biggest drawback especially in areas that receive snow. When you are driving on snowy roads in 4WD and pull into the Starbucks parking lot that has been plowed its not easy to park until you unlock the CDL

I'm curious how many PT kits are running in trucks with worn rubber bushings (control arms, panhard, etc.). I replaced every rubber bushing on the LX with new OEM and it tighted up SIGNIFICANTLY. After that was finished, I went part time. Maybe all that wandering, death wobble and what not is due to worn suspension bushings? I also installed caster plates prior to the bushings and PT which helped the wandering a lot.

 

[rghouse]

Sorry, haven't read you all, but the things seems to be if you like full time or 2WD on a converted full time ...can't say much here, my car has manual hubs from factory, it is just great, thing is that I now leave hubs locked just not to get down when the need comes for 4WD (getting old) nothing different with or without hubs locked or unlocked, just that when locked the diff actually moves so I inspect for shortage of oil a lot more than before...I've know of some folks that have had a tough time removing front shat on a full time as the car moves very slowly, guess computer has a lot to do with it...

Can you give us some more info on stock PT 80 series from SA? (I dont see any specs on your signature). What year? model? lifted? lockers? Gear ratios? MPGs? Engine? etc.?

I understand the Part time cruisers are sought after in your region over the full time, is that true? What other features (Drive train etc. not amenities) did the SA cruiser come with (that you know of) that differs from USA models?

 

[sunrk]

With my 80, when it's in neutral on the t-case it really is in neutral. If I want 2wd I put it in 2h (normal setting), if I want 4wd I put it in either 4h or 4l and go outside to lock the Aisin hubs otherwise it's still only in '2wd' road-wise.

 

[Jason Andrews]

I'm curious how many PT kits are running in trucks with worn rubber bushings (control arms, panhard, etc.). Maybe all that wandering, death wobble and what not is due to worn suspension bushings?

Most who are considering this mod have done many of these PM items before doing the PT kit. In addition, if they haven't checked their tie rod ends, wheel bearing tightness, and upper/lower trunnion bearing condition then they are asking for wandering and death wobble since 2WD will accentuate any problems.

I was just traveling 60mph on paved highway. If I was driving the Cruiser I would not have had the 4WD engaged. Then this....40mph sidewind. What are you gonna do if there is potential to hit slick roads? Drive with CDL locked on curvy paved roads creating high stress and heat in the t-case for many miles, OR pullover at the drop of a hat to lock the CDL or even worse get out and lock the hubs before you even do that? If I had to do the part-time kit again I would think long and hard about it. It's not for everyone!

 

[cybrstar]

Are you guys adding toe to compensate for the lack of thrust vectoring?

This is true for those that are running in 2wd. You need to run more positive toe than normal because naturally the tires want to move towards each other causing negative toe. Compared to when your driving AWD the tires naturally want to toe out.

And the LC’s factory settings are for more toe in.

I personally love my part time kit, was running locking hubs before I installed the unit recently. It feels more like a car and not a tank. Plus better gas mileage for longer travels between stops for a gas station. I’ve driven through everything with the part time. Wind snow rain. The LC is so heavy that it doesn’t care what you throw at it.