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Post by russiankid on Jan 25, 2015 17:03:40 GMT -5
I've been searching around trying to understand how the 4 wheel system works on my Sport. So from what I gather, the passenger side half shaft is engaged and disengaged with the freewheel clutch which is controlled by the vacuum solenoids under the airbox. If that is the case, when in 2H, the driver side and passenger side axles should not be dependent on one another. I jacked up my Sport this morning and noticed that spinning one wheel in return spins the other the opposite way (as an open differential would). However, shouldn't the passenger side be disengaged from the diff?
Another question is should the 4wd light flash when you first put it in 4wd, and once you move a few inches it lights up solid? Sometimes, it'll be lit solid instantly, but other times it will take it a second of rolling in drive before it lights up solid.
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Post by ES_97Sport on Jan 26, 2015 13:03:46 GMT -5
... So from what I gather, the passenger side half shaft is engaged and disengaged with the freewheel clutch which is controlled by the vacuum solenoids under the airbox. If that is the case, when in 2H, the driver side and passenger side axles should not be dependent on one another. I jacked up my Sport this morning and noticed that spinning one wheel in return spins the other the opposite way (as an open differential would). However, shouldn't the passenger side be disengaged from the diff? Correct. When disengaged, the the left and right are independent of each other. In 2WD turning the passenger side wheel should do nothing to the differential carrier, drive shaft, driver side half shaft, etc. If that's happening when in 2WD then the axle is in 4WD. I don't remember how that works in respect to whether applying vacuum engages 4WD on the axle or disengages 4WD. If applying vacuum engages 4WD then something sounds like its stuck and not disengaging. If removing vacuum engages 4WD then a vacuum leak may be allowing engagement of 4WD. Some of the other guys have been fiddling with this so they may be able to chime in. Been a long time since I've had to touch that myself.  That is normal behavior. Same principal as manual hubs. You have to get everything to line up to engage. So, sometimes you get lucky and everything engages immediately and sometimes (most of the time) things have to spin to align and then engage. With manual locking hubs you can hear them 'click' as they lock as you rock the vehicle a bit. Nothing out of the ordinary. Edward |
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Post by russiankid on Jan 26, 2015 13:12:21 GMT -5
Luckily the front axle is stuck in 4wd mode rather than not being able to engage into 4wd. I'll have to do some more research and see what the issue is as this doesn't help my gas mileage.
Another thing is that my cruise control doesn't work, and from what I have read the free wheel switch is usually the culprit. I wonder if a bad freewheel switch also plays a roll in engaging and disengaging 4wd.
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Post by dclambertt on Jan 26, 2015 18:03:34 GMT -5
Another thing is that my cruise control doesn't work, and from what I have read the free wheel switch is usually the culprit. I wonder if a bad freewheel switch also plays a roll in engaging and disengaging 4wd. When my cruise went out it was only a split in the vacuum hose, and once repaired it's been fine. |
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Post by ES_97Sport on Jan 26, 2015 19:09:06 GMT -5
Luckily the front axle is stuck in 4wd mode rather than not being able to engage into 4wd. I'll have to do some more research and see what the issue is as this doesn't help my gas mileage. Another thing is that my cruise control doesn't work, and from what I have read the free wheel switch is usually the culprit. I wonder if a bad freewheel switch also plays a roll in engaging and disengaging 4wd. You're lucky it didn't do what mine did. Try to engage/disengage repeatedly. That sucked. Un-driveable.  Loose ground wire. Sigh. Yep. Suck gas it will and won't do anything nice to your drive train either. No idea there. I've never had any issues with the cruise on any Sport. Edward |
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Post by tirill on Jan 27, 2015 2:00:49 GMT -5
Edward....
Well, I have tried to understand the 4WD on my 2000 Pajero Sport, but I must say, like "russiankid", I am still confused.
Anyhow it seems like U have 100% knowledge about it, so I will plague U with a few new questions.
When I engage from 2WDH to 4WDH on my transfer box, what happens then?
The forward propeller shaft is engaged inside the transfer box by means of an synchronized splines coupling and starts rotate??
When the propeller shaft is rotating and COUPLING in position, an electrical switch is activated that activates the 2 solenoid valves and applies vacuum in the front RIGHT drive shaft and another splines coupling that "locks" the system.
I have for MANY years believed that the 4WD engagement ONLY consisted of the right drive axle vacuum engagement, but now I am very unsure about this. When I move the lever from 2WD to 4WD there is obviously something mechanical happening in the transfer box. What??
So, when I am driving in 2WD in normal road, what is moving in the front axle?? Only the left drive shaft and the differential is rotating hystericly in the the front axle?? The propeller shaft and the right driveshaft is still??
So, what do U gain with this strange design??
I was told when I bought my Pajero Sport 2000 that there is no idea,, or even not POSSIBLE to install manual hubs to reduce fuel consumption. This due to the 4WD was designed the way it is. Now I am more doubtful about this.
The fuel consumption has always been a bit of problem with that car, and the gas prices here in Europe. I can manage by means of "keeping an egg " between my foot and the pedal to reach 100km on 10 liters on road.
More normal is 13-14 Liters on 100 km....
My car should really had been a Diesel engine, like most others markets, but the car tax system in Sweden is extremely unfavorable taxed for diesel cars 10 years ago, so 95% of the Pajero Sports are petrol cars here.
In France, Germany and other European markets it is the opposite
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Post by russiankid on Jan 27, 2015 10:39:57 GMT -5
I'll have to check my vacuum lines and see if one of them is split.
Edward,
The passenger side half shaft being constantly engaged to the differential doesn't really hinder the drivetrain, it just sucks on the gas mileage as you're having more parts in rotation. The transfer case is still disengaging the front drive shaft so no issues there.
Tirill,
From what you're describing that is how I imagine the system works. The transfer case engages the front driveshaft which in return spins the front differential rather than the front left wheel free spinning the differential and driveshaft which free spins until the transfer case is engaged into 4wd. Manual hubs would eliminate this for sure, but you'd have to perform the swap first and if you were ever stuck, you'd have to hop out and lock the hubs before you can use 4wd.
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Post by bdmontero on Jan 27, 2015 12:50:49 GMT -5
Or be smart and lock them in first;D
Sent from my SM-N900V using proboards
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Post by ES_97Sport on Jan 27, 2015 14:44:21 GMT -5
... Edward, The passenger side half shaft being constantly engaged to the differential doesn't really hinder the drivetrain, ... That is correct. (brain going in a different direction than my fingers) [/quote]... The transfer case is still disengaging the front drive shaft so no issues there. ...[/quote] Correct. With the transfer case disengaged there is no bind between the front and rear drive trains. I'm not sure that's actually correct. I know everything from the wheels into the differential turns even in 2WD. So, that would be the driver side half shaft as well as both the passenger side half shaft sections. I believe that includes the carrier and therefore drive shaft. If you lock the driver side hub and unlock the passenger side hub on my big Sport which is the equivalent of 2WD on a stock Sport, and turn the driver side wheel the drive shaft turns (which means the carrier is turning). Granted that's with an ARB but unlocked its an open differential - the same as the front of a stock Sport. So, if I'm correct, its not 'more parts', because everything turns in 2WD same as 4WD anyway. Just no driving force from the transfer case. Dang. Now I'm going to have to jack up my little '97 and test this out and make sure I'm correct. GRRRR! I just found out we have weather moving in on Fri. Anyone have a correctly functioning non-AWD Sport they can jack up and test this? I may not be able to before it snows again. Edward |
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Post by ES_97Sport on Jan 27, 2015 15:28:57 GMT -5
... When I engage from 2WDH to 4WDH on my transfer box, what happens then? Simplified, when the transfer case is shifted from 2WD to 4WD (i'll ignore 4LO as everything here works the same excepting the gear ratio in the t-case) ... 1) The transfer case shifter engages the 4WD HI gear set which splits power to both the rear and front drive shafts. 2) The solenoid on the axle engages and the passenger side split half shaft becomes a solid unit. At this point both wheels are connected to the differential. 3) You are now in 4WD. Excluding what electronics do what, its actually a relatively simple system. Roughly, that is correct. They're helical cut gears. The Mitsu t-case is a chain drive, so the front output shaft (for the front drive shaft) is connected to the input shaft via a chain. (think bicycle and the chain connecting the pedals to the rear wheel) There is a terminology issue here. The drive shaft is the propeller shaft. This is the unit that comes out of the transfer case and connects to the differential (front or rear). The shafts between the wheels and differentials are called axle shafts. The housing is the axle assembly. There is nothing for the drive shaft to 'couple' with/to. A transfer case is nothing but a manual transmission with fewer gears and two outputs. So, shifting from 2WD to 4WD HI to 4WD LO is just like shifting gears from 1st to 2nd to 3rd in a 3-speed M/T. Once you shift from 2WD to 4WD the drive shafts are turning - independent of anything else. This is a mechanical link actuated by the gear shifter (and you), just like manual transmission gears. I don't know how many solenoids, but yes, vacuum is applied which slides a splined sleeve over both shafts 'coupling' them together into a single unit. With some makes of vehicles you would be correct. However, you are half correct. The front axle shaft is half of the equation. The engagement of the transfer case into 4WD is the other half. This is how both the Montero as well as the Montero Sport work. Everything in the axle housing turns. Unlike Ford or some others, Monteros and Montero Sports do no utilize a automatic locking hub system - our wheels are fixed to the half shafts. On the drive side this means that it turns the entire half shaft as well as the spider gears inside the differential carrier. I believe that also includes turning the carrier itself as well as the drive shaft. On the passenger side the same thing happens. The wheel turns the entire uncoupled outer section of the half shaft. The DRIVER SIDE wheel turns the passenger side inner stub section of the half shaft. The 'stub section' is the little short piece that fits into the differential and couples with the outer passenger half shaft. So, ... DW--- DIFF -- ----PW ________^^ this would be the 'stub section' or stub shaft DW - driver side wheel PW - passenger side wheel DIFF - differential and carrier Shift on the fly. That is the entire point of this convoluted mess. There is no point otherwise. Thank all the people who don't want to get out and lock manual hubs. And this may sound sexist, but it really is mostly women that demanded this. Its not a 'strange' design. In fact its less convoluted than some other shift on the fly designs. What it is is a STUPID CONCEPT. Unless you have All Wheel Drive (AWD) that is a load of crap. You absolutely CAN install manual locking hubs and it does save a considerable amount of fuel. Installing manual locking hubs and leaving them unlocked unless you need 4WD is the #1 top of the list fuel saver. AGAIN - as long as you DO NOT HAVE AWD. AWD turns everything all the time and the transfer case design relies on having the front engaged or damage will occur to the t-case. Edward |
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Post by jkdv8 on Jan 28, 2015 14:42:57 GMT -5
I think applying vacuum engages it for towing purposes. On another note I think one of mine lines is split. Noticed my cruise doesn't work anymore.
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Post by russiankid on Jan 28, 2015 21:04:37 GMT -5
I haven't got around to checking the vacuum lines or checking if the freewheel clutch mechanism is stuck or the solenoids are bad.
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Post by ES_97Sport on Jan 30, 2015 12:24:38 GMT -5
I think applying vacuum engages it for towing purposes. .... Can you explain? I'm not sure what you're saying here. Edward |
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Post by jkdv8 on Jan 30, 2015 15:21:00 GMT -5
Oh yea I was referring to tow truck towing not trailer towing. In the event you need a tow truck more than likely the engine would be disable. You wouldn't be able to apply vacuum to unlock it. So even if it was in 4 wheel drive, when you turn the engine off it goes back to 2wd. That's how I understood it. I could be wrong.
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Post by ES_97Sport on Feb 2, 2015 18:26:58 GMT -5
Oh yea I was referring to tow truck towing not trailer towing. In the event you need a tow truck more than likely the engine would be disable. You wouldn't be able to apply vacuum to unlock it. So even if it was in 4 wheel drive, when you turn the engine off it goes back to 2wd. That's how I understood it. I could be wrong. Ok. I believe that is correct. Applying vacuum slides the splined coupling over the shafts and links them together. However, I believe that if the vehicle is in 4WD and then turned off, vacuum is maintained and the vehicle remains in 4WD. There is a large vacuum canister on the passenger side that I think is there to maintain vacuum in the system while the vehicle is off. Edward |
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