black bear Posted September 27, 2011 Share Posted September 27, 2011 Trying to decide whether to buy Kaiser auto lockers. Has anyone had experience of these? Looking at Kaisers website the explanation of how they work is brief. I understand that when driving straight forwards against resistance (heavy going or uphill), the diff is effectively locked and both wheels on axle will rotate at same speed as crown wheel. When cornering, the inner wheel drives at same speed as crown wheel and outer wheel is forced to "overrun" the inner wheel causing it to effectively free-wheel. If whilst cornering the inner wheel loses traction and spins up to speed of outer wheel, the diff will lock the outer wheel providing traction. All this is fine until a hill descent. It appears that both wheels will overrun the crown wheel and there will be no engine braking? There is no mention of this in their explanation. Ashcroft's recommend installing only in rear axle, presumably to provide some engine braking? Kaiser state that their differentials can be put in both front and rear axles so you would free-wheel down hills or on overrun. Can anyone confirm my understanding is correct as I'm not happy about the lack of engine braking. Quote Link to comment Share on other sites More sharing options...
BogMonster Posted September 28, 2011 Share Posted September 28, 2011 I don't know how they work but don't believe they would make something that can freewheel down a hill! Dave Ashcroft who sells them is on here as a member so may show up to comment hopefully. Quote Link to comment Share on other sites More sharing options...
CwazyWabbit Posted September 28, 2011 Share Posted September 28, 2011 ...... It appears that both wheels will overrun the crown wheel and there will be no engine braking? There is no mention of this in their explanation .... Erm, wouldn't that also mean you have no reverse either..... My guess (and it is just a guess) is there must be more to it than a simple 'ratchet' mechanism Quote Link to comment Share on other sites More sharing options...
MrKev Posted September 28, 2011 Share Posted September 28, 2011 It looks like a sprag clutch, but set up to work with drive in each direction, but also with free wheel in each direction if the torque comes from the driven member. Sort of a cross between a sprag and a centrifugal clutch perhaps - maybe the needle rollers in the bearing cage 'fly out' and engage when drive is applied. Quite elegant, but I can't see how it could permit engine braking on a decent, for example. I would worry about only fitting them on the rear purely on the assumption that you always drive down hills - what happens in the case of a failed ascent? Watching for a knowledgeable explanation with interest. Kev Quote Link to comment Share on other sites More sharing options...
CwazyWabbit Posted September 28, 2011 Share Posted September 28, 2011 This help? Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted September 28, 2011 Share Posted September 28, 2011 Pretty sure, as with the old Detroit lockers which work on the same principle IIRC, the reason they are recommended for the rear only is because they can cause steering and handling issues if used up front. Also, Detroits were recommended only for vehicles of over 100" wheelbase due to twitchy handling on anything shorter, it may also be the case here. Quote Link to comment Share on other sites More sharing options...
black bear Posted September 28, 2011 Author Share Posted September 28, 2011 I've watched the video over and over but cannot see where there would be engine braking. Fourth diagram is showing overrun of outer wheel on a curve. The motion of of the wheel drive member is forcing the rollers into the spaces of the outer drive member connected to crown wheel. This allows the overrun to occur. So if both wheels are forcing it's respective rollers into the outer member (as in hill descent) then both wheels will overrun and no engine braking. Kaiser do not mention hill descents in their documentation but do state that there will be an improvement in fuel economy Dave Quote Link to comment Share on other sites More sharing options...
matt bristol Posted September 29, 2011 Share Posted September 29, 2011 Wouldn't these be illegal if fitted to front and rear as you would effectively have a freewheeling vehicle when not on the throttle? ie its not actually connected to the drive train. Quote Link to comment Share on other sites More sharing options...
Deej Posted September 29, 2011 Share Posted September 29, 2011 As well as the other points raised, if you are correct the handbrake also wouldn't work as it's on the transmission. I just can't believe it would work in that manner due to all the ridiculous problems it would cause! There must be more to it. Quote Link to comment Share on other sites More sharing options...
CwazyWabbit Posted September 29, 2011 Share Posted September 29, 2011 The 'secret' seems to be at 1:38 in the video. My guess is that notch in the two red cages is designed in such a way as to only allow the diff to release when one wheel is going faster. If both are going faster then the red cages are stationary relative to each other and it won't release. Pure guess obviously. Feel free to debate 1 Quote Link to comment Share on other sites More sharing options...
C18RCH Posted September 29, 2011 Share Posted September 29, 2011 Just found this on another forum: Here are a few answers to some common questions from reading this thread and from what was asked at the Expo: 1. Both axels are 100% locked to Drive Speed and neither wheel is able to turn slower than the Differential Ring Gear in forward or Reverse at any time. So no wheel spin or sudden 'unloading' or locking of the diff mechanism. 2. Both axels are free to turn faster than the Ring (though not at the same time) if they are being turned faster by the wheels. The wheel on the outside of a bend, going over a rock or into a hole or depression can therefore turn faster than the other since it has more distance to travel. So no snatching, chirping of the tires, drag or resistance when trying to turn or go over uneven ground. 3. It's going to be about the same price as an ARB uninstalled, which is about $900. Installation should be cheaper though as there are no holes to drill, air lines to run and compressors to mount and wire in, etc., etc. 4. Installation was a breeze. I removed my 3rd, took it to Desert Rat in Mesa, they unbolted my stock carrier and removed it, unbolted my Ring Gear and pulled the bearings from the stock unit, refitted them to the Kaiser Unit, bolted the Kaiser Unit into my 3rd housing, checked the run out on the Ring, checked the meshing of the Ring with the Pinion and adjusted it, handed me back the 3rd and I took it home and bolted it back in. Total installation cost was 2 hrs of shop labor and a couple of hours of mine. 5. US Distributors/Retailers are The Expeditioneers in Chandler, AZ. Contact details are here www.expeditioneers.com but they don't have it up on their web site yet so you'll have to call them. 6. No it doesn't need any special type of oil or maintenance. 7. No it doesn't make any noise that I can hear from the driver's seat in operation. 8. Its only new to us here in the US. It's been on the market about 5yrs or so elsewhere and is made by a company that's been in the vehicle parts manufacturing business since the early 60s. 9. In use it operates much the same as a Detroit but inside it's much different and the 'release' is much, much better. I run an open top LR Defender 90 and I can't hear it in operation no matter what type of driving I am doing. The demo unit on the stand at the Expo made a clicking noise, but in use on my truck, inside the diff housing and immersed in oil it's pretty much silent to the driver. On the road you do not know it's there. It doesn't suddenly unload and make you think you've snapped a shaft or CV, it doesn't chirp or bump the tires and there is no resistance when cornering. My open front 3rd housing is about the same temperature to touch after a fast highway run as the locked rear, so it's not creating any more friction or generating any extra heat. It feels exactly the same as an open diff. Off road it again doesn't announce itself other than by the fact that there is no wheel spin when you lift a wheel. The wheel continues to turn at the same speed as you're moving. So no sudden jerk when you touch down again or find traction. Your wheels are not fighting the ground to overcome a locking force like with a Detroit or locked to the same speed as with an ARB which means you don't lose traction in loose or slippery areas so much. You don't have to think about it. No approaching an obstacle and then having to 'lock it up' half way through. Off and On Road I think it's one of the easiest designs on the rest of the driveline I have come across. Because there is no force needed to overcome the locking action in a corner, no fighting between evenly locked wheels on uneven ground for traction and no difference in wheel speed before it locks up then there is much less force being transmitted back into the hubs, shafts, R&P, UJs, trans etc. This was one of the biggest factors for me. One of the often overlooked costs with fitting lockers is beefing up the rest of the driveline and that aint cheap. That's why I stayed unlocked so long. It's kind of hard to describe how it works without seeing it but I'll give it a go. Refer to the exploded diagram that's been posted on here a few times and I'll go through the parts. 1. Starting from the left is a carrier housing end plate. 2. Next is an axel drive unit (notice the splined hole in the middle where your axel shaft goes and the shallow grooves around the outside). 3. Then 30 or so needle bearings that fit into the grooves around the axel drive unit. 4. Not shown in the blow up but shown in red on some of the other diagrams/videos in the thread is the bearing cage. 5. The disk is a slip washer or thrust washer used to keep the 2 axel drive units separated from each other. 6. Big thing with all the holes is the carrier center housing (note the grooves around the inside and the depth and shape of them). This bolts to the housing end plate. The holes around the outside and the groove in the middle is to allow oil to flow through and around it. 7. Starting from the right this time is the other housing end plate. This one is bigger as the Ring Gear is bolted to it. Note the thrust plate on the inside face, there is one on the other end plate as well. These with the slip washer keep the axel drive units in place and separated from each other. They are not clutches and there are no springs. 8. Outside Cover for the center housing. 9. Bearings for the other axel drive unit. 10. Other axel drive unit. So how does it work? The answer is really simple. In normal operation you are transmitting drive to the wheels from the trans by rotating the carrier housing using the pinion driving the ring gear. As the carrier rotates the shape of the grooves on the inside of the center housing force the needle bearings down until they are pressed into the shallow grooves on the outside faces of the axel drive units. Because there is insufficient room for the housing to pass over the bearings in the shallow grooves then it forces the drive units to also rotate. These rotate the axels and the wheels and you have drive. Since this operates on both drive units you have 100% drive being applied to both wheels at carrier speed. Neither wheel can go slower than the carrier because of the bearings being pushed into the grooves on the drive units. If you look at the grooves on the carrier you will see that they are symmetrical so the same action occurs both forwards and in reverse. The action of applying a driving force from the carrier to the axel is what 'locks' it up. Kaiser says that the shape of these grooves, the manufacturing tolerances used and the materials that the bearings, carrier and drive units are made from is the key to minimizing premature wear. So how does it 'unlock'? Well it doesn't really. Its more that it 'allows' the wheels to turn faster than the drive input. So the carrier is turning and the bearings are being forced down into the drive units. Now imagine you are turning a corner. The outside wheel must travel further than the inner in about the same period of time as you go round the corner. So the inner wheel continues to turn at the same speed as the carrier is rotating (it can't go slower), the outside wheel is made to go faster by the ground turning the wheel. This speed increase means that the axel is now trying to turn the carrier faster than the carrier is being driven by the driveline. What happens now is that the drive units tries to turn faster and forces the bearings out into the grooves in the carrier. The grooves in the carrier are deep enough to allow the bearings to clear the grooves in the axel drive unit. This means the axel drive unit is free to turn as fast as it wants on that side while the other wheel continues to get drive from the carrier. As soon as the speed of the faster axel slows to match that of the carrier because you have finished the turn, come down off the rock or cleared the hole then the carrier once again becomes the driving force and the bearings are pushed back down into the drive unit and drive is reapplied. The last bit is the cage that is shown in red in some of the drawings and videos but not on the exploded view. You don't want both wheels to be able to turn faster than the carrier. If they did then you would not be able to use engine breaking on a hill descent, you couldn't use a transmission brake when parked on a hill (sorry, LR reference) and so on. What stops both wheels free spinning is the cage. The two halves are joined in the middle but able to rotate against each other slightly. Because the bearings are set into the cage, it stops both sets being able to travel up into the grooves on the carrier at once. Both can be down, but only 1 set can be up at any one time. Sorry if that sounded a bit like kindergarten but I was trying to keep it simple. In practice this action is taking place all the time as its pretty rare for both wheels to be turning at the exactly the same speed all the time except on a very straight road. The key is that if there is a difference in the speed of the wheels then the slower wheel is the driven one. Here is what I learnt from talking to the Kaiser guys: Its manufactured by a Brazilian Company based in Sau Paulo (sp?) and it has been on the market over there for about 5 years. The company who makes it has been in business for 48 years and they specialize in manufacturing OEM parts for the Heavy Equipment and Agricultural markets. It is the market leader in the local locker market. Somebody in the thread asked why there are so many bolts holding the carrier end plates on? Well consider the markets that they come from and a little bit of 'over engineering' might start to make sense? They have waited to introduce it to the US market so as to make sure that the manufacturing processes and any kinks where worked out. They have been and continue to work with materials selection/preparation and manufacturing tolerances for example to make it as strong and hard wearing as possible. Besides 4x4s they market it for race cars, drag cars, rally cars, vans, trucks, tractors, etc. so it gets pretty well tested in many different applications. They are confident in the product enough that they specifically state that their warranty is not biased by any modifications you may have made to the vehicle. They don't care if you have chipped the ECU, are running 37s, an under drive, etc. Some of the other manufacturers out there may make claims of longer warranties until you read the fine print. In case you're wondering, I do not work for and have no official affiliation with Kaiser or The Expeditioneers. I make no money or gain in any way from sales of these units. I have one fitted to my truck, plan to get another one and I have spent some time grilling the guys that make it so as to better understand it myself. I work on my own truck and I like to know how the bits fitted to it work so I can fix them or remove them when they break out in the middle of nowhere. I firmly believe this to be a good product. I don't want to see it get a bunch of bad press or bad mouthed because it's new and people don't understand it or think it's doing something it isn't. Quote Link to comment Share on other sites More sharing options...
black bear Posted September 29, 2011 Author Share Posted September 29, 2011 Thanks C18RCH, this is exactly what I wanted to know. I didn't work out what the two red cages were doing! I'm going to put them in both axles of my Disco. Ashcrofts are selling these units at £50 +vat cheaper than their own Air operated Locker and no other parts required, apart from some new bearings. If these are so good it will probably be leading brand in UK! Dave Quote Link to comment Share on other sites More sharing options...
Escape Posted September 30, 2011 Share Posted September 30, 2011 Thanks C18RCH, this is exactly what I wanted to know. I didn't work out what the two red cages were doing! I'm going to put them in both axles of my Disco. Ashcrofts are selling these units at £50 +vat cheaper than their own Air operated Locker and no other parts required, apart from some new bearings. If these are so good it will probably be leading brand in UK! Dave Still sounds like a bad idea to put a normally locked diff in a front axle... I wouldn't hesitate for a second and spend the little bit extra on 2 airlockers (real happy with those in my Range)! Quote Link to comment Share on other sites More sharing options...
landroversforever Posted September 30, 2011 Share Posted September 30, 2011 In my mind, if they are only £50+VAT cheaper than an Ashcroft locker, I would happily spend the difference to buy something that I know is going to work, and work well. Quote Link to comment Share on other sites More sharing options...
CwazyWabbit Posted September 30, 2011 Share Posted September 30, 2011 In my mind, if they are only £50+VAT cheaper than an Ashcroft locker, I would happily spend the difference to buy something that I know is going to work, and work well. An Ashcroft locker needs more to make it work though.... compressor, switches, solenoids etc Quote Link to comment Share on other sites More sharing options...
landroversforever Posted September 30, 2011 Share Posted September 30, 2011 Thats a fair point, I do already have one air locker and therefore the kit... but If I didnt, I would still rather spend a bit more and go for the air locker than a more unknown locker. compressor + solenoids/switches etc aren't going to be that expensive. A Kaiser isn't cheap enough in my eyes to make it worth going for. Quote Link to comment Share on other sites More sharing options...
CwazyWabbit Posted September 30, 2011 Share Posted September 30, 2011 I do agree with you, just wanted to point out it wasn't a simple £100 more gets you two Ashcrofts. If I had the money for lockers I'd much rather some that I was in full control of them... but then I'm a bit of a control freak anyway! lol Quote Link to comment Share on other sites More sharing options...
qwakers Posted August 21, 2016 Share Posted August 21, 2016 Still sounds like a bad idea to put a normally locked diff in a front axle... I wouldn't hesitate for a second and spend the little bit extra on 2 airlockers (real happy with those in my Range)! i thought id resurrect this thread to reply to this (and maybe this thread should be stickied?) ive just taken my kaiser out of my front axle. the reason being twofold 1) it causes the steering to resist when on hard surfaces. sometimes you cant get full lock (definitely dangerous) 2) even Ashcroft cvs break in less than a hours use off road. i dont know why, but im guessing its unlocking and locking at unexpected moments and shock-loading cvs. so id recommend anyone thinking about a kaiser in the front..... just dont....... 1 Quote Link to comment Share on other sites More sharing options...
CwazyWabbit Posted August 21, 2016 Share Posted August 21, 2016 Cheers for the update Qwakers, how long did you have the locker in for? Quote Link to comment Share on other sites More sharing options...
qwakers Posted August 21, 2016 Share Posted August 21, 2016 a total of 3 challenge events.1st time i ran it i had 33" insa turbo special tracks with standard cvs and it took all day but i eventually destroyed a cv. also noticed steering issues on hard ground but put it down to a dodgy steering box(later proven to be perfectly serviceable), 2nd time i ran it i destroyed 2x standard cvs in less than 10 mins. 3rd time i ran it i had Ashcroft half-shafts and uprated cvs in because i wanted it to last all weekend (3 day event) 1st day was a comp safari style speed trial and night stage, they survived that fine, 2nd day was a special stage ccv style and it lasted the 1st special stage (fastest time of the day too) and then i blew both front cvs winching out of a riverbed. i know they should have survived that im only running a un tuned 200tdi.... so the only conclusion i can come to is.... the diff. never made it to the third day. Quote Link to comment Share on other sites More sharing options...
tuko Posted August 21, 2016 Share Posted August 21, 2016 i thought id resurrect this thread to reply to this (and maybe this thread should be stickied?) ive just taken my kaiser out of my front axle. the reason being twofold 1) it causes the steering to resist when on hard surfaces. sometimes you cant get full lock (definitely dangerous) 2) even Ashcroft cvs break in less than a hours use off road. i dont know why, but im guessing its unlocking and locking at unexpected moments and shock-loading cvs. so id recommend anyone thinking about a kaiser in the front..... just dont....... I have the Kaiser locker in the rear axle, I have to say for offroading it is great BUT the moment your on asphalt it's a vocal beast. The shock load when it unexpectedly unlocks will shake the entire vehicle. Knock on wood, after 3 years of use my halfshafts are still together. I agree with the above comments if it was installed in the front, don't. In the rear it is great in the loose stuff but can be rather vocal, which has made me rethink an air locker for the rear sometime in the future. Quote Link to comment Share on other sites More sharing options...
CwazyWabbit Posted August 21, 2016 Share Posted August 21, 2016 Cheers for the info, shame it wrecked your events. Quote Link to comment Share on other sites More sharing options...
qwakers Posted August 21, 2016 Share Posted August 21, 2016 that comes under the heading of i should have known better or more accurately **** happens 1 Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.