Oddie
AntiSeptic Sandal Wearer
- Posts
- 26,178
- Location
- In a puddle in Kernow
nothing for this project i mean! Was gauging really whether it's worth it at the mo!
Salisbury axle
- Thread starter Oddie
- Start date
This site contains affiliate links for which LandyZone may be compensated if you make a purchase.
G-man
BBQ king
- Posts
- 12,065
- Location
- essex.... in the middle somewhere
thats what i was doing then just decided to go for it, who dares wins and nothing ventured nothing gained etcetc
Trewey
Cockernee, Pasty munchin bastid.
- Posts
- 20,091
- Location
- Kernow - Near England
The Detroit is a limited slip diff. If one wheel loses traction, it ensures that torque is transmitted to the other wheel, but never more than 75%.
Something like an ARB can transmit 100% of the torque to the one wheel with grip and is therefore more likely to break sommat than a Detroit.
The other major difference is that the Detroit works automatically, even if you don't want it to, wheras the ARB only locks when you lock it.
So, I guess each has it's pros and cons.
Personally, the simplicity of the Detroit appeals.
I wouldn't try to fit one. I'd buy a diff with one ready fitted from this guy
http://crowndiffs.co.uk/diffs.html#det_lock
then either keep the standard diff as a spare, or sell it on flea-bay.
Add some Ashcrofts half-shafts and HD drive members and away yer go - unstoppable.
Something like an ARB can transmit 100% of the torque to the one wheel with grip and is therefore more likely to break sommat than a Detroit.
The other major difference is that the Detroit works automatically, even if you don't want it to, wheras the ARB only locks when you lock it.
So, I guess each has it's pros and cons.
Personally, the simplicity of the Detroit appeals.
I wouldn't try to fit one. I'd buy a diff with one ready fitted from this guy
http://crowndiffs.co.uk/diffs.html#det_lock
then either keep the standard diff as a spare, or sell it on flea-bay.
Add some Ashcrofts half-shafts and HD drive members and away yer go - unstoppable.
G-man
BBQ king
- Posts
- 12,065
- Location
- essex.... in the middle somewhere
u sure trew, i thought it split the torque evenly across the axle as it just locks it
Trewey
Cockernee, Pasty munchin bastid.
- Posts
- 20,091
- Location
- Kernow - Near England
but if one wheel is just spinning, then all of the torque goes to the other one if the diff is locked.
Well. apart from the tiny bit needed to spin the wheel.
G-man
BBQ king
- Posts
- 12,065
- Location
- essex.... in the middle somewhere
the axle gets 50% engine torque(assuming center diff is locked) (also ignoring gearing reduction or increase) and the axle also being locked (same as welding the diff) will also just split the torque 50/50 regardless of if one is spinning or not, if you had a quafe torque biasing diff it could send more of the torque to one wheel or the other (or a fancey ediff like in the nissan GTR)
Trewey
Cockernee, Pasty munchin bastid.
- Posts
- 20,091
- Location
- Kernow - Near England
a locked diff forces both wheels to turn at the same speed, but if only one of them has grip then all of the torque goes through that one. don't confuse torque (turning force) with angular speed.
Trewey
Cockernee, Pasty munchin bastid.
- Posts
- 20,091
- Location
- Kernow - Near England
theoretically, if the centre diff and both axle diffs are locked and 3 wheels are on ice, then almost 100% of the engine torque would be transmitted through the one wheel with grip.
G-man
BBQ king
- Posts
- 12,065
- Location
- essex.... in the middle somewhere
so we agree tho diff lock is better!!!
Wouldnt a detroit locker tend to keep you in the straight ahead position on sharp bends due to its relative inflexibility as an LSD. Could lead to nasty incidents. Wouldnt ARB be better so you can swith it off for safer road driving
PS a locked differential makes both wheels on the same axle rotate at the same speed no matter what the traction under the wheels. I think that each wheel can apply as much rotational force as the traction allows for. This means unbalanced torques on the shafts. So unequal torque and equal rotation is the result.
PS a locked differential makes both wheels on the same axle rotate at the same speed no matter what the traction under the wheels. I think that each wheel can apply as much rotational force as the traction allows for. This means unbalanced torques on the shafts. So unequal torque and equal rotation is the result.
Trewey
Cockernee, Pasty munchin bastid.
- Posts
- 20,091
- Location
- Kernow - Near England
Dunno?
I think they only start to lock when there is a significant difference between wheel speeds, which you wouldn't get on the road....maybe?
I think they only start to lock when there is a significant difference between wheel speeds, which you wouldn't get on the road....maybe?
jai_landrover
Well-Known Member
- Posts
- 13,408
- Location
- Luton
Been away for a bit,
Are you really going ARB? Ive seen 3 broken all 24 spline at the local winch challenge event. Personally after seeing how little abuse they took before breaking I wouldn't risk all that money. It is nice to be able to turn the loackers off though mabe Kams or Jack Mcnamerer (I can't spell one of those days)!
Trewey
Cockernee, Pasty munchin bastid.
- Posts
- 20,091
- Location
- Kernow - Near England
ave yer seen the price of Kams???????!!!!!!!!!!!!!!!!!
G-man
BBQ king
- Posts
- 12,065
- Location
- essex.... in the middle somewhere
£680 isn't it?? its less than arb as you don't need the compressor and all the gubbins that go with it
jai_landrover
Well-Known Member
- Posts
- 13,408
- Location
- Luton
Ok a Detroit Locker isnt a LSD its a true locker. a Detroit Truetrack is a LSD and is suitable for the front of you Landy or whatever this will explain its operation and clarify things for you:
Some trucks are available with limited slip differentials (LSD) as a factory option. These units help move power form the wheel that is spinning to the one that is not spinning by means of internal clutches. LSD's are great in street and occasional off road situations but do not provide 100% lock-up that results from using a true locker like the Detoit.
When driving in a straight line the Detroit locker is normally locked. On dry pavement, when cornering, the outer wheel over-running the speed of the axle unlocks the outside axle shaft. Power is applied to the inside wheel only. This can cause a noticeable under-steer. Additionally, if enough power is applied while in the turn, the axle will lock up and the vehicle either slips wildly, spins or straightens out suddenly. These differentials sometimes make a clicking noise when cornering; some find this objectionable. Now... after the corner and the locker re-engages, you can expect to feel a loud BANG. This may also cause a steering jerk. When this first happened after the installation, we were expecting to see parts behind us since we didn't know what happened. We soon found this to be a normal charactoristic of the locker.
Taken from a Yank site I think it explains it better that I could of. Jai
Some trucks are available with limited slip differentials (LSD) as a factory option. These units help move power form the wheel that is spinning to the one that is not spinning by means of internal clutches. LSD's are great in street and occasional off road situations but do not provide 100% lock-up that results from using a true locker like the Detoit.
When driving in a straight line the Detroit locker is normally locked. On dry pavement, when cornering, the outer wheel over-running the speed of the axle unlocks the outside axle shaft. Power is applied to the inside wheel only. This can cause a noticeable under-steer. Additionally, if enough power is applied while in the turn, the axle will lock up and the vehicle either slips wildly, spins or straightens out suddenly. These differentials sometimes make a clicking noise when cornering; some find this objectionable. Now... after the corner and the locker re-engages, you can expect to feel a loud BANG. This may also cause a steering jerk. When this first happened after the installation, we were expecting to see parts behind us since we didn't know what happened. We soon found this to be a normal charactoristic of the locker.
Taken from a Yank site I think it explains it better that I could of. Jai
G-man
BBQ king
- Posts
- 12,065
- Location
- essex.... in the middle somewhere
ok so detroit locker = unsafe
Trewey
Cockernee, Pasty munchin bastid.
- Posts
- 20,091
- Location
- Kernow - Near England
I was referring to the truetrac.
This is what Steve Haworth, the proprietor of Crown Differentials says about them....
The Detroit Truetrac is known all over the world. Now manufactured by Eaton transmissions who recently bought out Trachtech incorporated.
The Truetrac is a torque biasing limited slip differential, available in 10 or 24 spline, front or rear. Advice should be sought by anyone wishing to fit one. Please feel free to telephone for advice.
I receive so many calls asking how a Truetrac works, so for those of you who do not know, here goes.
Please also see the text at the bottom of this page for more technical information.
With a Truetrac, when one of the tyres starts spinning faster than the other due to a lack of traction, the worm gears on that side screw out and start to press against the inside of the case, which causes it to slow down (or prevents it from speeding up depending upon how you look at it) and in the process prevents the torque in the powertrain from being dissipated via the path of least resistance. Think of torque in the powertrain as electricity, it will always follow the path of least resistance. Torque will do exactly the same thing, which is why an open diff operates exactly opposite from how you would want it from functioning off road and also why a traction enhancing diff works so effectively (especially in a vehicle that originally had open diffs). Many people do not know that when an open diff looses traction and starts to over run the other side, if it has no resistance, it will spin at twice the input speed. This is why cross shafts have a hard time with aggressive off road driving i.e. they can't handle the shock loads of the torque transfer. Truetracs have a 3 to 1 torque biasing ratio. I translate this to you by restating it as a Truetrac can transfer about 75% of the available torque to the tire with traction. This is less than a full locking diff, which can transfer 100% but it's a damn site more than zero i.e. an open diff.
I hope that helps and makes sense. Now, there are Truetracs for the front and Truetracs for the rear. The gears in the Truetracs are cut primarily for strength and are directional. Although they allow for reverse rotation, example reversing etc, the front units must be used in the front axles and rears in rears.
It is possible to make a rear into a front and vice versa, this is a matter of removing gears from one side to another and turning them around so they are driven on the opposite side. Torque settings are critical when rebuilding the Truetracs and so are a few other factors. This can be done in our workshop or the technical data can be provided.
I would advise not to do this with a unit under 12 months of age as it will void the warranty.
MY PERSONAL OPINION
Truetracs are a very nice piece of kit. These really are very strong, tough, rugged and reliable units indeed. With a manufactures warranty of 100.000 miles you cannot go wrong.
I have only ever seen one broken and this had been in a vehicle for quite some time used for racing where constant shock loading and bigger then normal engine size/tyres have been used.
GOOD POINTS
Helical worm gears (no clutch plates to wear out) (some clutch plate driven lsds are very good). 100.000 mile warranty.
BAD POINTS
Cannot think of any ☺
They score 10 out 10 with me.
This is what Steve Haworth, the proprietor of Crown Differentials says about them....
The Detroit Truetrac is known all over the world. Now manufactured by Eaton transmissions who recently bought out Trachtech incorporated.
The Truetrac is a torque biasing limited slip differential, available in 10 or 24 spline, front or rear. Advice should be sought by anyone wishing to fit one. Please feel free to telephone for advice.
I receive so many calls asking how a Truetrac works, so for those of you who do not know, here goes.
Please also see the text at the bottom of this page for more technical information.
With a Truetrac, when one of the tyres starts spinning faster than the other due to a lack of traction, the worm gears on that side screw out and start to press against the inside of the case, which causes it to slow down (or prevents it from speeding up depending upon how you look at it) and in the process prevents the torque in the powertrain from being dissipated via the path of least resistance. Think of torque in the powertrain as electricity, it will always follow the path of least resistance. Torque will do exactly the same thing, which is why an open diff operates exactly opposite from how you would want it from functioning off road and also why a traction enhancing diff works so effectively (especially in a vehicle that originally had open diffs). Many people do not know that when an open diff looses traction and starts to over run the other side, if it has no resistance, it will spin at twice the input speed. This is why cross shafts have a hard time with aggressive off road driving i.e. they can't handle the shock loads of the torque transfer. Truetracs have a 3 to 1 torque biasing ratio. I translate this to you by restating it as a Truetrac can transfer about 75% of the available torque to the tire with traction. This is less than a full locking diff, which can transfer 100% but it's a damn site more than zero i.e. an open diff.
I hope that helps and makes sense. Now, there are Truetracs for the front and Truetracs for the rear. The gears in the Truetracs are cut primarily for strength and are directional. Although they allow for reverse rotation, example reversing etc, the front units must be used in the front axles and rears in rears.
It is possible to make a rear into a front and vice versa, this is a matter of removing gears from one side to another and turning them around so they are driven on the opposite side. Torque settings are critical when rebuilding the Truetracs and so are a few other factors. This can be done in our workshop or the technical data can be provided.
I would advise not to do this with a unit under 12 months of age as it will void the warranty.
MY PERSONAL OPINION
Truetracs are a very nice piece of kit. These really are very strong, tough, rugged and reliable units indeed. With a manufactures warranty of 100.000 miles you cannot go wrong.
I have only ever seen one broken and this had been in a vehicle for quite some time used for racing where constant shock loading and bigger then normal engine size/tyres have been used.
GOOD POINTS
Helical worm gears (no clutch plates to wear out) (some clutch plate driven lsds are very good). 100.000 mile warranty.
BAD POINTS
Cannot think of any ☺
They score 10 out 10 with me.
- Posts
- 14,902
- Location
- Doncaster
Not if you drive within the capacity it was designed for. No-one drives locked diffs at high speeds or when there's lots of grip ... or fi they do they're fsckwits.
G-man
BBQ king
- Posts
- 12,065
- Location
- essex.... in the middle somewhere
i was refering to the fact it is locked unless you are cornering.....then it only drives the inside wheel causing understeer
boydy1989
Well-Known Member
- Posts
- 3,063
- Location
- Northants/Oxfordshire/Warwickshire
I do.
Yes i know, lead foot disease, etc etc. The result is though, if I try to pull away a bit promptly outta a turning, the inside wheels spin and i get understeer.
If i had a self locking diff, then i would get understeer, it would lock, then tremendous understeer.
A LSD would prevent that as it would allow different speeds enough for the corner but stopping them spinning up - which is why they fit them.
Trewy is right - locked diffs means same turning speed but you can get 100% torque to one wheel.
The main issue with breaking these from what i have gathered is not so much 100% torque through one wheel, but if another spinning wheel suddenly finds traction, as the shock loading with that much weight in gears, wheels etc something usually gives.
if you dnt believe me about the understeer, try going round a mini roundabout in the wet at 15/20 miles an hour with difflock in and out - i was stunned at the difference with difflock in, HUGE understeer -therefore, if i ever afford difflockers i want to switch them manually.
that was all!
