Thread: The Ashcroft Locker

Originally Posted by Slunnie

But to be fair, how does this compare to the current ARB locker which was an update to the old one? I was under the impression (perhaps incorrectly) that amongst other changes, the new ARB locker had a different activation system.

Hi Slunnie,

I compared our locker to the older RD56 as it's much more similar to this design than the later RD128, yes the RD128 does have a totally different locking mechanism, better in one way in that it has done away with the fragile plastic cage used in the RD56 but worse in 2 ways, the main problem is the reduced engagement of the newer locking collar, the RD56 had 6mm, the RD128 has 2.5mm, this can allow it to kick out when locked with a big bang, another disadvantage is the air feed pipe has to run over the crown wheel which is fiddly and can cause it to catch on the ring gear if not fitted correctly, both designs suffer from the main housing failing and of course air leaks,

Originally Posted by ashtrans

Hi Slunnie,

I compared our locker to the older RD56 as it's much more similar to this design than the later RD128, yes the RD128 does have a totally different locking mechanism, better in one way in that it has done away with the fragile plastic cage used in the RD56 but worse in 2 ways, the main problem is the reduced engagement of the newer locking collar, the RD56 had 6mm, the RD128 has 2.5mm, this can allow it to kick out when locked with a big bang, another disadvantage is the air feed pipe has to run over the crown wheel which is fiddly and can cause it to catch on the ring gear if not fitted correctly, both designs suffer from the main housing failing and of course air leaks,

Dave, the main housing failing ? Do you mean the crownwheel bolt flange breaking off the carrier? That has always been a concern i've had with both ARB and JacMac carriers. I use liberal quantities of locktite on both the interface and the crownwheel spigot diameter in the hope that it will releive some of the drive loads from the flange.
Wagoo.

Originally Posted by wagoo

Dave, the main housing failing ? Do you mean the crownwheel bolt flange breaking off the carrier? That has always been a concern i've had with both ARB and JacMac carriers. I use liberal quantities of locktite on both the interface and the crownwheel spigot diameter in the hope that it will releive some of the drive loads from the flange.
Wagoo.

Bill
Have you heard of any JacMacs failing in this area?I was unable to find any reports of any failures,which was a major contributing reason for me going for the JacMac in the first place.

Dave
When I saw your new locker,I thought it looked similar in operation to the JacMac and liked how it also engages the locking collar a lot more than some of the others!Which they will swear is perfectly adequate.But I like a bit of over engineering,rather than under engineering,but maybe I am just a bit anal in the engineering of things.

Wayne

Originally Posted by ashtrans

Hi Slunnie,

I compared our locker to the older RD56 as it's much more similar to this design than the later RD128, yes the RD128 does have a totally different locking mechanism, better in one way in that it has done away with the fragile plastic cage used in the RD56 but worse in 2 ways, the main problem is the reduced engagement of the newer locking collar, the RD56 had 6mm, the RD128 has 2.5mm, this can allow it to kick out when locked with a big bang, another disadvantage is the air feed pipe has to run over the crown wheel which is fiddly and can cause it to catch on the ring gear if not fitted correctly, both designs suffer from the main housing failing and of course air leaks,

Thanks for this Ashtrans, the 2.5mm dog certainly sounds like a backwards step. It looks like you've done a development on the JacMac locker which I always considered to be the benchmark.... shame he is so difficult to deal with. Why is your hemisphere stonger than ARB's? Well done and congratulations on the new air locker!

So is anyone selling these in Australia, and for how much ?

Originally Posted by LowRanger

Bill
Have you heard of any JacMacs failing in this area?I was unable to find any reports of any failures,which was a major contributing reason for me going for the JacMac in the first place.

Dave
When I saw your new locker,I thought it looked similar in operation to the JacMac and liked how it also engages the locking collar a lot more than some of the others!Which they will swear is perfectly adequate.But I like a bit of over engineering,rather than under engineering,but maybe I am just a bit anal in the engineering of things.

Wayne

Wayne. I have heard about 2 LandCruiser versions that have broken in that area.I got the loctite idea when I read about Renault using it instead of bolts to fasten the crownwheel to the carrier on one of their models.
My JacMacs have now been in for over 8 years of mainly high torque very low gear work and haven't given any problems, touch wood.
Wagoo.

Originally Posted by wagoo

Wayne. I have heard about 2 LandCruiser versions that have broken in that area.I got the loctite idea when I read about Renault using it instead of bolts to fasten the crownwheel to the carrier on one of their models.
My JacMacs have now been in for over 8 years of mainly high torque very low gear work and haven't given any problems, touch wood.
Wagoo.

Bill
Well I hope that mine lasts a while with all the power that my 200Tdi develops,But now I am tossing up between reduction gears or an Ashcroft Underdrive to go with my 4.11's and 35's,I know it isn't anywhere near the same reduction that you have.But I know my luck,and I don't like to push it too far

Wayne

Originally Posted by Slunnie

Why is your hemisphere stonger than ARB's?

the ARB is quite thin walled and cast iron or similar material, ours is thicker and made from billet UK spec EN24T,

Dave