Probably because they do not have $1,100.00 to spend on a new head, same reason most people rebuild engines instead of buying new ones.roscoFJ73 said:
BJ74 vs HZJ73
- Thread starter petermac
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Electric Hubs
Beanz:
Having had one of my electric hubs apart, I suspect that they have exactly the same physical strength as a standard hub of the same size.
If you haven't had one apart yet, they are identical to manual hubs, but with a tiny little spur gear on a tiny little electric motor engaging a ring gear on the exterior of what would be the dial in a normal hub... The little motor rotates with the hub, and receives power via some brushes and slip rings on the spindle... The one major potential strength differance is that the hub is attached with 4 bolts, rather than the 6 used in the typical manual hub. I suspect that shearing those bolts may not be the most common failure mode of a hub, but I haven't blown up these hubs. (touch wood)
Potential reliability issues of the electric hub, that don't exist in manual hubs:
- Wiring.
- Switch and control system - The hubs check to make sure they are engaged or dis-engaged each and every time you turn the key on.
- Slip rings and brushes.
- The little motor
- The gear train.
Potential reliability issues that exist in mechanical hubs that don't exist in the electric hub.
- The seal on the exterior of the dial.......
- The nut that turns (or doesn't turn) the dial...
Jim.
PS - I'm a mechanical P.Eng. that designs machines for a living - and my electric hubs will get changed out the second time they let me down... or before. I subscribe to the KISS principle.
I've had my hubs not engage already.
Beanz:
Having had one of my electric hubs apart, I suspect that they have exactly the same physical strength as a standard hub of the same size.
If you haven't had one apart yet, they are identical to manual hubs, but with a tiny little spur gear on a tiny little electric motor engaging a ring gear on the exterior of what would be the dial in a normal hub... The little motor rotates with the hub, and receives power via some brushes and slip rings on the spindle... The one major potential strength differance is that the hub is attached with 4 bolts, rather than the 6 used in the typical manual hub. I suspect that shearing those bolts may not be the most common failure mode of a hub, but I haven't blown up these hubs. (touch wood)
Potential reliability issues of the electric hub, that don't exist in manual hubs:
- Wiring.
- Switch and control system - The hubs check to make sure they are engaged or dis-engaged each and every time you turn the key on.
- Slip rings and brushes.
- The little motor
- The gear train.
Potential reliability issues that exist in mechanical hubs that don't exist in the electric hub.
- The seal on the exterior of the dial.......
- The nut that turns (or doesn't turn) the dial...
Jim.
PS - I'm a mechanical P.Eng. that designs machines for a living - and my electric hubs will get changed out the second time they let me down... or before. I subscribe to the KISS principle.
I've had my hubs not engage already.
Jim_Hbar said:
Hi and thanks, Jim. Yes, I am aware of the 4 vs. 6 hub studs issue in the electric hub, which is why I think these things are a liability rather than an asset. Hub studs are already one of the weaknesses in the Toyota axle. The development of FROR's chromoly studs and 100 series hub stud modification pioneered by the Aussies are in response to this weakness. Now, reduce the number of studs by 33% in the electric hub...
Dave
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Might be a little off topic, but say the concern is more off road.
Looking to put 37 inch tires, is the torque of the bigger 6 gonna pull you up and over things better assuming everthing about the vehicles are equal???
Rob
Looking to put 37 inch tires, is the torque of the bigger 6 gonna pull you up and over things better assuming everthing about the vehicles are equal???
Rob
Tapage
Club 4X4 Panamá
Radd Cruisers said:
Rob yes .. are much more effort not only for those more bigger dires with more diameter and more weigh. You must need to regear you veicle to proper handle and keep the performace equal ..
Also you can do some engine mod to get more power to keep running well more biger tires.
If you catually have 33" tires wieh 4.11 gears ( I supose ) you are growing to 37" not only 4" ( that appears little ) are 12% more diameter and a lots of more lbs ..
If you regear for 4.56 are 10% more gearing, but you need 12% or more ( weigh, lift, aerodinamic etc ) so the other option is 4.88 that offer 18% more gearing than you 4.11.
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Good Tech Dave, my question is solely on power with the same gearing.
Bottom line, the 13BT and 1HZ, make the same down low torque to drag ya over the obstacle????
Rob
Bottom line, the 13BT and 1HZ, make the same down low torque to drag ya over the obstacle????
Rob
crushers
post ho
the 13BT makes 29 kgm at 2000 rpm, the early 1HZ makes 28.2 kgm at 2000 rpm
the 13BT makes 120 hp at 3400 rpm and hte 1HZ makes 135 hp at 3600 rpm.
the biggest difference will be the lack of sensitive throttle with the 1HZ on rough terrain in a manual.
the 13BT accelerates faster than the 1HZ, is noisier than the 1HZ and thirstier than the 1HZ.
for me, either engine is a beautiful thing. the one nice thing about the 1HZ is you can add a turbo cheap and suddenly the 1HZ is a totally differnt beast.
either way Rob you will be happy in the end.
cheers
the 13BT makes 120 hp at 3400 rpm and hte 1HZ makes 135 hp at 3600 rpm.
the biggest difference will be the lack of sensitive throttle with the 1HZ on rough terrain in a manual.
the 13BT accelerates faster than the 1HZ, is noisier than the 1HZ and thirstier than the 1HZ.
for me, either engine is a beautiful thing. the one nice thing about the 1HZ is you can add a turbo cheap and suddenly the 1HZ is a totally differnt beast.
either way Rob you will be happy in the end.
cheers
crushers said:
As Bruce has mentioned, this is not an issue on Charla's 13BT equipped BJ42, leading to the idea it is all linkage related, which means there is possibility of a solution. Poo will be getting a 13BT soon, so it will be interesting to see as well...in a 60.
crushers said:
For sure!
gb
crushers
post ho
there was a 5 speed BJ74 with us yesterday and no complaints so i am sure that this might be truck by truck related...
"olSmokey" was fine off road till you tried to go quickly down a trail then it would act up...
"olSmokey" was fine off road till you tried to go quickly down a trail then it would act up...
Maybe I am missing something, but I think I like the idea of having a weak link in there. I am refering to the hub discussion. Whether you have electric, or manual, it has to be the easiest thing to fix should it break and probably the cheapest. Granted no one wants to break anything, but if I were to pick a piece of the drivetrain to break let it be a hub any day of the week. Beats the hell out of breaking birfs, inners, pinions, arbs, ujoints, D/L tubes, etc. A little ratchet, socket, allen, hammer, paper towels, grease, and a $10 aisin and youre on your way. Or dont fix it just take the blown up bits out and tape it all up with mil tape or duct and go home.
Jim_Hbar said:
I have had many of the electric hubs apart, mostly to try to pull out the sheared off dowel pins on friends trucks. The dowels either shear or oblong the hole and then the bolts begin to go. The electical mechanism seems to do just fine.
PS I have a PhD. in engineering.
The electric hubs found on post 1990 70 series trucks are weaker than the manual hubs. Anyone here that is doing serious wheeling orders the manual hubs when buying a LC. They were both offered as options.
