Simple LJ80 : improving articulation

Mine was still with the stock shock absorber. Max travel was around 40cm.

Wondering if that can be improved, I tested my car into max articulation as possible by wheeling one front wheel into rock while the other front wheel into sewer/hole.  Then i removed the screws holding the shock absorber for the lower front wheel and the wheel dropped lower than before. It is maxed at 50cm. At the same time i measure the minimum travel on the upper wheel(on the other side) and i got 30cm. 

The old shock had 25cm to 40cm. While the new measurement is 30cm to 50cm. Calling my nearest spare part store i got one for toyota innova rear shock absorber which fit the new setting for front LJ80.

For the rear, I noticed the wheels doesn't articulate as much as front wheels. As I removed one link of swaybar/stabilizer it added some travel to the rear wheels. Negative effect is the body tilted more at the same setup. This may affecting the feel when offroading, and as well stability when cornering.

Simple lj80 : winch wheel fail

Vespa 12inch rim, welded to jimny disk-brake, mounted on the wheel with help of screws, spacer and modified wheel nuts.

Put the car on the ditch , 2wd-Lo (unlock the front hub), attach the winch to the wheel and tree in front. Result = failed.

Why, it is because the open rear diff. All power went to the left rear wheel as the right rear had more load due to wheel winch. 

Solution :

- need one more wheel winch to balance load

- or, use diff locker on rear

As there are no mechanism to hold the tension on the winch, i assume it shouldn't be use to pull vehicle uphill.

Simple Lj80 : Goodyear Extragrip 7.00 r15

It does provide extra grip, it is slim enough, yet tall enough, and somehow doesn't give that modern look like mud tires. 

I triend 7.50 r15 but it is too big that reduce articulation (hit the upper wall on slight flex. 7.00 is just enough 

Simple LJ80 : Differential locker !

What locker can be fitted to LJ80?

1. Spool, minispool or welded diff, cheap, reliable (if done properly), but may put much stress on the axles.

2. Auto-locker. I got 1520lr powertrax which can be fitted on front or rear "closed" stock diff. It use stock side gears and as it is autolocker, basically it will lock under gas/throttle and will release if coasting.

3. Selectable locker. 

I have been digging this option since there is cheaper Chinese air locker (Hflocker?) which is copy of arb and found that rd207 (for small diff front lj80 or sj410 early generation) is using 22spline shaft and 8bolts ring gear. Stock diff of lj80 is small "closed" diff, but 10bolt ring gear. There is sj410 diff (normally 8:41 or 8:43) which is small type (early generation) and as well "open"type diff. The open type diff has 8pinion bolts !! Some friend confirm that this work but you need to pay the cost of the locker, the new diff (front and rear) and as well the modification. And it work only for front 22spline axle shaft!

Based on that, i choose 1520lr in front diff. Why? it is cheap, it allows me wheel normal in 2WD event with front hub locked (slight ratcheting on turning, that's all). And still get traction on 4WD.

It get slightly difficult to turn, but the same i get when i use rear locker.

Why not autolocker in the rear diff?

Because it affect my 2WD quality as it lock the rear everytime i give throttle. Turning while throttling on slippery road may drift the rear wheels.

Front locker is pulling and better at riding/crawling obstacles. Rear locker will only push you forward bumping the obstacle.

A little note about closed/open type diff. - The closed diff mean the worm gear is inside closed diff housing. You can't see the worm gear/side gear without opening the side diff plate. It has 1 long pin and 2 short pin for the 4 worm gears.

1520lr locker works for this 3pins closed diff. 9:41 stock, 8:43, 11:51 diff mostly found as closed diff.

- The open diff mean you can see worm gears and side gear directly. It has 2worm gears and 1pin and i belive bigger side wheel. It is normally found in 8:41 and some rare 8:43 diff.

Having a diff locker, the power delivered under control, no wheel spinning (other than when needed), no trail damage, less shock on axles (it is not brute force !).

And my 2WD is not affected at all. Auto-locker in front is perfect for daily driver !

WTH Kershaw, your composite knife broke against woodstick !!

Just got this snapon edition composite knife. Chop chop chop.. Knack !.. 

WTH, it broke! Shame on you Kershaw !

LJ80 speedometer : Full Tank !

Tested, the adjustment of bimetal regulator fix the previous issue

LJ80 Troubleshoot : Fuel Meter never Full, Coolant Temperature doesn't move..

It's been a while i notice these gauges response in my Lj80. Fuel never pass 3/4 and coolant temp never move. As i read both are resistive type response, which should easily be checked. 

Is the gauges broken or wiring broken or sensor broken?

 

Fuel meter responds, means no wiring issue, fuel sensor may have issue or the gauge display it wrong.

Coolant temp not responding, can be wiirng issue, sensor issue or gauge issue.

First I check coolant sensor , comparing to other (car/new sensor). My thermistor read 400 ohm when cool and 140ohm when hot (car runs for sometime). The other thermistor read 400 when cold. Ok no issue on sensor. How to check cable and gauges. As the gauge made from bimetal type,it should have coils to heat it up.it means it is "Ok" to short the sensor side just to check if it respond. So i connect the sensor cable to ground. And after few seconds, i notice that coolant temp  needle move on the gauge. OK, i have no wiring issue and the gauge respond. But what is wrong?

Comparing the coolant temp vs fuel meter gauge, both have no sensor issue (at least it give reading), it has no wiring issue, but both may have gauges issue. 

I remove the speedometer from console (4screws), remove cables (socket) and odometer cable, i need to remove plastic cover of steering wheel to be able to get the speedometer out. 

Thereare 6 screw on the back, remove them, now i got the back plate of the speedometer out. All thing inside are mounted there. 

After checking/guestimating the connection, i inject 12v and ground to it. And measure some points inside.

Basically, it has 3 bimetals. 1 acting as regulator (on the right side of fuel meter), 1 acting as the display of fuel ( on the left of fuel meter), and one acting as display of coolant temp (on the coolant temp gauge).

Regulator works by having a single coil from the bimetal point to ground. The bimetal itself will be connected to side metal giving 12v. When it connects, current flows, bimetal (regulator) gets hot and bend, as it bend 12v disconnected. This way it act like pulse width modulation, sending burst of 12v pulses on the bimetal (regulator) itself.

When voltage raise up, the bimetal become hot faster, means faster to disconnect, this way it regulate the output to stay on the target value. This happen vice versa.

Checking the regulator output with analog meter, i got 4 volts. It is connected to 2 gauge bimetals (shared). On the back of the pcb there is written 7V on the regulator out line. Now i understand that the issue of my gauges is due to less voltage on regulator output. With less voltage, the 2nd and 3rd bimetal will get less heat = less bending = less value on display.

How to increase the regulator output?

1. Cut the regulator coil (disable it), get a LM317 voltage regulator and a potentiometer, set the output to 7V. This is the modern way. But i may add some soldering/components on the back of speedometer.

2. Bend the metal pin inside(where 12v connected to bimetal (regulator). This will make bimetal need more bending to disconnect, means it will give longer time of 12v connected means output will have bigger 12v duty cycle (higher output). After several bend and check (with analog voltmeter) it give me 7V and time to test. I connect 120ohm resistor between coolant temp input  to ground and it works now. Gauge move halfway. 

Time to reasembly everything.. Or should i reset the odometer as well.. Maybe later .