XJ Mods VSB 14

[alexbrown64]

I wanted to get stuck in and get the Jeep completed so that i can test drive for a few weeks before getting the re-gear.

Last night i dropped under the old girl with a digital protractor and took all the angles. Everything had been thrown about a bit over time and with all the tire and suspension mods in the last few years.

Front: My diff angle was 82.5* (1.5* true castor). This put me well out and was why my steering was so light and wandering. For a 5" lift it needs to be about 86* (5* true castor).

Rear: I have a double cardon drive shaft in the rear. Relative to the diff, my pinion was pointing down about 4.5*. This could get vibey at speed. Your supposed to have about 1.5* to allow for axle wrap.

I wrote everything down and worked out a plan for the next morning.

Well, this morning i got out all the tools, jacks, jack stands, rattle gun, etc.. I knew the rear would be a bit of a hassle.

I tackled the front first. This part was easy. Undo the upper double adjustable control arms and twist them 1 revolution at a time until i had the correct angle. I brought it into spec, locked the lock nuts and took it for a test drive. As suspected, by adjusting the rear of the diff down, it alters the pinion angle for the worse. Its always a compromise. Steering felt great and no wander, but a small vibe was introduced at higher speeds. Also, the pull to the left is more pronounced.

The rear was a pain. I have a 12mm lift block under the springs. My idea was to convert it to a shim. I decided on 2* first. Jack car, remove wheel, remove U bolts, jack leaf springs, lower diff and get block out. Machine block to get desired angle. Reinstall and do the other side.

I did this and got my shaft/diff angle down to 3*. So i did the whole thing again taking the blocks/shims another degree to 3*. This put the diff/drive shaft arrangement to within 1.5*.

Packed everything away and took it for a test spin. Jeep feels much better. Rear end doesn't feel tight. Might be my imagination, but she feels looser and more powerful.

Anyway, that's all the major projects finished (i think).
Now its time to fill the tank, and drive, drive, drive.. and keep ironing out wrinkles and bugs.

The regear will slow the rotation of the drive shafts and helps eliminate vibes, as well as set it back in the correct powerband.
I might be getting the offset ball joints to alleviate the left pull. I think this is mainly an Australian feature.

Cheers,

Pic below showing the control arms and pinion angle and castor. Lower adjustable control arms used to centre wheel in wheel arch when lifted. Upper double adjustable control arms used to set castor. Very easy with these, as just undo the nuts and twist arms.



Pic below of the lift block/shim. Easy to do. I used an online trigonometry calculator to punch in length of plate and angle required. It then tells you how big a wedge you need to remove. In my case for 2*, i had to remove 4mm at one end. Sliced it and diced it with a grinder. Only problem was that i had to redo them and make them 3*.



Pic below showing drive line angle. With the lift block/shim, the pinion angle came back at a nice 1.5*. Pic also shows the Brown Davys long range fuel tank (125 litre), airbag suspension and rear disc brake mods (complete with ABS).



Finally getting somewhere....
Could be a daily driver soon....

[oldon]

Nice work Alex, you'll have to open a jeep custom shop. when you put the 4.56 gears in the drive shafts will be spinning faster for the same vehicle speed. You might have to play with angles a bit more yet. If you end up with steering a bit light maybe a return to centre damper will help though I think those kind of things are a bandaid solution. Tried a few of those steering stabilizers on trucks over the years, none of them worth a pinch of sh-t. With your perseverance I think you'll nail it.

[alexbrown64]

Originally Posted by oldon

Nice work Alex, you'll have to open a jeep custom shop. when you put the 4.56 gears in the drive shafts will be spinning faster for the same vehicle speed. You might have to play with angles a bit more yet. If you end up with steering a bit light maybe a return to centre damper will help though I think those kind of things are a bandaid solution. Tried a few of those steering stabilizers on trucks over the years, none of worth a pinch of sh-t. With your perseverance I think you'll nail it.

Thanks Oldon, your right about the shafts spinning faster if i had stock gears and went to 4.56. But i already have 4.88 gears from when i had 35" tyres. Now i have 33" tyres, she's out of sorts. The 4.56 gears should slow things down a bit.

Steering was light when the caster was well out. Its back to where it should be now, which makes the steering heavier and much better. But, the front drive line angles get worse and introduce some small vibes. Return to centre is good.

Temperatures are great at the moment. Been driving around most of the day, and its pretty hot here. Most of the time, she is sitting at about 85C on the Engine Watch Dog.

Suspension feels good, all electrics working well, transmission and engine smooth as silk. Brakes now are really good. Black Magic front pads on new calipers and rotors. Discs on the rear. Best they have ever been.

All thumbs up so far.

Cheers,

[alexbrown64]

In the search for a smoother running daily driver, i have decided to swap tyres out. I am pretty much over the Maxxis Big Horns i have on. They have only done about 1000 ks and i will be selling them. They are way too noisy. Sounds and feels like i am driving a tractor.

I have settled on a set of Nitto Trail Grapplers. If you read the write up on these, they have excellent reviews. Aggressive on the sidewalls, but a more compact tread pattern to make her drive better on the road.

They are on order and i hope to get them fitted up in about 2 1/2 weeks. Will give a review of them when i take her for a spin.



Cheers,

[oldon]

My apologies Alex, I should have remembered your gear ratio. I also should have known you wouldn't be running stock ratio with big tyres. Keep the write ups & excellent pictures coming.

[darksidecustoms]

Originally Posted by alexbrown64

Yep, i see what you want to do. You could cut that lower 1/3 of the bull bar off. You would loose those park light/indicators though. But, the XJ has park lights in the main headlight, and you also have those upper indicators. I actually have the ones on the sides working too. When i fitted the Bushwacker flares, i had to remove the small side indicator lights. I kept the wiring and bulb/holders and just mounted them in the big side indicators lights. I think a had to drill a big hole to mount the bulb/holder in there.



As you know, the Jeep alloy bull bar has massive 5mm plates that bolt right through the chasis in about 5 places. Very strong. I think the ARB bar for the XJ used those same plates. Also, as an option (ive got the brochure, but never seen any others) you could get the Jeep alloy bar with a winch fitted.



Love to see some pics of yours when its all fitted up. Its a good fun little project.



Cheers,

I’ve been running without the chin since I put my alloy bar on my post update. Likewise running the bulbs in the corner markers but I have a modified DRL controller so they behave the same as JKs (on with parkers but still flash with indicators).

Been wanting to do this winch mod for a long time, never thought of a universal plate though.. thought I’d have to get something bent up to fit. Sparesbox on eBay have a universal plate right now for $33 shipped (might be an eBay Plus special but too hard to pass up)! Light on the details for the listing but the manufacturer website says it’s 5mm for that part no. https://rover.ebay.com/rover/0/0/0?m...2F163825646994

How did you attach it to the bull bar plates?


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[alexbrown64]

Darkside, I think all those universal winch plates come out the same factory. Yep, they are a big solid 5mm chunk of steel. They are actually wider than you need to fit between the XJ plates, so you just measure and cut a bit from each end to keep it all nice and central.

Pic below of my OEM plates that hold the original Jeep bar on.



Its a bit hard to see in the pic below, but you just choose the height you want for the winch, and set the universal plate between the brackets and tack it in.
Check the height and fully weld it.



Pic below is of the winch in position.. Theres a bit of playing around measuring and cutting the bull bar and setting up the slot for the hawse or whatever that bit is called that the winch rope runs through... The universal plate includes the section that the hawse bolts to.

Mine fitted perfectly in the space between the grille and bar. Once bolted in, the 5mm brackets running through chassis and the universal winch plate form a strong frame that take all the weight. The bull bar just slides over it and gets bolted to the front of the plates with the 8 bolts that you original had to undo to remove it.



For $50 you have turned the original Jeep bull bar into a winch bar..