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Hydro Assist - Diff Cover to Knuckle Mount

Davev78

Member
Joined
May 27, 2020
Member Number
1562
Messages
13
Loc
Somewhere between Galveston and Houston, TX
Let’s try some tech

Car info:
JKU Rubicon, 2” lift, adjustable lower arms, 37” milestars, your basic mall crawler.

Needed hydro assist since I like to to turn my wheels in the rocks.
Over the years, I noticed that most hydro assist set ups want to rotate the tie rod. This is particularly true with offset tie rods like in a JK. At some point in cycling the steering, the ram and tie rod will be misaligned causing the rod to rotate. There are a couple of things to do to combat this such as rotate the tie rod ends so they are clocked at opposite end of their travel or you can put the hard plastic washers between tie rod ends and the knuckle. These can work, but the cylinder still is trying to flop the rod, these methods just push back. Usually you set the ram parallel with steering straight and all is well.

Since my JK sees a lot of street time, I wanted to come up with a more direct mount.

I mounted my ram to my diff cover (ruffstuff) and to the driver side knuckle.

I built a bracket for my knuckle that bolts to the tie rod bolt, unit bearing bolt and another drilled and tapped bolt. Then I welded the bracket to the knuckle. The knuckle is cast steel, so pre heat, ping welds as you go, and wrap up for long cool down. Used MIG welder. Two tabs on the diff cover and the ram is mounted.

It is a really tight fit for the ram, I only have 2” of bump stop extension. It all just cleared, maybe 1/4” of clearance. There was no way to get a hydraulic hose on the outside ram fitting, so I made a hard pipe extension across the ram body.

The ram is 8” stroke, I adjusted the stop externally on the ram so the steering stops just before the steering stops in the knuckle touch. I might have 2 washers on each side behind the stop bolts.

I drilled and tapped my steering box, got hoses made locally. Other than my time probably in it for $400. Stock pump.

it drives really well on the street. There is absolutely zero play in the steering wheel. In the rocks it works as expected. It really transformed how the Jeep drives at highway speed. The steering is actually heavier than stock. I does suffer from low flow at idle, so trying to whip into a parking spot you can’t turn the wheel fast enough. But really this is easy to get used to. I am afraid to put a higher flow pump because it drives so good at speed, I don’t want it to get twitchy.

I’ve been running this for about 1.5 years, probably 6k miles and several wheeling trips. It has worked great. Checked the knuckle for stress cracks and all looks good. No leaks at the diff cover. Haven’t killed any nuns yet.

pics or it didn’t happen... will make a new post for the pics.
 
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Davev78

Member
Joined
May 27, 2020
Member Number
1562
Messages
13
Loc
Somewhere between Galveston and Houston, TX
Pics

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Rob50lx

Red Skull Member
Joined
May 29, 2020
Member Number
1660
Messages
90
I like the idea; I wish it would work for me.
I'm already running into issues with JKS track bar hitting Teraflex dif cover and Synergy sector shaft/track bar brace.
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ExWrench

Random Dude
CAL4
Joined
May 19, 2020
Member Number
29
Messages
2,271
Loc
East Bay, CA
That's interesting - I dig unique solutions :D
As long as your execution is sound, that looks like a winner. :beer:

One note: it is possible to have a hydro assist ram not rotate the tie rod, requires getting them parallel:

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