External hydro assist on stock toyota steering rack

madtaco461

BRO-runner
Joined
Oct 6, 2018
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3,803
Age
39
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Socal
Sometimes you need to draw the whole thing up and be like nope this isn’t a good idea.

I like the custom rack approach. Have you looked into basing it off the late model tundra rack? A lot of stuff can carry over and save on engineering time. Basically all you need to design is the housing an slide section. Though I could be missing something because our trucks are rear steer.
 

Blender

Swiftie
Joined
Oct 4, 2018
Messages
2,772
Location
Chandler, AZ
Sometimes you need to draw the whole thing up and be like nope this isn’t a good idea.

I like the custom rack approach. Have you looked into basing it off the late model tundra rack? A lot of stuff can carry over and save on engineering time. Basically all you need to design is the housing an slide section. Though I could be missing something because our trucks are rear steer.

Started there and determined flipping the 2G Tundra stock parts to function behind the axle would point the pinion into the front driveshaft. Looked around for non-Toyota options, but didn't find anything viable.
 

Arcticelf

Head BFH Operator at Gray Man Fab
Joined
Apr 23, 2019
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1,167
Location
DelCo PA
While i'm here, I haven't abandoned this, but it was pushed aside for a while.

Instead of the external powerpack i'm shifting towards a new housing for the stock rack assembly. Reuse the control valve and maybe the rack gear in a machined housing. Allows increased piston diameter and improved mounting points. Looked around for a stock vehicle rack that i could reuse the control valve and a larger rack from, but me being behind the axle steering is certainly not the norm among modern vehicles. Flipping stuff upside and backwards down changes the steering pinion angle. Been learning about hydraulic seals. My other hobby stuff is all under 350 psi, so it's easier. Parts will be two easy to machine cylindrical parts, then one complex piece to replicate the factory swagged housing.

I did find a machine shop that will cut sector gears onto a custom 50mm dia rack. way bigger than the stock 32mm and could omit the slider entirely. From my research most helical gears are proprietary so i can't lean on a standard. Instead i need to have them measure and reproduce the stock profile. I don't do gear design at work so i gotta learn more than the basics.

Crossmember is refined a bit in terms of interior structure and alignment "cams." Still a ton to do and i'm starting to find a few inconsistencies in the scan. Also, i need to make a full kinematic model of the suspension/steering to verify it'll drive ok. Was going to avoid that, but the steering heims just don't fit in the exact stock positions.

Phase 1 will be the crossmembers and improved mounts paired with a stock steering rack. Next phase would be the larger rack itself.

View attachment 80848
You definitely want to do a kinematic simulation of this and make sure the bump steer, camber curves, etc. are all reasonable.

And once again, baller work.
 
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