AHC Front Pressure vis-a-vis Bull Bar + Winch (1 Viewer)

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I'm looking into putting a TJM T13 bull bar + Warn Zeon winch w/synthetic line out front. I measured my pressures after cross leveling as per YOTAMD's cheat sheet and I was @ 10 in H and 9 after maxing my TBs. I just realized you're supposed to check pressures from L to N, so I will go back and check that. At any rate, my bull bar/winch combo is going to be around 250lbs if I did my math right. My question is will reindexing two splines make sense at that weight or should I just go aftermarket TBs? Rear pressure is fine as is the accumulator. I don't plan on running around in day to day driving in anything other than N height. I'll only go into H when I need it. I'm not looking for more lift. I just don't want to stress the AHC system any more than necessary.
 

GTV

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Don’t worry about spline count, just reindex as much as you can. If you’re still running out of thread on the adjuster with the bumper on (which is doubtful) then you may want to consider standard OEM LC torsion bars.
 
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I'll give it a try. My pressure up front is 5.5 right now.
 

suprarx7nut

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I'm looking into putting a TJM T13 bull bar + Warn Zeon winch w/synthetic line out front. I measured my pressures after cross leveling as per YOTAMD's cheat sheet and I was @ 10 in H and 9 after maxing my TBs. I just realized you're supposed to check pressures from L to N, so I will go back and check that. At any rate, my bull bar/winch combo is going to be around 250lbs if I did my math right. My question is will reindexing two splines make sense at that weight or should I just go aftermarket TBs? Rear pressure is fine as is the accumulator. I don't plan on running around in day to day driving in anything other than N height. I'll only go into H when I need it. I'm not looking for more lift. I just don't want to stress the AHC system any more than necessary.

#1: Perhaps don't buy a big steel bumper if the goal is to minimize stress. There are a few great aluminum bumper options that are plenty strong and half (or less) the weight of the elephant TJM. Those old-school steel bumpers score quite low on the "performance per weight" category to me.

#2: The math tells me OEM AHC torsion bars are the closest thing to correct until you add about 500#s over the front axle. Reindexing may be necessary to get the pressures correct if you add 250 lbs. Some folks have had good luck with OEM non-AHC T-bars. I'd max out the OEM AHC ones before escalating to that.

#3: Get those measurements in N height and see where you are. The H pressures are helpful too (the system can't do much above 10 Mpa without running into fail-safe territory), but the N pressure is the one you really want to start with.
 
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I'm no engineer, but common sense tells me the OEM TBs/AHC shocks on the LX were never intended to hold any substantial extra weight for prolonged periods of time. Reindexing/tightening them simply preloads more stress/lift on the A arm, but I'll see what works in time. I maxed them already to see what the pressure is and it's sitting at 5.5. My problem is I can't find any aftermarket TBs that are rated for weight, but won't lift the front. Maybe I'm missing them. I don't want/need added lift - until I do. In those situations I'll put it in H and return to N afterwards.

The bull bar will deal with the legions of kamikaze deer out here. The Australians know how to build steel bull bars for exactly that purpose. Lightweight examples, such as the Dissent bumper, are utter rubbish as bull bars. They hold a winch and lights, but that's pretty much it. I'll never own anything from Dissent simply because I think their logo is dog s***.

The Zeon will present a mounting challenge, but I hope to overcome that when the time comes. If I can't I'll be shopping for a different winch.
 

hoser

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You can fit any size T-bar in the front and adjust it for zero lift. As for the Zeon winch, if you are talking about the control box not fitting, the control box can be relocated elsewhere. There is a kit for it.
 
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Good to know. I'm aware of the kit, but I hope to do my own and mount the control pack right on top of the bull bar if possible.I wanted the Brumby from Sherpa, but held off if favor of the Warn which is more easily serviced here in the states.
 

suprarx7nut

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I'm no engineer, but common sense tells me the OEM TBs/AHC shocks on the LX were never intended to hold any substantial extra weight for prolonged periods of time. Reindexing/tightening them simply preloads more stress/lift on the A arm, but I'll see what works in time. I maxed them already to see what the pressure is and it's sitting at 5.5. My problem is I can't find any aftermarket TBs that are rated for weight, but won't lift the front. Maybe I'm missing them. I don't want/need added lift - until I do. In those situations I'll put it in H and return to N afterwards.

The bull bar will deal with the legions of kamikaze deer out here. The Australians know how to build steel bull bars for exactly that purpose. Lightweight examples, such as the Dissent bumper, are utter rubbish as bull bars. They hold a winch and lights, but that's pretty much it. I'll never own anything from Dissent simply because I think their logo is dog s***.

The Zeon will present a mounting challenge, but I hope to overcome that when the time comes. If I can't I'll be shopping for a different winch.
Not that the title means anything, but I am an engineer and I'm not sure I understand any of this, lol.

The OEM AHC TB and shocks are made to hold the same weight as the non-AHC variety. If we're getting particular I think the LX AHC system is actually designed to hold MORE weight. The LX weighs more, after all. The hydraulics are not variable. The mechanical T-bar is.

Preload stresses the A-arm? The shock/spring combo provides the vertical support force. The A-arms control lateral motion. Adjusting the T-bar on AHC doesn't change A-arm stress to my knowledge.

Torsion bars have no specified lift. You dial in the lift with T-bar adjustment (non-AHC vehicles) or with height sensor movement (AHC vehicles).
 

hoser

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The bull bar will deal with the legions of kamikaze deer out here. The Australians know how to build steel bull bars for exactly that purpose. Lightweight examples, such as the Dissent bumper, are utter rubbish as bull bars. They hold a winch and lights, but that's pretty much it. I'll never own anything from Dissent simply because I think their logo is dog s***.
I left this comment alone earlier but I guess I'll address it now. I understand the logo can be a bit controversial but it does have several different roots. AFAIK, all of those previous roots have nothing to do with the company. IIRC, the name and logo was actually born here in the 100 series section. Kind of an informal contest. I've never met Ben but I've seen his products and the evolution.

In my opinion, Dissent has been designing and producing a lot of great products. They are a small company and aren't hindered but such things like Australian Design Rules (ADR). They put out new products constantly.

TJM is certainly a good company. They put out a lot of mid-grade products. But nothing is on the forefront. I have purchased several TJM products as well. So I'm not dogging them. If animal strikes was my primary concern, I wouldn't choose TJM nor Dissent... I'd choose ARB.
 
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Why don't you PM me and I'll be happy to explain anything you don't specifically understand.
 
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I left this comment alone earlier but I guess I'll address it now. I understand the logo can be a bit controversial but it does have several different roots. AFAIK, all of those previous roots have nothing to do with the company. IIRC, the name and logo was actually born here in the 100 series section. Kind of an informal contest. I've never met Ben but I've seen his products and the evolution.

In my opinion, Dissent has been designing and producing a lot of great products. They are a small company and aren't hindered but such things like Australian Design Rules (ADR). They put out new products constantly.

TJM is certainly a good company. They put out a lot of mid-grade products. But nothing is on the forefront. I have purchased several TJM products as well. So I'm not dogging them. If animal strikes was my primary concern, I wouldn't choose TJM nor Dissent... I'd choose ARB.
Why would you choose ARB over the TJM T13? I had an ARB in the past and it was fine, but I chose the T13 because I like it's winch cradle, the center has no tube, the tubes are larger in diameter than the ARB and there are access holes already in it to run my cable for the control pack. I also prefer feet down rather than feet forward as on the ARB. As far as the Dissent logo goes, it doesn't matter what was intended. It won't be on anything I own. Dissent products are what they are. Light weight, new, very expensive and illegal in most other countries. Their bumpers are in no way comparable with the Australian bull bars. Their primary purpose is to prevent vehicles from being disabled in oblique and direct frontal animal strikes. They save lives in the bush every year.
 
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