Sensor lift

[gamecock2009]

While my 2000 LX is in the shop for a few replacement hoses and new spark plugs my mechanic is gonna try and do the sensor lift for me. All I want is an inch, maybe inch and a half so I sent him this picture I found in another thread and told him to just do about half of the top measurement. Any other thoughts? Also need to get the damn tech stream up haha

 

[suprarx7nut]

Pressures should take priority over the sensor lift. Or rather, if you want a sensor lift, first you have to measure and plan pressures. Front is easy and free, but be sure you have the new rear springs and/or spacers installed before you try to set the rear.

If you set the heights first, you might just over-pressurize the system and it'll be stuck on low and you'll have to come back with new springs and do it all over again. That's no fun.

Pressure first, sensor lift second.

 

[gamecock2009]

Pressures should take priority over the sensor lift. Or rather, if you want a sensor lift, first you have to measure and plan pressures. Front is easy and free, but be sure you have the new rear springs and/or spacers installed before you try to set the rear.

If you set the heights first, you might just over-pressurize the system and it'll be stuck on low and you'll have to come back with new springs and do it all over again. That's no fun.

Pressure first, sensor lift second.

Good point, and it seems as whenever I get to the sensor lift that cranking the t bars will help get me back into spec. My front end is lowwww though. Hate the rake

 

[suprarx7nut]

Good point, and it seems as whenever I get to the sensor lift that cranking the t bars will help get me back into spec. My front end is lowwww though. Hate the rake

Yup T-bars are easy and free. Rear just needs a spacer and/or springs. Still easy, but costs a few hundred if you need new springs. I got the King springs and even after the Dissent rear and an SS1 system with one drawer, I'm still at 5.1 Mpa pressure. Spec is 6 something so I can afford a bit more weight and/or a sensor lift. If you're going for an armored build with stuff in the back, probably need King springs. If not, a 30mm spacer might be all you need.

 

[gamecock2009]

Yup T-bars are easy and free. Rear just needs a spacer and/or springs. Still easy, but costs a few hundred if you need new springs. I got the King springs and even after the Dissent rear and an SS1 system with one drawer, I'm still at 5.1 Mpa pressure. Spec is 6 something so I can afford a bit more weight and/or a sensor lift. If you're going for an armored build with stuff in the back, probably need King springs. If not, a 30mm spacer might be all you need.

Not armored anytime soon, might even try and bring the rear down half an inch. The techstream can’t recognize my vehicle so I’m trying to troubleshoot that with no luck

 

[BEG]

As @suprarx7nut already mentioned, a sensor lift will affect your AHC neutral pressure, which has a major impact on the function of the system. In order to keep the pressure within spec, the system needs a certain amount of preload applied by the mechanical springs (t-bars/coils) and the amount of preload these springs can apply is determined by the ride height.

If you adjust the sensors, you have to be prepared to address the pressure issues that will follow. This will definitely include adjusting the torsion bars, but could include reindexing them or even replacing them with thicker bars if you're very heavy. It will most likely include changing rear springs and possibly adding a spacer on top. If you haven't kept up on the maintenance of the system, this would be a good time to do it, since operating at a higher N ride height than intended could expose any weaknesses in the system.

With regard to lifts in general, they are not very effective on IFS rigs. You don't gain any additional tire clearance since you don't actually move the pivot point of the front control arms away from the body, just further down their arc. You also lose precious down travel, which makes the vehicle more likely to lose contact with road surfaces over bumps and uneven ground.

 

[gamecock2009]

As @suprarx7nut already mentioned, a sensor lift will affect your AHC neutral pressure, which has a major impact on the function of the system. In order to keep the pressure within spec, the system needs a certain amount of preload applied by the mechanical springs (t-bars/coils) and the amount of preload these springs can apply is determined by the ride height.

If you adjust the sensors, you have to be prepared to address the pressure issues that will follow. This will definitely include adjusting the torsion bars, but could include reindexing them or even replacing them with thicker bars if you're very heavy. It will most likely include changing rear springs and possibly adding a spacer on top. If you haven't kept up on the maintenance of the system, this would be a good time to do it, since operating at a higher N ride height than intended could expose any weaknesses in the system.

With regard to lifts in general, they are not very effective on IFS rigs. You don't gain any additional tire clearance since you don't actually move the pivot point of the front control arms away from the body, just further down their arc. You also lose precious down travel, which makes the vehicle more likely to lose contact with road surfaces over bumps and uneven ground.

Yeah I’m holding off for the time being until i get techstream figured out. I’m not even necessarily wanting a “lift” i just want the damn forward rake to be gone haha. Once pressures are figured out and taken care of then ill go ahead and play with the front sensors to get a bit of lift in the front and might even lower the rear maybe half an inch.

 

[gamecock2009]

This old user’s setup is what I’m going for.

 

[brauski]

Not armored anytime soon, might even try and bring the rear down half an inch. The techstream can’t recognize my vehicle so I’m trying to troubleshoot that with no luck

For what it's worth I can't see my AHC data if I tell my version of Techstream that I have an 02 LX. Figured out that if I tell it it's an 01 LC I can see the pressures. So mess around with similar years/models and one should work.

 

[gamecock2009]

For what it's worth I can't see my AHC data if I tell my version of Techstream that I have an 02 LX. Figured out that if I tell it it's an 01 LC I can see the pressures. So mess around with similar years/models and one should work.

Ill try that, i just click the auto connect button and gives me the cannot connect to VIM or whatever

 

[Mauser]

Ill try that, i just click the auto connect button and gives me the cannot connect to VIM or whatever

In setup go to VIM select and change the interface setup from TIS Techstream VIM to XHorse - MVCI

 

[BEG]

Yeah I’m holding off for the time being until i get techstream figured out. I’m not even necessarily wanting a “lift” i just want the damn forward rake to be gone haha. Once pressures are figured out and taken care of then ill go ahead and play with the front sensors to get a bit of lift in the front and might even lower the rear maybe half an inch.

There is a +/- 1.5" rake baked into the design of the suspension. "Leveling" the front end will have an adverse effect on the handling of the vehicle.

 

[gamecock2009]

In setup go to VIM select and change the interface setup from TIS Techstream VIM to XHorse - MVCI

It’s already on that setting

 

[suprarx7nut]

This old user’s setup is what I’m going for.

View attachment 2313932

Do you have a picture of the current rake that you're wanting to eliminate?

 

[gamecock2009]

Well this may all be pointless because just found out my front shock is leaking so that needs to be replaced and if that’s the case I might just switch everything out.

 

[suprarx7nut]

Well this may all be pointless because just found out my front shock is leaking so that needs to be replaced and if that’s the case I might just switch everything out.

No, no, no, no. haha. No.

If a front AHC shock is leaking, it often just means it's "weeping" because it's over pressure and the torsion bar needs to be adjusted. This is very common and the fix is free.

If the mechanic doesn't know what the neutral pressures are, he really can't do anything else as far as diagnostics.

I'll say it again. Pressures first.

 

[gamecock2009]

No, no, no, no. haha. No.

If a front AHC shock is leaking, it often just means it's "weeping" because it's over pressure and the torsion bar needs to be adjusted. This is very common and the fix is free.

If the mechanic doesn't know what the neutral pressures are, he really can't do anything else as far as diagnostics.

I'll say it again. Pressures first.

You are the man, I’ll get this all sorted out. And it probably is out of spec at 240k and previous owner didn’t know anything about the suspension. So the shock, if it’s over pressure, is literally just expelling fluid?

 

[suprarx7nut]

You are the man, I’ll get this all sorted out. And it probably is out of spec at 240k and previous owner didn’t know anything about the suspension. So the shock, if it’s over pressure, is literally just expelling fluid?

Yeah, exactly. The shocks are not really shocks at all. They're hydraulic rams. If you pressurize the ram towards the very top end of its spec, it's common for them to weep some fluid. It doesn't mean they've failed, necessarily. It often just means the rams are living under high pressure and you need to adjust the system to get pressures back into their normal range.

This sort of thing is what leads to the myth of AHC being an expensive and broken system. You really need a mechanic that knows how to diagnose AHC. It's not super complicated, but it is different than traditional suspensions. Unfortunately, the common approach is to throw an expensive parts list at a vehicle owner. If the vehicle owner agrees to the expensive repair estimates - in this case, say you replaced the front shock (ram) - they often end up with the same problem because it was never diagnosed correctly in the first place. The owner then swears of AHC and rips it all out - even if it just needed a simple torsion bar adjustment which is free and takes 5-10 minutes.

Ask the mechanic if he has Techstream or another tool that can read the AHC neutral pressures. If not, you probably need to go pickup the vehicle once he's done with other tasks on the rig and get techstream yourself or call around until you find a shop that has Techstream and knows how to troubleshoot the system. There are a lot of good mechanics out there that have no idea how to work on AHC.

 

[Mauser]

My front left shock was seeping for a long time. When put into high mode it would drip. I adjusted the torsion bars and cleaned the shock. I haven't had a leak at all since.

This last Saturday I replaced my rear coils with well worn 80 series springs and got my rear to the lower end of spec after adding a rear bumper. I also did a little bit of a sensor lift too.

 

[BEG]

Well this may all be pointless because just found out my front shock is leaking so that needs to be replaced and if that’s the case I might just switch everything out.

Again, @suprarx7nut beat me to the punch, but "leaking AHC shocks" is a common "diagnosis" from uninformed mechanics that cost a lot and does nothing to address the problem. However, it's important to know what kind of leak we're talking about. Usually, leaks from excessive pressure come from the visible midpoint of the shock actuator and weep down over the lower shock body. Leaks from the top of the shock usually indicate worn seals that can be replaced relatively easily. Here's Toyota's diagram on shock leakage. IME, even some of the higher level leaks can be corrected when pressures are back in spec.