Higher mileage servicing info (Archives read and please help)

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Q

Quick

10 Year
Joined
Aug 17, 2013
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56
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Hello Folks,

Fairly new to the community and yes I have read several archives on the maintenance but still need some help to stream line info for my Indy tech.

The vehicle in question is a '99 LX 470 with 170,00 trouble free miles :D

1)- AHC servicing; Lexus will not service the AHC :mad:

The fluid in the reservoir is on the low side. The ride is slightly stiff but the accumulator testing showed the fluid in the reservoir is still moving around 7-8 points.

Possible to get a set of instructions may be off FSM showing the flushing sequence?

Do I go ahead and change the springs (coil overs) to OME 6868 and also does OME stands for OEM or is it a company?

Do I change the front springs too and then adjust the TB?

Would the new springs/coil overs make the truck sits higher?

2)- Transmission/differential fluid replacement;

Possible to get a "how to" info may be from the FSM for my Indy?

3)- Drive shaft lubing:

I am going to take the yolk off and clean the splines and all that before paking with Molly grease but once again possible to get some instructions from a manual?

Appreciate all the help and thanks for being patient with me.

Later
 
Trunk Monkey said:
Why won't Lex service the AHC?

Search for FSM or look in the FAQ, there's an FSM for 2004 you can download for free-99 that will have the info you want (and more).
Click to expand...

I was told they remove the fluid from the reservoir and replace it witht he new one and don't flush the system :rolleyes:
 
Quick said:
Do I go ahead and change the springs (coil overs) to OME 6868 and also does OME stands for OEM or is it a company?

Do I change the front springs too and then adjust the TB?

Would the new springs/coil overs make the truck sits higher?
Click to expand...

OME = Old Man Emu
OEM = Original Equipment Manufacturer

There are no front springs, just shocks and TB.

Yes the truck would sit higher if you switch to OME, but this is a very common lift method.

For the record, 868s would be ridiculously stiff if you are stock and don't load the truck.
 
FlammableFishie said:
There are no front springs, just shocks and TB.
Yes the truck would sit higher if you switch to OME, but this is a very common lift method.
Click to expand...
TB = Torsion Bars = Springs (just not Coil springs - theese are straight instead - no difference, the spring steel twists just like in a coil spring)

OME is NOT a common lift method for AHC vehicles. At least you would have to lift quite a bit then. Otherwise you have no shock absorber function. With AHC, you have to always keep the Neutral Pressure within specs. Otherwise the vehicle will not behave well (=possible loss of control in an emergency situation).
 
uHu said:
TB = Torsion Bars = Springs (just not Coil springs - theese are straight instead - no difference, the spring steel twists just like in a coil spring)

OME is NOT a common lift method for AHC vehicles. At least you would have to lift quite a bit then. Otherwise you have no shock absorber function. With AHC, you have to always keep the Neutral Pressure within specs. Otherwise the vehicle will not behave well (=possible loss of control in an emergency situation).
Click to expand...

Lol I was incredibly unspecific I guess. My apologies. And yes, I misspoke when I said there are no springs in the front, I meant no coils. When I said OME is very common I meant on trucks without AHC.

And just to add, it is always an option to remove your AHC system and go to the LC suspension system. I don't know what's entailed in that though... There are several threads on here about it.
 
I was under the impression that with age, the normal OEM springs would sag and they should be replaced to take the pressure off the AHC system, isn't that right?

Any instructions on adjusting the front TB?

I guess I got confused with all the OME and the coil over discussion :)

Thanks for all your kind responses ;)
 
Quick said:
I was under the impression that with age, the normal OEM springs would sag and they should be replaced to take the pressure off the AHC system, isn't that right?

Any instructions on adjusting the front TB?

I guess I got confused with all the OME and the coil over discussion :)

Thanks for all your kind responses ;)
Click to expand...

You are correct in that springs sag and loose spring rate over time, and yes, this will increase the neutral pressures in your AHC system. Here's what I'd do in your situation, firstly baseline your AHC and all other maintenance items and determine what you want to ultimately do with the vehicle. I wouldn't be replacing any coils just yet as, based on your description, you have only 7 or 8 increments of AHC fluid range between Hi and L ,this is minimum and suggests your globes could be done or are not far from being spent so new coils aren't going to solve that issue. So, I'd change the AHC fluid and read your neutral pressures and see where that takes you. Front neutral pressure can be lowered 0.2Mpa per turn on each torsion bar adjusting bolt and rear neutral pressure can be lowered with 10 or 15 mm trim packers, cheaper than new coils and might buy you some time while you determine if your globes are shot. There are a number of informative threads here on AHC maintenance and testing, key words to narrow down search are neutral pressure, TechStream and member Uhu writes worthwhile stuff on the subject. It's a safe bet that your neutral pressures are high and out of spec, in the absence of working TechStream you could exchange the AHC fluid, ensure your ride height and cross level are in spec then crank each TB bolt say 2 full turns and stick 10mm trim packers in. I'd hazard a guess that this could get you closer to spec. Finally, if you can't get more than 7 increments of fluid range you'll need to decide to repair the AHC system or ditch it for a conventional OEM LC system or go with an upgraded after market system tailored to you needs.

Sent from my iPhone using IH8MUD
 
Who is your "Indy Tech" who needs an FSM write up to change diff lube?

The forum can be a lot of help but at the end of the day whomever does the work need to have a basic level of competence working on vehilces.

As suggested, take care of all the basic maintenance before you start swapping parts around. It can take a lot of research and understanding to be successful with an alacarte approach to suspension. If after a flush you are not happy with the AHC then consider having a pro install a full replacement system.
 
Quick - FYI I picked one up not long ago that had 167k on the dial. It had great records from the Lexus dealership and had never been offload. The records state that AHC fluid was serviced but from the looks of the fluid when I flushed it, I can not see where they did anything more than what was in the bottle - so I am not that surprised by your dealership's response.

Thoughts:

You're Indy mechanic shouldn't be asking you for info - let that be a red flag and push off from them immediately. Also take it as the opportunity to do some of this yourself. Prior to getting mine I had not done anything to a vehicle in more than 20 yrs. I am telling you now, there is enough info on here and things were thoughtfully constructed enough so, that basic stuff - really is basic.

Consider reading the info on doing the AHC flush yourself (you'll need 2 cans of fluid, a 10mm wrench, some tubing, and a couple of empty gallon jugs). Take it to a reputable transmission shop and have the trans fluid flushed (I did). Change your own oil. Lube your drive line. Get around to other fluid changes systematically. Drive it and see how it does for a few months. During that time, ask around about other Indy mechanics - go talk to them. When the vehicle throws a code, go to Auto Zone and have it read, search for it here and decide if you want to tackle it or have the mech do it - but at least you have an education about the problem before you take it to them.


Good luck
 
Man, the information on the AHC stuff is so over whelming that I am about to go out and pull some one else's hair out :D

Some of the posts are older and some have been up-dated so it's very difficult to figure out as to what the final verdict is ?

So in nut shell, can some one be patient enough (please, ignore my new b status) and post as to following questions regarding the pressure readings;

1)- What things (Tech stream/cable) would I need for my '99 LX 470 and where to buy them?
2)- How do I go about using it?

Thanks
 
AimCOtaco said:
Who is your "Indy Tech" who needs an FSM write up to change diff lube?

.
Click to expand...

MrGreenJeans said:
Quick - FYI I picked one up not long ago that had 167k on the dial. It had great records from the Lexus dealership and had never been offload. The records state that AHC fluid was serviced but from the looks of the fluid when I flushed it, I can not see where they did anything more than what was in the bottle - so I am not that surprised by your dealership's response.

Thoughts:

You're Indy mechanic shouldn't be asking you for info - let that be a red flag and push off from them immediately.


Good luck
Click to expand...

My Indy is not asking me for any info but It's for my education and understanding so that I make sure it's done right?

My Indiy has no problem with the differential/transmission/drive shaft servicing but he has no clue as to how to service the AHC?

Different threads have different recommendations so that's where the confusion is.

Though changing the fluid is definitely the first step but checking the pressures and correcting them makes a lot of sense too.

Thanks
 
Quick said:
My Indy is not asking me for any info but It's for my education and understanding so that I make sure it's done right?

My Indiy has no problem with the differential/transmission/drive shaft servicing but he has no clue as to how to service the AHC?

Different threads have different recommendations so that's where the confusion is.

Though changing the fluid is definitely the first step but checking the pressures and correcting them makes a lot of sense too.

Thanks
Click to expand...

Here is an AHC procedure, from a thread in the LC/LX FAQs and also a height/neutral pressure adjustment procedure. If your indy works on toyotas regularly he hopefully has a legit (or otherwise) copy of TIS techstream.
 

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