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Understanding the Toyota E15x series gearboxes, a basic guide to...

Discussion in 'Drivetrain' started by Stig, Mar 12, 2012.

  1. Oompa

    Oompa Well-Known Member

  2. Stig

    Stig ST162 Guru Donated!

    Yes, there have been several attempts at getting a front AWD lsd diff made and all have failed due to price & demand. I don't see it happening unless they link forces with ST162, CelicaTech, Toyspeed, Toyota Celicas online etc

    Kev, my question is whether the later dual syncros will fit athe early single synco boxes. E56 is dual E153 is single afaik
  3. Redrkt01

    Redrkt01 Well-Known Member

    A comparison between an 1995 Euro ST202 E56 and a 1995 JPN SW20 E153 found that at the least KEY, SYNCHROMESH SHIFTING, NO.2, RING, SYNCHRONIZER, NO.1, and RING, SYNCHRONIZER, NO.2 are the same. Now that is with what appears to be an daul synchro E153.....I'm unsure of what models had the early single synchro E153. I tried to look at a 1993 ST185, but those are E151Fs.

    And get this: the E56 factory viscous LSD does indeed have a bar running through it. And the rotation test will not work on a viscous. There is no friction to cause the fluid to heat and expand so it won't work. So the only test is the spline length. There is all kinds of information backing this up on Toymods and 6GC.
    Last edited: Mar 21, 2012
  4. Stig

    Stig ST162 Guru Donated!

    E153's from 1993 have the revised synchro's

    There is so much B/S on the web - don't believe these self proclaimed experts!

    The JDM ST165 locking transfer is a fwd car - it only drives the front wheels.
    When traction is lost on the front wheels (due to not having LSD) the driver locks the transfer with a switch which sends drive to the rear wheels.
    It can only be used on slipery surfaces, ie mud, sand, snow, ice or prone to break the coupling collar

    The ST165 viscous diff is also a fwd car, the viscous transfer is only activated when there is a difference in speed between the front and rear wheels.
    As you rightly said the viscous coupling is activated by friction.
    So when travelling forward with all wheels at the same speed - there simply is no power transferred to the rear wheels, the system is designed to provide traction to the rear wheels only when the car is stuck or sliding or the front wheels are spinning.
    Once the coupling overheats it loses it's ability to transmit power, a problem with early WRC ST165's

    There is a huge power loss in the GT4's when travelling forward, caused by the rear wheels being dragged and having to turn the propshaft and viscous coupling.
    Add to that a 250kg weight penalty and it is easy to realize why a GT4 isn't that impressive compared to a GT-R, add water, ice or mud and the GT4 does gain an advantage

    The WRC cars used XTRAC gearboxes and drivetrains with dual LSD's and a locked transfer, you will see them spinning the rear wheels out of corners etc, which can't be done with a normal ST165/185/205 - unless you use the JDM locking transfer on sand/mud
    Last edited: Sep 23, 2012
  5. Redrkt01

    Redrkt01 Well-Known Member

    From an owner/tuner perspective what can we do to improve upon these limitations?
  6. Oompa

    Oompa Well-Known Member

    There was a guy on Alltrac.net named Mario doing uprated viscous couplers for around $800 US on exchange. What they do is test your unit to see where it was at in terms "wear" then they can ascertain as to what they need to do to give you the right amount of "Lock". The unit is sealed from factory so they machine off the end so they can properly clean the plates and then put in an uprated fluid to give the right result. My understanding is the viscosity of said ,(Silicon based?), fluid is very important and variable to make your coupler grip at the appropriate rate. I dont know who can read this but worth a read if you can! http://www.alltrac.net/phpBB2/viewtopic.php?f=43&t=36743
  7. Stig

    Stig ST162 Guru Donated!

    Well, that's the $1 000 000 question
    Unless you have a huge budget - not much
    Bruce has highlighted the coupling - thanks, other than that there's front and rear LSD which cost a small fortune.
    Other than that there's customizing the gearbox, straight cut gears, sequential boxes, carbon driveshafts, ... it get's dilly from there.
    Maktrak, Hewland, Xtrak boxes are the ultimate upgrade and without $30 000 burning a hole in your pocket - forget it

    For the US/EU GT4's I'd start with the gearbox, the 205 box it the one to have but make sure it's the 4.2 diff version
  8. Oompa

    Oompa Well-Known Member

    Doesn't the 205 box, E154f ONLY come in 4.2? As per your chart on your JDM TEMS Thread?

    E154F 3.384 1.913 1.258 0.918 0.731 3.545 4.285 ST205 - revised synchros on 2,3,R,5
    E154F .................................................. .........ST205 Rallye - revised synchros on 2,3,R,5
  9. Stig

    Stig ST162 Guru Donated!

    So that's another upgrade thread that bit the dust, as usual everybody wants and when someone makes it happen the rest hide.
    That Mario does sound cagey though, I wouldn't be surpised he was doing it in his garage for $100.
    The fluid is probably a trade secret, I wonder if there's info on the web about the stuff as he says he can vary the torque, there must be different grades.

    Interesting also is how much the boxes have degraded in 20yrs, how much power is still actually getting to the wheels as one guy states he can lock the rears with little effort on the handbrake?
    150Nm is a joke considering the car weighs 1500kg and up to 400hp is trying to get past it

    Bruce, the JDM ST165/85 are 4.2 while everyone else got 3.9. I don't know about the O/S 205, maybe someone on Alltrac can tell you?
    There may be some money in exporting old 4.2 ratio's?
    The list is in progress, there are different versions everywhere, so forgive me if there's discrepancies
    Last edited: Sep 24, 2012
  10. Oompa

    Oompa Well-Known Member

  11. Stig

    Stig ST162 Guru Donated!

    That is what I'm doing with the LSD box, good to show the guys what we're talking about

    Obviously he doesn't know that the 4.2 has a blue speedo ring, which makes life a lot easier
  12. Redrkt01

    Redrkt01 Well-Known Member

    Ha! I used to frequent that NZ site a while back! I forgot all about his tutorial and parts list. Good post!
  13. eNtraxGT88

    eNtraxGT88 Well-Known Member Donated!

    redrkt and stig, i've been reading every post regarding e boxes that you guys have been putting up every day on multiple threads, and i just want to say that i've learned many things and i appreciate all the research you guys are doing for the st162 community.
  14. Stig

    Stig ST162 Guru Donated!

    Cool, glad somebody is paying attention

    I'm just glad we are finally getting to the truth, I've been misled for so many years,
    ie the videos Bruce posted - I now know how to convert a GT4 to RWD using the stock gearbox.

    That kiwi site is old, some good info on motors and heads but the gearbox stuff is way off, ie a VC isn't able to sense anything and it doesn't transfer power away from the front wheels, if anything it shares power.
    The power at the rear wheels varies from 0-20%, maybe more depending on the difference in F-R wheel speed.
    Put 50% through a fixed (locked) coupling and the coupling breaks, I've also heard of propshafts and rear diffs breaking
  15. Redrkt01

    Redrkt01 Well-Known Member

    I actually thought the kiwi site tutorial was pretty good on how power is diverted from one side to the other. I don't think the author really meant "sensing" as in it has a sensor or something. I think he used that term as a sort of euphemism for how the mechanical parts work.

    Kev, would you mind posting links to the information you posted earlier regarding the ST165 systems? I'd like to read for myself (and likely re-read two more time after that).
  16. Stig

    Stig ST162 Guru Donated!

    Those are my own notes
    You need to watch these videos a few times to understand how the 165-205 AWD system works

    I'm so glad Bruce found these as it proves I was right all along and the internet "Guru's" actually don't fully understand what they are talking about.
    It's kinda hard to explain but in pictures & videos it's soo much easier
  17. Redrkt01

    Redrkt01 Well-Known Member

    I just got a chance to watch them and they are interesting.

    There is one thing I would like you to clean up though.....After reviewing the video and comparing the info contained in post #24 I have come to the conclusion that the early mechanical version doesn't make the ST165 a simple FWD car. Only when it slips does it revert to FWD, blocking the rears from getting power until being locked. In straight line driving with the wheels moving the same speed the power ratio from front to rear is 50/50; The video says as much. I understand the difference, but someone may read that post above and find themselves really confused about whether the ST165 is 4WD or FWD.

    Something doesn't sit right with me about the viscous coupling system being a FWD car as well. My belief is that in straight line motion power distribution is similar to the mechanical system with a 50/50 power split front to back. Just because there isn't a speed difference between the front and back during straight line doesn't mean power isn't being delivered. There is friction in there, but it is relative to the motion. When one of the front wheels slips and that motion increases so does friction and thus more power goes to the rear wheels. The question is not whether power is delivered to the rear wheels. The question is how much power is being delivered. I really do think that the rear wheels are getting at least 50% of the power most of the time. Aside from my hunch, I have lingering questions about how they could rightfully call it a full-time system if its not or how the USDM market literature in 1988 and 1989 speak specifically about the 50/50 power split; It just seems like a lot of lies and false advertising if what you say is true.
    Last edited: Sep 25, 2012
  18. Redrkt01

    Redrkt01 Well-Known Member

    I'm glad you're getting something out of the discussion. Not many people in our community use the E series unless they have an ST165. And those are rare in this site irrespective of it 4th Gen dedication. I've had to figure out everything on my own. I have one and use one so I try to bestow the knowledge I have so it's easier for the next guy to make the leap to the Gorilla boxes.

    There is still a lot of misinformation out there and on these posts as well. I know I've been guilty of it (unwittingly). But I try not to.....
  19. Stig

    Stig ST162 Guru Donated!

    You need to watch the videos again
    The JDM is fwd, when it gets stuck the driver engages the rear wheels with a switch, it cannot be used on normal roads

    The VC car does not supply the rear wheels when travelling forward because there is no friction in the VC. Therefore 100% is going to the front wheels and only when there is a difference between the front and rear does it start working

    I don't know where you keep getting the idea of a 50/50 split, only the JDM is capable of that and only when all traction is lost,
    people have driven them in the locked position and the result is the coupling I pictured earlier
  20. Redrkt01

    Redrkt01 Well-Known Member

    I do not need to watch the videos again.

    I saw the part where the driver gets stuck. That is the part that you claim the ST165 to be FWD and I acknowledge that point. When the car gets stuck in the video it is the only point where that is true. Go watch the video #2 again at 0:50 minutes. The narrator clearly says that power is distributed 50/50 front to back during normal straight-line driving. So it is not true that power only goes to the rear during slip and only when locked. The video is where I get the idea as well as where it is plainly written in the BGB (RM114U, 1989 TOYOTA CELICA REPAIR MANUAL, page MT-43 E50F2 Manual Transaxle). And I'm not talking about when the diff is locked on the E50F1. So no need to cover that. I'm sure the collar does break if it is used improperly. I'm speaking to non-locked, non-slip straight-line driving.

    Your response is basically a repost. You didn't answer any of the questions. I watched the videos and anyone else that does will notice that video #2 @ 0:50-1:00 minutes contradicts your earlier post and repost. That question need to be addressed as does a post edit.

    Also, I'll repost my points that need addressing:
    Last edited: Sep 25, 2012

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