Avalibility of engine braking with auto trans.

[Roctoy]

I live in Engadine, Sutherland Shire but my work enables me to get around Sydney easily most days so if you want something to do testing on, my truck's available.

Chris

[Tonka Tough]

I am hoping to do a T700 conversion into my FJ40 with 327 over the next month or so...I'd be really interested to know how the testing goes.

The 327 has a bit of a cam late so this convertor sounds like it would work well with that setup. I will definitely look at getting one. What would approximate changeover/non-changeover price be?

If you're sending out info via email my address is jasono@argoit.com.au.

Based in Melbourne.

Thanks,

Jason

[Zeyphly]

I would be interested in this as well if it works with a turbo 400 behind a 350 chev

[MQ080]

We are still waiting to hear back from Anthony ... what's going on? Do you have the box in yet? ...testing time...

[landy_man]

back to my tf727...
is it not possible to fit larger torque converter off another auto ??? that would allow fitment of clutch

[MQ080]

back to my tf727...
is it not possible to fit larger torque converter off another auto ??? that would allow fitment of clutch

It is possible to fit larger converters in some cases, 727s do come in various sizes it has the opposite effect of fitting a stall speed converter
there are drawbacks from the point of view that the vehicle will tend to bang or thump when selecting gears, it will tend to creep when gears are selected at slow speed and when coming to a halt it will also be necessary to keep your foot on the brakes when stationary and in gear,
These are sometimes used when low down torque is required, there are some advantages but there is a trade off in drivability they will not retard an engine to any degree. There is a better modification that can be done to any converter to achieve the same result without going to a smaller converter it is called backstall. this will give you a marginally lower torque multiplication. We quite often do this modification to tow trucks.

[N*A*M]

get your act together grimace. i want to know how this turns out.

[landy_man]

OMFG...dont tell me Grimace is the test pilot....

we will be waiting a while for his POS to be running

[Carl Coight]

YEAH Go the T700!!!!!

[GRIMACE]

Its been tested buy the auto mob and very soon I will be taking it out to ormaeu I am just sorting out afew things that need to be done.

So far its different, sometimes when you let off and the engine braking is not so high the box drops a gear and the car slows down very rapidly, the pedal is obviosly very sensitive when you let if off now aswell.



VERDICT SO FAR


IT WORKS

more to come soon

[MQ080]

OMFG...dont tell me Grimace is the test pilot....

he was the first to take up the offer...

[viperguy]

any real good news yet? would be keen to get this done to my auto 91 mav.... how is the over drivabilty? town? highway? not effected by oversize tyres etc etc...

[GRIMACE]

My RR has 33s on it, I would say that bigger tyres would be less touchy felly on the accelerator.

I mean with 29s the car would be zipping forward and when you let off it would slow down pretty damn quick.


Just remember the Mod does not affect acceleration at all just stops the autos free coasting effect when you let off of the accelerator. Hence why you get all your engine braking.
The car seems to be slowing down approx 20-40% quicker depending on speed/engine revs.


I am hanging to get my front diff all together again so I can take it to ormeau to see the difference in 1st low downhill. My vehicle used to go a good running speed down hill, it was fast and if the ground was not dry pretty scary I always used to have to feather the brakes (this is not a good practice at all whilst down hill 4wding) and was always catching up to the mofos infront of me .
I will report soon on all the offroad benefits and also any changes to fuel economy

But with the limited testing I have done so far, I would say anyone that wants to build a vehicle that is goin to be used as the weekend 4by and wants an auto trans GO FOR IT, its bound to be 200% safer and in the end I beleive that safety comes first



Cheers
Anthony

[N*A*M]

whats the turn around time if you had the complete vehicle lenny? and how much is the forum discount?

[viperguy]

would the constant hook up cause any fuel consumption issues? im guessing that if its like a manual it wouldnt, but i thought id just ask... im keen to know the costings and overall drivabilty... thanks guys

[MQ080]

whats the turn around time if you had the complete vehicle lenny? and how much is the forum discount?

Generally 2 days to do the job, a day each way in transit (Syd-Mel & vice versa) 4 days all up. But i think you would be better off getting it fitted down there. Therefore all the would be needed to be sent up is the converter. Discount is something to worry about after all the testing is done.

Viperguy,

I can only give approx effect upon consumption after Anthony gives me some figures

[mickrangie]

I like the sound of this....

but

might be a stupid question... what stops the engine from stalling if you remove all the coasting action?

[GRIMACE]

It doesnt affect the forward slip of the torque convertor so the engine can still spin forward and the torque be consumed abit buy the converter just as per normal so at light its just like normal and when accelerating its just like normal.


MQ080 will probably explain it alot better than myself

[ORSM45]

the engine wont be allowed to spin slower than the gearbox.

[GRIMACE]

never look at it that way

[WJM]

Dear forum-members,

This topic & thread was mentioned on the DTLC-list, and after some debate I also asked Rodney from AutomaticTransmissions for his opinion about reversing the lockup, as I have always been very fond of engine braking with a diesel....below the comments he allowed me to post to this forum as well.
Bottom line: could work in a lighter vehicle for incidental or low power demands, but towing & heavy continuous use seems out of the question.
(note that his latest products involve lockup for lower gears as well, *and* that it is good offroad-policy to shift an auto into low-range, to keep the lockup active, and the heat away from the torque converter in the first place (also by revs/gearing of course).

(btw, most of this DTLC-thread & some earlier notes I had collected about slushbox lockups can be found here: http://www.a1.nl/phomepag/markerink/lockauto.htm )

xxxxxxxxxxxxx
From: "Hudson-Davies Family" <rodtina@optusnet.com.au>
To: <w.j.markerink@a1.nl>
Subject: Re: AT Valve Body replacement and Lock up
Date: Thu, 17 Jun 2004 16:04:19 +1000

Hi Willem it's Rodney here from Wholesale Automatics. First of all thanks
for bring this message to my attention. I have read all the responses and
even gone to the web site message board that started this and read through
all of there messages. Where do I start? I would first of all like to let
you know that removing a Lock-Up from any convertor in a vehicle that is as
heavy as a Landcruiser or Nissan Patrol will shorten the life span of the
transmission due to over heating especially when towing. This can be as bad
as only getting 5,000Km out of your transmission after removing the Lock-Up.
It can't be done, I know! I have already been there and done that years ago.
I have a full time job trying to stop these things from over heating at the
best of times. The worst offender is the A440 hydraulic transmission but
they all do it to some degree because of the small size of the convertors
that are used in all Landcruiser and Patrols. You can not afford to remove
one of the major components that keeps the transmission within an expectable
heat range ( 60-120C ).

We have built many low stall convertors and it took as 3 years to work out
how to lower the stall speed without having to enlarge the convertors outer
circumference or having to remove the Lock-Up plate. I tell you this with a
passion because we have reconditioned, modified and changed these
transmissions so much over the last several years that I know them inside
and out. I know how they will respond when you fit a Turbo or do a V8
conversion. I know what sort of a heat to expect from a certain
transmission on a 34 degree day towing a 24 foot long caravan with a
standard engine going through the mountains or even across the Nullarbor.
Just as a twist to this story and to prove a point I have just got off the
phone to a customer of mine that has a GU Patrol and noticed lack of power
in the engine, struggling to maintain 80 Km and a transmission that was
getting over 125C on a flat stretch of road between Echuca and Deniliquin
towing a caravan. We had fitted one of our standard reconditioned
transmissions, Extreme valve bodies and our new transmission oil temp gauge
kits several months ago for his trip to the Cape and also left him with
sticked instructions to pull over if he ever got to 140C. He was concerned
at 125C and rang me, I asked him to change from Gas to Petrol and with in 4
minutes the transmission was back down to 80C he speed was back up to
cruising speed and had all his power back. What had happened was that he
was holding his foot on the go peddle so much that the convertors Lock-Up
was wasn't getting a chance to engage. No Lock-Up and the transmission was
in trouble straight away! Needless to say he has a problem in the gas system
some where (Should of asked him if lack of it was the problem!) I'll find
out later.

We can lower the stall speed of the convertor without having to remove the
Lock-Up and in the lasts month or two decided that we no longer do this
unless an V8 Conversion is being done, In this case the Low Stall Convertor
is a must otherwise the convertor will overheat due to the high stall speed.
The more power you have the higher the stall speed goes. We have instead
developed a Lock-Up Manuel Over-Ride Control Relay, Switch and wiring
harness that comes ready to install into all Toyota Land Cruiser and Nissan
Patrols. Please see Link to news release for full details. Reducing the
stall speed of the convertor behind a factory fitted Engine resalts in
sluggish take off's, The stall speed drags the engine Rpm down to far on a
Std factory engine. We spent a long time trying to find the fine line
between better engine braking and sluggish take off's. We instead designed
the lock-Up Over-Ride and got the best of both worlds. Steep down hill
docents with 100% engine braking and no overrunning what so ever. One side
effect if you can call it that is that the A442F transmissions will require
the Extreme Valve Body as well, The Patrols don't need the valve Body for
this and I haven't done one for the A750F 5 Sped yet. Looking for a
guineapig!

In my eyes he perfect heavy duty accuracy pack for both the Land Cruiser and
Patrol Automatic Transmission is:

Extreme Recalibrated Valve Body:
http://www.automatictransmission.com.au ... ewsId=4651
http://www.automatictransmission.com.au ... ewsId=8169
http://www.automatictransmission.com.au ... wsId=11360
And the A750F 5 Speed that I have photos of but not made a news release for
yet.
I think Greg Goulden would kill me if I didn't give it to him first as
promised. Works great but!

Temp Gauge Kit:
http://www.automatictransmission.com.au ... wsId=12031

Lock-Up Manuel Control Unit:
http://www.automatictransmission.com.au ... wsId=12101

Large Oil Cooler if not already fitted:

Synthetic Transmission Oil:

If you or anybody have any questions regarding this matter then please feel
free to ring me direct on 0415393755. As you can imagine there is no
possible way I can explain all the fine details without boring every body to
tears. Please feal free if there is something I did a useless job of
explaining. And in the case of Greg feel free to edit the links out. I
will understand!

Kind Regards
Rodney Hudson-Davies
Wholesale Automatic Transmissions

[GRIMACE]

i think someone is trying to make a sale and advertise .


Its funny you say that removing a lock up is bad cause it will casue the auto to over heat when towin then contradict yourself and say that a guy you knew was not getting any lockup when towing....deeeerrrrrrr The auto when towing is not inclined to lock due to the sheer fact that lockup is only generally engaged while your on the higway in semi coasting mode, with little load on the engine.

When towin heavy loads all the lock up would do is slow you down, and increase then load on the actuall auto itself.....



if your worried about heat upgrade the cooling system, in my eyes I would rather the safety on offroad descents and more engine brakin then the lack of lock up when doin 100Ks plus. or when towing a 3ton load.


cheers
Anthony


EDIT: Not saying his lock up thing is bad or good I think it is a great idea the beauty of the way Len has done mine is you dont even have to worry bout it, it does all the work for itself

[dumbdunce]

maybe I should apologise for introducing this idea to DTLC/80SCOOL; WJM remember all along I said it was NOT a mod you'd do for a tow rig! it is an OFFROAD modification! - but you mentioned engine braking with autos and this was topical.

I also mentioned however, what Anthony has already said, is that when you're towing, the lockup only operates near coast, when you're hauling up a hill or accelerating the lockup is disengaged - autos heat up when you tow, there's no two ways about it.

Len P will surely have some wisdom to share on this...

cheers

Brian

[cuz]

I had my T700 modified in Brisbane to manually lock the converter clutch up via a switch,so I can deicide when it works.It's behind a 6.2 L chev diesel and works well.

[WJM]

maybe I should apologise for introducing this idea to DTLC/80SCOOL; WJM remember all along I said it was NOT a mod you'd do for a tow rig! it is an OFFROAD modification! - but you mentioned engine braking with autos and this was topical.

But if the lockup can't stand the torque of towing, how can it stand the reverse torque of engine + shock loads?
(is it a 'break'-problem, or a 'wear'-problem btw?)

I also mentioned however, what Anthony has already said, is that when you're towing, the lockup only operates near coast, when you're hauling up a hill or accelerating the lockup is disengaged - autos heat up when you tow, there's no two ways about it.

But that would mean that an auto at full throttle always has an effectively lower gear ratio than an equally gearboxed/diffed manual....
Never read anything about this before, and it would be quite relevant for high-speed driving....
(and the same observation of rpm dropping when letting it coast should at least be combined with rpm raising when flooring the pedal....never observed that in any slushbox I have driven thusfar either....
(admittently no 4x4, but the fuel-argument holds just as strong, or even stronger for lighter & modern 2wd's, which I did drive....can't believe none of them had a lockup, that would be a silly omission in the fuel department)

OTOH, the GMC Cyclone did have overheating box problems with German typical high-speed use....
(but then again, even Patrol manuals required larger oil coolers for towing in Europe....)

Willem (who has just dismissed the option of a slushbox Land Cruiser completely, if all this is true....why waste power into heat, when you can have speed instead....) Jan

[bogged]

theres a thread on nissan section

also a buy deal on them

[robbie]

http://www.automatictransmission.com.au ... wsId=12101

thats the link to this new Manual Control Lock-Up switch/relay/loom.. anyone know how it would actually work?

[MQ080]

Being able to disengage a lock up converter electronically has some great advantages for the 4x4 driver, using it for retarding is opening a tin of worms so as to speak. To be frank it does not have the mechanical ability or durability to perform this task without causing major problems let alone expect it to be 100% effective and safe.


Most lock up converters should only apply in the top end of any driving range they are designed to reduce converter slip which can vary but as a rule about 8%.
The material to do the locking up is nothing like a manual clutch it is only 1mm thick and same consistency of transmission bands and clutches and it is common practice for these to burn out if any slip takes place. The reason why the previous mention of the Nissan overheating would have been due to slippage not the fact it was disengaged.
When the customer switched to petrol he would have had an increase in engine RPM and horse power and the lock up would have been in an acceptable lock up mode not semi
or partially engaged. To engage lock up at any speed lower than the 8% will only cause slippage and unwanted heat.
To add a manual switch to cause this to happen does not make any sense.
When you add extra weight to a vehicle such as towing or uphill driving applying a slipping lock up creates a tremendous amount of heat which is a killer in any auto. If the converter lock up should apply at 80 klms but in actual fact it is applying much earlier due to higher engine RPM and extra load the result is the torque of the engine is greater than the frictional ability of the lock up lining to apply 100%, you either get lock up shudder or slippage.

Many people blame the converter for this problem not realizing the burnt out converter is the result of the problem not the cause.
.
Unfortunately there are few tell tale signs to indicate a lock up is slipping until it is too late.

Toyota had a distinct problem of the converter clutch coming on early some times as low as 60/70 if you add a boat or a caravan it will come on even earlier. It is to the owners’ advantage if he could by pass the lock up and run the transmission at higher RPM it would prolong the life of the transmission; this is done in many transmission shops to bring the lock up on at about 90 or 100 klms. To do this manually would be an asset when towing.

Rodneys modification in this area is an excellent idea.
It is common knowledge in the transmission industry if a lock up comes on very early it will stall the engine.( When the engine is below acceptable torque band).

To apply lock up in a down hill application on an engine with low engine revs could be a disaster.
The problem being if it is applied early it will stall the motor as the motor does not have the low down torque to overcome the extra load applied by the lock up apply, no power steering and no brakes would only add to the drivers discomfort not improve the situation.
This is only a comment not a criticism. To use a lock up converter in any other application but to improve fuel consumption in the higher RPM range will result in early converter & transmission failures.

Removing the lock up could never lower the stall in fact it would raise the stall as it would be reducing rotating mass which equals additional horse power.

[GRIMACE]

I want to add to this.....................

First of all len you have covered all the thoughts I was thinkin.....second of all fuel economy seems noticably worse ? ? ? not sure why it may be something else.

Second of all there is a slight clunkying sound (more noticable than b4) every time you let of at low speeds its like a clunk grind not bad but you can hear it... it sorta seems asif the engine braking kicks in and of and on of afew times only when you goin real slow ? ? ? Its mainly in high range when breaking at lights you get to almost stop and the auto goes to first then you get the clunk and some wierd sounds ? ? ?

I am currently assuming that this whole clunking sound is actually my worse than desirable driveshaft angles loudin up under pressure, and hence when I finally stop breakin my POS and get the cash to fitt the DC driveshafts (shouldnt be too long) it will prob all go away.

And also off road you really need to be gental with it (maybe you dont but i feel asif i do ? ? ?) in that i mean if I am on a flat hill in say third, low and cruising along and it starts to come to a slight down hill slope instead of just dropping it into second i feel its much better to break alittle and then change the gear and I would definately not drop it into first as it will lock up or jerk forward and back for a short period of time until the engine rev settle and the breaking becomes and even amount



Anthony

All i all I am still happy with the results, I am gonna look into this fuel issue it may be cause I did abit more offroad work (my car chews the juice offroad) but not 100% sure.

[Leprecaun]

Ant can you keep posting your comments about this, i am interested in doing this mod as a few days ago went up a 30+Degree hill which was washed out loose dirt. Got up fine using the loud pedal but going down the hill was a experience, using the techniques outlined and which every auto 4wd driver practises. I would of liked to just coast down in low first and occasionally tap the brakes to adjust the descent. Let me know if your going to Ormeau as I'd like to check the system out!