Question for transmission Guhrus?

[Archive]

Can someone explain to me the pros and cons of the "mystery switch" and when best to use, or not use the "over drive" off. What is the impact on transmission wear for both?

Bill K. You touched on this a little in one of our conversations, but I didn't quite understand it all. Try again?

Thanx

------------------
'95, 2500, 4X4, ext cab, white, Banks Power Pak, Kondolay TC, Bosch 215, Wiley Coyote strapped to my grill
Parts On hand to install Kondolay valve body, BD Gov Spring Kit, Bully Dawg Propane, Horton fan and 16cm housing
Parts on order are Griffin Radiator

 

[Archive]

Banshee,

A lot of people feel they need the mystery switch generally for 3 reasons.

1)Transission is too busy, keeps comming in and out of lockup , making it a nuisance to drive.
This is usually caused because of a TPS (throttle position sensor)problem, bad electrical connections, possible solenoid problem or temp sensor problem. You can add a mystery switch to overcome these problems or you can fix the problem that causes the lockup to come in and out.
I always believe its best to fix the cause of the problem because quick fixes like the mystery switch has more damaging ramifacations on the TC and transmission.

2) People that tow generally like to add a mystery switch or torque loc, as their temp sensor starts to climb and they feel that by adding a mystery switch , torque loc that keeps the converter locked up all the time it will reduce the temps or hold temps in check.

The overheating problem is usually caused by
the TC during in fluid coupling.

What this means is the vehicle is actually being propelled by the ATF oil. There is no mechanical parts that are directly coupling the engine and transmission. The shearing of the oil inside the TC is what is generating the heat.
The engine is operating at one RPM and the transmission is operating a different RPM.
The difference in RPM is what's causing the heat or fluid coupling as we call it.

If your fluid coupling is efficient(tight)you would not generate excessive heat.
Once again it is better to fix the problem rather that bandaiding it with a mystery switch or torque loc.

3) If your transmission is overheating out of lock up, you got a TC that is not tight enough for your applications.

Mystery switches and torque locs
CAUSE PRE-MATURE TC CLUTCH LINING FAILURE!!

I would rather not sell you any torque converters if you are intending to use mystery switches and torque locs as i know of the damage they cause.

Any device that forces lockup to remain engaged during hard excelleration while they dont seem to do any damage during exhaust brake application WILL DEFINATELY CAUSE DAMAGE DURING HARD EXCELLERATION.

I know what all the ADD'S say, we all use extra lining, etc, etc, I know a lot of the other guys are putting fancy front covers, and bigger heat syncs etc.

To me that is a true indication that they have a very poor fluid coupling because of the milled stator they are using.
It doesnt matter how you dress it up, it whats inside(the stator)that counts for efficiency.
The more efficient your TC is , the less the jump in RPM from fluid coupling to lockup.

The less the jump to lockup from fluid coupling the less heat generated and the less damage done to your TC clutch lining.

See thread Trany shop in Alaska,
they kept TURBO TERRY'S truck in the shop for 3 days because they could not feel the jump from fluid coupling to lock up. With milled stator converters they were installing they were seeing 300-400rpm drops, this is the industry norm rpm drop from fluid coupling to lock up under hard acceleration.
In Turbo Terry's truck they only saw a
50rpm drop under hard excellerarion with our steel stator converter. They thought something was wrong with the TC.
This is the reason we designed and manufactured the steel stator TC for the Cummins, we know the importance of fluid coupling and milled stators and gadgets cant do the job without causing TC and transmission damage.

I do not use overdrive at all in town with 354 gear ratio's, or for that matter anything below 50mph.

Hey isnt that the reason you guys got the AFC and governor spring kits.
Sorry for the long windedness but it imperative you understand the potential harm these devices cause the TC clutch lining.

I AM DEAD SET AGAINST THESE DEVICES FOR THESE REASONS.

Bill Kondolay

 

[Archive]

Bill, your post was well said. If I can understand it anyone can.
Thanks,Bob

 

[Archive]

Excellent explanation,Bill. You probably just saved me alot of unwanted headaches as I was going to install one of these"mystery switches" for towing. Thanks alot

------------------
1997 2500 4x4,Amsoil throughout,ready for more power

 

[Archive]

Bill,

Thanx for the explanation. I had installed the mystery switch for when I was towing, however, after installing your new TC and the governor kit, I didn't see a need for the switch any longer. Just wanted to verify everything before removing the switch. I thought driving with O/D off was the correct way to go under 50, but will it generate more heat or less with O/D off. Also, in the owners manual it recommends driving with O/D off when towing and in hills. I presume this is also good advice?

Thanx Again

------------------
'95, 2500, 4X4, ext cab, white, Banks Power Pak, Kondolay TC, Horton Fan, Bosch 215, BD Governor Springs, Wiley Coyote strapped to my grill
Parts On hand to install Kondolay valve body, Bully Dawg Propane and 16cm housing
Parts on order are Griffin Radiator

 

[Archive]

Bill,

What is happening when during hard acceleration with the lock-up switch on? Why would this be causing damage? On TST's web site they claim that you can cut 0-60 times with the simple addition of the switch. You have also told me on another post that I should actually accelerate faster when not in lock-up. How can this be?
I read your post above many times and kind of have an understanding of what is going on. I do feel I have better acceleration in 3rd with the switch on in the lock-up position. Is this because of milled stator in my TC, or because it isn't "tight" enough. I hope most of the info you need is in my signature. By the way my BD TC is the 215L. I never installed the switch for any of the symptoms that you have listed. I just thought it was the BOMBing thing to do!! Wish now I woulda waited for your TC & VB. Any further explanations would be greatly appreciated. #ad


------------------
John McEachern
Fort St John B. C. Canada
1998 12v, 4X4, QC, auto w/tc switch, air, tilt, cruise, 3. 55 gears, TST #6, Isspro boost/pyro/transmission gauges, BD VB&TC, CC industries headache rack and rails, JVC KD-SX949 Cd player, forest green,
Kelly Safari MSR 285 75 16, K&N airfilter.


[This message has been edited by Swamp Donkey (edited 10-17-2000). ]

 

[Archive]

I second Banshe's question above...
I live in a mountainous area, where I’m able to drive 35-55 mph most of the time. I find that if i’m just cresting the 55 area, the trans will float in and out of OD a lot. I experimented for a month just keeping the OD out for this type of driving, and all other considerations aside, my mileage went UP! I gained 1. 5 mpg. I’ve noticed that pyro reads 100 deg. cooler, boost is steady, and trans temp goes down. At 55, I’m holding about 2150 rpm (3. 54). Is this ok to do?

------------------
'95 2500 LB 2WD, auto, 67,000--Westech gauges, Prime-loc, Brite box, Back-off Box, Line X, Flowmaster muffler, Borgeson steering shaft

[This message has been edited by Kodiak (edited 10-18-2000). ]

[This message has been edited by Kodiak (edited 10-18-2000). ]

 

[Archive]

I strongly believe the automatic transmission should be kept out of OD, anything below 1500RPM'S when you are empty,
1700rpm's when towing,you are going to find your fuel economy will not suffer and your transmission and tc will thank you by living longer.
The higher the engine rpms, the greater the pressure within the tc.
The greater the force pushing on the tc clutch lining against the front cover the more holding capacity of the clutch lining without shuddering.
Some of you will notice when in OD locked up around 1100-1200rpms you will feel a slight shudder, but as the rpms become higher the shudder goes away.

Swamp
I am probably going to get in a lot of trouble for saying this but oh well you asked so here goes.
CNC milling of the oem stator sounds expensive and hi tech, however its about a 35. 00 milling process sometimes even less based on your quantity.
Now think about this,fancy packaging, marketing and warranty papers does not change the fact that its a cheap milling proccess. A milled oem stator TC is in-capable of providing efficient enough fluid coupling to handle the cummins engine. Hence the need for lockup devices during acceleration.
If you are going to install a mystery switch for acceleration purposes, why not just do that on your stock converter, why spend all that money just to add a mystery switch. Its going to destroy the tc clutch lining anyways.

I know what everyone says, we have more lining and better lining, blah blah blah,
you know what? funny thing is we all tell you to install valve bodies or shift kits including myself.

Why do you think that is,its because vb pressure increase has a greater impact than the extra clutch lining.

The extra lining just means its going to take a little longer for it to burn out.

That is why we designed our steel stator TC to not need mystery switches or lockup devices for acceleration.

You dont buy a steel stator converter for the clutch lining, its for efficiency in fluid coupling .

Have you ever wondered why some manufactures are putting bigger and heavier front covers to act as heat syncs? Could it be the jump from fluid coupling to lock up is so great that they are actually slipping the clutch during the initial engagement and that it generates so much heat,approx 750degrees and higher.

The BIGGER the RPM drop from fluid coupling to lock up the GREATER THE HEAT generated.
Bill