Engine/Transmission (1994 - 1998) Carnage?

[JoshPeters]

When I installed that controller/mystery switch I was hoping to use the torque converter as more of a clutch than a "fan" as it's designed. The converter does a good job of robbing power. I was hoping that the transmission would continue to operate normally even with the lock-up engaged. Right now I have the controller set up as "late" as it will engage. Which seems to be 36 mph or so. I like being able to supprise people light to light when I'm driving to and from work. It's probably pretty hard on parts leaving that switch locked in. Has anyone suffered ill effects by leaving this switch on? Anyone modified the valve body so I don't have this problem? What am I going to damage running it this way? I'm going to put in the Suncoast converter ASAP.

What kind of power will my transmission handle with the Valve body and converter?

As much as I'd like to drop a manual trans in this truck, I don't have the time, money, or hoist to handle the truck. I appreciate all the feed back on this. You people have probably seen this a thousand times by now.....



thanx again

 

[mullady76]

I wiped out my TC which in turn killed my transmission by using the mystery switch all the time. The truck was fast and fun when I locked it up in 2nd gear, but the cost of a new transmission wasn't that much fun.



Sean

 

[JoshPeters]

Were you running the stock converter or an aftermarket? I've been changing my trans fluid every 10-15k miles to keep the swarf out of the transmission.

 

[mullady76]

I had a stock transmission and TC at the time. The only thing done to the truck at the time was a TST #6 plate in the stock location. Also I drive very aggressively and like to do alot of stoplight to stoplight racing. If you have the money get the transmission done.



Sean

 

[JoshPeters]

What went bad when yours went out? The Converter? Clutches in the trans? I'm wondering if I can't just pull the thing appart and modify what I need to when I do the converter.

 

[MikeR]

Go ahead and run your mystery switch like you're planning, and you find out like the hundereds of guys before you that it destroys the converter.

The next weakest link to go is the O/D clutches.



These switches are a bad idea, and if someone still really wants one, it should only be used for downhill engine braking, NOT for accellerating.

 

[mullady76]

I was told that the converter was flexing which caused the material on the lock up clutch to disintegrate and then get pumped through the transmission.

 

[DuallyDean]

Josh--

You like drag racing light to light? DON'T switch to a manual. I did that swap to my Dually, but I wanted a heavy-hauler, not a sprint car. Manuals are great for pulling, but they introduce more noise into the cab via the gearshift. I used to be able to make those Hondas with the "soup can exhaust tips" look silly from the stoplight, but no more. With the manual, I have gotten quite familiar with the concept of "Turbo Lag". Each shift of the gears.



Well built autos shift hard under power and never drop boost. I would still have an auto if the ATS triple-lok had come out 6 months sooner. I personally know of 3 trucks now that have these convertors and I am really impressed with all three. Cost to get the convertor and well built trans is on par with a quality transmission swap.

 

[Josparkz]

If I understand this right , you have to use the switch to obtain lockup. It will not happen automatically anymore. And likewise , if you are locked up and stop , forgetting to turn your switch off , you will stall your engine . This would now be part of your normal driving proceedure , not just for use with an exhaust brake . Is that correct ?

 

[JBlock]

Why not put a capacitor

Why not put a Diode control in the normal circuit in parallel with the switch so the stock engagement is still there if your not using the mystery switch.



It seems you should be able to auto lock up normally and only call on the mystery switch when needed. The Diode should prevent the Mystery's switch from back feeding the normal transmission circuit.



The diode should act like a check valve one way flow of the electrons.

 

[mullady76]

All the switch does is provide a ground for that wire u tap into, I never had any problems with the switch. When the switch is off the TC locks and unlocks normally.

 

[Howard Durand]

The "Mystery Switch" is a good tool for use while towing a load but should not be used like a manual clutch for acceleration purposes.

My switch has three positions. Center position allows the TC to operate normally which is where I keep it most of the time.

Right position unlocks the TC which is something I use occasionally to get the EGT down.

The left position locks the TC so I can use the exhaust brake.



If your TC will not lock up with the switch off, it is not wired right.

 

[JoshPeters]

I am better understanding why that switch is left off under

accelleration. I like "rowing the gears" so a manual would be

a good choice for me. What I don't really understand (being new to this kind of situation) how I will damage the trans with the lockup switch engaging at 35mph. Without it, the truck is very slow. Could there be something wrong with the suncoast valve body I bought? The ad I looked at when I bought it (it's in issue 40) said 2nd, 3rd, and 4th gear lock up. Without that switch on I only get 3rd if I'm so light on the throttle it does no good, or at 48mph. Should I call them? Or is it only designed to lock up when I manually lock it in those gears?

 

[98rammer]

look at my truck profile... the fluid coupling does suck very much, however, my stock/unlock swithc keeps the lockup clutch from slipping when accelerating hard. you can only go so far with the line pressures on a stock auto before you'll create some big internal and possible external leaks.



Tom

 

[DuallyDean]

Josh--

It isn't so much that you will damage the transmission by locking up at 35 MPH, you will damage the lockup clutch in the TC, and all that garbage will then flow out and into the rest of the transmission. When that happens, fluid passages in the valve body plug and crap gets into the servos and bearings and everywhere else that it really shouldn't be.



Why does the TCC fail when used like this? Because it is about the size of a Suzuki Samuria clutch. Can't expect something like that to hold 100% of the torque of your Cummins now, can you? If you want a TCC that will hold up to that kind of duty, you need one of the new generation multiple clutch disc convertors. I have had extremely positive experience with the ATS Triple-Loc convertor, and understand that there are now others on the market. These convertors have a clutch pack similar to those in the transmission itself, and there is absolutely no question about when they lock up--YOU FEEL IT! They do this without raising line pressure, which increases the life of the lip seals in the transmission The ballpark on one of these convertors is going to be around $1,400. 00, plus core charge.

 

[JoshPeters]

OK, Back to the beginning, I HAVE an upgraded valve body by suncoast. I HAVE the Suncoast Torque converter (not in yet, working on it). I have a #6 fuel plate, all the way forward, and a 14cm turbo housing. Obviously I have opened a can of worms with the mystery switch. My question really becomes, what goes bad in these tranmsissions? What will happen if I put in 370's? When you guys blow these trans's what goes bad?

I hear torque converter, and OD clutches. Stuff floating in my trans, no good. I change the fluid and filter religously ever 10-15k. I have to pull the trans to do the converter... ... I'm wondering if I can do any quick mods to the trans while it's out.

 

[DuallyDean]

Josh--

You really have covered the weak areas of the transmission, there is really nothing more to do. I do not have any experience with the Suncoast convertors, my personal experience was with a BD convertor, circa 1996 (I believe they have been improved since) and while it was a major improvement over stock, I rate the ATS Triple-lok much better. A work friend who lives in St. Paul has a 24v dually with this convertor and Banks go-fast stuff on the Cummins. It is strong now, and big injectors are due to arrive by the weekend. I ended up driving it for several days last week and the transmission feels great. If the transmission is prone to failure, the bigger injectors should prove it. The transmission is stock except for the ATS valve body. I helped install the VB and Convertor. I am quite sure my friend would be willing to discuss his experiences with you.

My own experience is limited to (eventually) failing the BD convertor which also polluted the transmission, taking out the OD clutch pack in a slow, painful death and requiring a full rebuilding by my transmission guy. I was dynoing 249hp/615lbs-ft in my '94 dually and towing roughly 19,000 GCWR in order to kill the transmission. It now resides behind a stock (for now) '94 3/4 ton that I use for a daily driver and sports a stock convertor--very bad decision. It will need a Triple-Lok before I hop that one up any.

 

[JoshPeters]

Thanx Dean,

I hear about guys tearing the transmissions out of these trucks, but no one will say what exactly other than the converter. Now that I know I'm "covered" I may go ahead with some more bombing.



Oo. Oo. Oo.