Engine/Transmission (1998.5 - 2002) Help w/TC selection

[dnesbitt3]

Not trying to start any wars but I am confused as to which direction to go. I have visited all of the sponsors websites looking for a TC and Valve Body for my truck and it seems like most of the equipment offered is for very heavy duty towing or highly modified trucks.



I use my truck for daily driving and occasionally pulling my 7000 lb camper and 3500 lb boat (not at the same time). Trips range from 100 - 3000 miles when towing. I interested in smooth shifts (not neck snapping drag race type shifts).



Planning on pulling the camper 10,000+ miles next summer around the USA and want my combo to be bullet proof.



Relevant Info:

98 Dodge 2500 2WD 3. 54 rear end

212,000 miles

Stock with no aftermarket goodies.

no plans to BOMB or even put an exhaust brake on

original transmission, TC - fluid and filter serviced every 30K

fp, trans temp, and EGT guages



What TC company would you recommend and why?? I greatly appreciate and value your input, you guys are the greatest.



Thanks,

Don Nesbitt

Aiken, SC

 

[DieselMinded]

Partial Post... ... .



The bigger the surface area of the TC the better ... . ask and compare..... also 2 TC's with the same diameter can be majorly diffrent ... its then a matter of what material the TC face is made of ,,,, Raybestos is premo-supremeo ... . dont get sold on VB's ask if its just a stock VB with a Shift kit ... most dealers will say yes ... . save your self $400 or so dollars and get a shift kit and have it put in your VB when the TC is done. if the VB is completely Custom to match the TC then get there VB.



A Single Disk will hold at the same pressure as a Tripple disk ... the tripple disk keeps the Pressures up on the trany prolonging its life as a Daily Driver .



Good Luck

DM

 

[fox]

[A Single Disk will hold at the same pressure as a Tripple disk ... the tripple disk keeps the Pressures up on the trany prolonging its life as a Daily Driver .



Good Luck

DM[/QUOTE]



DM, make this alittle more clear, please.

The TC doesn't change the pressure in a trans. If you are refering to holding power, say that.

If a trans has its design issues addressed, a single disc will hold the Cummins.

 

[DieselMinded]

The Tripple uses the pressure from the VB to keep tention up on the trany. Keeping the bands tight and minimizing streaching .



the TC dont change the pressure ?



... right ... ... but a tripple TC makes better use of the Pressure Supplied by the VB.



A single disk will hold a cummins ?



Most certianly !!!!!! a single disk is the TC of choice for many high Horse power CTD ... . reason being for the pullers ... when there launching with the sled they have the VB a Crankin' ... ..... that TC is LOCKED no ifs,ands or buts about it,,,also with a single theres less moving parts.



Im in no way a trany expert ,,, but I did exstensive research before I picked my option. and Ive talked to all the major TC companies . . and I have a pretty good idea about how this bizness works.



DM

 

[tractorface]

I like my Goerend brother's transmission a lot. The shifts are very smooth. Drive a few trucks if you get the chance. Good value as well. Check em out and good luck

 

[Hohn]

Since we're basically voting, my order of preference would be:

1) Suncoast

2) Goerend

3) ATS

4) BD

5) DTT



Now, if you're going with a full transmission, not just TC and VB, then I'd go

1) Suncoast

2) Goerend

3) DTT

4) ATS

5) BD



jmo as a stick shifter.

 

[tractorface]

to clarify my statement

I suggested GB because it sounded like the guy wanted a smooth shifting, reliable, affordable unit. If he was drag racin I would have said DTT or Suncoast even though I am sure a GB transmission would work great the other guys specialize in that. They do have a different feel drive a few. The converter and valve body make a ll the difference in how it "feels"

 

[SEmerson]

Any vender can make a trans shift soft or hard. This has to do with the setup of the vb. For example my 97 has neck snaping shifts. And my 01 which my wife drives has soft shifts. Both are DTT tran with the same tc. They just set them up as reqested. I have had great customer service with DTT and would buy them again. Also while a triple disk tc is a great selling point a single disk will hold fine in a properly setup trans. If a vender has low line pressure he will need a triple to stop the slipping. But then you have increased wear on all the other parts. :-{}

 

[GLASMITHS]

Any vender can make a trans shift soft or hard. This has to do with the setup of the vb. For example my 97 has neck snaping shifts. And my 01 which my wife drives has soft shifts. Both are DTT tran with the same tc. They just set them up as reqested. I have had great customer service with DTT and would buy them again. Also while a triple disk tc is a great selling point a single disk will hold fine in a properly setup trans. If a vender has low line pressure he will need a triple to stop the slipping. But then you have increased wear on all the other parts. :-{}

Exactly. I have the "livestock" vb, so you can tow a livestock trailer and not knock the cows down!! I did not want a neck snapper either. All the t/c are the same. Its in the vb that controls the shifts. Yes it is firm and you better be ready to take off or have your foot firmly on the brake before putting it into gear. :-laf

 

[tractorface]

"All the TQ are the same"

No way I will agree to that one. Some are tighter than others for starters, the differences are huge. I agree that the valve body controls how smooth she is for the most part. My point was that you will find vast differences here between Brand A, B, C, and D. I have driven in a DTT truck with a livestock VB and it feels quite different than my truck feels. No flame just pointing out the there are differences.

Dnesbit

You'll need to call around a little. Sounds like you just want to upgrade the converter. Some guys won't want you to do that with thier stuff. I don't blame them. Just call the major players and ask questions. I think you'll be surprised at how helpful some of them are. Be careful if you go with a "name brand" TQ from some company that is used to selling stuff for gassers. I would strongly suggest you stick with the Diesel guys that know thier way around a torque monster My last piece of advice is this. Even if you are at stock power levels an aftermarket TQ/transmisson can make a huge difference in how your truck drives

 

[GLASMITHS]

"All the TQ are the same"

No way I will agree to that one. Some are tighter than others for starters, the differences are huge. I agree that the valve body controls how smooth she is for the most part. My point was that you will find vast differences here between Brand A, B, C, and D. I have driven in a DTT truck with a livestock VB and it feels quite different than my truck feels. No flame just pointing out the there are differences.

Dnesbit

You'll need to call around a little. Sounds like you just want to upgrade the converter. Some guys won't want you to do that with thier stuff. I don't blame them. Just call the major players and ask questions. I think you'll be surprised at how helpful some of them are. Be careful if you go with a "name brand" TQ from some company that is used to selling stuff for gassers. I would strongly suggest you stick with the Diesel guys that know thier way around a torque monster My last piece of advice is this. Even if you are at stock power levels an aftermarket TQ/transmisson can make a huge difference in how your truck drives

My bad!! You are correct. I have the 89%, there is a "91" % and a "93" race t/c. The reason I bought the 89% and "LIvestock" v/b is because I did not want harsh shifts. There is no way you can slip my setup with a stock engine. And it is firm but not harsh.

 

[tractorface]

I don't think you could slip your setup with 700HP either :-laf

 

[GLASMITHS]

I been trying, but... .....

 

[Will Manchester]

Here is a technical explanation (a bit long) of holding capacity, this can be applied to TC's, manual clutches, clutch packs inside a transmission, etc:



When looking at holding force between 2 surfaces, the equation is F=uN (or Force = static coefficient of friction * the Normal Force applied to it). Notice that surface area is NOT part of this equation.



Your normal force (lb, kg, etc) is the combination of the pressure (psi) created by the pump & VB combo and the surface area (in^2, m^2, etc) of the piston (technically, the OD of your lockup clutch and ID of the piston bore). Pressure * area leaves you with a force (lb/in^2 * in^2 = lb).



The coefficient of friction (a dimensionless variable) of a clutch in an automatic transmission will vary by its composition, however the range is very small (somewhere between . 14 - 17). What you are looking for is something that will have a long life, wont burn easily, and most people want an engagement that isn't too harsh.



So, you multiply the normal force times the coefficient of friction, and you get a force. But we are looking for the torque holding capacity. The equation for torque is T=F*D (or Torque = Force * Distance).



Force is what we derived above.



Distance can be a bit tricky to define if you want an exact number (it involves some calculus). Distance is defined as the length (in, ft, m, etc) from the center of rotation to the point of interest. With a clutch, there is not 1 specific point on the clutch where all the force is being held. However, virtually all of your lockup clutches are about 1 inch wide (give or take just a little). You can make a very good approximation by using the center point of the friction itself (example: ID=10", OD = 12", therefore D=5. 5"). If you had a friction that was 3" or 4" wide, this approximation would not be very accurate, but I have never seen one to date.



You should have enough info now to calculate your holding capacity for a locking torque converter with a single disk! Just make sure your units all match up. Ultimately, you'd like to have a number represented in lb*ft. (not lb*in!).



If you are looking at the holding capacity for a multi disk application, modify the fist equation for finding holding force between surface: F=xuN, were x = the # of frictions in the converter. Therefor with a given line pressure, a double disk TC will hold 2x the torque, a triple disk TC will hold 3x the torque, a quad disk TC... you get the point!



Bottom Line: You can only significantly alter the holding capacity of a clutch pack in 3 ways (assuming that we are constrained by size limits - which we are).

1. The number of clutches in a clutch pack.

2. The pressure applied to that clutch pack. (You are not going to double or triple your pressure, btw)

3. Both!



All of the calculations above assumes that the TC is fully locked up. Imagine a 600HP truck accelerating in the fluid coupling, an the VB commands the lockup signal: the TC clutch is now having to make the engine RPM match the transmission and driveline RPM. This is where slip usually starts, and your "u" is now a dynamic coefficient of friction, which is MUCH small than the static coefficient of friction. To combat this problem, the VB is "valved" properly for the application and converter being used. If you "slam" the fluid into the piston, it is easier to ensure a lockup w/ minimal slip. If you ease the fluid into the piston for a nice cushy lockup, you greatly increase the risk of slip occurring and never reaching lockup (the dreaded TC shake). A triple disk has 3 disks all doing the same amount of work as the 1 disk in a single disk converter (remember F=xuN). Therefore, your single disk converters will typical rely on a VB that uses much higher line pressures (BTW, this pressure is common to the entire transmission, not just the TC) and be valved for very quick lockup. Look at all the sled pullers out there using a manual transmission: they all use multiple clutches and a pressure plate with BIG springs - this will ensure that the clutch "grabs" when they are done spooling their turbo and fully release the clutch pedal.



Oh, and one last thing - surface area. Surface area does not do much in terms of holding capacity, but does play a role in longevity of the friction and its ability to trap ATF. The wider the friction, it has more area to "wear" and absorb heat. However, the pressure seen on the friction itself is reduced as the surface area increases - this increases the likelihood of the ATF behind the piston can compromising the seal between the piston-friction-cover. The narrower the friction, the greater the likelihood for burning the clutch and shorter life, but you will have a better seal. Most TC designers have found a nice balance.



----------------





For all you manual transmission guys out there, same principal applies here. Your pressure comes from the springs in the pressure plate itself. However, the coefficient of friction has a much broader range here (look at the SB line up - same pressure plate on all there single disks!).

 

[tractorface]

Wow. Excellent post. Thanks. I knew there was more to the single disc versus triple disc than meets the eye.

 

[GLASMITHS]

Why put more than one disc in, when only one is necessary? The last info I have on line pressures, the triple discs' are about the same as mine -depending on the set up. One of the "triple disc" vendors posted their line pressures 2-3 years ago and it was the same as mine. Does theirs hold better. Whats better when it isn't necessary.

 

[Will Manchester]

Why put more than one disc in, when only one is necessary? The last info I have on line pressures, the triple discs' are about the same as mine -depending on the set up. One of the "triple disc" vendors posted their line pressures 2-3 years ago and it was the same as mine. Does theirs hold better. Whats better when it isn't necessary.

Torque converters do not determine line pressure, that is the job of the valve body. The valve body is basically the brains of your transmission, it determines base line pressure, max line pressure, how fast pressure increases, when shifts occur (other than OD and TCC lockup - those are electronically controlled), how hard the shift are, etc, etc, etc. Almost all the transmission manufacturers out there are using very similar pressures. Tow valve bodys will be a bit tamer line pressure and milder valving to give softer shifts, race VB's are set up with higher pressures & faster shifts. They can all build you a VB any way you want it. And again, pressure is pressure, weather it be at the pump, inside the VB, at the TCC, at a clutch pack, etc. More pressure = more holding capacity & harder shifts (fills cavities quicker). There is with out a doubt a limit - too much pressure and you will damage the transmission.



I am not sure where the "usable" pressure limit is, but lets suppose it is 50% higher than OE. Most would say that an OE transmission will hold approx 600 Ft-Lb's, right? So 600*1. 5= 900 Ft-Lb. Now, we upgrade to a triple disk converter with you ungraded VB: 600*3*1. 5= 2700 Ft-Lb



A good valve body with a stock converter would most likely be fine at your HP levels - however without your modified TC, you would not be getting the benefits of the modified fluid coupling. If you were to put in a triple disk converter, it would TRIPLE your holding capacity of your TC (given the same clutches). So, lets say that in your current configuration, you are able to hold approx 900 static Ft-Lb (meaning that TCC is locked up and then you apply full power). That's great, you even have a good buffer there. Now, lets suppose you jammin up a hill with a 10K trailer behind you in the fluid coupling - full power - and command lockup (Now we are in the dynamic coefficient of friction area - much weaker). Suddenly your TC starts to shudder (also known as slip). So, your TC clutch has started slip - therefore the coefficient of friction goes down by some percentage. The next time you are in a similar scenario, it happens again, but takes less power, and every time this happens, it gets worse and worse and worse. At this point, your sluffing of friction materials off your TC clutch which gets pumped throughout your tans, thereby eventually destroying it. So, with this same example with a triple disk converter, you have 3 disks, all grabbing just as hard as your 1 - End of problem and no slip. Plus, now you have a VB/TC combo that will hold 2700 static Ft-Lbs. Now you run into the next week link - the transmission (input shaft, intermediate shaft, output shaft, clutch packs... ... )

 

[GLASMITHS]

Does the triple disc hold better? Whats better when it is NOT necessary? I'm out of the copy and paste thread.

 

[Will Manchester]

Yes, a triple disk converter holds 3x the torque, given that the same VB clutch dimensions. I’ll let you decide why it is better. I am not trying to tell anyone to go out and buy brand xyz converter, I am simply trying to give some theory so you can make an educated decision when purchasing a TC and VB. Both are very important aspects of the transmission and need to be looked at together for a specific application.



Furthermore, the lockup portion of the converter does not solely define the ability of the converter. You must also take into account the drivability in the fluid coupling. This can spawn just as many arguments as “who’s lockup is better” – is there really a right answer for everyone?

 

[Jetpilot]

DTT... ... .