Low stall converter - yes or no?

[Ozymandias]

Hello together



I'm from Switzerland and this is my first technical related question in this great forum.



First i did use the forums search engine for this question but the results didn't gave me a clear answer.



I'm going to go to modify the 48RE in my Truck, it is used only as a Travel Truck, no Trailer, no Towing or anything else, just Traveling to remote areas in Europe and Northafrica.



What I have bought is a TransGo Shiftkit and the GM Solenoid Kit, and now my TransTech said I should also install a DualDisc TC, ok, they are prone to failure.



But should I also install a lowstall TC?

I would like to have the rpms a little down but in some Threads here is written that the engine doesn't have enough power on 1700rpm to pull the truck?



The Engine is completely Stock and will stay Stock, he has far enough power for what I use the Truck.



I just want a Trans that works well and dont left my stranded somewhere in nowhere. :{



Oh, i forgot, it's a MY 04 - 2004. 5 with 130'000Mi and the Trans works well except the very annoying downshifts even with slightest Throttle application, may I need to check the TV Cable.





Thank you for your patience with my english and for your help





Ozy

 

[HBarlow]

The engine has more than enough power and low rpm torque to pull a low stall converter, that's not the problem.

A low stall converter will give up a lot of driveability. When stopped, a firm foot on the brake will be required because the converter will be trying to stall and launch at idle. I had an '06 with a full built 48RE with DTT parts because I was hauling trailers commercially and needed it for durability and reliability. It was tough and performed great but it was not as easy to drive as the OEM transmission.

Every aftermarket modification involves a trade-off from the smooth and easy performance of a factory truck that even a wife or girlfriend can drive comfortably.

 

[cerberusiam]

As you are staying stock and not towing a dual disk is probably excess for the cost. A lot of run single disk converters with no issues on stock and lower power applications. That said, an aftermarket single disk has anywhere from 110-120% of the OE converter when it comes to clutch surface. Also, a billet cover on the TC and increased apply pressures via a shift kit will negate the problems seen with the stock TC. Do not be afraid to go with a single disk TC for your application.



Frankly, the reason a multiple disk TC is so popular and pushed by manufacturers is they can make them hold the power with cheaper parts and engineering. The concern is some of these cheaper parts do not hold up that well for a long happy life.



When you start talking stall on a TC it gets complicated because there are 2 stall levels and they are not neccessarily what you could call pertinent. Flash stall is the rpm the TC will start transferring power with moderate throttle, full brake stall is where the engine rpms will not rise adianst the fluid coupling. As described a full brake stall under 1800 rpms will cause some major bogging. Usually that needs to be around 2100-220 rpm for best results. A TC with a flash stall of 1600 rpms and full brake stall at 200 rpms is usually quite driveable. The turbos on these trucks spool pretty fast so as long as you keep the stall reasonable you won't have issues. Flash stall is also effected a lot more by TQ. Since these have considerable low end TQ even a flash stall of 1600 with heavy throttle cna easily become 2000 rpms or more. I have what would be considered a 1600 rpm stall and it is not tight enough, even stock. A lot will depend on the builder but a TC that is costing you in the $600-$800 USD range is usually not going to be so tight even with an advertised 1600 rpm stall.





What you WANT is a converter that is more efficient in fluid coupling. That will enhance the stall plus put the power to the ground much more efficiently. The stock TC is cheaply made and loose to save the parts. Its efficiency is probably 70% on a good day. What you want is an efficency rating at 80-85% with a heavier stator. Modifications to that stator will give you the stall and efficiency that is required but it needs to be stronger to handle the power. Modified stock stators have a finite life time behind these diesels. They work for a while but they are not what I would consider a good buy. I am working on replacing #3 modified stock stator because it has almost reached its limit. The other 2 broke and had to be replaced.



Don't skimp or jump at the first TC you want. Research them and talk to the builders. The TC is the heart of the trans, it needs to be as good a spossible.



In summary, yes you want a lower stall TC. Yes, you want a higher efficiency TC. Yes, both can be made to work quite well with stock power and not sacrifice driveability.

 

[Mark31]

Ozy, the factory tc was always one of my least favorite things about my truck. I now have a low stall single disk tc in a stage 1 transmission and it is like night and day difference. Maybe i do have to hold it a little more at a traffic light, but I don't really notice it. But when the light turns green, the truck moves off smartly, as though a 1000 pounds had been taken off. The real joy of the low stall is when I hook to a load! Mark

 

[Ozymandias]

Thanks a lot for the answers.

A question to cerberusian, do you have a recommendation which TC I should order?
It doesn't bother me if it costs 1500$ I just want the TC you told me, the reliable efficient Part.

Then I can watch out how to get it to Switzerland.

 

[Ozymandias]

I searched around a little and found this



http://www.ebay.com/itm/Cummins-Die...Parts_Accessories&hash=item589bf30655&vxp=mtr



Does anyone know anything about this TC?



Who makes it, is it reliable, can I trust in?



Thanks again for your help with this issue, I'm really new to the Ram and need to learn a lot.

 

[HBarlow]

Probably not.

There are five or six quality 48RE builders known and respected by TDR members. Among them are DTT (Diesel Transmission Technology in BC, Canada), Goerend, and others. Other TDR members will add to my comment naming two or three more.

Contact those companies describing your wants and needs and ask them to recommend their TC that is best for your truck and your application. Don't buy their high-performance, heavy towing, sled-pulling model or you will hate it.

Regardless of what some folks may tell you, there will be a trade-off in smooth, easy driveability. Any torque converter that stalls at a lower engine rpm will lurch into gear a little more aggressively when you pull the shifter into D and will require a firm foot on the brake pedal to hold it in place. No aftermarket converter will perform exactly as seamlessly as the OEM converter does but will offer advantages if that's what you want.

 

[cerberusiam]

Does anyone know anything about this TC?

Its purple, not a good sign. Trusting stuff off E-bay is a bit off a gamble, you may or may not get what you expect.

As far away as you are, and, where you intend to go I would call Goerends and tell him you want the best single disk he can build for good efficiency, stall, etc, for stock power.

Goerends is probably the premier builder of TC's at this point.

As far as being different from a stock TC when you put it in gear, yes it will. Not a bad thing though. As least if you feel a firm bump when it drops into gear you know it is solid. It takes little or no extra brake pressure to hold them even with a 500 rpm drop into gear, given brakes are good. A lot depends on the design of the TC how hard they push at an idle.

 

[Ozymandias]

Thanks Cerb
Thanks Harvey

I'll write an email to Goerends this evening after work.
Hopefully they will ship to Swiss.

Do it once do it right is always my way.
Hate it to doit twice and pay double.