auto trans

[BRayls]

those that complain of the weak auto. are most of you stock or bombed? if bombed why not say how weak the cummins was for not being higher in power stock? now I know that both can be fixed,to last in a higher power situation. I just never understood why anyone would expect the unit to live in an application that is 25-50% more power than stock. I do not work in the assembly portion of the plant. but I can assure you that we all take pride in building good units. unfortunately they all cannot be perfect. please keep sarcasm to yourself,as I really would like to know. this said I would have an auto if not for towing,and knowing it would not live to my abuse. Oo. my 97 was auto with 260rwhp stock trans with v-b like the 03's have, 147,000 of my miles. they ain't all bad.

 

[nwjetboat]

I have a gripe with the design guys. . Why doesn't Dodge put a more efficent converter in their auto? DTT does it, and has done it for a long time. Most of all the gripes would be solved with a converter that didn't drop 300 rpm unlocked to locked mode.

 

[Big_Daddy_T]

My take on the converter efficiency is as such. You can manupulate its accelerating characteristics by installing a higher stall converter. I changed stock for a low stall and without uprates it negatively affected acceleration. Took longer to build up boost. A high stall will give the appearance of a faster truck. Gets more off the lots. Also it protects the transmission to some degree I have read. It seems that a high stall would actually have more torque multiplication by my limited understanding. This would in fact be detrimental. Dtt has said the transmission will last longer with higher rpms. This is probably two things. Low line pressure and torque multiplication. I use higher rpms and my trannies have given me good service.

I had supermentals and a drag comp on a transmission with 180k on it. It had a poopy aftermarket converter and a vb. It survived with my box on 5x5 for 10s of thousands of miles. Mainly because I manually shifted to keep the rpms up. Also I found driving with the pedal to the metal would keep the pressure up enough to keep it from slipping. Even though I had way more power than the transmission or poopy converter were ever designed for.

 

[hasselbach]

let's see, the cummins makes make torque at about 1400 rpm, yet the converter stalls about 1600-1700. How does that make sense? by the time the converter stops stalling, you are well beyond the torque curve. maybe good for a super gas car, but miserable for a diesel truck with a limited rpm range.

 

[XJSuperman]

What "curve"? THe torque 'curve' for the cummins is pretty darn near flat... so if it stalls at 1700 RPM which is only 300 RPM above the torque peak... I bet $$ you're still at almost peak torque. PLUS... how often do you sit at 1400 RPM? When I had my auto the only time I saw 1400 RPM was when accelerating from a stop and slowing down. Rarely was I at 1400 RPM unless I was going REAL slow at which case not much heat will build up in the transmission unless you are REALLY loaded.

What bothered me the most about the auto trans was it didn't lock up in 3rd (or 4th which is OD) until 50 MPH... If it had locked at say... 45 MPH or even 40... that would have been much better.

 

[hasselbach]

I've got at least 25 pulls with a stock 600, and they all peak at around 1400 and trend downward after that. Point being, why is the converter stalling 300 or more rpm after the greatest point of torque? that's stupid, the converter is way too loose. I've had many of my customers complain about the same thing, and those that got tighter converters ALL say the truck starts and slows down 100% better. Plain and simple, this converter is not suited for this motor, period. With this much slippage, all you are doing is wasting operating efficiency. No wonder the mileage is so bad, your torque is making heat in the converter, and no moving the truck.