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Discussion Starter #1
I'd been under the impression that the automatic tranny in my 07.5 was a very stout unit, pretty sure I got the impression from my readings here.
Tonight, I saw a couple threads that definitely contradicted that opinion.
One spoke of a blown tranny warranty claim denied because an Edge unit caused the failure, and another had a bunch of guys calling te auto basically weak overall, and suggesting the manual tranny.
Before this, I hadn't noticed many threads about blown/damaged automatics. Head in teh sand, maybe?:confused013:
I know opinions are exactly that, opinions.

Not only did I think the auto was capable of holding up to some extra power, but I thought that the tuners/programmers had built in safegaurds to tone down the shifts and help protect the tranny.

When I do my deletes, if I(just for example's sake) add an XRT, stack an mp8 with it, etc, is it THAT certain that I'll cause damage to the tranny?
 

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Depends on how you drive it.

If say you have it on the 120HP tune with the MP-8 @ 100% and your just beating on the truck, its only a matter of time before something gives. Boosted 4x4 launches will kill it in a couple tries.

If you take it easy and aren't mashing the throttle in higher gears (showin off) you'll probably be alright, just watch your trans temp and maybe a larger cool/oil pan too.

For me, I tend to drive like a nut if I have to be somewhere in a hurry but otherwise drive like grandpa to keep my mileage in check.
 

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ya i have and tranny leaking issues from like 2 months after i bought my truck i knew this tranny was not stout at all. and the dealer neglected to put the right fluids several times when they were trying to fix the leaking issues. but now the tranny slips with it on hot between 4 to 5 gear. but like the dealer told me i need it to show some type of code or bring it in to where it does not move at all. but i am already going to start saving up for some type of tranny up grade.
 

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isn't the upgrade problem that there isn't much availible yet?
 

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Discussion Starter #5
Depends on how you drive it.

If say you have it on the 120HP tune with the MP-8 @ 100% and your just beating on the truck, its only a matter of time before something gives. Boosted 4x4 launches will kill it in a couple tries.

If you take it easy and aren't mashing the throttle in higher gears (showin off) you'll probably be alright, just watch your trans temp and maybe a larger cool/oil pan too.

For me, I tend to drive like a nut if I have to be somewhere in a hurry but otherwise drive like grandpa to keep my mileage in check.
That last statement describes me too. LOL.

Are you saying that it's harder on the tranny to romp on it to pass in 4th than it is to romp on it in first to get into traffic?

Anybody with similar concerns to mine wll benefit from searching "68rfe" in the 6.7 section. There are a ton of threads when using that term.
It sounds like the next big trend in the evolution of the new dodges will be shoring up the tranny. Plenty fine in stock trim, but apt to fail when behind a modified motor.

Sucks. I'm glad I already feel like the truck is fast. Maybe I can fight the tuner/programmer urge.

Is there much of an increase in performance just from the emissions deletes?
 

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From what I have read, 1-4 have a much larger friction surface so its easier on them then it is on the overdrive clutches (5-6) that are smaller.

Its normally you either lose all forward/rearward movement or 5-6 gears with too much power thrown at it.

- I drove my truck All stock and it was very quick when not in a Regen.

- Next step was 4" turbo back exhaust w/ stock muffler, much louder inside and out and was quick just like stock but nothing to write home about.

- Next was same as above with EGR unplugged and was just the same out come, only less smoke now.

I have yet to put the deletes back on since getting a PMT, but with a PMT in all Stock form, this truck CAN HAUL ARSE! Im talking seat planting power in Extreme.

Once I get the rest of my new down-pipe I will have to keep the PMT in Performance and drive carefully not to hurt the tranny any more then I like.

I will agree these are really fast for a stock truck, when I test drove it for the first time I spun the tires passing a parked city bus.

But then I got beat by a Chrysler 300C (Hemi) and a Cobalt SS...something HAD to be done.
 

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The sprag is the weakest part. I have broken two stock and one Suncoast sprag which they are working with me to find the problem. Have not had much clutch problems but do have the Suncoast mega kit. The tranny's are weak in my opinion. I have rebuilt mine three times and finally found a used one with under 10k on it. I take it easy now untill I work the kinks out.
 

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The sprag is the weakest part. I have broken two stock and one Suncoast sprag which they are working with me to find the problem. Have not had much clutch problems but do have the Suncoast mega kit. The tranny's are weak in my opinion. I have rebuilt mine three times and finally found a used one with under 10k on it. I take it easy now untill I work the kinks out.
How are your transmissions blowing up? Racing? Normal driving? Towing?
 

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I blew my first torque converter boosted launching. My second in pretty much the same fashion except they had to replace 5th & 6th. those were both with less than 10,000 miles on the truck, and just running the edge on hot. I now have 39,000 miles most of it towing my camper, with Edge on hot and mp8 100% I ran over twenty thousand miles without a problem. I got my tax return ordered a Goerend Triple disk did two boosted launches and now the stock converter is pretty much gone. You can drive these transmissoins pretty hard without them giving up but there isn't a stock transmission out there that will take that kind of punishment.
 

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Discussion Starter #11
Stock tranny still good at 150,000. I tow somewhat heavy. fluids look great every change. Never find any metals or clutch materials in pan
I'd say you are a great example of what a stock auto is capable of when used appropriately.
You work it hard, but are on top of your maintainence. Your mods have been to improve the truck's dependability and monitor.
I can't see myself exactly following in your footsteps, but thanks for giving an example of wht it can do.
 

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I blew my first torque converter boosted launching. My second in pretty much the same fashion except they had to replace 5th & 6th. those were both with less than 10,000 miles on the truck, and just running the edge on hot. I now have 39,000 miles most of it towing my camper, with Edge on hot and mp8 100% I ran over twenty thousand miles without a problem. I got my tax return ordered a Goerend Triple disk did two boosted launches and now the stock converter is pretty much gone. You can drive these transmissoins pretty hard without them giving up but there isn't a stock transmission out there that will take that kind of punishment.
Thanks for providing more detail. So boosted launches were the culprit.
 
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I would say be Conservative as much as you can and save it for a once in a while romp.

I've had all sorts of mods done after 19 of these. Never lost a tranny.

How you drive it and regular maintainence are the key.
 

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From what I understand, the 68RFE is physically too small to upgrade enough to hold a bunch of power with larger internals, such as billet drums, shafts, clutch linings, etc.

I know that some of the best in the biz are looking into what can be done, but I don't hold out much hope for any 68's withstanding 1K HP.
 

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How are your transmissions blowing up? Racing? Normal driving? Towing?
The sprag broke while backing up (loaded 14k). When it broke, the low/reverse piston breaks the bevelled spring and clips. Then the low/rev clutches get burned up.

I bought the mega kit to replace the low/rev clutches but did the others while I was in there. Got another sprag and blew it out. So I went with the suncoast sprag and blew it up.

When the drive shaft spins less than 150 rpm the low/rev clutches are used. After it exceeds 150 rpm the clutches release and the sprag takes over. With a lot of weight and torque the sprag takes a beating with the switch takes place. The stock sprag has a plastic retainer. Big design flaw.
 

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:hehe:
From what I understand, the 68RFE is physically too small to upgrade enough to hold a bunch of power with larger internals, such as billet drums, shafts, clutch linings, etc.

I know that some of the best in the biz are looking into what can be done, but I don't hold out much hope for any 68's withstanding 1K HP.
We don't need it to withstand 1,000 horsepower yet (nobody is making over 700 with a 6.7).

Something reliable in the 500-600 rwhp range would be great.
 

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The point is: don't expect too much yet from the 68 (less, IMO, than the 48)... remember the 6.7Ls make a bunch more torque than the older common rails - and torque is what breaks stuff.
 

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I agree with you.

For the guys that want to 1,000 HP trucks, they'll probably have to wait for a 48RE swap.

But for those of us only wanting 600 rwhp or less, I definitely think it could be built to handle it.
 

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Possibly, but don't hold your breath.

600 RWHP from a 6.7L is gonna be well over 1500ft-lbs, and I doubt a 68 can be built to handle that... the S67 had to be de-tuned from 230ish down to 170HP max just to help the driveline live longer - even then it'll be interesting to observe how long the hard parts last with 450 HP and over 1100ft-lbs. to the pavement through a tranny rated for 650ft-lbs.
 

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I'll be interested to see whats on the market. Somebody will figure something out - even if its a swap for a 48RE.

The power options for these trucks are finally hitting the market and the next logical step is the transmission.
 
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