First post on this Forum, guestion about the 68RFE and towing

[cornstalk1]

First off I would like to say hi to everyone, I have been on this forum looking around, but haven't posted anything. I have 2011 Ram 2500 with the Cummins.



I tow a 36 ft 5th wheel weighing between 10,000 to 12,000 lbs depending on load. I have a Smarty Jr. with delete pipe and down pipe. When I tow with T/H mode and E/B on at around 60 to 65 mph which is about 1700 rpm's (4. 10) rear end. I get a shudder when going up a slight incline or over pass. I live in Central Illinois so no big hills around here. I have been told not to tow in 6th to shift it to 5th, but others say they tow that much all the time in T/H mode and don't have any problems. I did have my Smarty on the tow setting which gives me about 70 more horses. I just changed my tuning to mileage giving me 40 horses. I haven't tried pulling with the new tune yet. I only have 15,000 miles on the truck by the way.



This is my first Ram out of 4 that I have had any problem towing with. My last one was an 03 Cummins that towed great, I'm starting to think I should of kept her. Maybe I just don't know enough about these newer transmissions, but I would think if the trans was having a hard time in 6th it would shift down to 5th while in cruise, but it doesn't. Any info you guys could provide would be great. This shudder has me frustrated.

 

[RustyJC]

It sounds like you're slipping the torque converter lockup clutch. At stock power levels, that isn't a problem towing our 16K GVWR 5th wheel with our truck (see signature) in 6th gear. There's a reason that Dodge beefed up the torque converter when they went from my 350/650 Cummins to the 350/800 HO in mid-2011. Apparently the 350/650 version of the 68RFE torque converter can't handle much additional torque when towing. In your case, perhaps the Smarty is messing with the torque management versus downshift logic in the computer (i. e. , allowing too much torque before forcing a downshift).



My 2011 does a good job of towing our 5th wheel in absolutely stock configuration, and I have the warranty backing me up. I'm not against bombing (my previous 2002 ETH/DEE dually was mildly bombed at 347/762 at the rear wheels), but these 4th generation trucks don't have the margin for added power/torque that the earlier trucks did.



Rusty

 

[cerberusiam]

If the 1700 is in 6th gear that is to low an rpm to tow that weight. Does the problem go away when you use 5th gear?

The 70 HP can throw a lot of TQ at the trans when pressures are low. That can will equate to slipping the TC clutch or even the gear it is in. Either way not a good sign. You need more rpms and pressure to tow with.

FYI, if you deleted or blocked the EGR be prepared. The next problem oyu have will be a head gasket if you use the truck to its potential.

 

[CUMMINZ]

I agree with the other posts. You are slipping the stuff behind the engine. Start using the shifter paddle when you tow. Anytime you see an incline coming up at the bottom of the hill shift to 5th (everytime). When you get to the top of the incline shift back to 6th. If you do this you will never feel that shutter. If the incline is great enough shift onto to 4th. I gross 27k with my 07. 5... I use the paddle all the time while towing. After a while you will get used to hearing & feeling the engine and it will come natural to downshift. My smarty 67 is running on 90hp and turbo turnrd up and tq management way down. I have had no problems. I don't over do any pull.

 

[Matt_L]

One other quick thing... .



What version of Smarty software are you running?

On the earlier versions they had trouble with the truck jerking when working hard, such as towing up hills.

Mine did the same thing when I first installed my Smarty, but with the latest updates it has disappeared.

The first time mine did it I too thought I was headed for transmission troubles, but like I say it was just a tuning issue.



PM me if you need to find out where to download the latest "ME" version for your Jr.

 

[HBarlow]

Chris,

Using the magic black box for increased hp and tq and attempting to tow a fifthwheel trailer in upper gears at low rpm is very likely to get you a transmission and then an engine failure. Both are extremely pricey to replace.

I hope you understand your OEM warranty is history already. You will not be able to fool Ram when you remove the box and deny performing modifications. The evidence is already in the ECM and PCM and will not go away.

 

[bedroc]

Sounds a lot like the problem I am having towing our 7k bumper pull camper. I have changed from Smarty to Mini Max. We are headed out later this week with the camper, I will take the same roads as last time. Hopefully we will have better results. Haven't bought H&S Overdrive unlock yet, want to see how we do without it first. Will post the results in my thread next week.











Here is the tread I started last Sept.

https://www.turbodieselregister.com...239063-Auto-transmission-shudder-while-towing

 

[CUMMINZ]

HB is correct on all points. It has taken me three years to finely tune my settings and never lug my motor. I have a great dealer and he handles my issues very well. Anyone that starts lugging these motors for any length of time will have issues.

 

[Cummins12V98]

Well I tow 28K combined in 6th on flat to hilly terrain at 62 mph @ 1,375 rpm. No shudder, shake of shimmy! Oh yea that is with 3:42 gears.

I just can't see why anyone would destroy their truck and warranty with a tuner on such a capable truck right out of the factory.

I tow the GrapeVine on I-5 North of LA at 55 or more. The Syskious in Northern CA at 55 or more.

It is no problem to tow in 6th!

 

[RDThompson]

I don't run a tuner either. Probably for some of the same reasons. I was just on a run from L. A. to Bend Or. towing a trailer with a 9500# trailer and vehicle combo. My trip encompassed the I-5 Grapevine and the Siskiyous and HWY 97 from Weed to Bend. It's all Uphill and some of it quite steep. My truck never faltered, I shifted down when I had to but the majority was in 5th.
My principle use for a Tuner would be to monitor my truck. However the displays of all the tuners that I've seen are too small to read comfortably while driving with Bi-focals. Are there large displays that can be attached? It's been a while since I have inquired of the tuner mfg's . I'm about 20k from the 100k mark so I am watching more closely.

 

[CUMMINZ]

Well I tow 28K combined in 6th on flat to hilly terrain at 62 mph @ 1,375 rpm. No shudder, shake of shimmy! Oh yea that is with 3:42 gears.



I just can't see why anyone would destroy their truck and warranty with a tuner on such a capable truck right out of the factory.



I tow the GrapeVine on I-5 North of LA at 55 or more. The Syskious in Northern CA at 55 or more.



It is no problem to tow in 6th!

I would bet with 3. 42s you don't stay in 6th. very long.

 

[Cummins12V98]

I would bet with 3. 42s you don't stay in 6th. very long.

I said 6th on flat to hilly terrain.

I will be the first one to admit 4:10's would be better for my 28K load but with 6 speeds it really performs well.

Dave Smith offered to swap the front and rear gears to 4:10 for $1,800 but so far I have decided to leave it alone.

At 55 on 6% grades I am 3rd. Temps are always good climbing or on flat ground.

 

[cornstalk1]

Chris,

Using the magic black box for increased hp and tq and attempting to tow a fifthwheel trailer in upper gears at low rpm is very likely to get you a transmission and then an engine failure. Both are extremely pricey to replace.

I hope you understand your OEM warranty is history already. You will not be able to fool Ram when you remove the box and deny performing modifications. The evidence is already in the ECM and PCM and will not go away.

I have talked to the dealership about that, they are the ones who installed everything and will cover anything that breaks even with the turner. The main reason for the turner is to take the EPA junk off. Plus if this was the case the owner before me had the same set up.

 

[cerberusiam]

I have talked to the dealership about that, they are the ones who installed everything and will cover anything that breaks even with the turner. The main reason for the turner is to take the EPA junk off. Plus if this was the case the owner before me had the same set up.

You might want to look into and H&S transmission tune if you are going to continue to run uprated power. The stock program is wholly unsuited in a lot of areas for added power, it needs help.

 

[cornstalk1]

I think I will just run the turner on the stock setting so the only difference to the truck would be the delete and down pipes.

 

[HBarlow]

I have talked to the dealership about that, they are the ones who installed everything and will cover anything that breaks even with the turner. The main reason for the turner is to take the EPA junk off. Plus if this was the case the owner before me had the same set up.

Chris,

You and I both know the dealership is not going to cover anything but their rear ends if/when you destroy an engine or transmission. Regardless of the hype some salesman or slick sales manager told you the dealer principal/gm is not going to pay for repairs out of dealership funds. Your warranty is void. If you experience an expensive failure Ram is not going to authorize repairs or replacement without sending a trained, knowledgeable, and smart warranty rep to examine everything including computer records.

If you purchased that truck from the dealer with emissions equipment removed and a magic black box installed your dealership violated federal and state laws and is subject to heavy fines and sanctions.

I'm sorry to see you driving down the road to a financial disaster.

 

[cornstalk1]

Chris,

You and I both know the dealership is not going to cover anything but their rear ends if/when you destroy an engine or transmission. Regardless of the hype some salesman or slick sales manager told you the dealer principal/gm is not going to pay for repairs out of dealership funds. Your warranty is void. If you experience an expensive failure Ram is not going to authorize repairs or replacement without sending a trained, knowledgeable, and smart warranty rep to examine everything including computer records.

If you purchased that truck from the dealer with emissions equipment removed and a magic black box installed your dealership violated federal and state laws and is subject to heavy fines and sanctions.

I'm sorry to see you driving down the road to a financial disaster.

Harvey, thanks for your post. I have been personal friends of the owner of the dealership for years and they do come through if something happens. I fully understand what your saying. I guess it's a chance I take. It's not like I'm abusing the truck. The Ram mechanic said these trucks run much better without the EPA stuff on it and in fact have less problems with the truck. I still don't tow outside what the truck is rated for and if in fact by turning my turner back to stock doesn't fix the shutter I will be taking it off.

Thanks again for your response.

 

[jkern]

Interesting thoughts on this thread... I have the same exact problem with my truck , only in first gear. When I try to start out with a load, even just 2000 pounds of sand or gravel in the bed, i get a shudder. It is usually worst when trying to start out while heading up hill. I have noticed this a few times, and try to not let it happen, so I don't have real good data, but it feels like a gear clutch or torque converter issue. This happend when it was stock, and still happens with a mini max and the overdrive software.

 

[RustyJC]

You're describing a completely different phenomenon. Shudder at launch as you describe is due to (1. ) pinion angle change as the suspension compresses under load or (2. ) spring windup. You'll find both opinions here, but I subscribe to #1.



Rusty

 

[cerberusiam]

When I try to start out with a load, even just 2000 pounds of sand or gravel in the bed, i get a shudder.

If it is only doing it loaded, or on a steep hill, or when you really have to get into the throttle, i is probably s just axle wrap from the TQ rise. The long front part of the rear springs are known for doing this on multiple platforms. Gives a better ride but has some drawbacks. The 2500 series and Mega's seem to have more issues due to the spring rates and the balance.