Tranny Problems!

[EZHAULER]

Hello, I could use some direction-I recently started pulling a 40' 5th wheel toy hauler with Gross weight around 19,000lbs and during our last trip (going north on HWY 101) through California and Oregon, I started having some issues with the tranny and or converter slipping? The road has lots of curves and step grades.
(I have pulled a 30' bumper pull toy hauler weighing approx 13,000lbs loaded with no issues! for the last 5 years)
below you can see everything I have added to my truck . I was pulling with it on level 2 (TOW MODE).
THE PROBLEM- the first time-was while accelerating onto the HWY on ramp,1st to 2nd gear was not bad- but going from 2nd to 3rd it shifted Really Hard! scary hard! I thought it dropped the tranny or rear-end on the ground, I lifted of the throttle immediately and it keep rolling with no abnormal noise, and the engine light came on but (there was a lot of traffic and no room to pull to the side of the road) so I gave it a little gas thinking I would get to the next exit. The tranny had kicked out of tow haul mode and would not shift (Limp Mode, I found out later) I made it off the road & shut down and inspected the undercarriage,under the hood- everything looked fine and tight with no leaks. After much contemplation of what to do? who to call? I started down the road (side streets) looking for a location that I could look up the closest GM Dealer and it drove fine, shifting normal, stayed in tow haul? by the time I location a dealer it was acting normal. I was told it did that to protect it's self! I like that answer, so we pressed on.
To make a already long story short, over time on the trip around 4,000 miles total, as long as I could keep up my momentum for the hills,it was fine- but at slower speeds (with the converter locked or not, per the attitude monitor) accelerating and or climbing up step grades the rpm's would take off-powering through the tranny and converter and it would shift hard and go into limp mode again.
Does this seem like a Transmission or Converter problem? Both? could it be a problem from the edge?
Sorry for rambling on, but after a little research it is going to be a little pricey to up grade the tranny. So I just want to be informed before I head that way and I don't have any local expert's to go to.

[DmaxMaverick]

The tranny is doing exactly as it should, under the conditions you've placed it. Simply put, you are grossly overloading the truck, and the tire size increase only compounds the problem. Likely, the torque converter is slipping, causing the limp mode.

Edge's "Tow Mode" claim relies on specific conditions to be called that (it's all in the "fine print"). Same with every power tuner. You've exceeded just about every parameter by installing oversize tires (changes final drive ratio), towing a trailer that's 5K+ over the rating, and ascending steep, sustained grades. Continuing to do so will cause irreversible damage to the tranny.

You have a few options (choose several). Tow with less power. Reduce tire size to OEM or re-gear the diff's to 4.10. Get lighter trailer. Upgrade the tranny to handle the load. Avoid steep grades. .....Or, continue and count on limp mode happening more often with each trip, until it won't clear out of limp mode.

Also, don't have any contact in CA with any CHP near the interstates. They WILL scale you, then you'll have to hire someone else to tow your rig. Add to that, about $2000 fines (or more), and a suspension of your commercial driver license. If you don't have a CDL, you aren't licensed for that load, anyway, then the fines double and you can't get a CDL for several years. AZ's commercial laws are very similar to CA's in this regard, so expect the same at home.

[EZHAULER]

DmaxMaverick-
Thanks for the reply, and advice. I was afraid that I might be adding to the problem thats why I came to this site.I don't want to hurt this truck or run it into the ground. Sounds like the first thing I need to do is correct the tire size, I've had these wheel's long before I ever planned on getting a 5th wheel- but I still have the stock wheels.
In the past I mostly towed with the Edge in stock (0) on the programmer, because the EGT's were so much higher when towing, but with the open 4'' exhaust it dropped the EGT's at least 150 to 250 degrees overall while towing- I don't have a issue with towing in stock form, the truck does great! I really like having the attitude monitor to watch everything!
any advice on the different tranny upgrades that are out there, Triple loc converter and upgrade kits or more?
Maybe I need to look into a 3500 dually if we plan on pulling this thing around like that- it's uvw is 13,500 & gvw is 18,900- I don't think I would ever have the trailer maxed out, but it looks like the truck is right there & I don't need any fines like that! or any at all!

[DmaxMaverick]

Realistically, you need at least a medium duty truck to haul that 5'er (55-6500). The dually has the same GCWR for that model year. Later model years gained 1,500# (up to 23.5K for a dually). You don't gain as much as you pay for with a dually. They truck is heavier, in itself, so the gain is less. Sure, I know lots of folks do it, but it isn't right, safe, or legal. The limits are there for a reason, mostly to protect us from ourselves.

My rig is slightly overweight when we are fully loaded for a week in the desert, but it's legal for the trip home (leave behind a lot of water and gas). My 5'er is ~14K, loaded to legal. And, my tires are taller than yours. We head over Tehachapi 6-8 times a year. Keep in mind, trailer weight declarations are almost always very conservative. You have to get it on a scale to know for sure, and don't be surprised if you're surprised. With an unladen weight of 13.5K, you are probably getting close to GVWR loaded up with gear, water, groceries, gas, toys, etc. I've been doing this a long time, and it's always been that way. Mine isn't a toy hauler, but I have a frame mounted MC rack on it. Usually, I only take 2 bikes, one for me and one for my son. Sometimes we'll take one or two more smaller bikes, and they fit in the truck bed (a skill in itself). My wife doesn't ride, but she camps, and has a lot of camping stuff. Then, it gets really heavy.

Sun Coast and ATS have some nice tranny upgrades. I don't think you need a Triple-Lock converter. A Sun Coast or ATS single disc would probably suit your needs better. They offer about 50-60% greater friction area, and higher clamping force. They claim north of 500 HP with those. Your problem isn't the gross HP, but the sustained load at max power. And, just because your EGT's are in check does not mean everything is OK. It's good, but the whole picture is larger than that. Be careful what you do with the upgrades. Once we remove weak links, it will find others.

I tow with added power, but I rarely use it. Way better towing mileage that way, and the ability to easily pass on a grade (there goes the mileage). My tranny is stock, I just don't push it past the envelope in OD. It will slip, if I let it. Synthetic ATF (Amsoil Torque Drive) is a significant improvement, also. Lower temps and no fade on long grades.

[Edahall]

Also, don't have any contact in CA with any CHP near the interstates. They WILL scale you, then you'll have to hire someone else to tow your rig. Add to that, about $2000 fines (or more), and a suspension of your commercial driver license. If you don't have a CDL, you aren't licensed for that load, anyway, then the fines double and you can't get a CDL for several years. AZ's commercial laws are very similar to CA's in this regard, so expect the same at home.

Just wondering but does CA impose these fines also on passenger vehicles used for towing? I ask because I'm towing a 26 ft Airstream weighing approximately 6000 lbs with a 82 1/2 ton 6.2 diesel Suburban rated to pull only 2500 lbs.

[Mark Rinker]

I wouldn't tow anything over 10K# with the Edge tow tune, even over flat terrain.

[DmaxMaverick]

Just wondering but does CA impose these fines also on passenger vehicles used for towing? I ask because I'm towing a 26 ft Airstream weighing approximately 6000 lbs with a 82 1/2 ton 6.2 diesel Suburban rated to pull only 2500 lbs.

They can, but I wouldn't worry. I've done worse. A Suburban towing a moderate size trailer won't get any attention. Heads turn when they see a 1/2 or 3/4, or even a 1 ton hauling a trailer with 3 axles, excessively long/large, or appears very heavy. License requirements and vehicle weight declarations on large combinations are taken very seriously. Any pull-trailer over 10K, or 5'er over 15K requires at least a non-commercial class A license. License classes are excepted if the rig is legal in the driver's state of license, but weight/length is strictly according to CA reg's.

[EZHAULER]

I wouldn't tow anything over 10K# with the Edge tow tune, even over flat terrain.

What do you mean, why not? is there something wrong with the tune or the Edge?

I don't run the truck hard (55-60mph) the only time it feels like it is working is on hills. I relize now that this trailer is way out of the league for my truck and I will be making some adjustments- looking into(different truck or trailer options).

[Mark Rinker]

My personal observations and opinion, based on side-by-side testing of three different tunes, is that the Edge tuning is the least optimized for towing heavy (>=15K loads) with an otherwise stock Duramax truck.

Pros? Edge makes great 'street racer' tunes for the go-fast crowd, and I like their Evolution digital gauges and code reading capabilities - but even the low end 'tow tunes' have high fuel rates, early in the RPM band, without enough boost dialed in for a good tow tune...

Results? More smoke, higher EGTs, more harsh 1-2, 2-3 upshifts, higher engine and trans operating temps.

[Kennedy]

I think the key issue is that the type of box being used lies to the ECM and takes over control of the fueling, therefore the ECM, TCM, etc are all making uninformed decisons about TQ management etc. Many people who have had these "slip protected" boxes find themselves facing trans problems in due time. On the flip side I find that one can equal or best the performance of these boxes with a properly tuned ECM and not have the issues that you describe.

[EZHAULER]

My personal observations and opinion, based on side-by-side testing of three different tunes, is that the Edge tuning is the least optimized for towing heavy (>=15K loads) with an otherwise stock Duramax truck.

Pros? Edge makes great 'street racer' tunes for the go-fast crowd, and I like their Evolution digital gauges and code reading capabilities - but even the low end 'tow tunes' have high fuel rates, early in the RPM band, without enough boost dialed in for a good tow tune...

Results? More smoke, higher EGTs, more harsh 1-2, 2-3 upshifts, higher engine and trans operating temps.

What are the other tunes you have used or compared it too! Do you think one of them would work better for my application?

[EZHAULER]

I think the key issue is that the type of box being used lies to the ECM and takes over control of the fueling, therefore the ECM, TCM, etc are all making uninformed decisons about TQ management etc. Many people who have had these "slip protected" boxes find themselves facing trans problems in due time. On the flip side I find that one can equal or best the performance of these boxes with a properly tuned ECM and not have the issues that you describe.

ANy recommendations of someone in Arizone or close by that you would trust to do this tuning? Does the ECM have to be in the truck to get this tuning you are talking about?