Summary of a Towing Trip (long)

[WyoJim]

ramfan2, I just weighed my outfit loaded and ready to go, before a trip to Penna. Without my wife in the truck, it weighed 9750.

Between Sheridan and Casper WY it is rolling hills. Running the cruise at 65 the stock truck would slow down and shift on quite a few of them.

With the EZ it just maintains 65 on all of them, but the TC began to slip, so I installed the DTT valve body. Cured the problem. The TC will have to be next. I thought I would be able to do without it, because as long as it is locked up and not slipping I don't figure it will wear much.

How ever a couple of days ago I went out of Jackson WY into Idaho. The grade is posted at 10%. With the OD locked out and the TC locked up it was no problem untill I caught a line of traffic following a dump truck at 20 mph. Now everything started to heat up. When the engine said 200 degrees I pulled off and let them go. And after while I went on over the hill my way. In 3rd with the TC locked and all was well, but the situation was such that I was trapped into running the way of traffic and I think it will take Bill's TC to handle it.

 

[hotel6]

another view

I just completed my first long haul with the new Fox 5er. I figure the weight was close to 8800. Went up I-25 then I 80 and I 84 to Boise. Ugly headwinds the whole time with mpg down at 8. 7. After a few days in Boise, we went up to Cascade which has several hills -mpg went up to 10. 4 for this leg-Boise-Cascade-Boise. Took the trailer off and scooted up to Weiser for the Nat'l Fiddling Championships 150 mile round trip- mpg at 15. 5. (Was averging 19. 5 empty before this trip) On haul back to Denver we wondered around SE Idaho-(US-30 area) got back on I-80E at Little America hoping to catch a nice tail wind home- no such luck. Had quartering and crosswinds all the way home, but the milage did go up to 10. 5. The Fox stands alittle over 11ft tall and makes a great bug catcher I suspect its frontal area also explains the low mpg going west on I-80. I did have to drop down to 5th gear on the two longer hills which brought the ETG to 650 and the turbo at 20. In fact most of the time going west the turbo was in the 15-20 range. Tried to stay in the 1800-2000rpm range but sometimes went to 2100. ETG stayed pretty much in the 450 range except on the hills. Overall I'm extremely happy with the way the trailer tows- steady and tracks excellently. Started out with a little over 8000 miles and now have alittle over 10,000 miles. Hope the mpg starts improving soon! And of course, I payed 1. 39 for fuel in Laramie knowing well that Denver would be higher-1. 59 But today they lowered the price to 1. 49. Guess I better fill up! Love that BD brake

 

[Fireman Dave]

Re: Silly

Originally posted by WyoJim

This has to be one of the silliest threads I have ever read.

FLAME AWAY

Let me start by saying I don't appreciate you saying this is a silly thread. I have to interpret that remark as your lack of understanding of what the TDR is all about. Judging from the responses on this thread, I would argue that this is a relevant topic to many - at least those of us who aren't as intelligent as you.



As for your other comments,



I agree with you when you say that OD is the most economical mode. However, I don't believe it's always the best for prolonged transmission life. I would hardly describe cruising down the road at 2100-2200 RPMs as "screaming" as you put it. What's your gear ratio? If it's a 4. 10, then, yes you would be screaming in 3rd. That's why I ordered a 3. 54.



You stated your weight is 9750lbs. I'm at 14,000. Your weight is similar to what mine was when I towed a pop-up. I always kept it in OD at that low weight. I would bet that anyone who understands the automatic transmission will agree that towing in 3rd is easier on the transmission since it's a 1:1 ratio. When in OD, there are planetary gears in action which increases the possibility for failure.



I don't claim to be an expert on transmissions, or anything else, for that matter. I was just sharing my experience and thinking, as I think most TDR members do here. We all learn from each other, and I'm interested in your experiences and opinions, too. I'm just not into talking down to others, and that's what your opening sentence was.



How's that for some flames?



Dave

 

[RobG]

Here's the thing about towing in Overdrive...



On flat ground, or even mildly rolling ground, I don't really see a big problem. BUT, once you're into serious hills, there will be trouble. This is assuming you have the power to stay at a speed where the TC would be locked up in 4th. This is also assuming you're carrying close to your GCWR in weight.



The 47RH/RE has a 4th gear that's essentially an afterthought. As we all (?) know, it's a 727 3-speed with an external 4th gear. That means that 4th gear isn't controlled by the valvebody. It's only controlled by springs. That is how the clutches are made to hold. Springs.



So when you put a good sized load on that gear, the springs can only hold so much, so when you're near your GCWR, 4th gear WILL slip in overdrive. And that will ultimately result in the death of your transmission.



I had a '96 RAM automatic with the BD super-low-stall converter and BD valvebody (this was before Bill K's setup was the out). It did just fine when all I was doing was towing my car on a flatbed trailer (max trailer weight of 6000 lbs).



Stuff happened when I got my Lance camper. That put my GCWR at 18,000 lbs. And during my trip to Colorado and back last Summer, my transmission bit the dust. I pulled most hills in overdrive at 65+ mph. I had no trouble doing so, what with ~300 hp at the wheels. It worked great until I was on my way home through Wyoming, and then, even on level ground, the transmission would shudder in 4th gear. I ended up making the rest of the trip in 3rd. When I got home and dropped the pan, there was lots of gray matter all over the inside of the pan.



So... unless you do a thorough transmission rebuild and put in better springs, you're doomed for a failure if you try to pull big hills in OD. And even then, I'm not 100% convinced it won't fail anyway.



And that is why I now have a 6-speed.



Rob

 

[KevinK]

Rob,



If I understand you correctly, installing an aftermarket VB and TC will not improve the situation of potentially frying the transmission by towing in OD under high stress. Am I understanding this correctly?



Thanks,

Kevin

 

[RobG]

Kevin:



You are correct. The only way to help the situation is to have the overdrive portion beefed up with stronger springs and more clutches... 'course if you do that, you might as well do the whole transmission.



Even then, there will be a limit to what it can take. Might be best to discuss this with the expert, Bill K.



Rob

 

[KevinK]

I did just talk to Bill K. and he said that here must be a bit of a mis-understanding. I didn't quite catch all the details he provided, so don't quote me on this.



He said that there is confusion over the gear in question. The gear controlled by springs only is the Over Drive Direct gear (or gears, I didn't catch if there are more than one) , which is used in 1st, 2nd, and 3rd, but not 4th. In true OD, the valve body does control the pressure applied. So, with sufficient pressure, there should be no slippage.



I apologize for the lack of detail, but I'm not very knowledgable about transmissions.



Bill said that the only time towing in OD is an issue is if the RPMs fall below 1700 or so. I tow a #10000 fifth wheel and usually set the cruise on 75. The RPMs are around 2000 (he did say that I was a lunatic on the highway).



Kevin