Going up the the "Hump to Pahump" which is signed as a 7% grade towards the end and about 15 to 18 miles long... was doing about 25 miles an hour in first gear and about 3,000 RPMs at times. No over heating though there was a kind of bang and the RMS suddenly drop to 1,500 or so. While still in 1st gear gradually increased power and was back up to 25 MPH again.
Soon then we were over the "Hump" and resumed normal driving (about 55-60 MPH)
The next day I got and oil change at Walmart ( good deal on Quaker State).
Transmision was pink and no burn smell so no change at this time. While towing our travel trailer to Pahrump got 11.3 MPG and on the way back got 12.3. These were hand calculated and got fill ups at the end of both legs. Stoped at the truck stop at Blue Dimond T&A.
Here are the results: Steer Axle is 2620 Drive Axle is 3000 Trailer Axil is 3520 and gross weight is 9140 LBS.
I don't think that this was too bad for our 1st "test" of our "new " TT and TV.
But don't know what the bang was and what caused the rpms to drop.
Any Ideas?

 

What motor?

 

Might have been the converter lockup. With a load, it may have been more audible than usual.

 

Sorry about that...have a 4.7 , has a bit over 61,000 miles.
Bought it from a dealer who sold it to a 83 year old women ten years ago. Her kids told her to sell it when she lost her licence at 93. Car had 58,000 miles on it at that time.. sleepy town in the desert 60 miles from Las Vegas.
But here is a funny thing...(?) the milage seem to have improved.... about 3-4 mpg. Better gas in Pahrump, NV. ?Thought that they used the same gas as Las Vegas.
Transmition seem to be very pink after this las tow.

Car is a 2003 Dorango SLT with 4.7 with factrory tow, 3:55 rear, 5
speed auto is rated by trailer life to tow 6500lbs. Weighed TT at T&A a few days ago and it is about 4,000lbs subtrating the TV weight of 5,140 from the GV weight 9140 lbs.. TT has an unloaded weight of 3010 lbs from Kelly Blue book (hard copy) .

I know ci,s is the secret of towing but I was hoping that being more that 2,500lbs less that max tow weight would be OK. And I still think it will be as this "HUMP at Pahump" is signed as 7% more than a mile from the crest and is 15 to 18 miles long.

all the best
bob

 

On the 4.7 the torque converter will unlock going down hill for better gas mileage