Attention: TDR Forum Junkies 
I just had a complete DTT transmission with all the billet steel parts built and installed. James Northrum in Midlothian, TX, an authorized DTT installer, did the work. I have only driven it 1000 miles and haven't towed with it yet but so far am very pleased. The converter is very tight compared to stock. The truck accelerates briskly at light throttle and quickly shifts up through the gears. In first and second gear it feels and sounds like a manual transmission as it accelerates up from stop. No more roaring motor and churning fluid with the loose factory convertor. The transmission holds the lower gears a little longer. Shifts are immediate and firm but don't slam the truck and driveline. The tighter converter requires a little more braking at idle because the converter wants to get the truck moving but it is not excessive or troublesome.
The truck has 135,000 miles on it already. The transmission seemed to be holding up well pulling very heavy trailers until about two weeks ago when I suddenly and simultaneously developed a driveline vibration between 62-68 mph and began losing transmission fluid from the rear extension housing seal.
A dealer in Kingman, AZ "diagnosed" a bad transmission extension housing and driveshaft ($1100 in parts) without even putting the truck up on a lift. I declined and had them install a new rear seal to get me home. After running it low enough on transmission fluid to slip the converter I figured it would have to be rebuilt and decided to have a heavy duty DTT rebuild and hopefully avoid future problems.
When the truck was disassembled I took the driveshaft to a driveline shop for inspection and rebalance. The u-joints and carrier bearing were fine. The shop removed the excess number of factory weights and rebalanced the driveshaft. The vibration is gone now.
There was some debris in the bottom of the pan but not much. I probably didn't actually do much damage running it low on fluid. The problem that caused the vibration and loss of the extension housing seal was the tailshaft bushing that the output shaft rides in was floating free, not in the press-fit location at the rear of the transmission housing where it should have been. The driveshaft yoke had apparently pushed it out of position. Don't know why. It may have been a result of excess driveline misalignment caused by pulling heavy fivers over rough interstate highways and bounding over dips. The new Bilstein shocks are, in my opinion, too soft and don't provide adequate rebound control. The OEM shocks were actually better. I will have to add air bags, I guess, and will replace the new Bilsteins when I find something better.
I am scheduled to pull a 5er from IN to ND tomorrow. I'll report on the new DTT rebuild after towing.
So far I am very pleased with the DTT transmission components and the job done by James Northrum. He keeps a clean, efficient one-man shop and got me in and out in a day and a half.
Harvey
The truck has 135,000 miles on it already. The transmission seemed to be holding up well pulling very heavy trailers until about two weeks ago when I suddenly and simultaneously developed a driveline vibration between 62-68 mph and began losing transmission fluid from the rear extension housing seal.
A dealer in Kingman, AZ "diagnosed" a bad transmission extension housing and driveshaft ($1100 in parts) without even putting the truck up on a lift. I declined and had them install a new rear seal to get me home. After running it low enough on transmission fluid to slip the converter I figured it would have to be rebuilt and decided to have a heavy duty DTT rebuild and hopefully avoid future problems.
When the truck was disassembled I took the driveshaft to a driveline shop for inspection and rebalance. The u-joints and carrier bearing were fine. The shop removed the excess number of factory weights and rebalanced the driveshaft. The vibration is gone now.
There was some debris in the bottom of the pan but not much. I probably didn't actually do much damage running it low on fluid. The problem that caused the vibration and loss of the extension housing seal was the tailshaft bushing that the output shaft rides in was floating free, not in the press-fit location at the rear of the transmission housing where it should have been. The driveshaft yoke had apparently pushed it out of position. Don't know why. It may have been a result of excess driveline misalignment caused by pulling heavy fivers over rough interstate highways and bounding over dips. The new Bilstein shocks are, in my opinion, too soft and don't provide adequate rebound control. The OEM shocks were actually better. I will have to add air bags, I guess, and will replace the new Bilsteins when I find something better.
I am scheduled to pull a 5er from IN to ND tomorrow. I'll report on the new DTT rebuild after towing.
So far I am very pleased with the DTT transmission components and the job done by James Northrum. He keeps a clean, efficient one-man shop and got me in and out in a day and a half.
Harvey
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I'm originally from Midlothian but A&M has me consumed at the moment.
