Engine/Transmission (1994 - 1998) At what HP level does a built automatic become unreliable?

[Blacksdieselhp]

I've got a 1996 truck with a pretty hot motor. It has a 6 speed and twin disc haisley clutch right now. But I'm thinking of buying a full built auto. I've ran them alot at the 500 hp range but this truck is supposed to be quite a bit stronger than that. What kind of power are you guys making and using a built auto for every day driving and towing? I Also race the truck every now and then. I love the 6 speed, but with the 4000 GSK, its a bit touchy to drive, especially with a trailer. I thought an auto might help this problem. But don't wanna loose reliability. The 6 speeds seem to take a pretty hard beating.

 

[Bobcat698]

I've heard they'll hold 900+ crank HP. . Not sure the top #s though.

 

[Hammer]

I have seen Jetpilot lay over 790 at the wheels,Offshoreracr and DLeonhard do 790+ at the rear tires and many guys in the 500-600 rear tires range and still daily drive them. Its all how you moderate yourself on the pedal when the trouble begins..... Andy

 

[BPonci]

I ran a full built 47rh from 2 different companys and they didnt seem to hold. They backed them up 100% but after 11 different times pulling the out and or droping the valve body down 7 times i had to throw in the towel. I now run a 6 speed with South bend new D/D clutch.

 

[DCreed]

im on my forth auto 3rd fully built!:{ ill never go auto again!

 

[Blacksdieselhp]

Well, looks like me an the old trusty 6 speed may be staying together.

 

[WaynesWorld]

Blacksdieselhp,

You were not asking to change , you just wanted to be reassured. :-{}



There are plenty of guys running 500 -800 hp on auto. I know 2 guys who changed their sticks in for auto's.



Its all in what you like. Oo.



WAYNES WORLD

 

[MMcCallie]

If you really want a tough automatic, a more extreme option would be to contact Scott at destroked.com. He has adapter kits to bolt up an Allison 1000 or a 4R100 behind any year 5. 9 Cummins. I'm not too sure about the Allisons, though beefy, since they have so many parts and such complicated electronics, but the Ford transmissions can be built much stronger than the Dodge automatics.

BTS 4R100 transmissions practically come with an I dare you to try and break this transmission gurantee. Talk to Brian Thompson at BTS about whether or not any automatic can truly be built to handle your needs. The destroked adapter plates and flexplates are guranteed to at least 1,000 hp for our diesels trucks. I have one mating my 4R100.

Also check out Maddog Madsen's truck with the E4OD holding under something like 1,100 hp. There is an article on his truck in the most recent issue of Diesel Power Magazine. For simplicity though, a manual won't have to tune shifts, etc. If you're stuck on an automatic, i think you can make it work but it may be more than you want to get into.

 

[Jim Fulmer]

I'll give you my little run down! Back in 02' James Northum (JTT Transmissions) a DTT builder out of the Dallas TX area built mine, nothing really big deal then as there were no billet shafts ect. At that time I was around 250 RWHP and pushed that setup to 670 and that is when the stock hub let go with 25K on the transmission (I think... . I'm getting old)



James fixed all the stuff that that broke, freshed up the other stuff and swapped the converter to a 91 over the 89. That was in the early fall of 03' since then I have not been below 700 HP and the truck has 163+K on it. Once a year or so I'll change the fluid and filter out (I run Ford Fluid) and run the bands. Since the fall of 03' nothing has broke, nothing! I pulled the transmission last year to change fix a blown freeze plug and the transmission fluid and converter still looked fine.



Jim

 

[Bandit1]

i love my auto, the stocker sucked but my built dtt is really nice (i am sure that all built autos are, this is jsut the one i picked), i had 562 back in oct, i should now be above 600, i drive it everyday and love every min of driving.

 

[DonTX]

I just think that power is awesome! Question for you, what does it do to your empty fuel mileage if you drive it fairly sensible (if you ever do) and pulling a load?.

i love my auto, the stocker sucked but my built dtt is really nice (i am sure that all built autos are, this is jsut the one i picked), i had 562 back in oct, i should now be above 600, i drive it everyday and love every min of driving.

 

[Bandit1]

when i do drive fairly sensable (which isnt often) i dont get below 15, doesnt matter towing (highway). i do still get 18-20 highway cruising, i have gotten below 15 when iwas hauling a 16ft trailer full of horse ***** through fields, first gear, 4x4. i even get fairly decent mileage when i plow snow, of course i do play around alot. everyone always asks me (esp. in my family) about the mileage, i buy fuel when i need it and thats it, i enjoy driving the truck way more now than i ever did. the only thing you can take with you in this life is th experiences, so make them good. everyday i drive my truck is a good experience and i love it!!

 

[BPonci]

I dont think its so much the hp that breaks them or blows thru them. I feel its the torque and what rpm you build it becomes a major factor. Low rpm vs line pressure. Acceleration vs rpm. Just food for thought.

 

[JFlagg]

I have to agree with BPonci on the torque statment. I don't have any experience with auto's behind diesels, but behind a 6-700hP gasser I've seen autos last well, but place the same auto behind a 6-700 HP diesel, most wouldn't have a very long life. I would have to say that double or triple the torque of the gas motors, which is what a solid diesel will do, is the main culprit. Just my 2 cents though, I love my NV5600. . . .

 

[paulb]

I dont think its so much the hp that breaks them or blows thru them. I feel its the torque and what rpm you build it becomes a major factor. Low rpm vs line pressure. Acceleration vs rpm. Just food for thought.

I agree with Brad as well. High torque and low rpm, will kill drive train parts.



Paul

 

[DonTX]

I can agree with you on all of that for sure. I realize you don't bomb one to make it get better mileage, but was just curious, and surprised that it don't do more damage to ordinary driving mileage.

when i do drive fairly sensable (which isnt often) i dont get below 15, doesnt matter towing (highway). i do still get 18-20 highway cruising, i have gotten below 15 when iwas hauling a 16ft trailer full of horse ***** through fields, first gear, 4x4. i even get fairly decent mileage when i plow snow, of course i do play around alot. everyone always asks me (esp. in my family) about the mileage, i buy fuel when i need it and thats it, i enjoy driving the truck way more now than i ever did. the only thing you can take with you in this life is th experiences, so make them good. everyday i drive my truck is a good experience and i love it!!

 

[tgrfan2]

If you really want a tough automatic, a more extreme option would be to contact Scott at destroked.com. He has adapter kits to bolt up an Allison 1000 or a 4R100 behind any year 5. 9 Cummins. I'm not too sure about the Allisons, though beefy, since they have so many parts and such complicated electronics, but the Ford transmissions can be built much stronger than the Dodge automatics.







!smissions practically come with an I dare you to try and break this transmission gurantee. Talk to Brian Thompson at BTS about whether or not any automatic can truly be built to handle your needs. The destroked adapter plates and flexplates areBTS 4R100 tran guranteed to at least 1,000 hp for our diesels trucks. I have one mating my 4R100.



Also check out Maddog Madsen's truck with the E4OD holding under something like 1,100 hp. There is an article on his truck in the most recent issue of Diesel Power Magazine. For simplicity though, a manual won't have to tune shifts, etc. If you're stuck on an automatic, i think you can make it work but it may be more than you want to get into.

I would be careful about going the A1000 route. Sam Memolo said a few weeks ago they are still having trouble building those to handle Isuzu engines!

 

[Bart]

I've got a 1996 truck with a pretty hot motor. It has a 6 speed and twin disc haisley clutch right now. But I'm thinking of buying a full built auto. I've ran them alot at the 500 hp range but this truck is supposed to be quite a bit stronger than that. What kind of power are you guys making and using a built auto for every day driving and towing? I Also race the truck every now and then. I love the 6 speed, but with the 4000 GSK, its a bit touchy to drive, especially with a trailer. I thought an auto might help this problem. But don't wanna loose reliability. The 6 speeds seem to take a pretty hard beating.

Would you elaberater on what you mean by "bit touchy to drive, especially with a trailer"? Too bad you're on the other side of the country. I have a built ATS with the new bullit input shaft and 5 disc t/c. I've been playing with the idea of converting to a six speeder.