th400 behind a 4.0L

cburgin

Well-Known Member
Joined
Mar 20, 2005
Location
statesville/boone NC
Will a th400 drain to much power from a stock jeep 4.0L? Also will it be driveable at all on the street with 5.13s and 40s as fair as it being a 3spd with the gearing?
 
I'm running a 999 3 speed auto in my rig w/ 4.0, 5.13s, and 40s. No problem road driving, but I do have a slight increase from a stock 4.0.
 
With almost comparable gearing (and the 700R4 you have is actually lower than the TF999 or TH400, if I remember right), I don't see why it would drain power. You would however have to get a CPS relocating kit from AA if you went the route without the jeep tranny.
 
cburgin said:
whats the slight increase on the 4.0L?
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Its a 4.7 stroker. When I ran regular compound tires, it would sit in one spot and blister the rear tires, by just flat footing it, no brake. It won't exactly do that with stickies.
 
336wheeler said:
With almost comparable gearing (and the 700R4 you have is actually lower than the TF999 or TH400, if I remember right), I don't see why it would drain power. You would however have to get a CPS relocating kit from AA if you went the route without the jeep tranny.
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I know all about the cps and such and I dont really know what the 700r4 has to do with it. yes the gearing is lower at 3.06 but I have a th400. Because of the size of the tranny and TC im wondering how much more power it takes to spin compaired to say a th350, 700, aw4. etc...and will it make the 4.0L perform like a dog trying to spin the huge th400
 
A friend of mine had a th400 behind a 4.3 chevy and it was a dog. He changed to a th350 and the performance was an amazing difference. When multiplying the gear ratio of the 700r4 and the ratio of the th350 or th400 it's alot of difference. With the 4.0 I can't see the need for th400.
 
jlshermanjr said:
A friend of mine had a th400 behind a 4.3 chevy and it was a dog. He changed to a th350 and the performance was an amazing difference. When multiplying the gear ratio of the 700r4 and the ratio of the th350 or th400 it's alot of difference. With the 4.0 I can't see the need for th400.
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His thing is he has a th400, 203/205 with the doubler sitting on the floor of this basement. 32 spline all the way through the drivetrain.
 
What Th400 are you using? the AMC one will bolt right to the engine.

you can also put a lower 1st gear in it
 
as csudman said, I already have the th400/203/205 32 splne all the way thru and tripple shifters. I just want to know how draining the 400 will be on the motor or if it will be a huge difference between a 700r or th350. I am using the chevy 400. Can I still do the lower first gear? I dont know if I would need it with the doubler and 5.13s though
 
th350 and th400 are no difference in power drain...a 700r4 has a lower 1st and would be better than both as far as low end grunt.
 
SkyHiK5 said:
th350 and th400 are no difference in power drain...a 700r4 has a lower 1st and would be better than both as far as low end grunt.
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I was hoping you would chime in. I know the 700 would be better for the low first gear. What about the low first gear in a th400? How would the steetability be? I am going to go th400. Any tips on building it? Rev man Valve body, TC, etc?
 
SkyHiK5 said:
th350 and th400 are no difference in power drain...a 700r4 has a lower 1st and would be better than both as far as low end grunt.
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There is a power usage difference between the th350 and the th400. The th400 uses about 60 hp to operate, the th350 uses about 40hp to operate. I think the 700r4 and the th350 are the same hp usage.
 
Your crawl ratio is still only going to be around 46:1.
THe th400/203/205 is a very strong setup. I'm running a 700r4/231/300 and I have a crawl of around 117:1. With the 203/205 setup the only gear selectios are 1.9 or 3.6.
With the 231/300 the choices are 2.62, 2.72, 7.12.
Just some food for thought.
 
jlshermanjr said:
There is a power usage difference between the th350 and the th400. The th400 uses about 60 hp to operate, the th350 uses about 40hp to operate. I think the 700r4 and the th350 are the same hp usage.
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Every magazine I have read so far has stated that the th400 uses about 30 hp to spin.. Where did you get your numbers they seem a bit high?
 
jlshermanjr said:
Your crawl ratio is still only going to be around 46:1.
THe th400/203/205 is a very strong setup. I'm running a 700r4/231/300 and I have a crawl of around 117:1. With the 203/205 setup the only gear selectios are 1.9 or 3.6.
With the 231/300 the choices are 2.62, 2.72, 7.12.
Just some food for thought.
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And you say only 46.1 but the TC almost doubles that and I would think that would plenty for an auto, correct? What gears are you running to get a 117.1 crawl? my numbers using 5.13s on your combo doesnt give me 117.1. Also, if I decide later to go to a 5.3 or a 6.0 the stock 231/d300 would be useless IMHO. With my way I am more than 3/4 closer to having a one ton drive train...
 
cburgin said:
Also, if I decide later to go to a 5.3 or a 6.0 ...
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if that is even a thought, just put it in.
if you don't like the 4.0' power, you're that much closer to the having the v8 swap done.
 
cburgin said:
And you say only 46.1 but the TC almost doubles that and I would think that would plenty for an auto, correct? What gears are you running to get a 117.1 crawl? my numbers using 5.13s on your combo doesnt give me 117.1. Also, if I decide later to go to a 5.3 or a 6.0 the stock 231/d300 would be useless IMHO. With my way I am more than 3/4 closer to having a one ton drive train...
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The transmission is 3.06, 231 is 2.72, 300 is 2.62, 5.38 gears in the axle. 117:1. I'm not being critical, just throwing out ideas, for lots of gearing and gear choices.
 
jlshermanjr said:
There is a power usage difference between the th350 and the th400. The th400 uses about 60 hp to operate, the th350 uses about 40hp to operate. I think the 700r4 and the th350 are the same hp usage.
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I've read those numbers....Ive seen different on dynos.

About 60 could look a lot like 55 and about 40 could look a lot like 45 then there is a 10hp difference and a good tune up can net that..... just food for thought.

BTW your crawl numbers seem off to me, but Im in a rush I will check the math later.
 
SkyHiK5 said:
I've read those numbers....Ive seen different on dynos.
About 60 could look a lot like 55 and about 40 could look a lot like 45 then there is a 10hp difference and a good tune up can net that..... just food for thought.
BTW your crawl numbers seem off to me, but Im in a rush I will check the math later.
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It's just simple math.......???????
 
The power difference will lesson depending on what axle gear you running. With the double set up, in the woods, you won't feel the difference.
 
csudman said:
FWIW, I got 50.380704 as the ratio.
TH400 = 2.48
203 = 2
205 = 1.98
Axle = 5.13
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This is what I got which would put it at about 100.1 with the TC which is plenty for an auto. I can also do the low first gear in the th400 from what some guys have posted here! Furthermore, I could later do the 3.1 in the 205
 
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