Pic heavy!!! TH400 Thread: tear down, inspection, upgrade & rebuild
#1
Pic heavy!!! TH400 Thread: tear down, inspection, upgrade & rebuild
Hey guys,
I used the day to take my spare TH400 apart. I am glad I did and didn't just fit it as I was told to...
The input shaft has LOADS of slack. I don't mean a few fractions of an inch, I mean about 3/8". FAR too much. The tranny has around 130k miles on the clock and going by what I found inside, it seems like all 130k were driven hard whilst neglecting the car...
This thread will deal with the tear down, inspection, upgrade and rebuild of my TH400.
I'll do a lot of pictures, as you can see. If you have questions about what you see or what I do, give me a shout!
I used the day to take my spare TH400 apart. I am glad I did and didn't just fit it as I was told to...
The input shaft has LOADS of slack. I don't mean a few fractions of an inch, I mean about 3/8". FAR too much. The tranny has around 130k miles on the clock and going by what I found inside, it seems like all 130k were driven hard whilst neglecting the car...
This thread will deal with the tear down, inspection, upgrade and rebuild of my TH400.
I'll do a lot of pictures, as you can see. If you have questions about what you see or what I do, give me a shout!
The following 4 users liked this post by Daim:
#2
At first. Read this article.
https://www.sonnax.com/tech_resources/237-playing-with-transmissions-setting-total-endplay-to-prevent-th400-gear-train-failure
you need to buy sets of adjustments shims.
This gave a soft- light gear shift from P to D and R and from D to R
I did an intermediate clutch upgrade. from three friction to five, from 4l85e.
This gave a soft- light every gear shift.
LOW GEAR PLANETARY
TCI Low Gear Planetary Sets 229700
https://www.summitracing.com/parts/tci-229700
this is if you want a sharp - quick start.
But there is a two bad thing, a very noisy first gear . And price.
https://www.sonnax.com/tech_resources/237-playing-with-transmissions-setting-total-endplay-to-prevent-th400-gear-train-failure
you need to buy sets of adjustments shims.
This gave a soft- light gear shift from P to D and R and from D to R
I did an intermediate clutch upgrade. from three friction to five, from 4l85e.
This gave a soft- light every gear shift.
LOW GEAR PLANETARY
TCI Low Gear Planetary Sets 229700
https://www.summitracing.com/parts/tci-229700
this is if you want a sharp - quick start.
But there is a two bad thing, a very noisy first gear . And price.
The following 2 users liked this post by xjsv12:
Daim (12-25-2017),
orangeblossom (12-26-2017)
#3
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orangeblossom (12-26-2017)
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#5
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orangeblossom (12-26-2017)
#7
Join Date: Jul 2010
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i dont know if this helps , but a few years back ,i had three T400 trans, was moving and no time to try to sell, brought them to scrapyard , got $25. US for each!
also at that time had three V12 engines, YUP , got $25. US for each!
cried when the yard dropped all into a GIANT shredding machine, it banged and shook loud noises.
value is in the eye of the beholder!
also at that time had three V12 engines, YUP , got $25. US for each!
cried when the yard dropped all into a GIANT shredding machine, it banged and shook loud noises.
value is in the eye of the beholder!
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orangeblossom (12-26-2017)
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#8
The torque convertor should be standard silver. Blue is uprated. Shifting at 4500 rpm (on full throttle?) Would indicate a bad setup...
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orangeblossom (12-26-2017)
#9
Yeah and with the baby blue pan I'm wondering if the whole trans is from something else. Yep shifts at 4500 full throttle and even if "manually held" in 1st. I'm thinking about doing a governor adjustment kit. Never had any experience with the th400.
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orangeblossom (12-26-2017)
#10
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#11
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orangeblossom (12-26-2017)
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#13
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orangeblossom (12-26-2017)
#14
Join Date: Jul 2010
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orangeblossom (12-26-2017)
#15
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orangeblossom (12-26-2017)
#16
Knowing nothing about the gearbox that comes as standard on the v12 or gearboxes at all for that matter. what is the general perception of the 3 speed box. Good bad or ugly!
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orangeblossom (12-26-2017)
#17
People here seem to hate the fact, that it is a three speed transmission. Sure, Jaguar went 4 speed later on but effectively and in my opinion, the 3 speed is the better choice. Less likely to go wrong and the tranny can with stand a lot more power than the V12 could make. 1200 hp and something like 800 nm vs. 300 hp and around 450 nm. The 3 has a few little down sides... One being, that it lacks an overdrive (3rd has a 1:1 ratio). A pro side for quarter miles is, that 1st goes to 120 kph (so about 70 mph).
As there is a huge aftermarket supply for parts, ranging from torque convertors with a higher stall speed, to reinforced shafts, gears, shift improvement kits, full manual shift (via selector lever) kits, different valves, different... you can basically tweak it to match your taste. Shifting fast and hard or sluggish and smooth.
As there is a huge aftermarket supply for parts, ranging from torque convertors with a higher stall speed, to reinforced shafts, gears, shift improvement kits, full manual shift (via selector lever) kits, different valves, different... you can basically tweak it to match your taste. Shifting fast and hard or sluggish and smooth.
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ronbros (12-26-2017)
#18
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i get it!
the longjohn guy wants to use a 6L80 GM trans , yup 6 speeds, actually a good idea.
but for the money may as well go all the way, GM now has an 8speed???
but that may be a little bit MUCH! donno.
pic of my old 4 speed 700R4, rebilt with a B&M kit in it, works great, and with my low axle ratio ,i couldnt live without overdrive.
the longjohn guy wants to use a 6L80 GM trans , yup 6 speeds, actually a good idea.
but for the money may as well go all the way, GM now has an 8speed???
but that may be a little bit MUCH! donno.
pic of my old 4 speed 700R4, rebilt with a B&M kit in it, works great, and with my low axle ratio ,i couldnt live without overdrive.
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orangeblossom (12-26-2017)
#19
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orangeblossom (12-26-2017)
#20