TH400 speedo question
Originally Posted by Dirty 30
whats the purpose of the governer?
Transmissions with manual valve bodies don't need them.
Originally Posted by 8a8mfh
It's basically a valve with weights on it that alters shift points as vehicle speed varies.
Transmissions with manual valve bodies don't need them.
Transmissions with manual valve bodies don't need them.
Originally Posted by Dirty 30
Can it be removed or something to raise shift points? When i run WOT from 1st to 2nd the tranny shifts by itself but too early, like 4,500 rpm. But from 2nd to 3rd it does let me shift at any RPM.
Make sure the vacuum modulator is connected to a manifold source, not a ported source.
Originally Posted by 8a8mfh
Yes, if you have a th400 remove the cover held on by four bolts toward the rear of the trans on the passenger side. You can make the inner weights lighter to raise shift points or buy a governor calibration kit.
Make sure the vacuum modulator is connected to a manifold source, not a ported source.
Make sure the vacuum modulator is connected to a manifold source, not a ported source.
Thanks!
-Jesse
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Verdad Gallardo From what I've experienced governor problems usually cause both shifts to be too early or too late.
So if you determine it is a governor calibration problem you can cut the nails off and remove the inner weights, grind a little off the sides, and reinstall using finish nails of the same size, crimp the finish nails with vise grips. It will look original, only difference is the factory used hardened nails.
So if you determine it is a governor calibration problem you can cut the nails off and remove the inner weights, grind a little off the sides, and reinstall using finish nails of the same size, crimp the finish nails with vise grips. It will look original, only difference is the factory used hardened nails.
Originally Posted by john kilgore
if you have not connected the electric passing, the trans DOES NOT know you are at full throttle. just put 12v to it through a switch and l think you will be amazed good luck
Im guessing the switch would be a WOT micro switch to the pedal? (i have DBW throttle body)
Originally Posted by frcefed98
Yeah but you lose your ABS if you do that, not what everyone wants right?
In the TH400 FAQ there are two part numbers that you have to order from either LS1speed.com or GM directly and you'll be able to get your factory speedo working again.
GM8655291 GM Speedometer Sensor $99.99
GM8655315 GM Speedometer Drive Sensor Rotor $65.99
There you go
Searching this site is hit or miss so lets just try to help answer questions.
In the TH400 FAQ there are two part numbers that you have to order from either LS1speed.com or GM directly and you'll be able to get your factory speedo working again.
GM8655291 GM Speedometer Sensor $99.99
GM8655315 GM Speedometer Drive Sensor Rotor $65.99
There you go
Searching this site is hit or miss so lets just try to help answer questions.
.. 
TECH Enthusiast
Joined: Sep 2003
Posts: 501
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From: bethel PA
Originally Posted by bjamick
So thats all thats needed to get the speedo to work?? I've got a TH350 but i want ABS but im wanting the speedo to work also ..
..a TH350 and TH400 use diffrent parts, the output shafts are diffrent sizes.
Originally Posted by lethal93ta
a TH350 and TH400 use diffrent parts, the output shafts are diffrent sizes.
.. So can someone help me out a lil 
What will i need to make the TH350 work. W/O spending $250.
TECH Enthusiast
Joined: Sep 2003
Posts: 501
Likes: 0
From: bethel PA
when I was looking to put a TH350 in mine the trans shop was just going to use my factory sender and pick up off my 4l60. then I decided to just go with a trans I know Im not going to blow.
this is the sensor out of a 93 4l60 it should work in the same hole a th350 has. its the same size as the pick up for the Th400 I got, it would fit in the th400 hole but i needed a pick up to work on the bigger th400 output so I went with the reluctor wheel on there. I dont know how the pick up is for the 4l60E but depending on how its made you might be able to use that, when I get my blazer back ill have to look how the speedo is.
this is the sensor out of a 93 4l60 it should work in the same hole a th350 has. its the same size as the pick up for the Th400 I got, it would fit in the th400 hole but i needed a pick up to work on the bigger th400 output so I went with the reluctor wheel on there. I dont know how the pick up is for the 4l60E but depending on how its made you might be able to use that, when I get my blazer back ill have to look how the speedo is.
Last edited by lethal93ta; Aug 13, 2007 at 04:18 PM.
Originally Posted by bjamick
Dammit .. So can someone help me out a lil
What will i need to make the TH350 work. W/O spending $250.
.. So can someone help me out a lil What will i need to make the TH350 work. W/O spending $250.
So if you have a short tail th350, get a BOP tail, reluctor wheel and sender off a 700, 4L60E. And thats it.
Originally Posted by 8a8mfh
Well if you have a short tail th350, it's as easy as swapping out the chevy tail housing with it's 3/4" speedo hole and getting a BOP (Buick, Oldsmobile, Pontiac) th350 tail housing, these have a 2" speedo hole, same as 700R4's and early 4L60E's.
So if you have a short tail th350, get a BOP tail, reluctor wheel and sender off a 700, 4L60E. And thats it.
So if you have a short tail th350, get a BOP tail, reluctor wheel and sender off a 700, 4L60E. And thats it.
.. I know some places sale a whole tailshaft with the modifications already made so the Stock speedo sensor will just plug right in. I think they are like $250 though 
Can anyone tell me what the two wires go to? I assume one is to the speedo but is the other one a power, ground, or what? And which wire is what? They are both gray and I can't find any markings. This is for a th400 and am connecting a Autometer speedo.
Thanks.
Thanks.