Author Topic: TH400  (Read 12153 times)

Offline cliffnuce

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TH400
« on: May 23, 2012, 04:15:19 pm »
Ok so I have read qutie a few threads on here about the TV cable and trans. I have a 86 K10 4x4 with a 350 I just put in it from a 69-75 truck. Now the truck seems to be stuck in gear. I got a Turbo 350 trans when I got the engine.

Is there anything I can do to get it out of gear?

Is there a simple fix or is the tranny shot?

Can I put teh 350 in with little mods?

I know alot of questions.  :-[

Thanks for any info.

Offline ncguy89

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Re: TH400
« Reply #1 on: May 23, 2012, 04:30:20 pm »
what do u mean by its stuck in gear? like it wont shift or it wont go in park. if it wont shift make sure u hooked up the vacuum modulator and its hooked up on the engine. if it wont go in park then might want to check ti shift linkage at the trans and make sure its adjusted right. just a few thoughts to start with! i just done the reverse in my truck i took a th350 out and put in a th400 and im alot happier with the th400. its not that hard actually the only thing you have to do is move the crossmember up there are 2 sets of holes in the frame and depending ont he transfer case you have you will have to have a longer driveshaft.
« Last Edit: May 23, 2012, 04:56:24 pm by ncguy89 »
1987 v20 - 350 tbi with towing cam, hummer wheels, stock otherwise

1984 chevy c-10 shortbed - kidney foundation truck (for my father)

Offline cliffnuce

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Re: TH400
« Reply #2 on: May 23, 2012, 04:58:39 pm »
I checked the linkage at the tranny. I have no modulator. It acts as if it wants to move when in park and if you go to neutral it kills the engine.

Offline ncguy89

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Re: TH400
« Reply #3 on: May 23, 2012, 05:10:28 pm »
if its a th350 it should have a modulator at the rear of the trans on the passenger side. it sounds like something with the shifter inside the trans. im not a trans guy so im not sure. hopefully somebody who knows more about transmissions can chime in.
« Last Edit: May 23, 2012, 05:15:24 pm by ncguy89 »
1987 v20 - 350 tbi with towing cam, hummer wheels, stock otherwise

1984 chevy c-10 shortbed - kidney foundation truck (for my father)

Offline cliffnuce

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Re: TH400
« Reply #4 on: May 23, 2012, 05:50:59 pm »
So I looked under the pan and I have 16 pan bolts so this means this is a TH700-R4, 4L60, 4L60E. Is this correct?


Offline ncguy89

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Re: TH400
« Reply #5 on: May 23, 2012, 06:48:00 pm »
i do know they have 16 bolts but only other way i can tell the difference is by the stamped code on the casing. it should be right above the pan on the drivers side or near where the tail housing bolts to the case
« Last Edit: May 23, 2012, 06:50:54 pm by ncguy89 »
1987 v20 - 350 tbi with towing cam, hummer wheels, stock otherwise

1984 chevy c-10 shortbed - kidney foundation truck (for my father)

Offline bd

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Re: TH400
« Reply #6 on: May 23, 2012, 08:24:57 pm »
Image of THM 350 pan (w/modulator, 13 bolts, sawed off corner)...
http://www.summitracing.com/parts/SME-1000/

Image of THM 400 pan (w/modulator, 13 bolts, "Texas" shape)...
http://www.summitracing.com/parts/SME-1001/

Image of 700R4 pan (NO modulator, 16 bolts, rectangular)...
http://www.summitracing.com/parts/SME-1008R/

How did the transmission function before the engine swap?  Did you unbolt the torque converter from the flexplate and leave it on the front of the trans or pull it with the engine?  Was the converter replaced?  Did the converter "spin" freely before it was reattached to the flexplate?  How much play was there between the flexplate and the front of the converter before the converter was bolted back up?
« Last Edit: May 23, 2012, 08:29:13 pm by bd »
Rich
It's difficult to know just how much you don't know until you know it.
In other words... if people learn by making mistakes, by now I should know just about everything!!!
87 R10 Silverado Fleetside 355 MPFI 700R4 3.42 Locker (aka Rusty, aka Mater)

Offline cliffnuce

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Re: TH400
« Reply #7 on: May 24, 2012, 03:23:31 pm »
Of course this is my sons truck so he says the transmission was fine. The torque converter spun fine and I left it on the tranny. There was about 1/4 of an inch of space there. I did (unknowlingly) set the tv cable after connectignto the carb. Mine is the 700R4. It acts as if it is stuck in gear.

When it is started it tries to lurch forward. If you shift to neutral it will kil the engine. I checked the linkage and adjusted it.

Could my whole problem be the lockout switch?

Thanks for the help.

Offline bd

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Re: TH400
« Reply #8 on: May 24, 2012, 04:48:32 pm »
...Could my whole problem be the lockout switch?

Expand this thought.  To which switch are you referring, exactly?  Do you have toggle control over TCC lockup?

Assuming the converter is installed correctly, converter and pump weren't damaged by misalignment, and TCC is not locking up, the transmission should not "kill" the engine, even if the shift linkage is out of adjustment. 
Rich
It's difficult to know just how much you don't know until you know it.
In other words... if people learn by making mistakes, by now I should know just about everything!!!
87 R10 Silverado Fleetside 355 MPFI 700R4 3.42 Locker (aka Rusty, aka Mater)

Offline cliffnuce

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Re: TH400
« Reply #9 on: May 24, 2012, 05:10:26 pm »
The lockout of course. No toggle. Well it is kind of hard to install a converter wrong.

Offline bd

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Re: TH400
« Reply #10 on: May 24, 2012, 08:16:08 pm »
Don't take offense - there are two engagement slots on the converter that need to align with the drive tangs in the pump.  I've seen professional shops do an oops during installation and lock up a converter.  It's agonizing when it happens. 

Two things stick my attention: 1) It was working fine before the swap; 2) It kills the engine going into neutral.

How does the fluid look and smell - bright red & clear, not burned?

In the meantime, perhaps someone else can share an idea.
Rich
It's difficult to know just how much you don't know until you know it.
In other words... if people learn by making mistakes, by now I should know just about everything!!!
87 R10 Silverado Fleetside 355 MPFI 700R4 3.42 Locker (aka Rusty, aka Mater)

Offline cliffnuce

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Re: TH400
« Reply #11 on: May 25, 2012, 07:52:57 am »
Didn't take offense. I understand the converter was never removed just pushed back from fly wheel. I'm just wondering if my son had problems with slippage before he blew his engine. You know how kids are don't tell the whole story.

The fluid needs to be changed. I have a line possibly on a tranny for 150 out of an s15 jimmy.

I'm just am trying to save him a few bucks hes only 17 and he pays for repairs not me.

Offline ehjorten

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Re: TH400
« Reply #12 on: May 25, 2012, 12:31:32 pm »
Have someone watch under the car while you shift through the gears.  Do this with the engine off!!!  Perhaps there is something wrong with your linkage and even though you think you are moving through the gears the lever on the transmission is not moving.

Alternatively, if your linkage is working properly then you may have a stuck valve in the valve body.
-Erik-
1991 V3500 - Gen V TBI 454, 4L80E, NP205, 14 bolt FF, D60, 8" Lift on 35s
1977 K20 Silverado - 350, THM350, NP203, 14 bolt FF, D44, Stock Lift on 31s
1969 Chevelle Malibu Sport Coupe - EFI350, THM350
1968 Chevrolet Step-side Pickup - 300HP L6

Offline DnStClr

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Re: TH400
« Reply #13 on: May 27, 2012, 08:46:27 am »
Could there be too much pressure on the transmission? Maybe taking another look at the TV cable adjustment is where you need to start troubleshooting. Hopefully, adjusting the cable will solve the problem.
There's a procedure given on the following site- with 3 pics. Also, Vilezomboni has posted about it a few times in the past on this site.

 http://www.transmissioncenter.net/700r4.htm
Don
87 Chevy Silverado

Offline cliffnuce

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Re: TH400
« Reply #14 on: May 29, 2012, 11:50:18 am »
Thank you both. I have looked at the linkage and it is moving. The fluid is nasty. The TV cable on mine doesn't have the adjuster on the end. When I installed the engine I didn't change anything. This truck which might have helped before has a 3" suspension and a 3" body lif on it.

I will try to readjust the cable again and change fluid before getting tranny