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Old 04-15-2021, 09:22 AM   #1
JFORRESTERSR
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Join Date: Jan 2019
Location: ST AUGUSTINE FL
Posts: 15
TURBO 400 shutter ISSUES

So if anyone is following my journey they know I have had several issues with my trans and trans guy. We have worked though most of them and with the help of this board and its knowledgeable members I have resolved many of my gremlins. So heres my latest issue LOL

after my trans guy put another t400 in it was shifting fine but then I noticed that at a dead stop take off if gave it more than .1/2 throttle it would shutter
but if I took off in low it didnt, coincidently one day i went to put it in gear and theres was nothing. after towing to the shop and an inspection the armature that engages the manual valve rod was not in the groove and he also felt that the rod was bent slightly and was difficult the engage into the valve body itself he worked it and emry clothed it and got it moving again. he didnt have another valve body but wants to change it an feels the shuddering could be due to the manual valve body rod/shaft clearances inside the valve body. Others have said it could be the forward clutches

so again i am looking for any thoughts on this matter and as usual I am greatful for the reponses


John
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Old 04-15-2021, 01:19 PM   #2
SeventyOne
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Location: Berkeley, Ca
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Re: TURBO 400 shutter ISSUES

Could be your torque converter or even dirty fluid/filter.
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Old 04-15-2021, 06:14 PM   #3
JFORRESTERSR
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New filter and fluid
If it was the torque converter then why doesn’t it do it in low l1
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Old 04-15-2021, 07:59 PM   #4
kwmech
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Join Date: Mar 2003
Location: Colfax-California
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Re: TURBO 400 shutter ISSUES

I would put a gauge on it to see what the line pressure is. Shuddering would indicate clutch slippage and a bad pump. Should have been the first thing the trans shop did.

BTW the pressure should be a minimum of 160 in gear. Shift kit power braking a little 190-200

Last edited by kwmech; 04-15-2021 at 08:10 PM.
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Old 04-16-2021, 09:52 AM   #5
JFORRESTERSR
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Re: TURBO 400 shutter ISSUES

does the line pressure change from D to low1
because again it takes off fine in low 1
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Old 04-16-2021, 10:58 AM   #6
kwmech
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Re: TURBO 400 shutter ISSUES

1st gear grabs a band along with the clutch pac (if I recall correctly)

just had another thought about a bad bushing between the input shaft and the output shaft. Little pocket bushing about 3/4'' in diameter....keeps the shafts centered with each other
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