transmission
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Junior User
Joined: Jul 2011
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transmission
my 87 350 is shifting poorly, it seems that when it is not warmed up she will not upshift. and even when she is warmed up I have to take my foot off the gas for her to shift. also will not go in reverse unless it is warm. I had her in a shop for something else and the guy said replace the transmission. others have told me it is the pump. any ideas
Senior User
Joined: Aug 2014
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ç6
Would have to be the cheapest transmission I have done up. I removed it, the shop did new clutches, bands, fitted shift kit, changed the stall in the torque converter, I reinstalled it. Tough old trans. Not efficient but hard to break.
Frmr Ford Trans Engr
Joined: Aug 1999
Posts: 24,732
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From: SE Florida
I agree this C6 needs to be rebuilt. It's worn out.
i ain't rite
Joined: Mar 2005
Posts: 65,564
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From: Marlboro Mental Hospital.
it sounds to me like the vacuum pump is tired and not drawing enough vacuum to let the modulator shift the trans properly.
vacuum pump is about $1,200 cheaper than a trans too.
vacuum pump is about $1,200 cheaper than a trans too.
Senior User
Joined: Aug 2014
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good point
If the brakes are vacuum and not hydroboost should show up there as well or Vrv?
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i ain't rite
Joined: Mar 2005
Posts: 65,564
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From: Marlboro Mental Hospital.
not really. the brakes will still work fine with 17 inches vacuum. the trans needs minimum 19 inches vacuum to work properly.
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Logistics Pro
Joined: Sep 2007
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From: Western Mass
Tom thats an interesting thought on the vacuum pump. I was hoping someone might jump in and recommend checking things like the vrv and whatever makes a C6 work before jumping to expensive conclusions.
i ain't rite
Joined: Mar 2005
Posts: 65,564
Likes: 5,601
From: Marlboro Mental Hospital.
without vacuum the trans will still go into forward, just not shift.
the easiest way for me to tell when the vacuum pump in my 88 is dying is when the trans starts shifting funny.
the easiest way for me to tell when the vacuum pump in my 88 is dying is when the trans starts shifting funny.
Frmr Ford Trans Engr
Joined: Aug 1999
Posts: 24,732
Likes: 2,661
From: SE Florida
All the seals in this trans are worn out. Vacuum isn't going to fix them.
Postmaster
Joined: Dec 2011
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All the seals in this trans are worn out. Vacuum isn't going to fix them.
Laughing Gas
Joined: Dec 2013
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I agree, put a vacuum gauge on and verify before anything else. A lot of money has been made off of people with a "bad" c6 trans that only has 1st and reverse. A little bit of vacuum line and all is well.