Hard shifting on auto

  • ahspros
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24 Jun 2013 12:19 #15153 by ahspros
Hard shifting on auto was created by ahspros
Have 86.5 automatic 928S with >78,000 on the clock. Replaced the center drive shaft and torque converter and now experiencing hard shifts on all ranges except fourth. How can this be adjusted out for a smoother shift?

Walt

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  • the flying scotsman
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24 Jun 2013 20:56 #15154 by the flying scotsman
Replied by the flying scotsman on topic Hard shifting on auto
when was the fluid last replaced? level?

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25 Jun 2013 10:45 #15159 by wallyp
Replied by wallyp on topic Hard shifting on auto
First thing to do is to check the Vacuum Modulator, which is the unit that controls the firmness of shifts.

Find the modulator - a pie-pan-shaped device on the left side of the transmission, with a vacuum line attached. Pull the vacuum line, crank the engine, and check for manifold vacuum on the line. If there is no vacuum (the most likely cause for your problem), check at the back of the engine compartment for a disconnect in the line.

Wally Plumley
928 Specialists
www.928gt.com

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  • ahspros
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25 Jun 2013 16:36 #15164 by ahspros
Replied by ahspros on topic Hard shifting on auto
Fluid is correct level, was changed about 20,000 miles back.
The modulator is on the driver side, correct?

Walt

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26 Jun 2013 07:08 #15168 by wallyp
Replied by wallyp on topic Hard shifting on auto
"...on the left side of the transmission..."

For left-drive cars, yes. Not in the UK, Japan, etc.

Wally Plumley
928 Specialists
www.928gt.com

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  • ahspros
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26 Jun 2013 11:55 #15173 by ahspros
Replied by ahspros on topic Hard shifting on auto
My 86.5 does not have a vacuum modulator as you described. Tried to attach a few pictures of the transmission showing both sides with no luck. Doing something wrong.
Will try again.

Walt

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26 Jun 2013 12:48 #15174 by dlbass93
Replied by dlbass93 on topic Hard shifting on auto
Easiest way to attach photos is to host them somewhere else, like photobucket. photobucket.com

Then you copy the URL for the image.
Click the 'insert image' button on the toolbar here, it is the mountains with yellow background icon.
Paste in the URL, and click OK.
Repeat for all the photos you want to add.

This saves space on the server, and you have a limited amount of space here anyway. Putting them elsewhere, like Photobucket, is a better option.

Sorry I'm no help with you car problem, thought I could help with the pictures though.

2015 Red/Black Honda NC700X
2015 Brownstone Metallic Chevrolet Colorado Z71
2006 Black BMW F650gs
1998 Ascotgruen Metallic BMW 318i - LS Swap Project
1988 Grand Prix White Porsche 928 S4 - Almost There
1967 Marina Blue Chevrolet Camaro - Project
1957 White Chevrolet 4400 Flatbed - Project

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  • ahspros
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27 Jun 2013 21:09 #15186 by ahspros
Replied by ahspros on topic Hard shifting on auto
Call the shop talked to owner (has 928) and will fix it no cost. He thinks it was done by his people during the dive tube replacement.

Walt

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