Transmission jerks under load

Matthunter76

Registered User
Guys,

I am from London and own a 91 SC auto with 70,000 miles. Have recently attended to a number of ignition, idle faults which I am happy to say have the left the engine running extremely smoothly. However, no rest for the wicked, the next set of problems with the car now has to be addressed. I have an intermittent transmission issue where the car will jerk quite strongly under hard acceleration. Transmission fluid is the right colour and at the right levels though I am unsure if it has ever been flushed and replaced. I also have an issue with the car not wanting to go into OD gear on the motorway, or highway as you guys call it. This again does not always occur. Living in the UK I do not have free and quick access to parts and most things have to be shipped from The States, so hoping a fluid change would be the preferred option to try first. Does this problem relate to a fluid change required or does it point to something more serious. With only 70,000 miles on this AOD transmission I find it hard to believe that the box would require a rebuild. This in any case would be out of my current budget.

Thanks guys in anticipation of any help or advice you might be able to give.

Matt Hunter
 
Good morning


I would:


1. Check the color/smell of the AFT. Dark brown to black means serious trouble. That includes a burnt smell.


2. Check the TV cable adjustment. Do search, Google, You Tube, HAYNES and or CHILTONS repair manuals.

http://sbftech.com/index.php?PHPSESSID=e62c0b267b1d4f7d71d8c7682ff80f44&topic=5448.msg50823#msg50823


3. Inspect the cable bushing for damage at the throttle body and the transmission.


4. Next do a filter/fluid change. Do not forget the drain the torque converter. Inspect the pan for heavy metal and or clutch material(s).



You might have a valve body with varnish issues. Following the filter/fluid change the use of AFT additive like LUBEGARD red or Seafoam TRANSTUNE might clear the issue.


Good Luck.
 
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Don't drive it anymore until you check #3....the bushing may be completely gone. If so, your transmission may not be too far behind.... :eek:
 
Don't drive it anymore until you check #3....the bushing may be completely gone. If so, your transmission may not be too far behind.... :eek:
The stock bushing is made from some type of plastic that deteriorates over time. The replacement bushing is made from brass.
 
The stock bushing is made from some type of plastic that deteriorates over time. The replacement bushing is made from brass.

Just gave my original plastic bushing (what was left of it) a well earned retirement party, replacing it w/brass over the weekend. $7.50 shipped. Clip only tried to escape once during installation.
 
Thanks

Guys,

Thanks a lot. Great advice. Fluid is the right colour and smell though is quite high on the level, not sure why this is. TV cable has been replaced as the bushing had perished. Filter and fluid change will be completed and hopefully this will solve the issue.

Will update with results when the job is completed.

Regards,

Matt
 
Does this also apply to the 94? I know it's a different tranny but I am having a similar problem. Mine has low miles and was stored for many years. The problem didn't become apparent until I changed tranny fluid (but did not drain the converter). It also doesn't occur until I've been driving for an hour or so, and may stop as quickly as it starts.
 
Does this also apply to the 94? I know it's a different tranny but I am having a similar problem. Mine has low miles and was stored for many years. The problem didn't become apparent until I changed tranny fluid (but did not drain the converter). It also doesn't occur until I've been driving for an hour or so, and may stop as quickly as it starts.

94+ has an electronic controlled 4R70W transmission so the quick answer is no (as there isn't a TV Cable).

-Tim
 
Keep in mind that a melted spark plug wire sitting on the headers will make the same symptoms, even if you just changed them perhaps one could be laying on top a header...but if your tach isn't going nuts then most likely than trans.
 
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Guys,

Thanks a lot. Great advice. Fluid is the right colour and smell though is quite high on the level, not sure why this is. TV cable has been replaced as the bushing had perished. Filter and fluid change will be completed and hopefully this will solve the issue.

Will update with results when the job is completed.

Regards,

Matt

I assume you will replace th bushing before driving.
 
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