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Discussion Starter · #1 ·
I need some help. I'm working on a non B-body car using a 4L60e, using a TCI stand alone controller. This trans came from a trusted vendor(who shall remain nameless for the time being since I havent had a chance to get ahold of him yet). The converter, also a trusted name, is new as is the whole trans cooler circuit. It's got less than 50 miles on it at this point. Around 2700 RPM, the trans starts making a groaning sound(sounds similar to the sound brakes make when you creep forward with your foot on the pedal). It gets louder from there, and starts vibrating pretty good. It's RPM dependant, and does it in all gears including Neutral. We dropped the pan tonight, and the fluid smells a bit funny and has lots of metallic swirls in it.

The car still drives and shifts fine, but the trans noise/vibration is getting progressivley worse. The car's owner wants the car for a show this weekend. Any thoughts about what the problem might be? Any simple tests I can do? I'm hoping I'm missing something obvious, but I'm sure I'm not. Thanks for the help.
 

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Off the top of my head, sounds like something mechanical. Don't know if it's the converter or the trans because both the pump and the converter are RPM-dependent. The builder needs to open it up and fix it. Nobody's perfect, and that's why they have warrantees. Tell the owner he can trailer it to the show and that's it.
 

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If you are hearing it in Neutral I would look at the converter.
 

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Discussion Starter · #4 · (Edited)
Our converter is a half breed. The trans is adaped to an Aston Martin V12. As such, the converter has a Ford engine side, and the mounting flange is spaced out 1/2" to accomodate our adapter plate. The overall length of the converter from bolt flange face to pump drive tangs is a calculated distance, not something we were able to actually measure. Could it be that the flex plate is flexing, and the converter is pushing to far into the pump? What would happen if that were the problem? Is there an easy way to check that? Just a thought.
 

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Our converter is a half breed. The trans is adaped to an Aston Martin V12. As such, the converter has a Ford engine side, and the mounting flange is spaced out 1/2" to accomodate our adapter plate. The overall length of the converter from bolt flange face to pump drive tangs is a calculated distance, not something we were able to actually measure. Could it be that the flex plate is flexing, and the converter is pushing to far into the pump? What would happen if that were the problem? Is there an easy way to check that? Just a thought.


I bet its going to be in the converter by the sound of the problem. Sounds like the custom converter wasent balanced right or has some clearance issue inside of it.

Its possible it could be a badly out of balance sunshell or possibly a thrust washer come apart in the transmission.

But again thats just my guess, i cant really see what couldmake the funny noise and vibe inside a new trans even in neutral. Good luck with the issue!
 

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Discussion Starter · #6 ·
New Information: The noise/vibration is engine RPM dependent, not trans RPM or turbine speed dependent. It picks up very consistently at 2700 RPM regardless of any other variables. It is still there with the converter locked so it can't be the converter's internals. Since it does it in neutral, I wouldn't think it could be in the input shaft or related parts. That makes me think pump, but i wouldn't think the pump has enough mass to generate the vibration we're getting :confused:
 

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Discussion Starter · #7 · (Edited)
I had a chance to speak with the vender. It's a boost valve problem. Apperently Trans-Go had some bad ones slip through with their holes blocked. The vender is building us another trans, so we should be good to go :)
 
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