Clunking Transmission?

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Aug 27, 2005 | 09:25 PM

skyler_lloyd

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Clunking Transmission?

Hi, my '85 auto (TH700R4 right?) has been making noise for some time now when I shift from park to drive or reverse. It has done this from day one, but I've never seem to think this was unusual for some reason. The trans. filter and oil has been changed recently. The noise is like a slightly hard shift but nothing dramatic, and only happens when I go from park and no other time does the trans. act funny. Could this be a mount? Where are the trans. mounts located? Any help would be great.

Aug 27, 2005 | 09:38 PM

Morley

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From: GA

The "clunk" or hard hit going from park to any other gear (except neutral) is normal for your year transmission. Later they put in a secondary valve body that helped to eliminate the hard hit.

Sep 5, 2005 | 01:39 AM

Shawn_65

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what year? I've got a '90 auto that does the same thing. When I'm in D it downshifts hard, but not in OD. Is this normal?

Sep 5, 2005 | 02:47 AM

Morley

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From: GA

I think it was 88 or so that it was added. Not sure I understand the downshifting thing...when you manually downshift from D to 2? Most autos do grab pretty hard when you do that. The clunk from P or N to R or any fwd gear is what was "fixed" later.

Sep 6, 2005 | 10:16 AM

gbody5

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From: Stuck in the 80's

Quote:

Originally Posted by Shawn_65

what year? I've got a '90 auto that does the same thing. When I'm in D it downshifts hard, but not in OD. Is this normal?

Mine does the same, and the rebuilt B&M 700R4 I put in my Monte Carlo did the same thing, it was a really bad clunk when in D and coming to a stop, I had to remind myself to make sure I was in OD to avoid it.

Appears to be inherent to 700R4's, probably in the valve body, the way it routes the fluid when in D as opposed to OD, my guess, not a tranny expert.

Sep 13, 2005 | 05:09 AM

skyler_lloyd

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I've also noticed that it likes to shift into 3rd a little early and very swiftly. Has anyone else noticed this?

Sep 17, 2005 | 09:59 PM

skyler_lloyd

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Is there anyway to avoid that early shifting into third durring casual driving when the rpms get kinda low? It holds 2nd longer under half throttle but "falls" into 3rd at less.

Sep 18, 2005 | 12:50 PM

gbody5

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From: Stuck in the 80's

You can make some adjustments with the Throttle Valve Cable, major adjustments can be made with the governor itself. B&M makes a calibration kit with different size weights and springs, it is pretty much trial and error but if you have the time you can get it done.