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Loose cruise control or what?

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Old 10-07-12, 03:42 PM
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SC400slide
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Default Loose cruise control or what?

Hey CL another quickie....
Yesterday I took the SC400 up to edgewood, which is about an hour away from were I live. Well, It was on cruise control at 81 MPH pretty much the whole way going up to edgewood, (the whole trip is uphill), and didn't even shift down, but than coming back....the cruise control was on at 75 I think and going down a very slight grade the RPM's would fluctuate ever so slightly, and the throttle kept tapping. So about every second it felt like the throttle was being depressed, and every time this happened, there was a slightly noticeable tiny clunk, every time the car would accelerate and than release. Sorta hard to understand, I know. It's hard to explain. It';s just something that bothers me somewhat...
I checked the cruise cable and bolt and they were tight, though, I will check again. Any ideas on what this "fluctuation" could be?
Thanks
Old 10-07-12, 05:12 PM
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Slack in the drive line.
Old 10-07-12, 05:48 PM
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I checked the drive line and all of the throttle bolts and cables. All are tight. What is the slight clunking? Loose third member?
Old 10-07-12, 06:08 PM
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Slack in either the trans mounts,motor mounts or bad differential ear mounts or a combo of all 3.
Old 10-07-12, 07:40 PM
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Tranny mounts are brand new. I just replaced them myself. I was going to do motor mounts but I decided not to for some reason. I will look into the diff mounts. Will get back to this thread...thanks for the help.

Last edited by SC400slide; 10-07-12 at 07:40 PM. Reason: Mistake typo
Old 10-07-12, 08:19 PM
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Diff mounts 8 out of 10 are bad from old age and the fact that they were way too soft from the get go and if you do any "spirited" driving this will finish them off real quick also look in to the carrier bearing and or the flex couplers in the drive shaft
Old 10-08-12, 07:32 AM
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OK I will thank you.
Old 10-13-12, 04:54 PM
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I have come to think that this is the motor mounts. Is it worth it to replace these?
Old 11-25-12, 07:39 PM
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Sorry for another "kinda old thread" bump but I would like further suggestions before replacing the motor mounts. I think the problem is getting a little worse. Depress the throttle, bump. Let go of throttle, bump. It jerks every single time letting go or depressing the throttle. The RPM's go up 200 every time this jerks as well, that's why I think it might be the diff missing rubber. Suggestions?
Old 11-26-12, 09:55 AM
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I just went under the car and looked for anything loose or broken. Diff rubber spacers looks brand new. Though the tranny selector is a little loose. This thunk feels like a big part, like the driveshaft. Suggestions CL?
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