700R4 "locking" under decceleration

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Nov 14, 2001 | 10:52 PM

phineas

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From: Dundalk, MD

700R4 "locking" under decceleration

I have a '91 RS with a 305 auto. I've noticed that a lot of the time (but not all of the time) when I'm slowing down (via brakes) the driveline feels like it locks up for a quick second at around 750rpm. Feels like someone just kicked the car from behind. Anyone have any clue what part of the driveline could cause this ? I'm sure it's probably tranny or TC related, but I'm not going to rule out the rear. Thanks!

Kyle

Nov 15, 2001 | 01:32 AM

Apeiron

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From: Mercedes Norte, Heredia, Costa Rica

Car: 1984 Z28 Hardtop

Engine: 383 Carb

Transmission: 4L60

Axle/Gears: 3.54 Dana 44

Could be just the transmission downshifting.

Nov 15, 2001 | 04:03 AM

transfixleo

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From: Webster, N.Y.

Does it happen more often in the D position?

Nov 15, 2001 | 05:16 PM

phineas

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From: Dundalk, MD

Well, I normally only drive the car in D unless I'm on the highway, since in the city I rarely get over 30mph and it's quite annoying when the trans drops into 4th at 40mph. So I would have to say that yes, it does happen more often in D

If you're thinking of something in particular, I could drive it for a week in OD and see if it's any different.

Nov 15, 2001 | 06:51 PM

transfixleo

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From: Webster, N.Y.

I don't think it will take that long, probably just one good drive. I think it is just the 'normal' 3-2 downshift clunk. The TransGo Shift Kit will fix this problem. The Reprogramming Kit is not as likely to take care of it since it is interested in all out performance but it isn't too bad.