# Motor Mounts, Transmission, Ideas? **URL:** \ **Category:** Maintenance/Repairs\ **Created:** [February 6, 2008, 8:57pm UTC](https://community.cartalk.com/t/motor-mounts-transmission-ideas/10307 "2008-02-06T20:57:52Z")\ **Posts on this page:** 2\ **Page:** 1
**Author:** ![Karen818](https://avatars.discourse-cdn.com/v4/letter/k/4491bb/32.png) [@Karen818](https://community.cartalk.com/u/Karen818)\ **Post date:** [February 6, 2008, 8:57pm UTC](https://community.cartalk.com/t/motor-mounts-transmission-ideas/10307/1 "2008-02-06T20:57:52Z")
It is a 97 Ford Explorer Sport with automatic transmission. Occassional I experience a thud and RPM’s drop to nothing for approximately 1 second. When it has happened I have usually been driving 65-70 mph on the highway. It does not always happen when driving that speed on the highway, just occassionally. I feel it more then hear it. It has the feel of rapid breaking, but just for that split second. Sometimes it will happen 20+ times in the course of a few miles. Other times I will drive 50+ miles without it happening at all. Vehicle has 180K. About a year ago I did start noticing that the transmission would “slip” (I think that is the correct term) when I would try to accelerate quickly from a stop. If I accelerate hard from a stop, I sometimes hit a point where RPMs fly up but the vehicle is not moving at that speed. Net effect it has caused me to actually drive less aggressively. With regular everyday driving I do not experience any “slipping”. I suspect the two may be related. Any ideas? ---
**Author:** ![Roadrunner](https://avatars.discourse-cdn.com/v4/letter/r/d2c977/32.png) [@Roadrunner](https://community.cartalk.com/u/Roadrunner)\ **Post date:** [February 7, 2008, 2:43am UTC](https://community.cartalk.com/t/motor-mounts-transmission-ideas/10307/2 "2008-02-07T02:43:22Z")
When was the last tranny fluid and filter change? If there is a little dirt/foreign material in the fluid, the pressure control solenoid (IF same as GM) may have picked some up and is sticking periodically. Then again it could be a faulty VSS (vehicle speed sensor). Like I said, ‘could be’.