fordsvtmfl

iTrader: (13)

Ok, so when i let off the gas and then hit is again real quick..(like in heavy traffic) sometimes i get a little jerk from right under me. the transmission shifts perfectly smooth..so what do you guys think this is?
just a clarification..the jerk does not occur during gear changes, and it does not affect the acceleration.

jcat_350

sounds an awful lot like the car is just doing what you tell it to. i don't see a problem based on your description. Might be feeling the lag in the electronic throttle but thats about all i can think of.

JeffTsai

iTrader: (1)

Possibly the transmission mount or motor mount is on its way out. That can cause some slop and play. When you give it gas, instead of transferring the torque instantly to the wheels...it has to flex first a little on the mount till it bottoms out then it moves the power out. Think of it as a circle with a stick in the middle. Normally the stick is encased in a solid rubber inside the circle, but when the mount goes bad...the rubber is gone. So the stick has to lean against the edge of the circle before power will go out the engine. Hope you can understand my explanation.

fordsvtmfl

iTrader: (13)

yea...i hadn't thought of that...i hope not...but sounds like that could be the problem.

jriggs

sounds exactly what was happening in my car. it was a bad tranny mount couple bucks and 20 minutes later it was fixed.

fordsvtmfl

iTrader: (13)

is there any way to visually see if thats the problem?

GSteg

iTrader: (15)

You can jack up the car and look at the tranny mount itself. A worn out tranny mount will be collapsed where metal will be touching metal. It's hard to explain, but if you can take a picture, we can probably tell you if it's still good or not.

GSteg

iTrader: (15)

Actually, instead of gasing the engine right away, slowly accelerate. Does the engine wind up before it jerks?

fordsvtmfl

iTrader: (13)

yea, i would know if its worn out...i guess my question should have been can you see it without having to take apart half the car.. lol and it only does the jerk when im already moving.. so lets say im going 30...i let off..it starts to slow down, and then real quick i hit the gas (and not hard...its hard to explain...but i kind of just tap it...like you were going to hit it but just before you really press down on it something makes you stop) and then i get a jerk under the car (not hard or anything...and it does NOT affect the motion of the vehicle..so the car it self does not jerk..just something under me..) and this only happens sometimes...like i have to get it just right...from a stand still it is perfectly fine...even when flooring it...

fordsvtmfl

iTrader: (13)

unrelated to the other jerk...when i floor it from a stand still, first i hear the intake take a big gulp of air...the rps build..and then it finally kicks in...not a jerk really...just like delayed acceleration...this is normal right? (just from a stand still, and it gets to like 5mph before it kicks in)

jcat_350

yep, normal. such is the electronic throttle lag. this is what i thought you were talking about before.

fordsvtmfl

iTrader: (13)

yea..i thought so...just wanted to make sure...

GSteg

iTrader: (15)

You can inspect the transmission mount without having to take it out. Unlike other mounts, these mounts dont show too many visible cracks when they're worn. You'll know they're at the end of their life when you see something like this:




Look at the circle part and you'll see the metal from the top half of the mount touching the bottom half. Mine was nearly touching when I replaced mine.

fordsvtmfl

iTrader: (13)

thanks alot for the info

humanoid

iTrader: (1)

How easy is it to replace these tranny mounts? How many are there?