I having a couple issues with my 01 mustang gt. First issue: I put 20 inch tires on my car and now the shift points seem to be all out of whack. So I had a shift kit installed. Its has cleared up a little bit. So my question I have is should I buy a programmer to remap the shift points? I know that the programmer that is sold by american muscle will calibrate the speedo up 19 inch tires. Second issue: I have a lot of shaking taken place when the car goes into over drive around 60-70 miles and hour. It feels like and unbalanced tire. Which i dont think is the problem cause I just put new tires on about two weeks ago. Im just curious if it could be the motor mounts, or maybe transmission. The reason I say this is cause I tend to feel it more when im crusin around at 50-55 with the overdrive off, and during accelaration . The transmission is making a squealing noise whenever the car is in gear. Well if anyone has any info please let me know. Thank you

 

For the tires if the overall height of the tire is more or less then the stock 26" hight it will make the speedo be off and cause weird/harsh shifting. If you look in the tire section we have a tire height calc posted and you can plug in your current tires to see if they are to big/small.

For the shaking if it just started after the wheels it can very well be the wheels are not balanced well. The fact that it only does it at higher speeds kinda leans me towards that as with slightly unbalanced tires you dont feel them shaking till you go faster.

If the tranny is making noise i would right away go check the fluide if its low it will make noises and its very very bad to run them low on fluide. Check those out and let us know, hope this helps some.

 

Hey thanks

I think the overall height of tires is about 22-23 inches. The shaking has been going on for sum time now. I thought i was cause I had bad tires on it. The new tires have cleared up the problem a lil bit. My steering wheel also clicks when I turn it so that could have something to do with it. I hit a curb a while back. It happened with the stock wheel and not the ones I have now. Like I stated I can feel it during accelartion also it feels like it in the driver side front but I can really feel all around and under the driver seat and passenger. But I will definately have that checked to make sure the wheel is properly balanced.

 

hey spike i dont see that height calcualtor. I have 255/35/20 is what i have on my car. Ford couldnt reprogram because it only went up to 255/35/19. Thats y i was wonder if I a programmer would fix the shift points. I was looking at the diablo programmer.

 

how did you hit the curb? I'll bet you bent something.

BTW.. 20's are ugly on Sn95's...

Last, SCT Xcal2 FTW. Predator suck ***. Voice of long experience.

 

I had it looked at once and they didnt see anything wrong. The 20 look real good on my 2001 mustang gt.

 

they clearly missed something or it wouldn't be shaking.

You're in the massive minority on how 20's look... 99.9% agree 20's never look good on a 94-04. But hey... it's your car. make it how you want it.

Now then... how did you hit the curb? What orientation was the car in, how fast, how tall a curb, any pics, cmon... details.

 

I lost control of my car when i was making a turn. Yeah i didnt think that 20's were going to look good until i found the ones I have on now.

 

if you hit the front end wheel(s) on a curb, then you need to check and see if the K-member has shifted. This sort of thing will cause vibration and steering to one side even with a PERFECT alignment and wheel balancing. Also, you need to pull the A-arms and look at the bolts to see if they're bent. Same with the swaybar end links.

You should also pull the brakes and wheels off both sides and spin the spindles and shake them. If they grind or catch on spinning or knock even a little during the shaking, then you smoked a bearing in the spindle and you need a new spindle. Upside on that would be that they're fairly easy to replace and pretty inexpensive.

I'll betcha a dollar I'm at least 50% correct.

 

damnit man. now that you say that....i had a lil misshap bout 2 yrs ago, ran off the road onto the apron (sp?)..it ended, then started again, leaving about a 6" drop in between the start/stop, blew out both right side tires, had to be put on a rollback and towed home anywho, it pulls a lil to one side, and vibrates around 50mph or so. all that stuff u listed i'll check out. thx redneck!

 

Hey thanks at least I will know what to tell my mechanic what to check. I will let the check this out when I get it inspected this week. I wil let you know if the find anything. Thanks once again.

 

well those tire sizes are almost an 1" and a half taller then stock and that is a problem. You will need to for sure tune that car or cheange tire sizes. This will cause the weird shifting etc... Red has you covered on the shacking i wcouldnt agree more. But like always red beats me to it lol.

 

tires that much different will certianly have an effect on overall drivability with EFI cars that care about tire size... like the mustang. The difference is about 5% in how far your current tires are in circumference from stock...

5% is enough to be problematic in multiple systems. Get thee to an Xcal2. You'll be happy with that and it'll grow with you.

 

Thanks. Is it pretty easy set up?. Everything is still stock on my GT except for the shift kit.

 

only about 10% harder than falling down.

 

LOL. Well i will definately have to check that out.