So I just got my SRT-4 less than a month ago. I test drove it driving it quite calm but being a test drive I did get on it a bit in 2nd and 3rd gear. Once I did buy it I noticed something in 4th gear. When up or down shifting it will grind but it will upshift just fine as long as I let the rpms drop to 2k or lower, absolutely no issues then. I just changed the transmission fluid today with Mopar ATF+4 and Mopar friction modifier hoping that hoping that it would fix the issue. I got it all finished up and went for a drive and it didn't fix it, it still does it just as it had before.

What do you think it could be? Could it be something to do with the linkage, or maybe a synchro? I just think it's weird that it's fine at the lower rpm.

 

Start by adjusting the linkage. Its underneath the shifter. Take the screws out from the center console. You will see the cable with the 10mm bolt (maybe 8mm cant remember). First put the shifter into 4th gear. Loosen bolt, wiggle the shifter a little so everything settles (keeping it in 4th), then tighten the bolt back up. If this doesn't fix it I would try adjusting the clutch pedal, if it gets better when doing this then more then likely your clutch fork is worn and needs replaced (very common). If all this fails try an AGP shift extender for 2nd and 4th (modern performance is where I get them from). If issue is still there then the trans needs pulled for a rebuild.

 

Thank you! I will try all of these things. It shifts just fine if I shift slowly so that's what I've been doing and I haven't had any problems. Hopefully one of these things will fix it for me.

When I bought the car there was someone else who wanted it. He wanted it bad enough to ask the pervious owner for my number and try to buy it from me the day after I bought it. He told me he knows a lot about srt4s and that he owns one already. I told him about the 4th gear problem and he was still interested in the car. That kind of convinced me that it probably isn't as serious as replacing the transmission or rebuilding it.