Thump When Shifting Into 2nd 5 Speed

Hey all, hate to report that my manual transmission seems to make a thump when shifting from 1st to 2nd. It isn't audible, but I can feel it in the floor board. Truck has about 7,500 miles on it, 5 speed transmission. What is even worse is that I suspect it may be a synchro, as it doesn't do it if I double clutch. I have tried every combination including waiting a long time in neutral and the thump always comes as I put it into second. Because of that I think it is not axle wrap.

I was wondering if you guys have any experience or theories about this issue. My first reaction is to change the fluid with Red Line, but if it ends up at the dealership for it I don't want them to be able to say, "Well you messed something up doing your own work." Should I be dealer bound to get it checked out? Thanks for any help.

 

Use the warranty! That's why you have it. You'll get it fixed and it'll be free. And you won't even have to get your hands dirty

 

You have a good point. I'll give them a call tomorrow. I'll post what it ends up being, assuming they don't tell me its "Normal".

 

If they tell you it is normal, you should question why. Then have them explain it fully. Then explain to them that you'll be back until it gets fixed to your liking.

Likely, the service writer could get the tech so he can explain why. At which point the tech will likely talk himself into delving deeper to figuring out the issue.

If the explanation is sufficient for you, then rock on. It could be normal.