I have a 2001 dodge cummins with a 5 spd. recently i have notice when i go into third gear it will grind something terrible unless i let the rpm go way down...this will happen when i am either shifting from second to third or if i down shift from forth to second....is that a sign that my synchros are going out or is there something else happening......i have heard that maybe if ya changed the fluids it will help sometime but i would rather have some more opinions from some other dodge fans.....please help and thank you

 

Probably synchros. How many miles? How many fluid changes? Does it help if you double clutch?

 

has 125000 miles i have put on 60000 of those not sure when the last fluid change was. double clutching dont help out a whole lot.

 

I had the same problem on my 98 with the 5 speed. I bought it not more than 3 weeks ealier. Thought it was the synchros and I could live a little bit longer. Then while moving across the country, my tranny started knocking and then pop, I couldn't move without extreme grinding in the tranny. Turns out that the owner before me refilled the tranny with the wrong type of fluid. It ruined all the bearings and the main shaft fell out of position. This caused the input shaft to break it's gear into 12 pieces. $3000 rebuild- basically everything. I would seriously have it looked at before your up a creek without a paddle. You might get away with only replacing a couple bearings. BTW, my synchros were fine.
Just my $.02