Engine/Transmission (1998.5 - 2002) 6 Speed grind when shifting fast. What causes this?

[Blacksdieselhp]

I've had several 6 speed transmissions that would grind going into a certain gear if you shifted it a little faster than normal. I've heard of a lot of people getting the sincros replaced but didn't help. What causes this grind. If you push the clutch all the way down and shift slowly it won't grind. Is this a clutch problem? I've got one truck that does it going to 5th gear and another that does it going into 3rd. My friends truck does it in 2nd, 3rd and 4th. Thanks in advance for the help.

 

[Rman]

This transmission is not made for racing. It's very strong and durable, with this comes a price. The transmission is very heavy, internally, this inertia when spinning makes it difficult to shift, the transmission has to slow down to shift, this is why you clutch. Say your pilot bearing is catching causing the transmission to spin while the clutch it depressed, it will be more difficult to shift than normal. Most of the time if I just match rpm's well and clutch properly I have no problems. Tight shifting is really just the nature of the beast. If you really want to race, buy a race car or get an auto. There's a nifty thread about a couple supras eating a viper's lunch, I'd sure like to have one of those.

 

[Gary - K7GLD]

IF you bought your truck/6-speed for racing, you bought it for the WRONG reason, and maybe shoulda got a vette or Viper instead!



Seems some owners mistakenly ASSUME that a 6-speed in a TRUCK is the same and performs as does a 6-speed in a sporty-car, and they soon find out how WRONG they are!



The gear train in the 6-speed is big and heavy, and designed for WORK, and moving heavy loads - just like the rest of the drivetrain. slowing all the mass of the geartrain for shifts is no small matter, and REASONABLE care in shifting is recommended and required for smooth and trouble-free shifting.



ABUSE the transmission and syncros in race-type driving, and you WILL pay a price in eventual syncro failure and resulting increasing gear grinds on shifts.



Sure, you CAN race with the 6-speed, some here do - but if you expected sports car shifting, you were dead wrong...

 

[Blacksdieselhp]

Yea, me too. I raced a 6 speed truck for a while with no problems, but I know it definately isn't a transmission suited for racing. I mostly tow with a 6 speed now. Just wandering if there was a common problem for this grinding. I can deal with it but it make sit a little harder to sell a truck. Thanks

 

[SMorneau]

Two nights last week I left work when temps were well below zero all day long. I could not downshift without some terrible grinding. So I spun donuts in the back lot on the snowpack and got the engine and transmission warmed up.