Cummins Diesel Forum banner

getrag weird noise???

2K views 20 replies 5 participants last post by  93ramrod 
#1 ·
hey guys, i started to notice something strange while down shifting, lets say if im in 4th and start slowing down ...press the clutch in and try to put er in 3rd it makes this unusual shaking vibration. its only when down shifting when im trying to push the shifter in to the lower gear, it wont want to go in untill im almost stopped....when shifting up its smooth as hell. any ideas?
 
#3 ·
Could be synchros, or maybe tring to go into lower gear, but the truck is moving too fast for the lower gear. Example for me, is down shifting from 5th to second. It refuses to go to second unless I am travelling less than 15 mph.
 
#4 ·
I'd say that its one hell of a bad idea jumping down that many gears. Your gonna end up hurting your clutch, squealing your tiers or if your running a good clutch and loaded down you can even snap your input shaft.

Good luck with that technique. Just down shift one gear at a time!
 
#5 ·
Not when you are slowing down to make a turn. The vehicle is already going slow enough to make the turn. I've been driving stick shifts for over 35 years. We even learned that technique in driver's ed.

I also live in a rural area, so it is very common to slow from 60 down to 15 mph for a turn off.
 
#7 ·
Still, down shifting one gear at a time is going to help you slow for the turn, you can't really argue that unless you are locking up your tires and screeching to 15 from 60.
 
#12 · (Edited)
Please explain on how one would lock up the tires and screeching when using the brakes to slow down, with the clutch pressed. Also, I do not engine brake, which going down gear by gear tends to do, unless you keep the clutch pressed. I do not down shift unless the truck is slowed down enough to do so.

I have a great idea...someone come ride with me and tell me what I am doing wrong, before ASSUMING anything.
 
#8 · (Edited)
You shouldn't be trying to put a getrag into 2nd at anything more than 15mph anyway!

When down shifting, match engine rpm with the throttle, NOT THE CLUTCH. You will notice that the transmission slides into gear easier if you have increased engine rpm after disengaging the clutch to match the next gear you are trying to select, in the same manner that if you time your shift properly with the decreasing engine rpm you can upshift without using the clutch. You can even downshift without clutching if you are good enough, but that's not relevant.



Not only will this technique feel easier, it will drastically reduce wear and tear on your vehicle. My dad would absolutely crap his pants if he rode with you people in a manual transmission vehicle.
 
#9 ·
Well, you have to remember, no freaking factory tach! Match RPM how?

Any way, I do not have any problems down shifting. Again I do not down shift gear by gear. When slowing from 60 down to 15, I use the brakes, not the clutch and engine. That is how I was taught. It has worked for me just fine. I have not destroyed and clutch or transmission.

I do not shift with the clutch engaged to the engine. I am not that good, and I do not grind gears.
 
#11 ·
I do listen. But I cannot tell 2000 rpm from 2200, or 2500 for that matter. Tach would be best for visual confirmation though. This is the only vehicle I have that does not have a Tach. Even my old Hinomoto tractor has a factory tach.

When I get some coin saved, I do plan on adding an ISS Pro tach.
 
#13 ·
ok soo when ive got the clutch in and slowing down...going the speed to match the gear im down shifting to thats when it makes the noise/vibration. it seems to do it from 4th to 3rd and then 3rd to second. im really easy on the clutch and always use the brakesto do mostly all the slowing down. i dont tow anything hardly and its a brand new clutch kit (south bend 13") with new thrw out bearing etc. it did it with the factory clutch too...thats why im puzzled.
 
#14 ·
Was the pilot bushing replaced? Was the flywheel replaced as well?

Unless there is something wrong inside the transmission, it should not do that.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top