Transmission Grinds When Shifting to Reverse

[MisterM]

whatsup guys, new to the form but if i get some good feedback, i plan on sticking around for a while. i have a 95 k1500 chevy stepside with a 5 speed transmission. At a complete standstill, even when holding in the clutch and letting it slow down for a bit, my transmission severely grinds when shifting into reverse. I try really hard to ease it into gear but it almost seems like the clutch continues to spin when disengaged. i can occasionally get it into reverse without grindage but not typically. i got 117 on the original clutch so i plan on replacing it soon but would like it to last me as long as possible because i need new tires and need to redo my rear differential. this is really bothering me and i almost feel like im gunna ruin something eventually. any help and insight would be greatly appreciated.

 

[LOWnEASY]

Try shifting in to 1st then emidiatly shift to revers. Shouldn't have to do it lightning quick, but put it in first them down and over to revers.

 

[kevrobster]

Try shifting in to 1st then emidiatly shift to revers. Shouldn't have to do it lightning quick, but put it in first them down and over to revers.

^^^ Agreed. I had the same issue with a manual shift car and found found shifting into 1st gear directly prior to putting in reverse resulted in a smooth shift every time, and it has held true for every stick shift vehicle I've driven, including my '95 k1500.

Can anyone with more transmission knowledge explain why this is?

 

[heavychevy98]

Usually all gears are synchronized except reverse. When you put it in a forward gear the synchros keep it from grinding and when it's in any gear, the gears themselves are not moving which makes shifting to reverse smooth. Now this is all assuming your sitting still. Did i Make sense??

 

[MisterM]

Thanks for the feedback guys, appreciate it. Still got a problem though, even after shifting into 1st, then straight into reverse it still has a really harsh grind and grab. (Got stuck in the snow today and wasn't fun)

 

[kevrobster]

Usually all gears are synchronized except reverse. When you put it in a forward gear the synchros keep it from grinding and when it's in any gear, the gears themselves are not moving which makes shifting to reverse smooth. Now this is all assuming your sitting still. Did i Make sense??

Thanks Heavychevy98. That does make sense.

MisterM, it sounds to me like your clutch isn't fully disengaging, so the gears are still moving somewhat when you put it in reverse. I'm no transmission expert obviously, but based on Heavychevy98's explanation, there should be no movement of the gears if you put the truck in a forward gear while the truck is sitting still and the clutch is depressed. No movement should = no grinding.

Just to clarify the method of shifting into 1st gear thing, make sure you're doing it in the right order: 1. Depress clutch pedal 2. Shift into 1st (do NOT release clutch yet) 3. shift into reverse 4. release clutch.

Hopefully someone else will chime in, but if this doesn't work, I would bet you've got an issue in the clutch system (master/slave cylinder, air in the lines, bad throwout bearing, etc) that isn't allowing the clutch to fully disengage.

 

[tanman_2006]

I know early NV4500's are nonsynchro 1st and Rev. Not sure on 3500's.

The 1st then rev thing aways worked for me too.

 

[MisterM]

It works. I think before I was just doing a somewhat aggravated version of shifting from 1st to reverse (stuck in the snow). I appreciate the help everybody

 

[98_k1500]

Try bleeding your clutch slave cyl. If it has a air bubble in it, it would cause this problem and its a virtually free fix, just cost you a little brake fluid.

 

[94 cheyenne]

kevrobster as heavycheavy said for the most part the reverse is non syncronized but from what manuals ive had a part ive also noticed that the reverse gear is a straight cut gear as well someone correct me if im wrong but that seems to me it would cause problems