Grinds going into reverse.

[JakeR22]

It's a '85 S-10 2.5 4 speed. I've only owned the truck for about a year. I was told the transmission was recently rebuilt.

When it's running and I try to put it into reverse, it grinds pretty bad, depending on how high it's idling. It wasn't this bad when I first bought the truck. Can I assume it's a bad synchro? Any sort of additive I may try to help this problem? I already changed the fluid, and that didn't help any.

 

[tom slick]

it could be a bad clutch also. reverse gear often doesn't have a syncro. what happens if you put it into a forward gear before reverse?

 

[Gary Allan]

As tom said, it may be the clutch (pressure plate, really). If you have a slightly hard time putting it into forward gears too, then it can be that.

Try waiting longer (and putting it into forward gears first, as Tom suggested) before you put it in reverse. If it's still there, and you're certain that your pedal adjustment (I don't know what you've got) is good, then I'd look to the pressure plate.

 

[JakeR22]

Pedal adjustment should be good. I recently replaced both the slave cylinder and master cylinder. There is really no adjustment to be made with it.

It acts up the worst when I've been driving it for awhile, and then try to back into my driveway. But when I first start it, it hardly does it at all, if any.

 

[rpn453]

Probably no synchros on reverse.

So it does this even when you stop the transmission by going into a forward gear first?

 

[Virtuoso]

Agreed. Most transmissions that do this; engaging a forward gear before selecting reverse cures the problem.

 

[mechtech]

Make sure your clutch is bled/adjusted.

 

[JakeR22]

I did a little testing. You guys were right, if I put it into first before reverse, it's just fine. I'll just do that. Thanks

 

[97f150]

Still sounds like a little air is still in there.