Manual tranny reverse grinding?

When i go to put my jeep in reverse (its manual), sometimes it grinds gears until it gets all of the way into gear. Is this normal, good, bad, deadly, or what? Does anyone else get that?

Is it hard to get into any other gears? What year? What model? What tranny? Reverse is not sycronized so if you are still moving when you try to put it in it will grind a little. If it grinds a lot and won't seem to go in its probably a bad slave cylinder or master cylinder and its not building up enought hydraulic pressure. Had this problem on a Wrangler once.

on mine (87) any faster than like 2mph(rolling backwards) it will grind when trying to go in so basically you gotta be stopped to get into reverse

Yeah, its only a light grinding when im moving (i think)... So that takes care of that....

stock XJ
'96- 120,000miles
manual w/ a 2.5L I 4

One last qestions: If im rolling backwards, is it still supposed to grind? Cause mine does.

Mine does this frequently, even at a total stop and even with the clutch all the way down. Sometimes it wont want to go all the way into the reverse position either. They way I get it to work is keep the clutch down, put it in 1st, then neutral, let the cluth up and down again, the put it in first and it slides right into reverse. What thats doing is just getting the synchronizers in line.

No its pumping up the hydraulic pressure so it goes into reverse.

my reverse grinds a little thought that was ok but it pops out of second when its cold

whenever mine has trouble i put it into first, then go from first to reverse, and that works for me... i dont know why...

BTW: what were the trannys for 5 speed? how do you tell the difference?

jeepguy97 said:

No its pumping up the hydraulic pressure so it goes into reverse.

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A guy at Aamco said that I could do that to line up the synchronizers to get into gear easier (or something along those lines.. this was over a year ago). What do you mean by pumping up the hydraulic pressure?

When you push in the clutch it is supposed to allign all the sycronizers right then and there. If it doesnt go into gear without grindidng something is wrong. Reverse is not sycronized anyway so what sycronizers are you lining up. By pumping the clutch pedal you are building up pressure. Just like pumping the brakes. If you have a leak in the clutch system pumping the pedal makes up for it and helps it go into gear.

If you are having problems with the clutch hydraulic system, it will be difficult to shift into any of the synchronized gears and reverse will be almost impossible. In your case, it's just a matter of learning the proper technique. Historically, the proper way to shift into reverse is to fully stop the vehicle, shift into a synchronized gear first and then into reverse. You shouldn't be moving at all, forward or backward.

Why does this work? At any given time, the input shaft may be rotating due to the tight tolerances between the clutch driven and non-driven discs, from previous clutch engagement or vehicle motion. The input shaft is meshed with the intermediate shaft so the intermediate gears may be rotating as well. By shifting into a synchronized gear, one of the output shaft gears is brought into mesh with with the intermediate shaft. Assuming the vehicle is stopped, the output shaft is not rotating, so meshing to the intermediate shaft stops the these gears as well as the input shaft from rotating. With rotation stopped, the reverse gear is free to mesh without grinding.

I know this is an old thread but I am having this problem now, grinding going into reverse (ZZZZZzzzzzzt kinda noise, as if something is spinning then stops spinning). So the info here makes sense. I'm trying to determine if I should be looking at my master cyl, slave cyl. or clutch itself. All are about 5yrs old, all replaced at the same time. Thoughts? '91xj 4.0HO Sport 5sp. stock. thx..

truckeejeeper said:

I know this is an old thread but I am having this problem now, grinding going into reverse (ZZZZZzzzzzzt kinda noise, as if something is spinning then stops spinning). So the info here makes sense. I'm trying to determine if I should be looking at my master cyl, slave cyl. or clutch itself. All are about 5yrs old, all replaced at the same time. Thoughts? '91xj 4.0HO Sport 5sp. stock. thx..

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How is the fluid conditon? Maybe try bleeding some new fluid through it.

Also check and see if there is some slop where the clutch pedal pivots under the dash.

1st-reverse does work in case you've never tried. A few months ago, I had to show a lady that has owned a 98 w/ax15 for years that her tranny and clutch were fine and reverse wouldn't grind if she started in 1st.

My Jeep has done this since the day I got it. Been wondering if I was the only one having the issue, but I guess not. I've always shifted into first, then reverse, and it's worked fine.

i always throw the girl in 3rd or 1st

before putting into reverse.

problem solved!

Mine does this as well.