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Grinding in all gears

1K views 12 replies 3 participants last post by  aldersonfilm 
#1 ·
This week seems to be the week of Jeep problems for me... My project YJ has developed a fun issue. Since I picked it up a month ago or so, it has seemed to have issues going into second gear. The moment you let off the gas, it pops right out. That was the first thing.
I recently put a 1.25" body lift on it, and the previous owner put on extended shackles. After the body lift, it still seemed to drive pretty much the same. No really road manner changes noticed. I recently had to figure out a 4x4 issue I was having, so I took the cover plate and shifter boots off. I was messing with the shifter a bit to get it out of the way, but didn't actually remove it.
Then today I took it out and as always it didn't want to stay in second. And then I noticed it didn't want to stay in fourth and had trouble with reverse as well. It didn't "click" into gear. All of these gears are in rear positions. It's almost like something is pushing the stick forward.
But it didn't stop there, on the way back from the gas station, it started grinding randomly while driving, not shifting. In every gear, including first. I didn't want to push my luck, so I headed home. The stick starts to shake around when I gain speed and then it grinds, like it's shaking out of gear.
There is also a rhythmic ticking/fluttering, in time with wheel speed.
 
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#3 ·
To me it sounds like you have three separate issues.

- 2nd, 4th, and reverse gears:
-- This is common with body lifts and MML or transfer case drop kits. You probably need to move the cover plate more rearward and possibly even clearance the trans tunnel. Take off the shifter boots and see if you are hitting the cover plate. If so, remove the cover plate and take a look to see if you are hitting the tunnel. Adjust/grind as necessary.

- Wiggling shifter/grinding:
-- Take a look at your motor and transmission mounts, including the torque arm bushings. Those are the most common causes of the shifter moving around. If it's moving around enough it could definitely cause some grinding.
-- It's a new to you Jeep. Have you checked all of your fluids?

- Rhythmic ticking/fluttering:
-- Need more info/a better description on this one...

Edit: Could you provide info on the Jeep so we know what we're dealing with here?
 
#4 ·
It's a 1994 Sahara, 4.0, 5 speed with what looks to be 1" extended shackles and a 1.25" body lift.

I'll pop the cover off again and see if it's getting blocked by the cover. I read somewhere that the dust boot around the shifter can choke up too high or get stiff from age and act as a spring, pushing the shifter forward.

I'll have to pop my head under there and check all the mounts. I've checked all fluids except for the transmission and transfer case, which I can do next.

The ticking/fluttering is hard to describe. It almost sounds like the exhaust tick of an old hot rod at idle, if you can picture that. It's audible when coasting, and sounds like it's in time with the wheels, but it's hard to say. Like a faint, metallic tick, or scratching sound. I'll have to test it out some more once I get the grinding issue sorted out. It's not exactly drivable the way it is.
 
#5 ·
Motor mounts appear to be fine. Hard to tell about the transmission mount as there is some leaked fluid saturating that area. Tried to limp it to my buddy's shop today, but it sounded terrible. I noticed that even if I physically hold it in gear, the stick starts to quiver and it begins to grind. Again, in every gear, but it slots into gear just fine. It's not until I gain a little speed that the quivering and grinding begins. Not on the clutch at all when this happens.
 
#6 ·
A few thoughts for diagnostics:

- Did you get a chance to look into your cover plate/trans tunnel/dust boot clearance?

- I would really recommend changing and inspecting the oil in the transmission. It's possible you have some internal wear that needs to be dealt with. Make sure to look closely for any metal or particulates.

- Maybe consider putting it on jack stands, putting the transfer case in neutral, and the transmission in a gear(s) that it will stay in. Crawl under with a mechanic's stethoscope and take a listen to the transmission. If you have help, checking it at a few different RPMs would be a good idea.
 
#7 ·
Ok, so update: I took off the cover plate again, and found that the rubber dust boot has bunched up after the body lift and was keeping the shifter from slotting into gear properly. So I just cut out the rubber around the shifter and that seemed to do the trick. I drove it around without the rubber on and it slotted into every gear perfectly. Tried jerking it a bit to test the synchros, but it stayed in gear just fine. Drove it around for a bit with no issue.
Then I parked it and left it for a few hours. I came back to move it and the same problem came back! It slots into gear perfectly now, but as soon as you get moving in any gear, it grinds horribly. Then all of a sudden, it just stopped doing it after a couple minutes of driving. Almost like it needed to get hot, and then no more grinding. Couldn't get it to do it again.
I was able to figure out the ticking/fluttering noise though. It appears to be coming from the transfer case, and it sure sounds like the chain. It goes into 4x4 just fine, but I'm wondering if that may play a role in the grinding... Thought?
 
#8 ·
It sounds to me like you really need to do a fluid change/inspection on both the transmission and the transfer case. I don't see how the transfer case could be contributing to the grinding, but checking fluid would also be step one for assessing the ticking.

The fact that the grinding goes away when warm points pretty strongly to a fluid issue in my opinion.
 
#9 ·
Checked the tranny fluid, looked fine. Took the fill plug out of the transfer case, nothing... Stuck my finger down in it.... Still nothing. Took out the drain plug. A little blackish purple syrup oozed out, accompanied by the strong smell of burnt walnuts. So that explains a lot...
 
#10 ·
Nice. I would throw some ATF into the transfer case (after looking for possible leaks) and see how much that helps out before ripping anything apart.

How did you check the transmission oil? Keep in mind that any particulates or chunks would settle to the bottom so you won't get the whole picture with the "finger dipstick" test.
 
#11 ·
I just pulled the fill plug out of the transmission and plenty of fluid came out. Much more than I was prepared for with my single measly shop towel.
Yeah, tomorrow I'm going to drain what's left in it and I'll check for metal. Would be surprised if I don't find some with the grinding that's been going on recently. It must have an old leak from somewhere that doesn't leak anymore due to the low fluid. It's definitely ver greasy under there, especially near the rear output shaft.
 
#13 ·
Already fixed that billiebob, it was the inner rubber boot that was bunched up, I'm assuming because of the body lift.

I drained the fluid today, what was left of it. Probably two table spoons came out, deep purple in color and burnt smelling for sure. Not metal on the drain plugs, but I stuck my finger in a pulled out some very small curly pieces of aluminum. I wonder id the chain is scraping along the case on the inside.
 
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