Clunking/Popping On Left Front Going Into 1st Gear

tjmorton

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Jul 19, 2020
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Fort Worth, TX
Hello all, back after almost exactly 1yr with a new problem with my 4 angry squirrels build.

Before I get started however I'd like to thank you guys for being my go to resource while I've been working on my TJ. The information and knowledge on this forum is incredible.

So, I'm currently getting a clunking, sometimes popping, sound coming from the front left or left center when taking off from a dead stop into first gear (5 speed M). It only happens from a dead stop, only in 1st gear and is gone as soon as the clutch is let out. Sometimes it sounds like its suspension/steering, sometimes it sounds like driveline and occasional I can feel a little something under my feet. I've read through some threads about similar issues but none that appeared to have a resolution.

The issue only started happening after completing the following mods.... Bds 3in lift, adjustable control arms all around, adjustable front/rear track bars, ZJ steering upgrade, sye and cv rear drive shaft.

I've spent 2 days crawling around under the Jeep check bolts, joints etc. and everything looks good. I'm at a loss trying to figure out how to trouble shoot further, hoping you all have some suggestions. It's very disappointing because I was going to take the upgraded rig out wheeling this weekend for the 1st time since I started working on it and now think I should probably resolve this issue first. Oh well.
 
Crossmember/ skid bolts into nutserts can look tight and be loose... I found one once because I had my hand on it shaking something else-

check those, the control arm ends on the left, the front left hub u joint , then if no luck pull the front shaft.
 
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Crossmember/ skid bolts into nutserts can look tight and be loose... I found one once because I had my hand on it shaking something else-

check those, the control arm ends on the left, the front left hub u joint , then if no luck pull the front shaft.
Thanks Andy.

Let me get your thoughts on this..... I initially wondered about it possibly being the transfer case skid plate or maybe even a trans mount. I did support the transmission with a jack stand when I did the sye but when I put the skid plate back the transmission had sagged quite a bit more then I thought. I had to use a floor jack to push everything back up in order to be able to get all the plate bolts to go back in. I'm wondering if the trans sagging could have stressed some mounts or something else? The skid plate itself is solid, doesn't move at all at this point. With the noise only coming while taking off in 1st gear I eliminated a trans/mount issue in my mind but maybe I need to revisit that idea?
 
Thanks Andy.

Let me get your thoughts on this..... I initially wondered about it possibly being the transfer case skid plate or maybe even a trans mount. I did support the transmission with a jack stand when I did the sye but when I put the skid plate back the transmission had sagged quite a bit more then I thought. I had to use a floor jack to push everything back up in order to be able to get all the plate bolts to go back in. I'm wondering if the trans sagging could have stressed some mounts or something else? The skid plate itself is solid, doesn't move at all at this point. With the noise only coming while taking off in 1st gear I eliminated a trans/mount issue in my mind but maybe I need to revisit that idea?

Not sure....Spray wd 40 on the mount bolts and skid tank to frame, if it quietens down that tells you where to focus.
 
if all that fails pop that diff cover off sounds like the start of some busted spider gears.
Thanks Jeff. I'm having it regeared to 4.88 next week at a local off road shop so hopefully that will resolve any potential gear issues. At this point in my Jeep experience gears are still a little alien to me. I'm learning as I go but not confident in what to look for if I pull the diff cover.
 
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This exact thing started happening to me last week, I'm curious to see what the solution is.
Once I figure it out I'll let you know. Every other issue i've had with the Jeep since I bought it last summer has been a fairly simple fix or at least had an obvious fix. Hoping this is as well. I think the fact that I'm having it re geared next week will eliminate a number of variables. We shall see.
 
Once I figure it out I'll let you know. Every other issue i've had with the Jeep since I bought it last summer has been a fairly simple fix or at least had an obvious fix. Hoping this is as well. I think the fact that I'm having it re geared next week will eliminate a number of variables. We shall see.
Definitely, I haven’t had too much time to investigate myself but I’m hoping it’s not something bigger like the clutch
 
Once I figure it out I'll let you know. Every other issue i've had with the Jeep since I bought it last summer has been a fairly simple fix or at least had an obvious fix. Hoping this is as well. I think the fact that I'm having it re geared next week will eliminate a number of variables. We shall see.
Any luck figuring this one out?
 
Not yet. Jeep is still at the offroad shop for the regear. Been there going on 4 weeks now, was supposed to be there 1 week. Various parts issues and delays with other jobs in the shop per the guys. It's a little frustrating but it's not my daily driver and I don't want them to rush it out so I wait....
 
Finally got the Jeep back yesterday. Drove it around quite a bit today. Popping/clunking noise is gone. Along with the regear the shop also replaced the rear spider gears. Shop said the rear spider gears were in pretty bad shape. I had them double check my steering/suspension/driveshaft work and they did have to adjust the rear driveshaft angle a bit as well. Jeffseven777 mentioned possible spider gears being the issue, I think he was probably right.

On a side note.... the regear is probably the best money i've spent on the Jeep thus far. Wow what a difference. Should have done that first instead of last.
 
Interesting find because I just pulled the rear diff cover off my Jeep last weekend and four spider gear teeth fell right out. Oddly similar situations🤔
Anyway so I’m working on my own re-gear my self. What gear ratio and tire size are you running now?
 
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I went to 4.88 from the stock 4.10. Running 33x12.5x15 Toyo OC M/Ts. The difference in 1st - 3rd is night and day. Also, had the Jeep in 5th for the first time since I bought it a year ago. Still quite a bit of down shifting from 5th to 4th on the highway but once up to highway speed 5th is now usable as long as I don't hit a big hill. Bought the Jeep with the intention to use it as an around town weekender and hunting/fishing rig. It won't see a lot of highway action but it's about a 2hr drive to my "spots" before I get off pavement so that drive just got a lot less stressful and now my F150 can get some R&R on the weekends.

Good luck with your regear. Let us know how it turns out.
 
Finally got the Jeep back yesterday. Drove it around quite a bit today. Popping/clunking noise is gone. Along with the regear the shop also replaced the rear spider gears. Shop said the rear spider gears were in pretty bad shape. I had them double check my steering/suspension/driveshaft work and they did have to adjust the rear driveshaft angle a bit as well. Jeffseven777 mentioned possible spider gears being the issue, I think he was probably right.

On a side note.... the regear is probably the best money i've spent on the Jeep thus far. Wow what a difference. Should have done that first instead of last.
YEA 3 dana 35 stock gear sets i have gone through i can hear spider gears miles away.
 
YEA 3 dana 35 stock gear sets i have gone through i can hear spider gears miles away.

Thanks for the input Jeff, learning as I go so this type of info is gold to me. Are spider gears failing a common issue with the dana 35? Any suggestion on how often I should check them or do you just wait to hear the noise? Also, any suggestions on a specific brand of gears to buy or upgrade options that have worked for you?
 
So, the clunk/pop came back, or more likely, never went away. Noticed it again day 2 after getting the Jeep back from the regear. Wanted to wait a little bit to update this post in case I was able to chase it down. Alas, no luck so far.

I went through the suspension/steering and made sure everything was tight. No issues there. At this point I'm thinking its ball joints, u joints or trans/engine mounts.

I'm fairly certain the front ball joints and u joints have never been service in 116k miles so I'm starting there. Got all new Spicer joints for the front and will tackle that here in the next week or so. I'll update after thats done.
 
I just got my Jeep back On The road after a total Dana 35 rebuild with re gear with locker and a total Dana 30 rebuild with ball joints, re gear, lunch box etc basically and thing that moves on the axles I replaced or serviced.
I did notice once it was back on the road, from starts if I punch the gas it shakes and shimmys all they way up through the stick shift.
I’m thinking mounts, either transmission or motor. I’m not sure if the transfer case has a mount or not.
 
I just got my Jeep back On The road after a total Dana 35 rebuild with re gear with locker and a total Dana 30 rebuild with ball joints, re gear, lunch box etc basically and thing that moves on the axles I replaced or serviced.
I did notice once it was back on the road, from starts if I punch the gas it shakes and shimmys all they way up through the stick shift.
I’m thinking mounts, either transmission or motor. I’m not sure if the transfer case has a mount or not.

The noise being mount related makes a lot of sense to me. Took the Jeep on a road trip last weekend to do some wheeling and while sitting in some stop and go traffic I noticed that I heard the noise anytime the Jeep rocked forward like when coasting in traffic, then accelerating, then coasting. The fact that I first noticed the noise when I reinstalled the trans case skid plate after putting in the sye and new rear drive shaft also seems to suggest that it could be the trans mount. I'm going to drop the trans case skid plate when I do the front drive shaft u joints so will just replace the trans mount at that time since it'll be accessible. This noise is driving me nuts so hopefully one of these things fixes it.
 
Check transfer case linkage bushings near the shift lever. You can get under the jeep and move things around a little by hand to see if you're getting any pops or clunks from there. If this is the issue, it seems like a minor thing when you're underneath but since it's mounted to the tub you can feel it in the seat and under your feet. The cable shifter fix is heralded as the best option but for $15 you can replace the bushings and see if the noise comes back. I smear some grease on all the bushings and the issue went away for about a week so that's how I diagnosed it when I had this issue.

Also if your lift has adjustable arms, make sure the lock nuts on the control arm length adjustments are on as tight as they can go. Even if those nuts don't feel loose they can be just loose enough to let the arm flex and it feels like something popping. If you don't have adjustable arms check your control arm bushings and tighten the bolts mounting the control arms. Check front axle u joints.

Try the simple, cheap stuff first. It can drive you crazy assuming it's all the terrible things that cost the most money but a lot of times it's a quick easy fix.