I am getting this low humming/strumming type noise that seems to be coming from the front end no farther back than the transfer case. It will make the noise for 1-2 seconds fade away for about 1 second and come right back. Very rhythmic. Any chance this is as simple as my front driveshaft? It seems most pronounced at 80MPH. It is louder with throttle but also does it coasting downhill. I'm going to remove it and see if the problem goes away but at that point I still figure it could be the driveshaft or transfer case. I had the transfer case open last month to install SYE and didn't see anything really wrong with it. I guess it could also be the transmission or exhaust (flowmaster that could be replaced) but I'm not really sure how to narrow this down.
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low humming strumming type noise from front end?
- Thread starter md21722
- Start date
Talyn
NAXJA Forum User
- Location
- Radford, Communistwealth of Virginia
Could be the drive shaft, could be pinon bearings.
When rebuilding the driveshaft, if you switch from the sealed to grease able centering yolk should it be rebalanced? Should it be rebalanced anyway after rebuilding? Trying to decide if I should do this myself for $115 in parts or so, or take it to a shop, or just replace with a TW shaft and have a spare.
With the front driveshaft removed, the rhythmic strumming at 80MPH has gone away and has been replaced by another vibration at 80MPH only on heavy throttle such as climbing a hill. This one feels more like its whole vehicle or possibly rearward. While investigating I found that the axles seem to run around 110F, transmission around 135F and transfer case around 180F. I am not sure if the transfer case should be the hottest, but it is right next to the catalytic converter and it is aluminum.
x-jay vision
NAXJA Forum User
- Location
- Albuquerque, NM
Re: Re: low humming strumming type noise from front end?
FWIW I just bought a brand new custom length front shaft from Driveshafts Direct for 200. It is great quality, though time will tell how it holds up.
Talyn
NAXJA Forum User
- Location
- Radford, Communistwealth of Virginia
Is your rear axle shimmed to point the pinion a degree or two below the driveshaft?
Yes its 2 degrees below.
I have the Tom Wood's 242HD SYE and driveshaft setup. Put on about 2,000-2,500 miles ago.
Driveshaft is 13.5 and pinion is 11.5.
Using 4 degree RE steel shims bolted to the spring pack with the centering pin.
Only thing in the suspension I haven't replaced is the control arms whose bushings. I am not sure if the bushings would cause this problem. By the looks of it they could be changed. I could have the tires rebalanced as well. They are BFG A/T 30x9.5x15 that I put on about 2,000 miles ago. Never really noticed any problems until this weekend when I was halfway through a 650 mile trip. No off roading on that trip. Last weekend I went on a 500 mile trip and didn't notice any issues. I could be that the additional miles have caused some wear in a component.
I have the Tom Wood's 242HD SYE and driveshaft setup. Put on about 2,000-2,500 miles ago.
Driveshaft is 13.5 and pinion is 11.5.
Using 4 degree RE steel shims bolted to the spring pack with the centering pin.
Only thing in the suspension I haven't replaced is the control arms whose bushings. I am not sure if the bushings would cause this problem. By the looks of it they could be changed. I could have the tires rebalanced as well. They are BFG A/T 30x9.5x15 that I put on about 2,000 miles ago. Never really noticed any problems until this weekend when I was halfway through a 650 mile trip. No off roading on that trip. Last weekend I went on a 500 mile trip and didn't notice any issues. I could be that the additional miles have caused some wear in a component.
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I've decided to rebuild my front driveshaft. If it doesn't go well, I may have a local driveline shop do it, or buy another shaft. To rebuild, the parts cost me $105.19.
3 x Spicer 5-1310X non-greaseable u-joints
1 x Spicer 211544X non-greaseable centering flange
1 x Spicer 286418 seal for non-greaseable centering flange
I decided to buy the entire centering flange rather than the ball replacement kit that would go inside it. They were neck in neck for cost and replacing the entire flange seemed easier.
I also changed the toe-in to 1/8" from 0-1/16". I'm not sure if that will help.
Right now I'm working on dropping the tank to change the fuel module. It has the classic symptoms of bad check valve(s) and twice now the Jeep has cut out for a split second for no known reason.
I should know more by the end of the week.
I do know that sometimes warn suspension parts can cause vibrations at certain speeds. Before I changed the ball joints I would get a vibration around 52-54MPH. It was a bit worse when I had the original steering and hubs but not gone until I changed those ball joints. So I still wonder if something like the control arms may fix the 80MPH vibration.
I ordered new bushings for the axle.
This jeep has a 2.5-3" lift and by the tables I would do better with an extra 1/4" on LCA. It seems like the IRO control arms are SIGNIFICANTLY cheaper than that JKS arms which look nearly identical (except for the JKS sticker). What gives? Is there any reason to buy the JKS?
3 x Spicer 5-1310X non-greaseable u-joints
1 x Spicer 211544X non-greaseable centering flange
1 x Spicer 286418 seal for non-greaseable centering flange
I decided to buy the entire centering flange rather than the ball replacement kit that would go inside it. They were neck in neck for cost and replacing the entire flange seemed easier.
I also changed the toe-in to 1/8" from 0-1/16". I'm not sure if that will help.
Right now I'm working on dropping the tank to change the fuel module. It has the classic symptoms of bad check valve(s) and twice now the Jeep has cut out for a split second for no known reason.
I should know more by the end of the week.
I do know that sometimes warn suspension parts can cause vibrations at certain speeds. Before I changed the ball joints I would get a vibration around 52-54MPH. It was a bit worse when I had the original steering and hubs but not gone until I changed those ball joints. So I still wonder if something like the control arms may fix the 80MPH vibration.
I ordered new bushings for the axle.
This jeep has a 2.5-3" lift and by the tables I would do better with an extra 1/4" on LCA. It seems like the IRO control arms are SIGNIFICANTLY cheaper than that JKS arms which look nearly identical (except for the JKS sticker). What gives? Is there any reason to buy the JKS?
I rebuilt the double cardan front driveshaft last night. It was easier than I had expected. A day or two ago I put Kroil on all of the u-joint caps and let it soak. I used the hammer and socket method to drive the ball joint caps off. The flange holding the centering ball had no grease left in it. Rather than try to use a hammer and socket to drive the u-joint caps back, I used my ball joint press which made short work of it. The Spicer centering flange came with a new spring.
Well I still get a noise even after rebuilding the front shaft and adjusting the linkage. Happens around 72-80MPH. I've not had a noise like this before, where it comes in and fades out and repeats continuously. I guess I'll pull driveshafts and see if I can change the noise. I hope it's an easy fix and not the axles.
I lifted the front end to check for any looseness. If I put a pry bar under the axle u-joint caps, I get up and down play on the axle shaft (not the stub shaft that goes into the hub). The drivers side has more play than the passenger side. The play can easily be seen by the eye.
This does not seem right to me but I don't have much experience in this area.
Is this play normal or should I be replacing these u-joints?
It seems unusual because they are Spicer 5-760X with about 3000-4000 miles on them. The c-clips are still there.
This does not seem right to me but I don't have much experience in this area.
Is this play normal or should I be replacing these u-joints?
It seems unusual because they are Spicer 5-760X with about 3000-4000 miles on them. The c-clips are still there.
Talyn
NAXJA Forum User
- Location
- Radford, Communistwealth of Virginia
U-joints are worn. They should be tight. Count the ears on the shaft be stretched apart?
On second thought, if the ears were "close" wouldn't they straighten out when the caps were put in? I mean, how would it all go back together if the ears were too bent? There shouldn't be enough clearance unless needle bearings were missing and even then I'm not sure it would work..
As it turned out, on both sides, it looks like one of the clips never made it all the way in. On the drivers side, I was able to replace the u-joint and get everything back together fine. On the passenger side side, the ear was bent in and the clip would never fit unless the ears were spread apart. I replaced the passenger side axle shaft. Now there is no play.
With the axle shaft u-joints all good, there are no more vibes. I still get the fail low humming/strumming type noise that comes and goes about once a second from around 65-80. Haven't tried going to very high speed to see if it stops. I did notice that curves and bumps can affect it some. Acceleration or deceleration have zero impact. I don't think its wheel bearings as they are really new SKF torqued properly and the wheels don't rock back and forth.
I think the problem may be the front output shaft pilot bearing in the transfer case. If I put my hand on the yolk and move I can always get a good solid clunk (my 01 XJ with the 231 does this too) but I think this one has more play and I can't make out any play in any other parts of the front driveline. I also get some clunks going over bumps. I can't help but wonder if that's the driveshaft. I used to think it was the exhaust hangers being a bit loose but now I wonder if its both.
When I bought this Jeep it had a budget boost with stock track bar. When I put the adjustable track bar in I had to shift the axle over 3/8" of an inch. I wonder if the old bearings could have had a wear pattern for when the axle was off center.
I think the problem may be the front output shaft pilot bearing in the transfer case. If I put my hand on the yolk and move I can always get a good solid clunk (my 01 XJ with the 231 does this too) but I think this one has more play and I can't make out any play in any other parts of the front driveline. I also get some clunks going over bumps. I can't help but wonder if that's the driveshaft. I used to think it was the exhaust hangers being a bit loose but now I wonder if its both.
When I bought this Jeep it had a budget boost with stock track bar. When I put the adjustable track bar in I had to shift the axle over 3/8" of an inch. I wonder if the old bearings could have had a wear pattern for when the axle was off center.
I can't feel any roughness in the front pinion or the wheel bearings. I put a Torqometer on the front pinion and turned it and it feels smooth as glass. I put my fingers on the coil springs while turning the tires and can't feel anything there either.
When I take it out of OD and run it in 3rd the hum is still there, so I don't think its engine or transmission pump/fluid related. The transmission only has one pump and its engine RPM driven right? If the pump was driven off the output shaft I could see where it may be transmission related.
Once I put the transfer case back together if the noise persists I'll take a second look at the front driveshaft and tires.
When I take it out of OD and run it in 3rd the hum is still there, so I don't think its engine or transmission pump/fluid related. The transmission only has one pump and its engine RPM driven right? If the pump was driven off the output shaft I could see where it may be transmission related.
Once I put the transfer case back together if the noise persists I'll take a second look at the front driveshaft and tires.
Results of more investigation:
Lifting the front end off the ground and turning the pinion yolk with a Torqometer (hollow, so it readily transmits vibrations)- The Dana 30 is smooth as glass
Lifting the rear end off the ground and turning the pinion yolk with a Torqometer, roughness similar to the 8.25 i removed for noise starting around 20-25 MPH. I remember it being smooth as glass when I put it in a few thousand miles ago.
Lifting the front end off the ground and turning the pinion yolk with a Torqometer (hollow, so it readily transmits vibrations)- The Dana 30 is smooth as glass
Lifting the rear end off the ground and turning the pinion yolk with a Torqometer, roughness similar to the 8.25 i removed for noise starting around 20-25 MPH. I remember it being smooth as glass when I put it in a few thousand miles ago.
mikerhyne
NAXJA Member # 1375
- Location
- Aurora, CO
This is a good thread as I'm tracking down similar sounding noises. I have a high speed vibration that oscillates that reminds me of yours. As well as noise at pretty much any speed only under power.
I have done an SYE, tcase rebuild, new rear shaft, rebuilt front shaft, new rear leafs and shackles, adjusted my exhaust hangers to make sure it's not vibrating against the leaf. I did have it re-geared a while back and suspect that is part of my noise.
At this point I just bought some used "street" tires since my MTRs make so much noise I can't easily figure out where the other noises are coming from. I suspect I have rear end issues but may have more going on too.
I have done an SYE, tcase rebuild, new rear shaft, rebuilt front shaft, new rear leafs and shackles, adjusted my exhaust hangers to make sure it's not vibrating against the leaf. I did have it re-geared a while back and suspect that is part of my noise.
At this point I just bought some used "street" tires since my MTRs make so much noise I can't easily figure out where the other noises are coming from. I suspect I have rear end issues but may have more going on too.
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