LX450 rides rough when under load ?? Help (5 Viewers)

[SpeedyCycles]

I purchased this low mile LX450 (48k) with cosmetic damage. I took it driving today, and notice that as I went faster (60-80MPH), it felt rougher. The entire vehicle seemed to vibrate just a bit, so I thought it was just old, bad tires. Then I noticed if I would shift into Neutral, it seemed to slowly calm down.

It is nearly unnoticable at lower speeds, however I did notice that when I was accelerating, I could feel/hear it just a bit, but letting off the gas and letting it coast, it would go away.

Again, my initial impression was that it is a tire issue. However, when I shift into neutral, it goes away. Or when I reduce from accelarating to decel. Almost like an out of balance drive shaft.


Any help or input would be much appreciated.

Frank

 

[Beowulf]

Frank,

Could be several things including one of the propeller shafts. Could be a bad U-joint. Could be mud inside the wheels. Could be bad tyres.

Your best bet is to divide and conquer; meaning isolate the problem to the front or the back then go from there. Swap tyres front to back. Test. (You'll want the CDL switch.) Drop rear shaft. Test. Drop front shaft. Test.

Post back when you've isolated the problem to something we can give you advice on.

-B-

 

[Rich]

I'd second u-joints. Power on, power off shouldn't make a difference with tire balance. Torque difference between power on power off could make a difference with binding ujoints. Though, at 48K I wouldn't be expected u-joint problems. Was the cosmetic damage caused by a thrashing off road?

 

[NorCalDoug]

Sounds like a driveshaft issue.

Did you get it all put back together?

 

[e9999]

read thread on buzzy 80s?

 

[SpeedyCycles]

The cosmetic damage came from a crash. As I understand, the vehicle slid into a ditch and tore up the drivers side, mainly fender, doors, and rear 1/4 panel.

Yes Doug, it is back together and running (rough). The wife gets the surprise this evening after dinner

I did a search, and I did not find any threads, so could you please post "Buzzy's 80's" link?

Thanks,

Frank

 

[NorCalDoug]

Buzzy link:
https://forum.ih8mud.com/showthread.php?t=37079

 

[e9999]

as Doug said, but this sounds more serious than a mere buzz. Can you elaborate a bit more?

 

[SpeedyCycles]

I read thru the buzzy thread, a lot of off topic crap. It makes me feel better that mine is not the only one.

OK, this is the newest/ most accurate assessment:

It feels like I have big mudders on it. When I get up to 70, it's "brrrrRRRRrrrrRRRRR". I shift into "N" after about 5-8 seconds it goes away. I still cannot tell if it is because the speed gets down 10 MPH by then, or if it took that long for the Tranny and revs to drop.

Also, I noticed the transfer case looks to have oil marks. It has not dripped a drop that I can see, it almost looks like it is just sweating a little bit.

I am having the tires balanced tomorrow, and the wheels aligned. I don't think this will get rid of it, but hopefully cross that off the list of possibilities.

Frank

 

[Darwood]

Sounding like mudders makes me think of the driveshaft u-joints, especially with the throttle on, throttle off behavior. Try greasing them and see if that helps any.

 

[SpeedyCycles]

Would that be a reasonable solution if it only has 48k miles?

Also, is that as easy are getting under the vehicle and greasing them? IE, is the driveshaft exposed?

 

[sjcruiser]

SpeedyCycles

There would be one nipple on each side (of the axles) along with the ones on the slip yokes. I could put more details here but if you search, you'll find much more information as to how, what & where to grease them.

 

[Beowulf]

There would be one nipple on each side (of the axles) along with the ones on the slip yokes.

sj might have nipples but U-joints have zerks.

The U-joints (there are 4) have a grease zerk in the center of each. There is a U-joint on each end of both driveshafts. There are no zirks on the axles. Apply grease until the old, black grease squirts out of the grease seals.

The driveshaft slip yokes (there are 2, one on each ds) have a grease zerk at one end. Apply grease until the ds moves, then STOP.

-B-

 

[Darwood]

The driveshaft slip yokes (there are 2, one on each ds) have a grease zerk at one end. Apply grease until the ds moves, then STOP.

This is where I disagree. I say only apply a couple squirts into the the slip splines to get some grease in there. If you add grease till they move, you more than likely have filled the cavity full of grease which does not compress to well.

 

[MC80]

If it's not mechanical, try checking the spark plug wires.

 

[IdahoDoug]

Not to rain on your parade, but an extremely low mile vehicle for its age being sold with an unclear history of damage points to a salvage vehicle. It's typical for them to sit for a long time - years sometimes - before a shop somewhere decides to buy the wreck. Then more time to gather parts, then more time for an extensive repair. You end up with a car that's got low miles for its age when it's finally back on the road again.

I mention this because more severe damage might have included the front axle/diff being damaged, or the front drive shaft being removed to repair, etc. The front drive shaft should be OUT of phase where typically they're assembled IN phase. A repair shop might not know it and this could be your problem.

You should also do a better job of describing if its speed or torque related. Sound speed related as when you let off torque changed instantly but the sound continued for 5-8 seconds. Could also be a bent rim, a tire that briefly popped a bead during the crash and swallowed some water/gravel/sand that would make balancing impossible.

DougM

 

[SpeedyCycles]

Not to rain on your parade, but an extremely low mile vehicle for its age being sold with an unclear history of damage points to a salvage vehicle. It's typical for them to sit for a long time - years sometimes - before a shop somewhere decides to buy the wreck. Then more time to gather parts, then more time for an extensive repair. You end up with a car that's got low miles for its age when it's finally back on the road again.

I mention this because more severe damage might have included the front axle/diff being damaged, or the front drive shaft being removed to repair, etc. The front drive shaft should be OUT of phase where typically they're assembled IN phase. A repair shop might not know it and this could be your problem.

You should also do a better job of describing if its speed or torque related. Sound speed related as when you let off torque changed instantly but the sound continued for 5-8 seconds. Could also be a bent rim, a tire that briefly popped a bead during the crash and swallowed some water/gravel/sand that would make balancing impossible.

DougM

Thanks for the input Doug. You are exactly correct, the last service history on this vehicle was late 2001. A rebuilder purchased it, and did not complete the project prior to his death. I purchased it from the bank that was holding the note. So, yes, it has been stored indoors for 3.5 years ~.

I went down a long hill yesterday, since it would maintain speed better. I went about 80 MPH, and shut the vehicle off. The significant buzzz didn't go away until I reached about 65 MPH if that helps.

I will report back after the inspection and wheel alignment.

Thanks for the continued input.

Frank

 

[SpeedyCycles]

The wheel alignment did no good at all. We took it on a 300 mile trip this weekend. The vibration gets pretty loud between approx 65-75 MPH. If I could maintain 80 MPH, it got pretty quiet again.

Frank

 

[IdahoDoug]

Pull both front wheel center caps, the pry off the metal grease cap. Do you see grease there where the splined axle and the drive plate you pried the grease cap off of come together? If it's dry there then I suspect dry spindle bushings. More detail on that when you report back. No need to jack the vehicle - this is about a 1 minute per wheel check if you're not good prying off the grease cap. Use a hammer and small screwdriver to start, then immediately use the largest one you've got to hammer/pry its edge all the way around.

DougM

 

[fzj80kidpen]

You mean largest flat head screw driver to gently pry off
I went through a very aggrevating vibration issue like this that ended up being a best wheel. Dealer replaced my driveshaft with a new hardened driveshaft before finding the wheel. It was on there dime so no harm to be.
That was a 99 ford ranger though.
Good luck