Strange vibration at lower speeds

[mr cribb]

I know this is a long shot but here's my question:

I have noticed a vibration between 25-40 mph. (2nd & 3rd gears) I have noticed this vibration over the course of the last 3-5 days.

I know that it could be any of the following:

Tire, u-joints, or worn out suspension parts.

My front suspension is in dire need of everything needing replaced tie rods/ drag links and shocks. I'm just really broke right now...

The vibration isn't absolutely horrible just annoying. It kinda feels more like the LF tire, but I'm unsure(hence why I'm asking here).

I can feel the vibration through the steering wheel and the dash kinda shakes.

Could this possibly be the transmission mount? I know anything is possible, I would like to try and narrow it down.

Anyone could you please point me in the general area, and if you need more info, I will do my best to give it to you.

 

[©H®I$]

Does it shake when you start accelerating? If so, then its probably your spark plugs.

 

[Roadrunner777]

I guess you have already thought of these things...

Tire, rotate front to back and see if it changes. While you are there, spin the tire and feel/listen for bearing issues.

U-Joints... roll under and give the driveshaft a twist.

Motor/trans mounts, pretty much visual inspection.

I think this might be why they bolt the big hunks of metal on the transfer case and rear diff.

 

[mr cribb]

Nope perfect idle.... Plugs and wires have 7500 mi on them... Both are motorcraft parts.

I haven't rotated my tires yet... U joints looked okay when I replaced my clutch 3k mi ago.

I know I need to do my front brakes cause my rotors are grooved, and the rears are getting to the point of taking more effort to hold for the parking brake.

I'm gonna look to see if there's a bubble or similar on the front tires.

Its just strange cause it is from 25 to right at about 45 mph. Then it goes away.

 

[mr cribb]

Well I checked for tire bubbles... None
Checked u-joints and there isn't any excessive play, they're still relatively tight.
So maybe it is a wheel bearing.

I haven't rotated the tires yet. I should be able to get to that this weekend.

 

[MrQ]

Is the vibration when you are braking or accelerating? If its during braking then its possibly a warped rotor.The other possibility when accelerating is that it could be bad engine mounts and yes possibly tranny mount.

 

[mr cribb]

It is only during acceleration.... More pronounced when going up hill vs level surface.

I mentioned trans mount earlier cause I had noticed some binding issues when trying to shift a couple of times and read on here that leaking fluid on the trans mount could deteriorate the rubber mount.

 

[MrQ]

Sounds like one of those three mounts aor possibly all of them. IIRC between 25-40mph is 2nd gear and is when the engine reaches its higher rpm range, so it stands to reason more vibration would be felt. Anyways, my $0.02.

 

[Roadrunner777]

This does sound like a resonance thing. I have had tires do this... the one thing to figure out is if you can duplicate it in different gears, i.e. is it really linked to speed or rpm. That will tell you if it is before or after the driveshaft.

 

[FIND]

I'd check balljoints as well

 

[mr cribb]

I have a question.... what is IIRC? I have seen it in this forum a multitude of times.

As far as higher rpm goes, my truck rarely sees anything more than 2500 rpms. I had it 3500 rpm once just to get out in front of traffic.

Most of my shifting occurs between 18-2200 rpm. (I like the idea of saving as much gas as possible, and not destroying my mode of transportation)

As far as replicating the action in a different gear.... if I use 1/4 throttle & shifting near the same rpms the vibration isn't as pronounced.

I found it more pronounced between 1/4-1/2 throttle.

 

[mr cribb]

I'd check balljoints as well

This wouldn't surprise me at all... If you saw my front end you'd probably pass out from the lack of maintenance done to it.

I'm trying to limp it along until taxes can be filed (I do mine about as early as legally possible) then I'm gonna try to sweet talk the wifey into letting me replace the worn out stuff.

 

[MrQ]

IIRC stands for "If I Remember Correctly." It sounds like the faster you accelerate the worse the problem which still leaves us with the big question of the bad front end, ball joints especially, or your engine and trans mounts. It's really hard to nail this one down without being there in person.

 

[mr cribb]

I get paid next week so I think I'm gonna start with the easier and cheaper stuff first. The trans mount and u-joints. Mount is $20 u-joints (last I knew) are $10 each.

I've only ever put motor mounts on the army humvees 6.2/6.5's when I did engine replacements.... So I'm not familiar with the difficulty level in which the explorer will require. I mean I got the jist of how its accomplished, just haven't done it in a long while.

Any insight on degree of difficulty is appreciated. Keep in mind I'm 2wd so I don't have a front pumpkin to deal with.

 

[FIND]

Don't start replacing things until you know what is bad. Why would you want to spend $40 you could save to fix the real problem? Balljoints are really easy to check. Jack up your truck so your wheels are slightly off the ground then grip firmly at the top and bottom of the wheel and try and rock it in and out from the top and bottom. Take a crow bar and place it under the tire, try and lift the tire using your crowbar. If the steering knuckle moves independently of the suspension at all, you need balljoints. Balljoints can and will cause a vibration at speeds EXACTLY like you described, often times a vibration or pulling to one side on braking as well, but not necessarily. Generally speaking with motor or transmission mounts, I have usually found they are at higher speeds, but lower speeds aren't far out of the ordinary either.

The mounts are easy to replace though. The transmission mount, you take off a couple 15mm nuts from the mount to the tranny, then take the two bolts and nuts out that hold the crossmember above the inside of the frame rail. Next, support your transmission with a jackstand or tranny jack and take out the three nuts that hold three bolts that are captured on a small plate holding the crossmember on the side of the other frame rail. Once you have all that out, you can drop the crossmember and change the mount.

Changing motor mounts isn't hard either. Get a cherry picker to support the engine, unbolt the mounts, lift the engine slightly, remove the mounts and replace.

Easier than a Humvee. Well, same process for motor mounts, just less mass.

 

[mr cribb]

FIND: You make a very valid point.... The trans mount has been causing a minor binding issue when shifting, so irregardless that'll get changed out. I was contemplating the u-joints cause if most of the stuff I've found so far has over 200k I would guess the u-joints are factory as well.

I'd never thought the ball joints would cause that kind of grief. I will definitely give that a good look.

 

[Roadrunner777]

That's good to know. I'm doing ball joints next week (and radius arm bushings tommorow). I can feel the sore muscles already! But, it will be good to have them done and out of mind, hopefully before snow.

Well, anyways, good luck with the vibes, I would still rotate that tire and see if it does anything.

 

[FIND]

Well, anyways, good luck with the vibes, I would still rotate that tire and see if it does anything.

Yeah, start with the free stuff.

 

[FIND]

FIND: You make a very valid point.... The trans mount has been causing a minor binding issue when shifting, so irregardless that'll get changed out. I was contemplating the u-joints cause if most of the stuff I've found so far has over 200k I would guess the u-joints are factory as well.

I'd never thought the ball joints would cause that kind of grief. I will definitely give that a good look.

Oh, you have a manual...... I don't know if the mounts are the same on them....

Binding with shifting? You sure that is the mount causing that? Lots of things can cause that..... It is pretty easy to diagnose if the mount is bad. If it is broken, it is bad, if it isn't broken, it is good.

 

[mr cribb]

Oh, you have a manual...... I don't know if the mounts are the same on them....

Binding with shifting? You sure that is the mount causing that? Lots of things can cause that..... It is pretty easy to diagnose if the mount is bad. If it is broken, it is bad, if it isn't broken, it is good.

According to the parts stores... a 2wd auto mount is the same as a 2wd manual mount. None of the stores had a listing for a manual trans mount for an Explorer, so I told them to look up a 92 ranger, then cross reference the part number. I then got my information that I just mentioned.

I did notice some vibration at 55mph in 5th gear, tach turning 11-1200rpm (guessing). It only did it at this speed while going up hill. If I down shifted to 4th @ 55mph vibration went away. Then I got it between 60-65 shifted to 5th no vibration.

As far as the binding goes it isn't so much a struggle to get it in gear as it's very quick to come out when I press the clutch (keep in mind this is go up a heck of a hill). I have only noticed this problem maybe less than 5 times.

I lean towards a bad mount, because I had an eclipse one time that was missing a trans mount, and caused all kinds of havoc.

Are we sure that U-joints wouldn't be a problem.... again I know ANYTHING is possible.... I'm under the impression that everything EXCEPT: all the fluids, spark plugs, spark plug wires, clutch kit and slave cylinder, water pump, radiator and hoses, heater core, and serpentine belt; all have over 200k miles.