Vibration getting worse

[bearcrawl]

I am getting a pretty bad vibration while coasting. Accelerating, fine. All the way off the throttle is fine. Coasting while just touching the throttle I am getting a pretty loud and fairly violent vibration. Could be the U-joints I guess. Seems to be coming from the rear of the truck (88' lla). How do I check the U-joints. Just installed Parabolics and that made the vibration worse.

[SafeAirOne]

How do I check the U-joints.

I'd chock the wheels, put the transmission in neutral and get under there and yank the driveshaft this way and that way near each universal joint and look for excessive movement.

[I Leak Oil]

The U-joints shouldn't have any play in them. As suggested, give them a push/pull test. Also, make sure the bolts holding the shaft to the transfer case and diff pinion flange are tight. Check the driveshaft slip joint for excessive movement also. Slim chance it could be the axle drive flanges are loose, pinion nut loose or transfer case output flange is loose.
Be safe a chock the wheels while doing this...
Jason T.

[adkrover]

I'm guessing the parabolics only accentuate the vibration because they are more flexible, they are allowing the rear end to transfer more vibration to the frame so you feel it more. It's unlikely that the spring job actually made it worse, you're just able to hear and feel it more now. Since it's not there under load (either positive or negative load) it must be in the drivetrain so if it's not the U joint, then check everything for play from the back of the transfer case all the way through the rear axle to the hubs. Could definitely be a more major problem with the ring and pinion. Drain the rear end and look for metal fleck in the oil.

[bearcrawl]

Went to town on the rear driveshaft. Everything seem nice and tight. all the bolt are there and tight. Could it be the ring and pinion?

[bearcrawl]

Very interesting new development. Pulled the fill plug from diff and had suction or vacuum. Could that be the culprit? Going to mess with the breather.

[scott]

have you drained it? use a paper coffee filter. i hope you find nothing metalic in there

[BackInA88]

I am getting a pretty bad vibration while coasting. Accelerating, fine. All the way off the throttle is fine. Coasting while just touching the throttle I am getting a pretty loud and fairly violent vibration. Could be the U-joints I guess. Seems to be coming from the rear of the truck (88' lla). How do I check the U-joints. Just installed Parabolics and that made the vibration worse.

Don't parabolics come with tapered shims to correct the pinion angle since they do lift the rig?
Have you tried pulling the rear drive shaft and just running on the front?
Did you check the flange nut in the center of the e-brake under where the drive shaft flange bolts up as Jason suggested?
Transmission mounts OK? Get a prybar and made sure they haven't separated.
If you take the drive shaft out use and angle finder level and check the mounting flanges at the trans and the diff, they should be the same or at least with in a few degrees.

Are the u-joints clocked correctly? The caps should be in-line front to rear.

Steve

[bearcrawl]

pulled rear prop shaft. Vibe still there. Really hoping trans mount is busted. Could this be a gearbox problem?
Checked flange nut in middle of brake under drive shaft. Tight and looked new.
Thanks for all the help guys

[SafeAirOne]

Don't forget the front shaft--It spins when you dirve too (unless you have front locking hubs and they're disengaged).

[bearcrawl]

Yep, got locking hubs.
thanks

[adkrover]

So if your saying you drove the truck on the front axle with no rear drive shaft and it still had the same noise, plus the vibration changed from loaded to non loaded as far as coasting vs. pulling, then it can't be in the rear axle. Without the rear driveshaft, the rear axle is in coast only mode and the throttle position should have no effect. You should do the same experiment with the rear shaft installed and the front shaft removed. Then you'll know it's not actually happening in the front axle. If it still happens when driving with rear axle only, it would have to be in the gearbox or engine.

[bearcrawl]

After a bit more research I have a feeling it might be my Fairey. Getting real bad now.

[SafeAirOne]

After a bit more research I have a feeling it might be my Fairey. Getting real bad now.

That doesn't sound cheap! :(

[I Leak Oil]

You may want to remove the OD and check the main shaft nut! If this is loose it can cause all sorts of noises.
Jason T.

[bearcrawl]

Jason, you are the man. Pulled O/D off and found no Main Shaft nut at all. Atleast thats what I think I am seeing.

http://i136.photobucket.com/albums/q163/rldahllof/IMG_2001.jpg

In fact when I pulled off the o/d the lock washer was flopping around. Where the hell did the main shaft bolt go? Guess I will have to take off the case bottom and see if it's in there.

[SafeAirOne]

I'm CERTAINLY no authority, but looks like a nutless shaft to me. :sly:

[bearcrawl]

Opened up pan and no nut no place. Magic vanishing nut. Or magic previous owner. Either way I hope this solves the problem.
Thanks again guys http://i136.photobucket.com/albums/q163/rldahllof/IMG_2002.jpg

[I Leak Oil]

Never ceases to amaze me what people do to these things!
Jason T.

[sven]

Wow, thats nuts:p ...sorry


On that first pic, the splines look a little worn. You may wanna check the matching splines on the input shaft.

[BackInA88]

Are you sure it isn't inside the pocket in the overdrive?
Isn't there and undercut behind were the splines engage?

[daveb]

I was going to suggest that, it would have to be in there as there is no way for it to fall out.




Are you sure it isn't inside the pocket in the overdrive?
Isn't there and undercut behind were the splines engage?

[bearcrawl]

I cant find it anywhere.

[jp-]

PO probably left it out. Just buy a new nut (only a few bucks) and maybe a tool to install it (if they sell one???). I made my own istallation tool. One time use; I designed it so that it would fail at the exact correct torque.:)

By the way, good call Jason. (Were you the PO by chance?):D

[I Leak Oil]

By the way, good call Jason. (Were you the PO by chance?):D


Errr...umm...no speak english!? No not the PO but I did stay at a holiday inn express last night!
Jason T.

[adkrover]

Rover's North has the best price on the tool (just bought one) and Rover's Down South will have the nut if no one else does. I agree it must have never been there since it can't possibly have come off the shaft while the OD is installed.

[bearcrawl]

Nope not it. :mad: Running out of ideas. Thinking about exhaust rattle. Rattles a bit @ a stand still. Louder at 20mph. Louder yet @ 50mph. Volume changes with speed. Seems to vibrate @ similar RPMs regardless of speed.
Amazingly shifts much nicer now with the main shaft nut on.

[bearcrawl]

Pulled O/D off and drove it. Exact same. Now I am really pissed.:mad: Have no Idea where to look next :confused:

[ArlowCT]

A few questions to help me try and figure out this problem...
Have you tried pulling the front drive shaft?
Did you replace the shocks when you did the springs?
Did the shocks get new rubber bushings and are nice and tight?
These are just a few things that have given me problems over the years.

And I just have to ask... have you had the tires balanced lately?

[bearcrawl]

Yep, new shocks, new tires, pulled both drive shafts just pulled the rear for a second time. still out right now. going to replace all engine trans. mounts Monday although they don't seem to be too bad. I am willing to try bout anything.

[Daurie]

Can you get a C clamp in there and clamp the trans mount to the cross member? I cant remember off the top of my head if there is room but if you could get a clamp between there nice and tight. If one side is lifting under slight throttle making a small gap it could be the culprit. If you try it and it will fit, I'd tether said clamp off somehow just in case.

[jp-]

A few more things to check:

-Engine fan, make sure you're not missing a blade.
-Wheel bearings, make sure they are tight.
-Rear diff pinion nut, make sure it's tight.

[SafeAirOne]

You can't fix it if you cant isolate the source (of course). You might try to narrow down the source of the noise/vibration by having a competent person either 1) drive the rover while you sit in the back and determine if the problem is coming from the rear axle or 2) do it the other way around with a competent listener.

Also, and this may sound rediculous but it works, you might try getting a small length of garden hose, fixing one end so that it points at a suspected noise source and stick the other end in your ear while someone drives around. Keep doing this until you find the source. Of course this may be more difficult in our normally noisy rovers. Needless to say, make sure the length of hose isn't going to get snagged on any moving bits.

Might have someone drive it around while you look and listen through the (removed) access cover under the center seat also.

[thixon]

Also, and this may sound rediculous but it works, you might try getting a small length of garden hose, fixing one end so that it points at a suspected noise source and stick the other end in your ear while someone drives around. (removed) access cover under the center seat also.

Not ridiculous at all. I've done this for years to diagnose anything from bad bearing in engine parts to valve issues. Works great.

[bearcrawl]

Interesting new advice. I was ordering a few new gaskets and came across a new opinion. A fellow @ a parts supplier, not our hosts, is trying to convince me this noise is normal. Would any of you consider his noise normal. Again @ highway speed I am getting a pretty loud pretty violent vibe or rattle. Sounds like its coming from the t-case behind the parking brake. It happens when I feather the gas coasting. Applying no real load either pos or neg. Not the O/D. Neither diff. Replaced Transmission / engine mounts. Tight main shaft nut. Nut under prop shaft is good (both ends). Parking brake is in good working order, although, are there any parts in the P-Brake that could be responsible for this. Going to pull speedo and inspect now. Thanks again guys for all the help.

[Daurie]

What you're describing doesn't sound normal to me.

At the moment I'm putting my money on a transmission mount.

[bearcrawl]

replaced both, keep em comin.

[Momo]

Take your floor panels out and drive around. You might end up seeing the problem as well as getting a clearer earshot of it.

[Tim Smith]

Try grabbing the e-brake drum and wiggling it. I'm wondering if your output shaft is loose like mine was a few weeks ago or if the brake drum has somehow just made it's way loose.

Another thought. This one is a bit dangerous so use your head... Have you tried jacking up the rear on stands and spinning up the rear tires? I'm wondering if a wheel balance has fallen off and is just making the exhaust rattle along the frame somewhere. Just a thought but you really shouldn't notice anything with tire balancing until about 30 mph.

[Les Parker]

Is there any loss of trans fluid from the handbrake backing plate?
My thought is either the output shaft bearing in the t. box or the rear drive shaft is out of balance (taken that the u/j's have been checked and are in good order)

2p

[xsbowes]

What type of vibration does it sound like? Mechanical or maybe more like sheet metal. I was getting a loud vibration at idle and could not figure out where it was coming from. I thought it was the transfer case because of its territorial marking capability. After awhile of searching for the source I discovered it was coming from under the driver's seat (LHD), I pulled my seat and access cover, the vibration was from the fuel tank (military type which is normally empty). For some reason the extension tube and the top of the tank vibrate obnoxiously loud. I don't think the aux tank is original because the cap is not the same as the passenger side and it is not POR coated like the rest of the undercarriage. It's not as annoying as the mystery toe heater (feels like direct exhaust on my foot but only when I'm moving).

[adkrover]

Ok, I've followed this thread for some time now and I'm starting to thing its about time you accept the fact that your truck (and all series trucks) make NOISE! It's either that or you rebuild the entire vehicle so you can eliminate almost all possibilities. Almost all because even rebuilt parts can be defective or installed incorrectly and no matter what, it will never sound like a new suv.