L Series Vibration/Booming

Hello all I have a very annoying problem with my L Series Freelander which I am hoping someone on here can advise or has had a similar problem and cured it. I have a vibration/booming through the cabin which only occurs between 1600rpm and 1900rpm in 4th and 5th gears when there is a slight load on the engine (its slightly noticeable in 3rd gear).

To date I know its not the VCU or prop bearings as they are new, its also definitely not the tyres as all four are brand new michelin synchrone's which are balaced correctly.

To be honest I am pretty stumped as to what is causing this, my next line of thought is the front half shafts.

Anybody got any ideas?

Cheers peeps

Mick

This might help.....http://www.landyzone.co.uk/lz/f9/hammering-noise-when-under-power-67206.html

wow what a long thread and in the end it was a half shaft problem, interesting mine is not really a thuding noise though and it only happens in 3rd,4th,5th gear (barely noticeable in third) between 1500-2000rpm only so in high gears at low revs.

Been looking trying the find the cause of the booming I have through the car at 1500-2000rpm on my L series and it appears there should be a bracket on the exhaust front downpipe which is missing. Could this cause this type of problem? If I am light on the throttle going through 1500-2000rpm its ok but if I put my foot to the floor when going through 1500-2000rpm the booming through the cabin occurs.

removed the propshaft today, the booming/vibration between 1500-2000rpm is much less noticeable with the propshaft removed but it is still there (my interior mirror still shakes!). So that rules at the prop/uj's at least, i knew it wasnt the vcu or centre bearings anyway as they had been replaced not so long ago. Obviously something is transmitting the boom/vib along the prop making it more prominent when the prop is fitted. I will find the problem one day

So far you have done what I did. The prop is transmitting the vibration from the IRD to the front VC bearing, which then couples it into the floor pan. Check for backlash in your front driveshafts. It's one of them that is the cause.

A lot of people are telling me its likely to be the IRD but if the IRD was knackered surely it would be noisy which it isnt? Anyway as you say it is going to be a half shaft or IRD problem so going to try a half shaft first. Will try the n/s first and if the problem is still there will put the new half shaft on the o/s and if its still there. If it is then I suppose I will have to live with it or get a new IRD.

Its not your IRD as this would be noisy. One of your CV joints is out of balance. Check for the back lash, its the clue to which shaft is the problem. Godd luck.

Ok thanks for the advice matey, I will try a shaft and will let you know how I get on, will probably try the n/s one first as from reading on the forum this is one that gives the most problem. One thing I have noticed since removing the prop is that my brakes now squeal! Did this when I last removed the prop to have the viscous and centre bearings replaced, wierd!. Putting the prop back on tonight as I no its not the problem (+ the brake squeal will go), will make the vibration/boom worse but also makes it easier to no if the fault has gone when the half shaft is replaced if the prop is on.

The whole action of braking will be different with the prop removed. The front disks are more domanent so with the props on there will be brake action being transmitted back to the back axle. This will stop the car pitching forward so much. Now everything is behaving differently so you may be having to brake harder, or possibly lighter as a result, hence the squeal. Not really a problem though. It it annoys then put copper grease on the back of the brake pads, where the caliper contacts them. Obviously don't put it on the pads or disks . This normally stops the noise.

Prop back on now more squeaking brakes but booming worse again with the prop on. Got a driveshaft coming next week, spent today taking off the engine mounts and engine tie rods just in case they were knackered, looked ok, put them back on and on and obviously no different. How do I check the back lash of the driveshafts, might try this tomorrow?

Park on level ground, engine off, in first gear, handbrake on. Jack up on-side front wheel. Try and rotate the wheel back and forth, rock it. It won't go round as the transmission is locked. However you will be able to see and feel any rotational slack in the in-board drive shaft joint (CV). There is going to be a small amount of slack but if its very obvious then that is probably the cause of the noise. Next do the other front wheel and try again. Its seems it could be either shaft. Mine was the On-side one. You are still doing all the steps I followed. My garage changed the shaft and fixed the problem but they couldn't actually find anything wrong with the old shaft!! Good luck.

Brilliant, thanks for the advice, will try that tomorrow as feel I wasted time today as I was hoping to find the problem. I have read all 5 pages of your thread with your L series, when you describe hammering what do you mean, like a drone/resonance through the cabin, I cant really say mine is a hammering noise? Mine has a boom/drone through the cabin, vib through the seat between 1500-2000rpm, when above 2000rpm the booming/vibration goes. My problem does sound similar to your thread but I am intrigued with the hammering you describe. Mine, like yours is definitely RPM related and not engine speed related, at what rpm did you have your problem?

Absolutely convinced you have the same problem.

Checked for backlash this morning, both driveshafts felt exactly the same, small amount of slack in both. Will try driveshafts next weekend then after that all that is left is the IRD and rear diff.

one thing i have noticed today, when the vibration booming occurs between 1500-2000rpm, if i press the clutch in (whilst still in gear normally 3rd/4th) and keep the revs at between 1500-2000rpm then the booming/vibration goes. What does this point towards, any ideas?

It points towards the drivechain unloading. Your engine is fine. Mine did the same.

update, new front driveshafts fitted, still exactly the same.

Hell, thats a bummer!! and a lot of expense with no gain. You must be gutted. Really weird because it sounded like you are suffering the same symptoms. Having thought about it my symptoms appeared to be RPM related, in that at first I'm thinking big ends. As it turns out there is nothing wrong with the engine at all. With my Freelander the hammering was speed related and was worse around 40-50 MPH. Put foot on clutch and it stopped, even if the engine revs were held where they were. Slower or faster than this and it died away. Is this not what you are getting and yours is definately rev related?

As I discovered the vibration was everywhere and it was so difficult to pin it down to a particular component. You removing of the prop is suggesting it is in the front and it would have to be to be rev related.

Things that come to mind. Its engine rotation speed related when the car is in drive but doesn't do it if the clutch is disengaged. That would suggest the clutch / pressure pltae / flywheel are not the cause. It still sounds like the engine is solid. Does it still do it if you shift into neutral and let the clutch back up? If it does then that would suggest gearbox. Does it stop if you put light pressure on the clutch pedal so to load the release bearling but not disengage drive?. I can't see it would be the IRD as this is road speed related, not RPM related. There again I swore blind mine was engine related and it was a driveshaft.

Go for the obvious things first. Gearbox and IRD oil levels okay? You've checked the engine mounts, its not there. This is getting stupid. The next steps would seem to involve pulling the transmission out and thats a lot of work. Its got to be worth getting a second opinion on this by a good LR garage before getting the spanners out again. You've followed the logical course and haven't got the result. you need to be sure that you're going to get a result next time. Maybe the garage can lift the car so that the engine and transmission can be run staticly. At least they you can be in the engine bay and hopefully be able to get a better idea of where the problem is coming from. Not so sure this is something I would like to try at home mind you.

I'm sorry you still have no solution and wish you the best of luck in getting this problem sorted.

Dave

Got to agree with Darmain in that you need someone else to drive this car and give a fresh opinion, in fact get as many opinions as possible before throwing any more cash away. It's proving impossible to diagnose the noise/fault on-line, one mans 'booming' is another's man's 'banging' and all that.
Reminds me of a colleague who had a van in the workshop with a whirring sound, he spent a few days changing bits, wheel bearings all round, driveshafts, diff and eventually gearbox. Then he unloaded all it's contents and even removed all the cupboards and shelving to eliminate vibration from them. Frustrated he asked if i'd give it a test drive. I was pretty smug when I returned 2 mins. later with it fixed. I'd removed the 2 ins. of insulation tape some ****er had put on the top of radio aerial.
Just proves that noises can travel through the car and be very deceptive.