Thumping from under the seat

I apologise if this fault has already been covered before but I've scanned the previous threads and can't see anything obvious.

1993 D90 200TDi SWB hardtop. No mods other than stated below.

I am getting a thumping noise/feeling from under my 90. It feels a bit like you are constantly driving over ridges in the road if that makes sense.

Here's the symptons, it has no effect whether in or out of gear, in any gear or position in t/box. It speeds and slows as I speed and slow. Bizarrely, it get's worse the longer you drive it, usually by 10mins plus it feels like someone is kicking me in the arse. It feels like it's coming from the rear or centre rear as opposed to the front. Eg: the thumping can be felt through the seat and floor far more than through the steering wheel.

Here's the history. Recently had O/S/R wheel bearing and shaft changed after the bearing exploded. Car has driven fine since replaced.

Just had rear axle casing replaced as original badly corroded. The replacement is off a 300Tdi, the mechanic says this makes no difference. I decided to have the shocks and coils changed while the axle was out and a poly bush kit of which half is fitted. Since and only since this work (last week) has the thumping been apparent. At 45mph it feels as if something is about to lose it.

I have BFG AT tyres fitted, standard suspension, the rear diff has now been changed in an effort to cure. The mech says the wheel bearings, shafts and prop are all good. I could have sworn it felt like the rear prop out of kilter or poss bent ? But having just removed the panel under the middle seat and gone for a drive, the prop appears to run true. I have checked my tyres (they are about 5000 miles old on brand new rims at the same time) the tyres show no signs of uneven wear or any damamge whatsoever. There are no flat spots, tears or bumps. My mechanic also says the front w/bearings are quiet.

My mechanic has many years working on Landrovers but is stumped. It has though, only been apparent since the casing was changed.

Can anyone, please, suggest anything or has anyone experienced it before?



Thanks in advance. JP

i'd be taking a prop off and driving it in DL for a short straight distance to find out if it's coming from the front or back first

Might be a silly idea, but is yer exhaust rubbing / hitting on anything?

rear diff breaking up .

I had the same thing when my rear diff smashed it self to pieces - felt like the gearbox was trying to break thru the floor.

The Mad Hat Man said:

rear diff breaking up .

I had the same thing when my rear diff smashed it self to pieces - felt like the gearbox was trying to break thru the floor.

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pessimist

wonder if a prop got separated and put back out of phase and is now unbalanced

Sean said:

pessimist

wonder if a prop got separated and put back out of phase and is now unbalanced

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Time will tell, Sean.

One thing strikes me, I bet your mechanic loves you! Something needs doing so you get a whole bunch of other stuff done at the same time. Don't get me wrong, I do the same, 'cept there isn't a mechanic involved.

Bit that concerned me is that in order to try to sort an issue that may be any one of the components that have been changed (though some more likely than others), he bolts on and presumably charges you for yet another component!

If you haven't got the confidence to do it yourself, I'd get a different mechanic to check all of the items the first one has fitted as I reckon there's a good chance something is wrongly fitted or sub-standard and if the mistake isn't obvious to the first guy there's a reasonable chance it will be to the second.

Replacing further bits isn't going to help I don't reckon.

Also, is this mechanic an independant Landy specialist or is it just a general service place you've taken it to?

Grippa said:

I do the same, 'cept there isn't a mechanic involved.

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snigger :bolt:

All valid responses, thanks.

I'm not against tools but I know my limitations and sadly, really short of time at present and need the landy. Hence the use of someone else.

He is an independent Landy spec, nothing fancy and, was recommended to me by two locals independently, one of which is a parts supplier of landrovers although I don't get my parts from him as I find Paddocks cheaper.

He hasn't charged me for the rear diff he's fitted but it would be a used one he's put in anyway.

I really thought prop but I cannot move it side to side with my hand and visually, it appears gto run smooth.

He says he is always careful to mark the diff/prop when removing them to make sure they go back exactly right, I can only go on his word, he has already removed and re-checked this.

Exhaust not hitting and is secure.

I did think about taking the diff out and running it, I discounted doing it myself as I thought I might not be able to re-align it properly and thereby, create a new or worsen the fault. It's presumably ok to run it like this though, to check ? I might get him to try this next, he may have considered it.

I'm loathed to take it anywhere else at the moment as I've paid to have him do it. He did come highly recommended. However, time is fast approaching where I will have little option I guess. Has anyone got any recommendations for a 2nd opinion in the Dorset region ?

The Mad Hat Man said:

snigger :bolt:

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Feck orf, you know what I mean.

Sean said:

i'd be taking a prop off and driving it in DL for a short straight distance to find out if it's coming from the front or back first

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As above Id do first for sure , I wonder if your mech checked the diff first or did he just throw the axle under it thinking that it was a good un ??

What your describing does sound like the diff carryer bearings are about to let go , even if it sounds like its turning quietly , the pre-load on the bearings could be way out and the diff is riding up in the bearings ...

But without being there --- well you know ??

Cheers, really appreciate the advice, will keep you posted

Can't get hold of the mechanic....his mobile is switched off !!! I've had to hire a car so I can get to work for 3 days before I'm off !

Something that's bugging me a bit. The replacement rear axle casing is off a 300TDi apparently, mine is a 200TDi. I'm told by the mechanic that this makes no odds, is that about right ? He did also say that the old casing had been bodged about a bit and the mountings had been re-welded on, a bit crudely. Is it possible that the driveshaft was set up to the position of the old casing and now the replacement one has gone on and the mounts are true, that this is now not true to the prop in some way ?

I'm going to have a bash at taking the rear prop out later as suggested and driving it to see if the thumping goes. But, like mentioned already, I guess that will only confirm it's something to do with the rear, it still wouldn't actually tell me if it's the rear prop, diff carrier bearing or anything else ? With that in mind, am I going to be able to mark and remove the prop with spanners and a socket or do I need something a bit more specialist to do it ?

Is there a check I can do myself for the diff carrier bearing or does it need opening up to check visually ?

Cheers. JP

JP90 said:

I'm going to have a bash at taking the rear prop out later as suggested and driving it to see if the thumping goes. But, like mentioned already, I guess that will only confirm it's something to do with the rear, it still wouldn't actually tell me if it's the rear prop, diff carrier bearing or anything else ? With that in mind, am I going to be able to mark and remove the prop with spanners and a socket or do I need something a bit more specialist to do it ?

Is there a check I can do myself for the diff carrier bearing or does it need opening up to check visually ?

Cheers. JP

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The axle and prop are not timed together , but the prop yokes have to be aligned ( rear only ) ]-----[ not ]-----o .
as for checking the diff bearings , the diff has to be removed . But if you dont know what to look for or looking at then its a bit of a waste of time .

one thing you could to tho is remove the halfshafts and check to see if there dead straight ..

Due to time/knowledge, I have taken it into another mechanic to check out and hopefully sort. I took him out for a drive this morning and the thumping was present so fingers crossed. Once it's diagnosed and rectified I'll update here. There's a few other bits need doing, n/s/f pivot seal, steering damper bushes etc so going to get it all done in one hit. He reckons he'll be able to do the front axle casing while it's there and, have a courtesy car for me to boot. I'm feeling much happier about the whole thing at the moment. Cheers

garages love jobs like that - hope it's not gonna cost you a fortune this time, the fact you're getting a courtesy car however suggests it's not going to be cheap

They're £30 an hour, the last guy was £25. I had some work done at this place before and everything works, nothings fallen off or developed into a thumping noise. I think that if you don't have the time or knowledge to do a job, you have to pay someone that does. I accept that, it's not ideal but when I get some more time there's plenty left for me to tackle. Vehicle repairs are not their main business, it's agricultural repairs, sales and hire, they just have a couple of mechanics who work on the farm stuff and do Landrovers as part of that. Thankfully, the courtesy vehicle is a 4x4 and not a jcb!

Well, it was the handbrake. Or rather the shoes, one was down to the metal. Apparently, there are two cylindrical pieces that house a small cam like piece in each. One of them was missing the cam and someone (*&*!@) had adjusted that side up to the max to compensate for the lack of this cam type piece. Consequently, when the shoe wore down to the metal and got hotter, the metal expanded and exacerbated the rubbing, hence why it got worse the longer it was driven. With the handrake drum removed, the noise is non-existent!

I'm having the remainder of the new shocks, coils and poly bush set fitted and a couple of other bits plus a full underside waxoyl and service done at the same time and should have it back by the weekend.

Well I didnt even think of the handbrake as the thumping was only after the axle was fitted .... but at least thats a cheaper fix , glad you got to the bottom of it tho