weird vibration

[lightwing]

Hi all, my 09 puma110 has developed a weird vibration at high torque loadings. Typically this occurs when changing to sixth gear at around 80 to 90km/hr going up a slight gradient and putting the foot right down.
The sensation is like driving over a rough patch of road, in fact that is what I thought it was the firs time it happened.
I have removed the front and rear drive shafts to test the front and rear ends with no difference, I have checked the Viscous fan, I have even removed the centre diff and replaced with a spare, I have checked all of the engine and gearbox mounts, I have replaced the gearbox/transfer case coupling shaft and I am running out of ideas.
Can anyone shed some light on this perplexing situation???
Any and all suggestions very gratefully accepted.
Chris

[n plus one]

That's right in the vibration band for the Puma motor IMO (and, just quietly, the perfect setting to build very high egts) - you don't have a free flowing exhaust that's causing droning? Just a thought.

Alternatively, I'd be double checking the nuts on the T/C output flanges (unlikely as you've changed the T/C, but I've had them cause something similar in the past) or maybe (just maybe) wheel bearings (though again, unlikely if you've pulled the front and rear props).

[lightwing]

Thank you for your reply N plus one. No I do not have a high flow exhaust but the vehicle has developed an exhaust related droning noise at the same revs as the weird vibration so there could be something in this. I have however checked all of the exhaust hangers etc. and can't find a reason for this particular noise.
The nuts on the T/C were a suspect but have been eliminated as have the wheel bearings. So this shall have to remain a mystery for the time being.
I guess I will have to just wait and see what happens. unless someone else has an idea as to what could cause this weird vibration..

[n plus one]

I'd be interested to know if it's gear or engine rpm related as this would help with diagnosis.

Can you get the same effect dropping your rpm right down in say third gear and get the same effect with a heavy throttle loading?

I can get a transmission shudder if I do that kind of thing, but it's only really if I bring the turbo on song very early in the rev range when being a bit lazy about my downshifts (ie easily avoidable in normal driving).

Hope this helps.

[lightwing]

thanks again n plus one for your reply. I have tried to replicate the vibration in lower gears, however this has proved difficult to do although a mechanic who looked at it said he could get it to vibrate doing as you suggested.
If you drive the vehicle normally and you don't come across just the right road conditions ie long fast uphill stretch then you may not experience the vibration for many kilometres. The fact that you asked about droning in the exhaust system has got me thinking as the vehicle has developed a droning in the exhaust system at around the same time the vibration started. It still remains a mystery.

[DazzaTD5]

Every Defender TDCi (puma) I've driven has a slight, what I call floating vibration from what i think is the gearbox. I actually believe its the mainshaft, right at that load/unload point. Some Defenders I doubt people even pick up on it, some never get noticed, I reckon all the MT82 boxes prolly do it but in vehicles such as a Ford Ranger, it goes completely un-noticed.

But saying all that, being an early 2.4lt? (with how many km's on the clock? round 70K - 100K) what you describe sounds like the clutch assembly. With the vehicle stationary, idling, drivers door open, in neutral foot on clutch, release clutch pedal. Do you hear a noise change, as in a louder rattle, or different tone (if its the clutch, this sound will be quite a noticeable change).

The below issues are common on the Defender TDCi (puma) but are far more exaggerated in a Defender 90.

*Clutch (driven plate springs loose).
*Wear in rear axles/drive flanges.
*Centre diff worn (side shims worn or completely gone).

The exhaust drone/rattle (more like a harmonic drone).
*Using 5 & 6th gear doing 60kmph (Ive had customers complain of this noise while doing just that).
*broken/loose heat shield bolt (lower bolt right on the bottom of shield (look through drivers inner guard)).
*Broken heat shield mount bracket (above exhaust manifold, front of engine).

Regards
Daz
P.S Comments re Defender 90 not relevant here (had it in my head it was a 90), but still ring true for others.

[lightwing]

thank you very much Daz for your summary of common Puma faults.
I have been through every one of your points, but unfortunately my problem still remains a mystery.
I do have a very distinct exhaust drone,(not the heat shield) started the same time as the weird vibration. My next step will be to chase down the droning sound and hopefully that will solve the vibration at the same time. The two things may of course not be related
I am going to go through the exhaust system first and see where that leads. Although a normal inspection of the exhaust system has not revealed anything unusual. If I can solve this problem I will post the results of any findings.
chris