Transmission Clunk of Doom!

Hi,

Im failry new to this Landy lark, well owning one anyway. Used to drive them in the army but if i broke I gave it over to REME mechanics (I was in a different bit of REME so such activity meant **** taking.)

Anyhoo I recently bought, via drunken ebay, a 1990 H, Defender 90 200tdi with raised suspension and all sorts of other gubbins underneath. Its done 180k and...well... you can tell.


I have a transmission clunk issue that mainly happens when throttling back/coasting to a stop. It makes no difference if im in gear or neutral. Basically there is a juddering as I slow down which can be heard and felt. The speedo needle also jumps around suggesting the transfer box is getting a good shaking. (i replaced the speedo cable the first week as the jumping was so bad you couldnt tell what speed you where driving, you just got a vague impression!)

A few weeks after I got it this became suddenly very loud at the start of a 180 mile journey but fortunately I was not far away from a very decent LR chap called Dan from Carew 4X4 in Pembrokeshire. We got it onto his lift and ran it with wheels off the ground and the clunking was quite obvious. I drove it with the rear prop shaft off for a test (dont ask about the handbrake drum....) and there was no noise, suggesting a fault at the back.

Dan changed the rear diff for me, though it was second hand of indeterminate age. The seriously reduced the problem but its not gone away. The UJs on the prop shats appear fine with no play.

I did some googling and was quite worried it was the input shaft from gearbox to transfer box. However I followed some advice and took off the PTO plate (turned into bugger of a job....and its only 6 bolts!) and bearing plate, removing the gear thingy. I could see the splines where in perfect nick and the gear thingy (sorry about the technical terms) was the newer version with oil holes, also in perfect nick. Phew!

Next I looked at the halfshafts and driving flanges and can see these are in poor condition, especially on the front. By removing the dust cap, lifting each wheel in turn and rocking them back and forth I can see definate play, with oil oozing out.

Is this likely to be the cause of this clunk? Whilst there is quite a bit of play in the front and a little at the back, im not experienced enough to know if this can send these knocks through the transmission.

Whilst I had a front wheel off the ground this morning I rocked the lifted wheel back and forth a bit and noticed a lot of play via the front diff but have no idea if this 'slack' is normal. Basically I had a wheel lifted, in 1st gear, handbrake on, with a slight turn. When rolling the wheel back and forth there was a good 5 degrees of slack before the wheel movement got through to the propshaft. is this normal?

I have limited funds and limited working space where I live, though I can pinch my dads drive (and his lovely air tools!) for a weekend, but I gotta get it off his drive by the sunday night or else! As such I'd like to do as much as possible in one go.

What are the experts thoughts then? Will a new set of halfshafts and flanges cure this? Have other had the same issue, done the same fix?

Thanks in advance for your time.

5 degrees of rotational play is very good.....worry when it gets to 30

How high is the lift? Is there any signs of the propshaft yokes snagging? Have you checked U/J's with the handbrake off and transferbox in nuetral?

theres loads of bits in the drivetrain, little bits of play in them add up quite quickly.

I get about 10 degrees of play in my props before the slacks taken up, you adapt to drive it.

Id check the drive flanges, these wear the most, and a cheap thing to change, mine got much better when I changed the rears, front on the list of roundtuits, but keep finding toys to buy, really need to get a grip.

sounds like you havnt driven one before, or not for a while, its summat you get used to.

blue beasty said:

5 degrees of rotational play is very good.....worry when it gets to 30

How high is the lift? Is there any signs of the propshaft yokes snagging? Have you checked U/J's with the handbrake off and transferbox in nuetral?

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Hi, The lift is 2-3 inches. In total its 4 inches higher than my neighbours stock 90, though its got 16 inch steelies and hoofing great insa turbo tyres on. Im several owners on from the guy who did the lift hence lack of knowledge. It does look awesome mind but I am aware that a lift can place extra strain on the transmission.

Will try UJs with brake off and Tx box in neutral. I dont think they are snagging, certainly no sign of shiney metal amongst all the oil and grime! I have bought some UJs with an eye on replacing them so might do this anyway when I sort the halfshafts etc out.

Cheers.

timtheenchanteruk said:

theres loads of bits in the drivetrain, little bits of play in them add up quite quickly.

I get about 10 degrees of play in my props before the slacks taken up, you adapt to drive it.

Id check the drive flanges, these wear the most, and a cheap thing to change, mine got much better when I changed the rears, front on the list of roundtuits, but keep finding toys to buy, really need to get a grip.

sounds like you havnt driven one before, or not for a while, its summat you get used to.

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Aye, its been 10 years since I left the army and soft, modern cars and vans have left me weak and wussy! I might see if my neighbour will let me drive his round the block. Its got half the mileage mine has so should be tighter and might give me a better idea of 'normal'

Im going to do the halfshafts and flanges anyway and hopefully this will take up some of the slack.

PS, im the same with toys etc as well....... In fact this landy is 2 tons of giant orange toy! Im currently googling cordless impact wrenches instead of ordering my bits.

yeah, was goona order me the front drive flanges last night, but a nice retro refurbed CB caught my eye instead, just happens that the one in the landy is on the blink, seemed like a good excuse

if the props are catching, its the yokes that hit each other on the way round, ie not enough movement for the angle.

Drive flanges tightened my transmission up considerably as the old ones were quite worn

+1 or 2 on the drive flanges. I thought I had something seriously wrong gearbox-wise on my 110 when I bought it. It was actually hard to drive it had so much back lash. I couldn't see much movement in the drive flanges but I replaced them anyway. All I can say is the improvement was huge. Still a bit of back lash but I have an LT95 in mine so I think thats expected.
I bought bearmach flanges which were a tap on fit (perfect) I wouldn't go for the £5 ebay ones.

Yup, it's worth having a go at the drive flanges. Mine clunked quite noticeably on drive take up and overrun and this reduced dramatically on changing the drive flanges. They seemed to have worn more than the shafts, so I'm still on the original half shafts. Other possibilities include slack in the suspension, especially the ball joint where the rear A frame joins the axle. See if there's any movement detectable on levering them about, rocking the vehicle back and forth etc.

Oh, and it's worth getting plenty of grease or oil on the splines too.

Thanks guys, Im going to change the front half shafts & flanges and the rear flanges. I had 'new' rear halfshafts when I had the diff changed but not new flanges and these have less movement than the front. I will let you know how I get on.

Just ordering it all now...

Have you checked the central ball joint for play?

I had a giant clunk and juddering when pulling away, pulled the shafts and there was a large amount of play at the drive flanges (I'm on 180k odd as well). Swapped the shafts and flanges for brand new ones and the play and most of the clunk has gone away. I did try various combinations of the new and old parts while I was doing it and both the shafts and the flanges were pretty worn so a new set of both was warranted.

Next thing on my list to do is to change the A frame ball joint to get rid of the small clunk that remains...hope this helps

TheKeymeister said:

I had a giant clunk and juddering when pulling away, pulled the shafts and there was a large amount of play at the drive flanges (I'm on 180k odd as well). Swapped the shafts and flanges for brand new ones and the play and most of the clunk has gone away. I did try various combinations of the new and old parts while I was doing it and both the shafts and the flanges were pretty worn so a new set of both was warranted.

Next thing on my list to do is to change the A frame ball joint to get rid of the small clunk that remains...hope this helps

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Sounds similar to mine. Part way through changing various things myself and the clunk is reducing. Bought new halfshafts for the front (wear is worst there) but for some eason (stupidity) forgot the front wheels actualy have to turn and therefore there is the whole CV joint malarkey.

Took a good few minutes to work out why the front shaft just wouldn't pull out like on the rear...... Anyhoo I fitted the new drive flanges on the front anyway just to see and its made some difference but not eliminated the rattle on overrun

Seems I need to order yet more parts then! Will get CV joints and gasket kit etc and finish the job this time.

Its only been 6 months since i my last post on this thread but I finally managed to get the halfshafts, CV joints and drive flanges changed on the front.

After a slight hiccup lasting 4 months involving incorrectly assembling CV joints I managed to get it all together last weekend and now a fancy new Tax disc is fitted as well!

First drive and it seems much of the clunking has disappeared. Before this work the transmission used to clunk on gear changes no matter how gently i applied the clutch. With new components its very smooth on gear changes and even dumping the clutch doesnt cause any clunking.

There is still some juddering as I pull upto a stop but that might be from the suspension joint.

On the original half shafts there was quite a bit of sign of wear on the shafts and front flanges. As such Im pretty certain thats what was causing the juddering

Only thing is... after 4 months of sitting idle the indicators seem to have gone potty! Think it must be the stalk or the rflasher unit sticking.. The fun of landrovers!