Mystery Rumble???

Hi, I have a 1987 Defender 2.5td and recently have noticed a rumbling from the underside whilst at speeds of around 40mph+, it seems to be most obvious at the bottom end of 5th gear. Also the noise inside the cab is noticeably louder. I am not in any way mechanically minded but it seems like it could be from the prop shafts, gear box or transmission?
Does anyone know what might be causing this, and any ways I could check to see what's wrong before sending it to the garage?

Thanks in advance for any replies,

Oli.

prop uj's. end of.

Could be the uj's, does the noise get worse or if it fades away and stops the faster you go then definately its a uj.

Likely to be propshaft related but could be a number of things.

the faster I go, the worse the noise/rumble gets. Its a bit like the shuddering you get if you are going to slow in a high gear.

UJ's almost certainly.

is it worse when yer going up a hill at about 50...or accellerating at about 50 (if such a thing is possible!!)???

yer, your pretty much spot on odenne. So if it is the 'UJs', is there a way of checking? Is it a big job to change them? and how much is it likely to cost? Thanks.

To check: Chock the wheels. Release handbrake. Get under the car, and grab the prop shafts, (connect gearbox to axles) and try to move the UJ's at either end - there should be no play up or down or 'twisting' in relation to the shaft and the flange. (The flanges will have a big of play from within the gearbox/diff)

One will have play in it.

about £8 for the joint (Hardy spicer, dnt bother with the cheap ones they will last a year)

Where abouts are you based? Im sure someone could help you change it. It aint hard really.

thanks very much boydy, greatly appreciated. Will go give the props a wobble tomorrow, then if it looks to be the UJs will order some and try fitting them myself.

I replaced mine about 6 months ago with non-hardy (GKN) ones and then now need doing again. Not difficult, just a bit fiddly getting the bolts off the propshaft. If there is any play at all between the splines then you should replace the whole propshaft as otherwise you will get a kind of "grinding" noise above 30 or so. You will be amazed at the difference!

Have just been outside and checked the props for movement. neither of them seem to move up or down or wobble, but they both will rotate a small amount (im guessing this is normal). However i did notice that the front prop is covered in oil, not sure if this is linked with the problem?
I'm thinking i might just buy 2 UJ's and replace the ones for the front prop anyway and see if it makes a difference.

Was the handbrake off when you checked?

Yer handbrake was off. I will go give it another proper wobble in a bit, i might have just been feeble the first time

Check the oil level in yer Transfer Box. If the front prop was covered in oil, the output seal may be leaking. It's not hard to replace.
http://www.landyzone.co.uk/lz/f38/how-replace-front-transfer-box-output-oil-seal-59242.html

Just been outside to have another look. The rear UJ on the front prop shaft has up and down movement when pushed. However it couldn't be moving more than a couple of mm. Would this tiny amount of movement cause the problems i'm experiencing?
Also I tried to see where the oil on the prop shaft is coming from. It looks like its dripping down from somewhere above, rather then leaking through the output seal... i guess thats another problem for another day

Sounds a bit basic but check the oil filter, my front prop was covered and turns out it was just one of the pipes that goes into the oil filter had come undone (it was proper gushing though!)

opedley said:

Just been outside to have another look. The rear UJ on the front prop shaft has up and down movement when pushed. However it couldn't be moving more than a couple of mm. Would this tiny amount of movement cause the problems i'm experiencing?
Also I tried to see where the oil on the prop shaft is coming from. It looks like its dripping down from somewhere above, rather then leaking through the output seal... i guess thats another problem for another day

Click to expand...

YES! That tiny movement is a UJ failed, the tiny needle rollers in it have turned to dust, and its failed.

As above, only ever use Hardy Spicer UJ's, as i have done 2 now, same joint, with cheap ones (out of my control as to which brand) and they ahve both lasted less than a year.

Thanks boydy, i will buy some new UJ's then, am just looking on paddock spares and there are 2 different hardy spicer UJ's, both look the same.

Ones says its a..... Propshaft UJ (HARDY SPICER) from CA252579 4 cyl and from CA254407 V8

........the other says it......Propshaft UJ (HARDY SPICER) to CA252578 4 cyl and to CA254406 V8

Does anyone know what the difference is, and which ones I should order? Cheers for being patient with my stupid questions!