ADVICE PLEASE...SHUDDER IN 4WD...

[obelixxx]

Hi all, am new to owning a series 2a 109 ex Military, and am slowly learning the "quirks" compared to my last defender.....
It has been a geat truck thus far and and after a bout or fairly tough 4 wheeling I found that I could not un lock the free wheeling hubs, and driving back on road with the wheel hubs locked presented a very large shudder at the front end, either with 4wd engaged or not.
After some manipulating and jiggling, still no joy. I thend ecided to give it a good does of reverse in case of wind up, which in the short term did the trick and I could now un lock hubs, shudder gone.
However a trip to the beach later that day, engaged hubs and locked diff in high range, sudder backas so an we hit 30-40km/h. again could not unlock hubs. Tried reversing again and then driving forward with hubs still locked, and was able to drve a short time without any shudder, then a distict clunck from I think front left wheel and shudder returned.....reverse again and was able to unlock hubs, shudder gone.....any thoughts would be greatley appreciated....wil check bearings today.......many thanks..

[NiteMare]

the shudder could be one or both of your front propshaft UJ's having given up the ghost or even the sliding joint worn beyond sensible keeping,.. not guaranteed tho

do you have the same size tyres (height) on both the front and rear axles as odd sizes will give you a nasty discrepancy on the road and it could be the tyres "skipping" while in 4x4 on tarmac (they'll slide happily on loose surfaces)

a very slim chance is you have mismatched differentials in the axles, someone "could" have fitted a higher ratio diff in the rear axle if the motor was primarily used on the road as just a car for lower revs at cruising speed (a friend of mine has a 3.54 diff in the rear axle only for exactly that reason)

but on re-reading your post i'm inclined to think that it's most likely a knackered front prop, no idea why your FWH's were difficult to unlock tho unless your 4x4 lever isn't actually unlocking...

you are going into low ratio and then back into high to change back to 4x2 aren't you ??

you do have the long spring under the head of the yellow knob ?? if that isn't there you will always be in 4x4 as that knob needs to be held ^ (up) to release 4x4

just a few ideas for you to look at , i'm sure someone else will be along with some more