[rodney]

hi all
seeking technical advice.
I own 1997 defender 110, every time I change gear or accelerate or decelerate there is a strong knock.
when driving with out rear driveshaft there is now knock, when driving with out front driveshaft there is a knock. There is now knocking sound when driving with out shifting gears.
any idea to the cause of the knock ?
thanks
Rodney

 

[jozg44]

At a guess I'd say that the knock is caused by wear in one of the Universal Joints in the rear propshaft. The noise is the slack being taken up in the system as the transmission comes under load. It went away when you removed the rear propshaft because (obviously) you had no UJs on at the time.
Replacment UJs are quite cheap (£15-25), easy to replace and the best pattern-part ones to use are Hardy Spicer ones- I now have them all-round and quality is good.

Jack

 

[scoobymick]

Sounds to me like the 'A' frame ball joint,pretty common

 

[rovertech]

i agree with jozg i think you have a u joint issue unless you have the rubber disk in the prop shaft by the rear pinion if you do i would say its that :beer:

 

[m0bcg]

if it isnt one of the propshaft universal joints then it may well be one of the bolts on the front axle that holds the radius arm in place.

usually its the left hand side of vehicle if viewed from the front of vehicle .

there are 2 rubber bushes in the radius arms where they connect to the front axle and a bracket welded to the axle with 2 holes in .

tighten the bolts up here because i expect one of them is a little loose or one of the holes in the bracket is slightly enlarged which makes it make a knock noise especially when cornering .

its not the rubber bush thats a problem but the hole in the bracket wearing a small amount, enough to make a knocking noise when the bolt moves .

i have had the same thing on a range rover and also on my 90 300tdi landrover .

 

[Defender Man]

I tend toi think 'A' frame ball. without driveshaft the rear diff not coming under any load. No torque reaction, no knock in 'A' frame ball. Easy to check, as are the uni's. Get under neath with a bar and lever between the 'A' frame ball and diff housing. There should be no play. To check the uni'. hold one side of joint tight and twist driveshaft back and forth. Again there should be no play

 

[rodney]

spot on

Sounds to me like the 'A' frame ball joint,pretty common

Thank you for the advice, the 'A' frame ball joint was warn out.
:clap:

 

[MG/WCB]

I doubt it's the u-joint (chk then anyway)... but I'd hazard to guess it's one of two; the rear axle shaifting about (A-frame pivot worn or lose, or rear axle link arm bushings at chassis)... but i'd check that the input gear has gone south. Pull the PTO cover and check the splines indide the INPUT gear; If all gummed up and rusty looking in there you have troubles! LR has known of the this problem for ages, and tried to cure it. You're in teh area of having the old gear... The NEW input gear will have 4 holes drilled in it to help lube splines, problem is, unless you increase the trasnfer oil level by a PINT (US) you won't get any splash oil to the gear. If gear is bad, mainshaft on gearbox will be too. www.offroadexperience.com/wcb