Transmission Clacking noise in 4x4

[Maurici]

Morning all.
Just bought a terrano as a tow thing for my race car. I've presented myself a few minutes ago. I landed here after browsing for information regarding this thread tittle.

The thing. When I bought the car, the guy told me literally "free running hub in the front left is slippling, don't use 4x4 till replaced"... The truck is doing very violent clacking noises when 4x4 is engaged. I trusted it, agreed a reasonable price and bought straight away a refurbished free hub.

Yesterday, I went to replace them, and I found my car doesn't have freerunning hubs. It is the locked hubs version. You can't imagine my rage in that moment. I felt absolutely idiot for being that trusty, but, at the end is my fault.

Then... Yesterday with the wheels out, I checked wheels bearings, and front CV joints, and the seemed all right.

Then, drove the car a bit with the 4x4 engaged for a few yards and:
Noise is very violent and sounds either in straight line or in full lock.
There is no diference between having load, coasting or being in overrun.
Its only present when 4x4 is engaged, car in RWD is really smooth and no noises can be found. The Clacking, that makes even shake the car, sounds like somewhere in the left side of the gearbox, but dificult to say from inside the car.

Taking in consideration that is a locked hubs version and even in 2WD all the front running gear is spinning anyway... Shall I assume that the problem leans in the transfer box? or there is something else I should check before burning it?

I could do with some good news...
I'm confident with a set of spanners and hapy to go under the car to do cheks, but not mega experienced with this 4x4 systems.
Not sure if I will repair it or not, but definitely I would like to diagnose what is wrong to make informed decision.
Many thanks.
Maurici.

 

[jims-terrano]

Firstly it is not your fault, quite clearly the person who sold it knew about a fault and indeed maybe they did believe it was auto locking hubs.
One of my trucks had a noise and vibration so we set about trying to track it down. Firstly we removed the front propshaft which turned out to be the source of the problem, UJ bearins were goosed and so was the sliding joint.
Perhaps if going in a straight line and certainly just a few yards removing the fixed hub would also assist too as it would remove stresses on front drive shafts.

Yes transfer boxes do go but have not heard of many.

Just seen time I gotta go.

 

[Maurici]

Removing front propshaft is a good suggestion that I had not thought about it.
however, I can't see it being the problem as it spins even in 2wd? and there is no noises at all in 2wd. (Again, I may be missing something here, im not experienced in this systems).

However, and now just gessing. As is going to be mostly a tow hack on asphalt, and that I have other cars to play, Is that an option to have it out permanently? taking the worst approach, and thinking that may be the transfer box that is gone... I cant see the point of having the front running gear spinning forever if is not going to be used? Definitely not up to the bussines for a new transfer box as I imagine they are costly and will be a bit more work than a morning so will just ignore it...

 

[solarman216]

From your description it does point to transfer box,remove the front prop and feel/turn the drive flange on the box this may give a clue, if only going to tow on good ground then leave prop off, and you will also have the ability to tow in low box for those difficult hill starts/climes if towing heavy loads, transfer boxes are available from a scrapper, indeed I have one here albeit off of a petrol, but think they are the same, Rick

 

[Maurici]

Thanks guys.
Will take the front prop today, and give s wibble to the transfer flange to see what happens. I may be able to feel the rattle, and also will be able to see if there is any sign of damage to the front propshaft (oh that would be soooo nice) but for my little knowledge, it all points to transfer.

Now again theoretically...
If i ever deciede to change the transfer...
Is that difficult to do for a half skilled DIY mechanic?
Can it be done from the floor with the car on stands?
Seen a tutorial, and appears to be a case of taking props out of the flange, disconnect harnesses and undó 7 or 8 casing bolts. It didnt seem that difficult, and not much trouble having to dismantle any other stuff as in your regular daily...
I get is heavy and difficult to handle, but, doable?
And for how much they go?

 

[solarman216]

worst part is you have to drop the rear torsion bar mounting X member, it can be done on the ground, I have done so but it is heavy and awkward, Rick

 

[Maurici]

worst part is you have to drop the rear torsion bar mounting X member, it can be done on the ground, I have done so but it is heavy and awkward, Rick

Cheers Mate.
That probably puts me off then. I assume is heavily spring loaded, and in all honestly probably every bit I will be taking off, will weight as muchs a my whole race car, so, maybe is not a good idea to be involved with it, and just have it done if I ever want.
Appreciatte your help.
once I've dropped the front propshaft will let you know my findings anyway... even if is only out of curiosity.

Thanks,
Maurici.

 

[Maurici]

well. front propshaft now dissasembled.
The shaft itself is spot on.
The transfer box does 0 noise with the wheels on the air and the flange moves sweeeeet....
Had a test drive with the low gearing on, and it works spot on...

no noises can be heard in the fron end either... what are your thoughts then?

Im confused.

 

[RJL Services]

when mine made funny noise i removed the front prop shaft and noise was gone the front u j were rusted i replaced them the new ones came with grease nipples not sure why nissan stopped fitting grease nipples on later type i refitted mine and all good now

 

[Blocky10]

Sounds like front prop ujs to me too.
They're not a lot of money and can be done with a large hammer and some old sockets. Any other equipment you have will be a bonus:lol
I know this as I done mine a couple of weeks back:thumb2

 

[solarman216]

Yes does sound like front prop, but you say it is OK, so how did you check it? bear in mind although you tried 4 wheel and low box, the drive assembly to the front axle will not be under load so might be quiet in this state, pull the oil and see what comes out, Rick

 

[Maurici]

Yes does sound like front prop, but you say it is OK, so how did you check it? bear in mind although you tried 4 wheel and low box, the drive assembly to the front axle will not be under load so might be quiet in this state, pull the oil and see what comes out, Rick

Front prop, now being out of the car, it's been really easy to check. No free play AT ALL in the joints, the sliding section is nice and tight, and has no play either.
Pulled the sliding section out too, and does not have any sign of slipping.

Front Ujoints, are still in the car, but with the wheels on the air, given them a good wible back and forwards and inspetect them from outside. not any free play out of normal.

Flange on the transfer box moves sweet as ****, and i couldn't hear any weird noise from underneath when engaged, neither when driving.

when the front prop was in, the clacking noise was so violent that you would expect to feel it by hand easily if you get to the part that is failing...

Today, will pull fluids out to see what I do find, will keep you posted.

Out of interest... is the front diff an LSD? A disks one?

 

[jims-terrano]

Only the rear diff is LSD, if you ever change the rear diff oil use genuine LSD oil as the rear diff is very sensitive.