No 4 wheel drive!!!!

[coachmanking]

Nissan Terrano 2.7TDi 1999 Model - With the recent poor weather i had to put the terrano into 4 wheel drive.....it didn't work! Although the shift lever moves and the light on the dash came on i still only had 2 wheel drive. I have been under the terrano this morning and can see the lever on the side of the gearbox move when the shift lever is moved. I also checked to see if the front shafts had engaged, i was able to turn them by hand whilst in 2 wheel drive and was still able to turn them when the shift lever was in 4 wheel drive. Would this indicate a problem with the transfer box? If so has anyone experienced a similar probelm and any ideas about resolving it? I last put the terrano in 4WD about 6 months ago and it was fine.
Any help or advice would be gratefully received.

 

[Terranosaurus]

Could be the transfer but most likely the free wheeling hubs.

Even in 2wd if you turn either front driveshaft it should turn only a small amount and then try to lock in the hub and you'll not be able to turn it any further.

 

[tezzer]

hi coachmanking, i've got the same problem, i'm sure it my auto hubs not engaging.









tezzer

 

[coachmanking]

Many thanks for the speedy responses.
I have been back under the terrano again and proved that the front propshaft is locking into 4wd and therefore i am assuming that the problem must point to the auto hubs.
Another question is once the hubs lock what happens with the front diff, how does this determine that the 4wd has been engaged? Sorry if it appears to be a daft question but i was assuming that he front driveshafts would lock once in 4wd regardless of the state of the auto hubs. Are you able to explain?

If the problem is the auto hubs are there any recommendations regarding replacing or repair? I see from other threads that many owners change them for manual hubs.... Do the club recommend Milners off road or are there any other suppliers?
Many thanks

 

[extreme-4x4]

why not try the auto hubs cleaning download first milners will charge you 150.00 for manuals you might not need them

 

[Toolbox]

With no diff lock in the front axle, if one hub is not locking in, all the drive through the front differential will go to it, as it is easier to turn just a shaft than to turn a wheel on the ground.

 

[Terranosaurus]

Likewise if neither hub is locking in then if you turn one driveshaft the other will turn (the other way.

First thing you need to do is pop your hubs off and see if they are complete. I have come across trucks that have had worn brake rings removed in order to mask the poor operatio of the fwhs and effectively creat a 2wd regardless of what you do with the levers.

In my mind there is absolutely no need to change to manuals. In fact last time out green laning someone with manuals had them play up and had to strip them by the sid of the lane in order to get them working and himself up the hairpin hill climb we were negotiating.

 

[makeitfit]

Hi Trex just kidnapping this thread a mo:augie
I've been considering changing to manual hubs to save haveing to do a reverse manouver somewhere when going from the rough to tarmac for example. Sounds daft I supose but when there's a bunch of other 4x4s up your chuff it's a bit tricky to find room!
We often go laneing and then need to drive a while on the road to the next lane, so thought manuals would let me do that.
Now you've put doubt in me mind
Can you elaborate on the pros and cons of the manual /auto hubs please:thumbs

 

[coachmanking]

I will take the hubs off tomorrow (weather permitting) and see whether there are any broken bits in there! If nothing obvious i will clean and regrease.
All bits should be there.... have owned the terrano for 7 years and not had any problems with these before.

 

[Terranosaurus]

Can you elaborate on the pros and cons of the manual /auto hubs please:thumbs

Not a lot to say really - but why don't you just leave the auto's locked in for the day. you don't have to reverse up after every lane, just do it at the very end of the day. Thats what I do, though I tend to find I reverse up soon enough anyway, in a carpark or whatever at the end of the day so I rarely actually conciously back up to dissengage the hubs.

If looked after auto's are fine - bar the initial problems of worn rings on my old Mav I have never had any problems since with either that one or my current one.

The key is to engage the hubs gently. When driving along and shifting from 2H to 4H you are fine everything rotates at about the same speed and no damage is done, its when 4H or 4L is engaged when stopped from 2H, the first engagement of the clutch needs to be done gently, its at this point that the damage gets done. The wheels are stationary but the shafts turn and it is the initial impact from the rotating bits trying to drive the non turning bits that does the damage. That and like a lot of things lack of maintenance. I'm not saying you need to strip em down ever service, but once in a while just popping em of and checking they are still full of grease etc is easy enough.

 

[makeitfit]

Thanks for that it's a lot clearer now (and cheaper)
What's all the who ha about winding up the hubs/gearbox all about then? So if after a lane bit I go onto tarmac and drop into 2wd will the hubs be OK for a mile or so before going back in the ruff?

 

[Terranosaurus]

Hubs will be fine for 1000 miles locked in - nissan even deleted em on later cars and just stuck solid drive flanges on. You may use slightly more fuel though as the front wheels will be turning the driveshafts and diff/prop shaft

The hoo har is over driving in 4wd on dry surfaces, different rotation speeds of the front and rear axle caused by tyre size and cornering will put stress on the whole drive system from transfere to tyres. Its usually the tyres that will slip but extra wear will be put on everything, bearings, UJ's and CVs are likely to fail earlier and there is a possibility you could outright break one of them - though unlikely.

The manual states that you should back up when you dissengage 4wd but this appears to be the only time in human history when the male of the species has both read the manual and actually follows it - ironically on this occasion its not really necessary. Nissan were just being over cautious IMHO.

 

[makeitfit]

:thumb2Fantastic, I feel quids in already cheers Trex
Now I dont have to back up like fool around the country:augie
Cheers
You can have your thread back now coachmanking:thumbs

 

[zippy656]

:thumb2Fantastic, I feel quids in already cheers Trex
Now I dont have to back up like fool around the country:augie
Cheers
You can have your thread back now coachmanking:thumbs

haveing read that make me feel better too. I back up when changeing back to 2wd. but the green light is normaly out befor then any way. but i still do it. just to be sure


if i didnt back up do they pop out when they can?

 

[extreme-4x4]

so what about gear box wind up then... does that happen ?
how ? when ?

 

[zippy656]

so what about gear box wind up then... does that happen ?
how ? when ?

yes, but from whats been said before.

happeneds when in 4wd. when the wheels move at different speeds, turning ect..

when in 2wd, and hubs locked, the lsd at the back is like normal and the front is similar, the center is where the wind up is from.

THat right guys? have i understod corectly from my time here?

 

[Bat21]

so what about gear box wind up then... does that happen ?
how ? when ?

Gearbox.... no, I suspect you are referring to transfer box wind up which will occur if you use 4WD on none slippy surfaces such as tarmac, as Terranosaurus says above:-

Different rotation speeds of the front and rear axle caused by tyre size and cornering will put stress on the whole drive system from transfer box to tyres. Its usually the tyres that will slip but extra wear will be put on everything, bearings, UJ's and CVs are likely to fail earlier and there is a possibility you could outright break one of them - though unlikely.

 

[coachmanking]

Stripped down the auto hubs today and found that all the parts were intact with no obvious problems. I copper greased everything and put back together in the reverse order that i had taken it out, tried it and guess what still didn't work!!!
Searched out my manual to check through and noticed that the spring was shown between the brake and the hub assembly and on my vehicle it was located between the 2 brakes! Stripped them down again and followed the manual instructions and it works! Must have been put back together wrong by the garage when they replaced my discs and pads!

 

[zippy]

Gearbox.... no, I suspect you are referring to transfer box wind up which will occur if you use 4WD on none slippy surfaces such as tarmac, as Terranosaurus says above:-

Does this wind up still occur in 4H or only in 4L?

Can you run on 4H in say icy roads where the road may be fine for a few miles then hit an ice patch.

sorry if this sounds thick but i generally am just that.:doh

Regards
Lee

 

[Terranosaurus]

Wind upi will occur in both 4H and 4L.

JUst try it for a second in a car park or similar. Engage 4H and drive off slowly - you'll notice the extra drag but if you try to turn the truck will almost grind to a halt.

PS - don't blame me if you break something, try this at your own risk but in my experience you will be fine doing it just for a second or 2.