Go Back   :::.Nissan 4x4 Owners Club.::: > General > The Clubs Virtual Pub

The Clubs Virtual Pub For general chat, so come on in and pull up a chair.

Reply
 
Thread Tools Display Modes
Old 08-02-2020, 03:21   #1
jims-terrano
Senior Member
Click here to find out how to become a paid up member
 
Join Date: Sep 2004
Location: UK
Posts: 12,965
Default Black Magic Diffs

Can anyone explain in very easy terms how diffs work and the differences in diffs and diff locks.
I get the principle that as you go around a corner one wheel is bound to turn at a different speed to the other and even then I’ve no idea how that works.
I know that if one wheel loses grip then it spins and the opposite wheel just doesn’t turn? How on earth is that supposed to be helpful?

I’ve always just accepted that they are black magic but just been watching a crazy russian YouTube channel and today they welded up the diff on a fwd drive lada and went for a drive around. It was hell to steer but it really improved driving in snow.
jims-terrano is offline   Reply With Quote
Old 08-02-2020, 03:36   #2
solarman216
Off road maniac
Click here to find out how to become a paid up member
 
solarman216's Avatar
 
Join Date: Dec 2009
Location: Bexhill on Sea
Vehicle: Y60 Patrol Me, 3 ltr Mrs
Posts: 17,299
Default

Not difficult at all, an open diff is just that a diff that allows different rotational speeds between inside and outside road wheels, but if one wheel is on slippy ground then that wheel will spin and the wheel on good ground will have no traction, so you are stuck, with a limited slip diff then subject to how much the clutch plates are designed to bite then at least some traction will be applied to the good grip wheel, but in my experience not usually enough to get you out of trouble, now a diff lock is the bees knees engage that and both wheels will turn no matter what, but get onto hard ground do not expect to be able to go round corners without something giving, usually jumping rear wheels under strain, Rick
__________________
Ex banger racer now off road maniac
Lokka on the front with manual hubs
Diff lock on rear
3 inch SS straight through exhaust
Manly winch bumper with 13000 lb winch
10 spike ground anchor, with multiple straps and blocks
Super strong body cills capped with scaffold pole
20% stronger springs all round
aggressive off road tyres on wheels so just swap.
Aim to get stuck and be completely self sufficient in extraction, love getting muddy, 2ft deep is good but rare.
solarman216 is offline   Reply With Quote
Old 08-02-2020, 08:51   #3
jims-terrano
Senior Member
Click here to find out how to become a paid up member
 
Join Date: Sep 2004
Location: UK
Posts: 12,965
Default

Thanks Rick so the crazy russians that welded their diff actual created a locked diff.
I agree about the terrano diff, I remember a long time ago when one of my front hubs wasn’t working I got stuck in mud and one rear wheeel span like mad and the other just sat there stationary.
jims-terrano is offline   Reply With Quote
Old 08-02-2020, 12:51   #4
terranosaurusdoug
Senior Member
Click here to find out how to become a paid up member
 
Join Date: Sep 2014
Location: Yorkshire, J33 M62
Vehicle: 2000 Terrano lwb 2.7TDI
Posts: 5,500
Default

Quote:
Originally Posted by jims-terrano View Post
Thanks Rick so the crazy russians that welded their diff actual created a locked diff.
I agree about the terrano diff, I remember a long time ago when one of my front hubs wasn’t working I got stuck in mud and one rear wheeel span like mad and the other just sat there stationary.
YouTube is your friend on this one mate it's all about the spider gears bud x
terranosaurusdoug is offline   Reply With Quote
Old 08-02-2020, 16:41   #5
Jay666d
Senior Member
Click here to find out how to become a paid up member
 
Join Date: Jul 2016
Location: Northumberland
Vehicle: Patrol GU3 (Y61) 3.0 SVE
Posts: 1,375
Default

My favorite diff video on YouTube: https://youtu.be/yYAw79386WI
Jay666d is offline   Reply With Quote
Old 08-02-2020, 17:31   #6
jims-terrano
Senior Member
Click here to find out how to become a paid up member
 
Join Date: Sep 2004
Location: UK
Posts: 12,965
Default

Thanks Jay, I still find the idea complicated so I’ll just accept that it works in the same way that I accept the wife is always right
jims-terrano is offline   Reply With Quote
Old 08-02-2020, 19:03   #7
Lazy-Ferret
Senior Member
Click here to find out how to become a paid up member
 
Join Date: Jun 2012
Location: Sevenoaks, Kent
Vehicle: Terrano 2.7TDi SE Touring
Posts: 5,221
Default

I remember my first Mecano set, and one of the first things the instructions get you to build is a Differential.

I must have built goodness only know how many and had no idea what they were for.

I went to automotive college and had to work on a diff, still couldn't work out the point, or physics. Eventually I got my second radio controlled car which was rear wheel drive, but had a diff, the first one had a fixed axle. Setting it up on the table, and for the first time I finally understood that until you see one working correctly, e.g. the drive going into the crown gear, and then comming out of the two axles, it will never make sense.

Suzs bought me a Lego 4x4 with tracks, and that has 3 diffs. Not realising it would matter, I put the front one in the wrong way round. It took me ages to work out why the rear wheels were going forward, but the front were going backwards. Even finally understanding how a diff worked, I had not realised they had a right and wrong way round.


Sent from my SM-G930F using Tapatalk
Lazy-Ferret is offline   Reply With Quote
Old 08-02-2020, 19:27   #8
Davey Boy
Senior Member
Click here to find out how to become a paid up member
 
Join Date: Dec 2015
Location: Dartmoor
Vehicle: Patrol ZD30 SVE
Posts: 960
Default

Quote:
Originally Posted by Jay666d View Post
My favorite diff video on YouTube: https://youtu.be/yYAw79386WI
Agreed Jay
A masterclass and a lab technicians dream!

D
Davey Boy is offline   Reply With Quote
Old 08-02-2020, 19:54   #9
Lazy-Ferret
Senior Member
Click here to find out how to become a paid up member
 
Join Date: Jun 2012
Location: Sevenoaks, Kent
Vehicle: Terrano 2.7TDi SE Touring
Posts: 5,221
Default

Quote:
Originally Posted by Davey Boy View Post
Agreed Jay

A masterclass and a lab technicians dream!



D
Thats a great video, but like all, it takes a leap of faith when it goes from explaing the diff, to how you get the drive into the diff.

Can you imagine health and safety on that last bit today?

Sent from my SM-G930F using Tapatalk
Lazy-Ferret is offline   Reply With Quote
Old 09-02-2020, 10:35   #10
Wallace
Senior Member
Click here to find out how to become a paid up member
 
Join Date: Aug 2018
Location: Middlesex
Vehicle: '97 Terrano II 2.4 Xtreme
Posts: 368
Default

Quote:
Originally Posted by Jay666d View Post
My favorite diff video on YouTube: https://youtu.be/yYAw79386WI
Great video, those display models must have taken hours and hours to make as all the brackets and fixtures were beautifully finished.

Jim, just to mess with your head a little more, here's an exploded view of the Quaife ATB!
Attached Images
File Type: jpg QUAIFE ATB.jpg (50.2 KB, 24 views)
Wallace is offline   Reply With Quote
Old 09-02-2020, 12:27   #11
solarman216
Off road maniac
Click here to find out how to become a paid up member
 
solarman216's Avatar
 
Join Date: Dec 2009
Location: Bexhill on Sea
Vehicle: Y60 Patrol Me, 3 ltr Mrs
Posts: 17,299
Default

The concept there it seems to me is that in the event one wheel loses traction the gearing is such that it will try and spin much faster than normal and via the inherent resistance in the small gearing impart some drive to the good wheel, could be quite noisy thou I reckon, Rick
__________________
Ex banger racer now off road maniac
Lokka on the front with manual hubs
Diff lock on rear
3 inch SS straight through exhaust
Manly winch bumper with 13000 lb winch
10 spike ground anchor, with multiple straps and blocks
Super strong body cills capped with scaffold pole
20% stronger springs all round
aggressive off road tyres on wheels so just swap.
Aim to get stuck and be completely self sufficient in extraction, love getting muddy, 2ft deep is good but rare.
solarman216 is offline   Reply With Quote
Old 09-02-2020, 13:54   #12
Wallace
Senior Member
Click here to find out how to become a paid up member
 
Join Date: Aug 2018
Location: Middlesex
Vehicle: '97 Terrano II 2.4 Xtreme
Posts: 368
Default

Quote:
Originally Posted by solarman216 View Post
The concept there it seems to me is that in the event one wheel loses traction the gearing is such that it will try and spin much faster than normal and via the inherent resistance in the small gearing impart some drive to the good wheel, could be quite noisy thou I reckon, Rick
A friend has one in his VW Polo, it acts like an open diff at low speed and doesn't affect the handling like a tight plate diff. It is quiet and made a huge difference to the traction. If we ever get back into the V8 Manta project that will be getting one for sure.
Wallace is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On

Forum Jump


All times are GMT +1. The time now is 15:03.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Images online photo albums