155 Q4 viscous coupling testing..

**nick** · 30-08-12, 17:50

hi guys
today i tested viscous coupling on my car..it is good condution..
[ame="http://www.youtube.com/watch?v=UORCFe8W4SE"]Alfa Romeo 155 Q4 viscouse couple testing - YouTube[/ame]

**Steve Webb** · 30-08-12, 18:37

Interesting method. Not sure its in the workshop manual though.

**nick** · 30-08-12, 18:40

yeah Steve..you are right..but it is simple

**MaxiBoost** · 31-08-12, 07:17

if rear turn free and car doesnt move, your VC is dead

nick, your rear faster than front ?
Im not sure this is correct?

this name is Jack test
be carrefuly when you test

here you find some bmw jack test video
you know bmw 325ix 4whell drive

[ame="http://www.youtube.com/watch?v=BYQr-sNXZps"]BMW E30 325ix Jack Test - YouTube[/ame]
[ame="http://www.youtube.com/watch?v=oGStw9TneN4&feature=related"]BMW 325ix jack test 2 - YouTube[/ame]
[ame="http://www.youtube.com/watch?v=a4exvt2_Yjc&feature=related"]BMW 325 iX 4wd-test - YouTube[/ame]
[ame="http://www.youtube.com/watch?v=4cbGeSJ9dHc&feature=related"]BMW 325iX VC test - YouTube[/ame]

[ame="http://www.youtube.com/watch?v=9B0ANOI3GcM"]BMW e30 325IX Transfer Case and Viscous Coupling Test - YouTube[/ame]

**nick** · 31-08-12, 07:45

i am not sure front and rear equal speed.

**Steve Webb** · 31-08-12, 08:16

I can't remember the figure, but I think the workshop method involves jacking one front wheel up and using a socket and bar type torque wrench on a wheel nut, turning the front wheel and seeing what torque it takes to move it.

**wrinx** · 31-08-12, 08:39

Does if the jack test account for load on a worn VC? I think the method described by Steve is better...although not as immediate!

wrinx

**MaxiBoost** · 31-08-12, 09:35

Originally Posted by Steve Webb

I can't remember the figure, but I think the workshop method involves jacking one front wheel up and using a socket and bar type torque wrench on a wheel nut, turning the front wheel and seeing what torque it takes to move it.

steve
this is your test I think ?

[ame="http://www.youtube.com/watch?v=7eoVaHLrjaM"]Freelander(Land Rover) VCU (Viscous Coupling Unit) Test. - YouTube[/ame]

[ame="http://www.youtube.com/watch?v=Oh01nQgh7z8&feature=related"]Freelander 1 2001 v6 Viscous Coupling Unit VCU Torque Test - One Wheel Up Test - YouTube[/ame]

**Steve Webb** · 31-08-12, 10:19

Yep that's pretty much it but you use a torque wrench to turn the wheel so you can see how much resistance there is.

**Steve Webb** · 02-09-12, 07:45

Originally Posted by nick

hi guys
today i tested viscous coupling on my car..it is good condution..

Just out of interest, where are you placing the jack? Under the rear diff?

**nick** · 02-09-12, 11:28

hi guys
we have tested viscous couple yesterday but we can not understand how the condution of viscous couple is?

**nick** · 02-09-12, 11:29

these are videos viscous couple test
http://www.youtube.com/watch?v=K39UN...ature=youtu.be
http://www.youtube.com/watch?v=fpS8j...ature=youtu.be
http://www.youtube.com/watch?v=7_0Qi...ature=youtu.be
http://www.youtube.com/watch?v=DedLU...ature=youtu.be
http://www.youtube.com/watch?v=uzpq8...ature=youtu.be
http://www.youtube.com/watch?v=laN5g...ature=youtu.be

**Steve Webb** · 02-09-12, 15:42

It looks to me as though the VC is a little loose, as in the fluid has lost some of its viscosity over the years and the unit might not be locking up as quickly or as solidly as it should be.
I certainly have to put more effort into moving the wheel when its jacked up, and I can't get it to move as quickly as you did in that last video.

Have you taken a look at this page on the website? http://www.berlinasportivo.com/pages/coupling1.php

**nick** · 02-09-12, 20:36

i bought new silikon viscous oil..oil is right? any idea?

**nick** · 02-09-12, 22:40

hi again
which silicon oil uses viscous couple? ak 60.000 or ak 100.000 ?

**Steve Webb** · 03-09-12, 15:50

I've just taken a look through this pdf: http://www.berlinasportivo.com/Techn...Drivetrain.pdf

Section 15 deals with the VC, its got loads of details about checking and adjusting the VC but I can't see anything in there about what fluid to use.

The number refers to the viscosity or thickness of the fluid, higher the number the more viscous.

**MaxiBoost** · 20-02-14, 22:45

I change my car`s viscous coupling and share with you
its very handling now, its very important part.
Car always oversteer when turn fast cornering before, now its like a train

You need drive car an half hour before the test. Vc must be come to operating temperature.
(thanks to @nick and @Barış from subaruimpreza.org forum)

Jack test:
wheels must be turn same speed when after car is moving
[ame]www.youtube.com/watch?v=Qt3jJAPvJ-0[/ame]

Before
you can see, rear wheels turn many time
and after the car move rear wheels turn faster than front.
[ame="http://www.youtube.com/watch?v=Dwsz9dLYutk"]Alfa 155 Q4 old viscous - YouTube[/ame]

After
rear turn just quarter before moving
then turn same speed front
[ame="http://www.youtube.com/watch?v=EvAYR8nE4TY"]Alfa 155 Q4 new viscous - YouTube[/ame]

This is handy check:
lift car, gear is neutral position and handbrake on (lock rear wheels)

Before
[ame="http://www.youtube.com/watch?v=vlqyVUpIO9k"]Alfa 155 Q4 old viscous - YouTube[/ame]

After
[ame="http://www.youtube.com/watch?v=_poBMRqSCec"]Alfa 155 Q4 new viscous - YouTube[/ame]

some pictures about viscous coupling:

**wrinx** · 21-02-14, 00:09

Thanks for that....I'll be checking mine soon!

How much is a replacement coupling or refurbishment?

wrinx

**MaxiBoost** · 21-02-14, 06:14

Originally Posted by wrinx

Thanks for that....I'll be checking mine soon!

How much is a replacement coupling or refurbishment?

wrinx

we dont %100 sure
@nick buy it from itally
seller tell him: "this is new" .

**Suzumushi** · 21-02-14, 15:42

Originally Posted by MaxiBoost

we dont %100 sure
@nick buy it from itally
seller tell him: "this is new" .

What kind of silicone oil have You used ?
(brand/type) will be very helpful

or meaby someone else can recomend ? something
as i have everything on the table i will do service for visco also.

regards

WS

**MaxiBoost** · 22-02-14, 14:02

Originally Posted by Suzumushi

What kind of silicone oil have You used ?
(brand/type) will be very helpful

or meaby someone else can recomend ? something
as i have everything on the table i will do service for visco also.

regards

WS

I install new vicouse now (not %100 sure)

but Im trying 30.000 cst silicon oil before
30.000cst (30k) very thin, dont use...
original visco use ~80k silicon oil I think
so my advice you can use 100k (100000cst) oil

you never full fill it
aprox %10-%15 air space need
put silicon oil %85-%87 in viscous coupling

and placement important also
VC have 37 metal plates
19 plate big (left in picture)
18 plate small

You put in case one big plate, one small, than one big, one small
but I dont know well direction
its well important too

last important plate face
how can I explane it I dont know
put all plate in case one face

take a plate your hand
touch corners and holes and feel it
one face sharp all plate
must be all plates face same direction

ask here any other questions

hakan