MK5 Diff Ratio

[Pmacnz]

Hi Guys, just joined the forum.
Bought a 1996 VG (MK5) 2.5TD manual 5 speed about 6 months ago as a delivery van, has a tail lift so is pretty handy.
Location is Perth Australia.
Anyway the issue at hand is what RPM is normal for this vehicle at 100kph (60mph)?
Mine is running at 3200rpm @ 100kp which is not ideal in my book. It is very low geared right through the range 1st being almost useless.
What is considered normal rpm @ 100Kph? and are there a various diff ratio for this model.
Thanks in advance for all input.
PMac.

[vanfox]

Go to: Mon Jan 29, 2018 7:47 pm Neils Transit all about changing diff.

[cherniy_chack]

Pmacnz,the ratio of 4.56 for the rear axle type 34 (5 studs) or 5.14 for the axle type 53 (6 studs) is the norm.
Your engine speed matches that.
Reducer 4.63 for axis type 53 can be found, 4,10 for axis type 34-none.

[Pmacnz]

Thanks guys, its a 6 stud axle so Ill be looking for a 4.63 ratio.

[cherniy_chack]

3200 rpm at a speed of 100 km / h?
Then at you more likely a reducer 5,83.
The gear ratio of the gearbox can be specified after decoding the sign on the passenger stage.
Section 16
Indicates the gear ratio of the rear axle by code:
B N L G J K M
3.91 4.11 4.56 4.63 5.14 5.83 4.18
http://transit-club.com/shield.gif
http://transit-club.com/sh_sield.gif

[Pmacnz]

Good info thanks Cherniy
Comes up as a J = 5.14
Look like I've found a better ratio second hand diff, looking forward to some better fuel economy and doing more than 90km/hr holding up traffic.
Crazy that it has such a low ratio, Perth is flat as a pancake, you'd have to travel about 4000km to find a decent hill.

[cherniy_chack]

Find the axis of 4.63-great happiness.

[wobbles]

did you complete this diff change ? mine is the same and was wondering what difference is

cheers

[rebuilder86]

im also in perth, mine is a mk5 VG 1999 SWB Low Roof, and at 100 kph in 5th its about 3100-3200 RPM, but i just checked that plate on the pasenger foot well, and provided i was looking at the right section, mine is a 4.63.
Im not sure how to do the maths to work out if perhaps mine actually got a replacement diff gears of the wrong variety at some stage in its life and also had the speedo adjusted to compensate perhaps?
Its jus tan obsurd rpm to be at 100kph, and cherniey telling us what we want is 4.63, well, thats apparently what im supposed to have, and it sucks!

[gotgcoalman]

My 4:63 ate itself ealier this year
Replacement was........4:63

An "indicated 90" (140 metric) before the noise gets too much is achievable fully loaded


Spedo shows 2 mph out @ 30 acording to those speed check light up things.
Not sure at higher speeds though.We'll assume 10% or so

No rev counter so I'll guess the RPM.
LOTS

Fueling turned up and extra air added via the rocker breather and blank plug on the manifold.

[rebuilder86]

A mate of mine, who is a genius has a program on his computer called gearcalc, and he used it to back calculate my diff ratio based on stock 5 sp manual, 100 kph, 5th gear, std tyres and we get 5.11. So if u have a 5.11 you should be at 3200 rpm at 100kph.

[twin wheel camper]

No genius’s needed all you need to do is jack up both rear wheels off the ground and put the van out of gear, then put a chalk mark or similar on the prop shaft and also on the tyre then turn a rear wheel and count how many times the prop shaft turns till the wheel turn 1 complete revolution, that’s it so if you have a 4.63 the prop will turn less than 5 times by the time the wheel makes a full revolution and if you have a 5.14 it will turn just past 5 turns.

[rebuilder86]

hes a genius coz he did it remotely.
woudlnt that methdo u describe, jsut turn the other wheel opposit direction?
i think ud need to get under the car and turn the prop shaft and do it backwards. unless u could somehow spin both wheel at the exact same time.
And even then, its liekly that one wheel woudl turn faster than the other because bearings arent perfect fluid.

[MinorMatt]

One wheel in the air, other on the ground. Double propshaft revs to give diff ratio.

Will be a 5.14 not a 5.11

[twin wheel camper]

One wheel in the air, other on the ground. Double propshaft revs to give diff ratio.

Will be a 5.14 not a 5.11

Matt don’t complicate things