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MQ centres

Posted: Wed Sep 24, 2003 8:47 pm
by Screwy
Hey guys,

I need a quick run down on the rules of swapping diff centres in an MQ.

1. Do the fornt and rear have to be the same ratio, ( id assume so but doesnt hert to double check ) ???

2. What effect would come of putting the centres that are in an MQ with an L28 motor into mine with an SD33 ??
The petty ones have a rear LSD, but im asking about acceleration, tyres, power etc....

Wouldnt the ratios be different for a petrol???

If not, then are the gear boxes in all MQ petty and diesels the same???

cheers,

BTW Thanks for all your help on this stuff ive been asking, its just ive aquired a petty SWB MQ, and am working out what parts i want to swap into mine, as well as the things i want to fix up.

Thanks in advance,

Screwy

Posted: Wed Sep 24, 2003 11:27 pm
by ozy1
for question number 1, if you wish to run the same size tires all round, the diff ratio must be the same otherwise you will end up with transmission wind up,

but, just say you were building a mud racer

i think it may be possible to run 2 different size tires on 2 different ratios, as long as the overall rolling diametre is the same,

anyone correct me if im wrong.

Shawn

all info in the above statement was believed to be correct until some one brighter than i, came along and shot me down quicker than you can say "WRONG"!

Posted: Thu Sep 25, 2003 6:02 am
by jessie928
ozy1 wrote:for question number 1, if you wish to run the same size tires all round, the diff ratio must be the same otherwise you will end up with transmission wind up,

but, just say you were building a mud racer

i think it may be possible to run 2 different size tires on 2 different ratios, as long as the overall rolling diametre is the same,

anyone correct me if im wrong.

Shawn

all info in the above statement was believed to be correct until some one brighter than i, came along and shot me down quicker than you can say "WRONG"!


If you run 2 different ratios you must run 2 different tyres with different diameters.

fir eggzaMPLE, if you run 4.6 at rear and 4.1's up front you need to put 35's on the rear and standard 31's up front to equalise the ratios or thereabouts.

JEs

Posted: Thu Sep 25, 2003 8:44 am
by ozy1
thats what i was gettin at,

Posted: Tue Sep 30, 2003 6:22 pm
by Screwy
Do u guys have any idea what the diff ratios would be on a stock MQ diesel (sd33) 4sp ?? or where to find it out ??

Because i have heaps of 4.6 spares, and want to know if i can use just one of them.

cheers.

Posted: Wed Oct 01, 2003 12:22 am
by V8Patrol
there are a couple of diff ratios availiable

C200===4.625 to 1
H233B==4.625 to 1
H260===4.875 to 1


Two gearboxes were alicated to the MQ Patrol, the F4w81A ( 4 speed) or the FS5W81A (5 speed) ratios are as follows...
F4W81A
4th..........1.000:1
3rd..........1.449:1
2nd..........2.157:1
1st...........3.519:1
Reverse....4.181:1

FS5W81A
5th..........0.825:1
4th..........1.000:1
3rd..........1.440:1
2nd..........2.370:1
engine with turbo
1st..........3.897:1
Reverse...4.267:1
engine without turbo
1st..........4.222:1
reverse...4.622:1

Two transfers are also availiable, the T130A and the T100L
Ratios are......
T130A
High.........1.000:1
low...........2.220:1

T100L
high..........1000:1
low...........2.074:1

Posted: Wed Oct 01, 2003 9:22 am
by Screwy
Thanks, How do i tell what mine runs though?

Posted: Wed Oct 01, 2003 10:47 am
by V8Patrol
easiest way is to get a mate to help for starters.... then jack up the back of the rig then put a texta mark you can see easily on the tyre and on the drive shaft. get ya mate to turn the wheel one full turn and you get under neath and count the revolotions the drive shaft does, it will do 4.6 turns if its a 4.635 to 1 diff centre and 4.875 turns if its a 4.875 to 1 centre.... so easy it makes ya sick !!!!