MQ Patrol 4 speed to 5 speed

[esp22]

Hi, does anyone know if a 5 speed gearbox can be fitteed to an 1985 manual diesel mq?Also what type of gearbox would i need?One from a gq?Thanks

[David_S]

Fit the MQ/MK 5 speed box. I fitted the SD33T 5 speed box to my P40 without much trouble except shortening the input shaft slightly.

Both the SD33 and SD33T came out with the 5 speed box (FS5W81A). According to a 1984 Australian brochure I have the 5 speed was standard on all models except the L28.

Should just bolt up but:

1) You will need new drive shafts or shorten/lengthen your existing

2) The front drive shaft may foul the chassis cross member which might need to be modded slightly

3) You will need to fabricate/fit new rear mounts

[V8Patrol]

What he said ......... but corrected slightly

1) You WILL need to shorten/lengthen your existing drive shafts

2) The front drive shaft WILL foul the chassis cross member which WILL need to be modded slightly or removed and replaced further back along the chassis rails ( about its own thickness ~150mm )

3) You WILL need to fabricate/fit new rear mounts

&
You will need to mod the existing floorpan ( cover plate) in order to accomindate the new locations of the gear and hi/low shifters.





The GQ / GU box wont work in an MQ......... unless your willing to do a diff change aswell ( diff centre offsets are differant )

[David_S]

V8Patrol is right you WILL have to do those things, except I did manage to mod the chassis cross-member without relocating it. I just set a steel half pipe on an angle to match the shaft into the member and put reinforcing plates front and rear.

But then my shaft was only just touching and I in fact ran it for some years without the mod at all - maybe the P40 engine lifts the shaft up a bit compared to the other motors.

And as for the transfer lever I found it easier to mod the lever rather than the floor pan. Made a cut at the base and then tapped the top until it cleared everything and welded it up. Had to repeat the exercise when I lifted the body 1".

[esp22]

is the 4 speed manual a good gearbox or is it worth replacing??Are there any problems known with gearbox?Thanks

[David_S]

is the 4 speed manual a good gearbox or is it worth replacing??Are there any problems known with gearbox?Thanks

I never had any problems with the 4 speed box in 180,000 km and have had none with the 5 speed either. I have seen some reports of the 5th gear (overdrive) giving problems with heavy towing. Others might like to comment.

The 5 speed box gives a lower 1st gear than the 4 speed which can be pretty high and 5th is an overdrive unit which gives better economy.

The ratios are (there are three 4 speed boxes and two 5-speed

4 speed : 3.520, 2.160, 1.450, 1.000, 4.180 Rev up to Jun 80
4 speed : 3,519, 2.157, 1.449, 1.000, 4.180 Rev
4 speed : 4.222, 2.370, 1.440, 1.000, 4.622 Rev
4 speed : 3.897, 2.370, 1.440, 1.000, 4.627 Rev


5 speed : 3.897, 2.370, 1.440, 1.000, 0.825, 4.267 Rev
5 speed : 4.222, 2.370, 1.440, 1.000, 0.825, 4.622 Rev

I don't know (without a lot of searching in the parts book) which boxes came with which model except that the boxes with the lower first gear came later.

David

[V8Patrol]

All the info on the gearing and which box from what model has what gearing is all listed in the MQ/MK bible.

[pongo]

i have all the crap here if your serious can most prob deliver if i can get a few days off, my kids are up there anyways.

Is yours a divirced box or all in one, maybe up for transfer as well, etc.

My 5speed aint never gunna die, so i guess i dont need a spare

( touch wood)

BUT, Is it really worth the $$ and effort

[nastytroll]

I have fitted 2 mq 5 speeds to sd33's n all I had to do was weld another gearbox mount to the chassis n use the 5 speed throw out bearing block as its about 5mm shorter, also had to use 5 speed rear tail shaft or both shafts. Its been a while.
Done 1 in a ute n 1 in a wagon. never had to mod anything else.
They both had tl130 transfers.