5spd conversion to 4.0P also MQ rear diff

[Dirtyhaze]

Hey guys.
I'm restoring a 76 swb and stumbled accross this forum so I thought I would throw some questions out there. Thanks in advance for any feedback.
So what's the best way to go with a 5spd? I read another thread, a Marks gearbox sounded popular but another guy suggested a cruiser box bolted to the back of the motor so as to use the cruiser clutch, bell housing and transfer case.
Basically after people's opinions and any issues involved with the change over.

The other thing I would like to do is put an mk/mq disc brake front end in. I've read that all you need is the diff, master cylinder, springs and the front mounts have to be brought out 10mm. Apparently this all bolts in without dramas?
Can you use a mk/mq Rear diff also? Because I would love a limited slip diff and the ability to run front and rear air lockers.

I have thought it might just as easy and as costly to buy another swb patrol from 1980 to 1995 and just do a body swap. Then I've got the possibility of having the 3.3 or 4.2ltr turbo diesel.

Thoughts?

Cheers guys

[RiverPatrol]

Going to have to wait for some Australian members for these answers. We didn't get the mq in the states to be able to try any of this.

[Johnny Roadkill]

Toyota parts in a 60 Patrol ?

Hey, if it works for you go for it - but all 3 of the 60 patrols I picked up for under a grand each had the Marks 5-spd box in them, so they're not hard to find. In my opinion, if you're going for a motor swap ( eg TB42, TD42, L28, SD33, P40 ) then use the 5-spd ( and perhaps the transfer ) from the donor if you can to save having to use adapters.

Fitting a front MQ diff involves either moving the spring mounts on the diff inward by 15mm each side ( can be tricky as I understand the pumpkin gets in the way on the short side ) or the chassis spring mounts outward by the same amount. I believe MQ ( or perhaps even GQ ) front brakes can be adapted to the 60 diff but if you want the locker option you'll have to do the MQ diff swap.

The rear diff I'm not sure about - there are posts on here about that ( it can be done ), just use the search option. I know there are differences between the MQ and MK, which is also explained elsewhere. If I can I'll get under my G61 and have a closer look at the rear diff this weekend which might be useful too ( G61 = G60 + MQ hardware ).

Having a look at the 60 and G61 workshop manuals on this forum might help too, they cover the 60/G60, G61 and MQ ( 160 series ) and comparing the specs might shed some more light on it.

good luck !
cheers,
D

[Dirtyhaze]

Thanks Johnny. Yeah I will get onto some reading.
How do you find the p4.0 with a 5spd on the back of it?
Will it sit on 110kph comfortably? And take off in first gear with ease, unlike the 3spd

[jazie]

I have the 4spd mq with p40 and it's a little underwhelming, wish I had the 5 and!

[Johnny Roadkill]

Hi Dirtyhaze,

I haven't had the time to drive the P/5spd much in the last couple of years unfortunately, and to be fair I've never driven a P/3spd Patrol to compare it with since all mine came with the 5spd already done.

Having said that, 1st is great - as others have said in the past a little short for road use maybe - but useful offroad or for towing and I suspect it would be a blessing when bigger tires are fitted to help the overall crawl ratio. For me, I like an overdrive 5th but to be honest the old P motor doesn't have the grunt to make full use of it except on flats or downhills, at least with the Stromberg carby fitted to mine - I haven't taken it past 90kmh personally, mainly because I have yet to rebuild the brakes properly - but if you want to do 110kmh without huge tires I think an overdrive would be good to keep the tractor-like P motor in it's happy zone. Perhaps with a Holley 350, extractors and a fresh rebuild it would come into its own. Looking at the ratios the Marks 5spd is almost like a standard 3spd with an extra gear at each end - and a synchro on first - I did take it up a loose rocky track last year in low range and in 1st it walked up nicely, even with 9.5" tires at road pressures.

Sorry, the weekend got busy - I'll measure up the differences between the spring separations in the G60/61 for you shortly.

cheers,
D

PS - if Swerve sees this he might have useful info for you - I understand he likes to drive his Patrols fast and has experience with the MQ diffs and lockers on a 60 Patrol.

[r1lark]

all 3 of the 60 patrols I picked up for under a grand each had the Marks 5-spd box in them, so they're not hard to find. In my opinion,

Wow, sounds like these Marks 5-speeds are thick on the ground in Oz. Maybe y'all can load up a shipping container full of them to ship to the USA?

[miller]

MQ diff will drop straight into the rear. Johnny has already answered the front diff.
Swapping a 60 body onto a later model chassis will get complicated as you will need to match the ADR's for the year of the chassis.

I have MQ diff up front in mine and a lockable rear diff thanks to a later model H260 internals.

A P motor at 110km/h???? Haha down hill with a tail wind!

Mark's 5 speeds do show up from time to time. I have 3 left. I wouldn't really say they are think on the ground, rare enough that people hang onto them when they get them and fetch good money when they sell.

I have 3 registered G60's, I drive them all. 2 have Mark's in them one is a factory 3 speed. I honestly don't know why people are so hell bent on swapping out the 3. I like the 3 speed, it's fun to drive and the vehicle is what it is.... 40 years old!
If it's not registered, get it registered, drive it and then worry about stuffing around with all that.

[r1lark]

I have 3 registered G60's, I drive them all. 2 have Mark's in them one is a factory 3 speed. I honestly don't know why people are so hell bent on swapping out the 3. I like the 3 speed, it's fun to drive and the vehicle is what it is.... 40 years old!

I do agree, there is not anything wrong with the 3 speed. I guess I was young and stupid, but in the mid-70s I drove my Patrol a lot at interstate speeds, sometimes on 6 - 8 hour trips. No problem keeping up with traffic, and the engine didn't seem to be wound too tight. And that was with slightly shorter tires than the originals. Granted, the nationwide 55 mph speed limit was in effect then, so I suppose I would drive around 60 mph.

[Johnny Roadkill]

ok, got under the Patrols with the measuring tape - here's the leaf spring separations ( centre to centre ) as close as I could measure them - there's a few mm of variance in how the u-bolts are positioned on the housings so I measured at the chassis mounts :

G60 - Front 700mm, Rear 1010mm

G61 - Front 730mm, Rear 1010mm

fwiw - I have had a look at lockers, nothing I can find for G60 diffs but ARB airlockers are available for C200 MQ front and C200/H233/H260 MQ rears ( H260 has different spline count than G60 version I think ), and autolockers are available also. E-lockers don't cover MQ diffs unless I've missed something. CIG lockers work on anything though, heehee

cheers,
D