The Nissan MQ Patrol 4WD FAQ File

Nov. 01, 2005 By Gary Winder
p>The Datsun/Nissan MQ Patrol was introduced in 1980 and continued in the same shape until until 1987. It is also known in some countries a the Nissan Safari. The model designation of both is the 'model 160'. This model replaced the G60 Patrol. The MQ Patrol came out in 2 door short wheelbase, 2 door cab/chassis and 4 door wagon (long wheelbase) form. Several different engines were offered: the SD33 3.3 litre diesel, a turbo diesel SD33T, the P40 4 litre petrol, and the L28 2.8 litre petrol. I have heard that there was a V6 model in Europe but I have not been able to confirm this. Patrols were shipped to Europe, the Middle East, Asia, Australia and South America with different options depending on where you lived in the world. The Patrol had several different body and trim options from deluxe packs with air conditioning, carpet and velour seats to bare bones vinyl floors and seats. The SWB had a removable resin rear canopy in a normal and high roof versions.

There are heaps of aftermarket parts available for the MQ patrol. However as it has been out of production for some time now, parts becoming harder to find and a little more expensive. There are still some basic aftermarket modifications you can easily make, such as suspension, bull bars, lights, wheels, winches etc. Panels and doors from the MQ are the same size as the later GQ and should fit onto your MQ without too many problems. Average price of a GQ door is about AUS$600. There is also some debate of model designations.

At some point in the MQs life, it became the MK and the change is noted by the headlights going from round to square. While some companies have products listed for both the MQ and MK, some just refer to years and some Nissan employees refuse say that there was ever an MK. In general, it is the 'MQ' term that gained the reputation and relates to the model shape. Suggestions and comments are encouraged. This is by no means the ultimate FAQ file. It is based on personal experience and a lot of reading. Some of the issues I have come across, you may not, and vice versa. If there is anything that you would like to add to the FAQ, please drop me a line.

ENGINES

1. Description

There are 4 engine available in the MQ range, two petrol and two diesels. The specs are as follows.
Enginetypedispcyl.bbore/strokecomp.max. [email protected]max [email protected]
L28Petrol2753686 x 79 mm8.6:1[email protected][email protected]
P40Petrol 6 85.7 x 114.3 mm7.8:184Kw [email protected]
SD33Diesel32466  [email protected][email protected]
SD33TDiesel32466  [email protected][email protected]

2. Things to watch for

The L28 engines are reputed to be strong engines. However they do blow smoke from about 100K. The only other weak spot with them is the head gasket. The L28 unit is a little under-powered in this car but is still no slouch. Towing is a bit of an effort. However there are many things that can be done about this. As this engine is popular in many different models in the Nissan range, there are lots of people doing lots of things to get more out of them. There are different crank, rod and pistons that will bolt into the block that can give you over 3 litres in capacity and different compression ratios.

The L28 was raced by many people and appeared in the Nissan/Datsun 280ZX in fuel injected and/or turbocharged form. Many mailing lists talk about this engine and there is an internal modification cheat sheet that is available. The P40 engine was carried over from the G60 Patrol. Don't know too much about it. Sorry. The SD33 is the MQ's diesel offering. It came in both normally aspirated and turbocharged form.

The Diesels are better suited to off roading and provide better low down torque and also better fuel economy. They also command a higher price on the 2nd hand market over the petrol versions. You can still buy 2nd hand Japanese engines today. Change your fuel filters every now and then! Don't forget the little one in the fuel pump too!

3. Modifications

L28. As this engine is popular in many different models in the Nissan range, there are lots of people doing lots of things to get more out of them. There are different crank, rod and pistons that will bolt into the block that can give you over 3 litres in capacity and different compression ratios. The L28 was raced by many people and appeared in the Nissan/Datsun 280ZX in fuel injected and/or Turbo charged form. Many mailing lists talk about this engine and there is a internal modification cheat sheet that is available. The best source of this info is at web2.airmail.net/bworley/z-club/l28combo.htm Other modifications that will give more go to the L28 include exhaust headers, which have the effect of increasing power slightly and also moving the torque peak into a more usable RPM range - depending on the design of course.

Porting and port matching the head will make the most of the extractors/headers as will a new cam and carburettor to suit. The correct combination of all components will give more grunt without the loss of too much bottom end power. Twin carburettors are an option and should be really easy to fit as they came out on L series engine as standard from Nissan. Electronic ignition from other models should also be easy to fit, and provide easier starting, smoother engine operation and idle. Fuel injection would be a little harder, but the head on my engine (N42) is already drilled to accept injectors. I'd like to put on a turbo, but a little impracticle in the bush. I think I'll go with KA24E pistons on L24 rods, N42 head. about 9.3:1 and just under 3litre capaciy. P40. Again, don't know much about this engine, but the same old route of compression, cam, carby and exhaust should get the thing moving.

Don't know of any common problems. SD33. Don't know much about Hmmm.... I'd get a SD33T and put it in. No question. If you can't, they tell me that exhaust headers / extractor do make a difference on a diesel engine. If it's old, take it to one of those places that cleans diesel engines internally. If they get it right, you'll notice the difference. Only other option would be a rebuild and clean up the head. I don't see why the only port'polish rules can't apply to diesel engines. SD33T.

Mike Fish from New Zealand email me and said that he has increased the boost on his SD33T from 6psi to 13 psi and this has resulted in an average increase of 25% in both power and torque. Mike has also fitted a 'FuelStar' to his fuel system and says it's given about a 10% increase in power and proformance, and also made the vehicle run smoother. See a diesel engine expert before you do anything like this as just winding up the boost is going to cause problems unless you know what you are doing. If it's worth doing right, it's worth paying someone who knows how to do it. And that's not me. Swaps There are heaps of engine swaps available for the MQ range. Marks 4x4 Adaptors in Melbourne Australia are the best here. www.ozemail.com.au/~marks4wd/ They make kits to allow the fitting of Holden trimatic and turbo pattern V8 engines, Chevrolet petrol and diesel V8s, Holden 6s, Isuzu Diesels, Ford 6s, Range Rover/Leyland V8, Oldsmobile V8 Diesel and the latest model Patrol engines - TB42 4.2 litre petrol and TD424.2 litre diesel.

Drivetrain

1. Description

Early model MQs had either a 4 speed manual or three speed automatic gearbox. '85 model diesels came with 5 speeds while the petrol models got the 5 speed in '86. The 4 speed model no. is F4W81A in Patrol. There are two types of Transfer case available, the T130A and the T100L. The T130A looks larger than the T100L, and can be identified by what looks like a flat rocker cover type top on it. The T100L seems smaller from the book, less bulk, less oil, less teeth, different ratios. The automatic transmission was a 3N71B if that means anything to you.

The SWB Patrol had the gear box mated to the transfer case while LWB models had a remote transfer case. The drive shafts run up the right side of the vehicle and both diffs are offset to the right side. These both hang down underneath the body and are covered by two bash plates, one simple alloy, one double plate steel. The amount that the transmission hangs down is a criticism of the MQ. Many Patrols have either very dinted bash plates or none at all.

There is also one other bash plate underneath the engine that joins onto the transmission plates. The gear box is accessed from the middle of the three plates and from there you can check, drain and fill the gear box oil. Filling is a little tight so I suggest an oil bottle with some sort of hose. The transfer oil can be checked from the back of the last bash plate. The park brake is a drum brake arrangement, mounted on the rear drive shaft. It is operated by cable to the hand brake lever. This mechanism looks a bit weak and I don't think it could stand up to being used for hand brake turns. I once had a mate (no longer) who tried pulling on the hand brake at about 100 km/h on a freeway and while it didn't break it, it didn't lock the wheels either. So I'd suggest to go easy on it and only engage it once the car has fully stopped. The gearbox also had provision for PTO equipment and a PTO winch is mentioned in the service manual.

2. Things to watch for

The syncros wear easily on the 4 speed. Mine are almost non existent.However at 392,000ks, I can't really complain. Only other problem is the oil seals between the gear box and transfer case. Oil travel between the two is the result. The clutches usually last about 150,000 - 200,000ks and it's a good idea to replace the clutch fork pivot and the bearing at the same time as the clutch. Trust me, I didn't and the pivot broke soon after, meaning that the whole lot had to come out again to put in a new pivot.

With a broken pivot, the cluch will disengage by about 99% when you push the pedal so sometimes it still has engough contact to keep the gears spinning. This can cause you to crunch between the gears. Usual replacement time is about 6 - 7 hours. Some people will drop the gear box to replace the clutch, others think its easier to remove the engine. The seal on my PTO cover started to leak. I had to make a new one from a sheet of Do It Youself gasket stuff from the local parts store. The oil seal on the front diff on my car cracked and the oil leaked out. This actually happened before I bought the car from my brother inlaw. He and my sister managed to drive it with no oil in the diff and you can guess what happened. AUS$1200 to fix. Lucky I got it at a reduced price because of.

3. Modifications

ARB Air Lockers and Detroit lockers are available for the rear differential. As limited slip 'diffs' were standard on most models, aftermarket lockers may not be needed unless you are either a serious off roader or your standard LSD is worn out. I don't know of anything available for the front diff at this stage. Check out the Diff info at http://www.off-road.com/nissan/nisdiffs.html Please note that some of the diff codes for rear diff's, are actually used as front diff's in the Patrol. Gear box Marks 4x4 adapters also make heavy duty 5 speed gear boxes with lower 1st and higher 5th gears. The box is based on a Nissan commercial box and will replace both the factory 5speed and 4 speed. When replacing the 4 speed box, the transfer case is moved back and the front drive shaft needs to be lengthened and the rear shaft shortened. This box also uses a 300ZX clutch kit, and as far as I know, there are heavy duty 300 clutch kits available such as Centerforce etc.

While Marks makes their gear boxes, I have been told that a genuine Nissan box from a light truck will go in with minor mods. Again, check out Marks 4x4 adaptors at www.ozemail.com.au/~marks4wd/ Two wheel options were available on both short and long wheel base Patrols. The normal 16x6.5 'skinny' rims and a few different sizes of tyres, or 10.5R15 LT wheels on 15x7 white rims. The 'wide' wheels were part of a factory option know as a 'wide wheel pack' and consisted of the wheels and tyres, metal flares, chromed steel side steps and a swing out tailgate mounted spare wheel and jerry can holder. In Australia at least, the wide wheel pack meant that the indicator lights were moved from the corners of the chassis down to the bumper bar. This was to comply with local design regulations that stated that you must be able to see the indicators with out obstruction. The new location of the spare was considered to cause an obstruction. The spare wheel on the 'skinny' models was mounted underneath the rear of the chassis, covering the fuel tank.

When buying second hand, watch out for people selling 'wide wheel' packs as a feature. Many are either rubber of fiberglass flares, alloy side steps and a single spare wheel carrier on the back. These are not factory wheel packs so don't let them fool you.

Brakes

1. Description

The brake system is fairly typical for this vintage 4x4 with front ventilated discs and rear drums with power assistance. The front disc caliper uses a single piston. Rear drums are supposed to be self adjusting.

2. Things to watch for

The braking power of the Patrol is below par compared to late model 4x4s. The brakes fade if used hard. Using harder compound pads to over come brake fad will make the rotors suffer with reduced life and warping. The back brakes need regular adjusting to ensure that the fronts don't do all the work. Calipers should be overhauled as the Kilometers grow.

I managed to go through a set of rotors in 30,000ks due to uneven wear. This was fixed by a caliper overhaul, although they are playing up agian. An overhaul is never as good as a new one, Unless you find a brake guru. The firewall also flexes slightly when you use the brakes hard, and can lead to other parts breaking or wearing out like the master cylinder and brake lines. I have not heard of this leading to sudden or catastrophic failure, just a bit of added wear.

3. Modifications

I'd love to put discs on the back or the later model Patrols twin piston calipers up front or both, however this would be expensive. Late model Patrols (GQs) went to 16 inch rims to allow the larger brakes, so you would be up for rotors, calipers, master cylinder and a complete wheel and tyre swap. When I win the lottery I'll let you all know how it goes. In the mean time I might just try for a set of discs at the back. A lot of people do this sort of swap on other Nissan/Datsuns, like 510s (1600 is Aus) so it shouldn't be too hard. I've heard of people grafting anti lock braking systems from 300ZXs onto cars, and I don't see why you couldn't apply this to the Patrol. One thing that I am sure of, is that the braking system needs to be improved before you go and add high power V8 engines and automatic transmissions. Mike Fish from NZ recommends metal king brake pads and says they are good for about 30% improvement in braking performance.

Suspension

1. Description

MQ Patrols all came with live axles and leaf springs. Early model Patrols had a lot of problems with the springs and any half serious driver fitted aftermarket spring kits. In '85, the MK come out with what was regarded as the best factory suspension. 6 leafs at the rear and 5 at the front, with the 5th leaf being flat. Various couplings of the front springs to the chassis were used, from rubber bushings all 'round, to greased metal all 'round and combinations. Sorry, but I can't be more specific as to what came out in what year.

2. Things to watch for

The rubber bushings wear easily, and those model with greasable bushings also wear if not maintained. Grease the suspension bushing VERY regularly. Once the shackle and bushes wear, the front will wander and steering will be a problem. Combined with braking, bumps, or warped discs, the front wheels can start to shake left to right and build up such momentum and force that the steering wheel is ripped from your hands and the front of the car bounces up and down a few inches into the air as the wheels jump violently from lock to lock. If you get anywhere near this point, spend money on fixing the slack in the front end..... fast!

A nice bloke sent me dropped me a line to say that his Patrol had the same wheel shaking, but it was the bearings in the front wheels (knuckle bearings and connected other bits). Come to think of it, I had these replaced when I had an adjustable knuckle bearing put in. (refered to as a king ping bearing in Oz.) The front left suspension geometry is also a problem as is with most 4x4s. It is termed the 'steer left' syndrome in Oz where the car doesn't like roads with camber. After market king pin bearings are made with an adjustment in them to allow correct alignment. These are sometimes prone to breaking if punished, this is because they offset the bearing seat, and this means that one side of the seat is thinner than stock.

Leaf springs also sag with time and lose their spring. Many Patrols sit low on the right side as that is where the driver sits and all of the running gear is also located along the right side. Aftermarket kits are set a little high on the right side to counter this. Australian steel is supposed to be better than Japanesse steel and is a selling point of my aftermarket springs. But I'm an Australian so I'd have to say that.

3. Modifications

Polyurethane bushings give better handling and deform less under load than rubber and they are available for the rear springs and shackles, and front springs and shackles. Replacement shackles are also available as a whole or just the greasable pins. Down point is that if you get dirt in the poly bushes, they wear quicker than the rubber ones. Gas shock absorbers, or dampers will stop a lot of body roll but will make the ride that little bit harder. Worn shocks really hurt the handling of this 4x4, so I'd put gas shocks on without a second thought. The on road performance gain is worth the extra expense. Shocks can be bought for normal height, or for longer travel if you by longer travel springs. Rancho in the US sell gas shocks for this model Patrol! Only $37 US buck each. I'd like some feedback on anyone who has a set of these please. Many aftermarket spring kits are available for the MQ Patrol and most will give you about 1-2 inches of extra lift, depending on how your current springs are. Some are just copies of the standard '85 springs made to match the original, and others give more lift, more load capacity, more travel etc.

Body

1. Description

There were two basic body shapes available. A 4 door long wheel base wagon and a two door short wheel base body. The LWB had a metal roof for the entire length of the body while the SWB had a metal roof only over the two front seats. The rear was covered with a removable resin canopy which allowed 'open air' driving. In other countries, there was a high roof version of the resin canopy which was several inches higher than that of the standard version. Towards the end of the MQs life, the SWB came with a metal canopy that was very similar in appearance to the resin canopy. The differences between the metal and resin versions were that the metal canopy was lined, color coded and non removable. The LWB seated 7, while the SWB seated 4, via two bucket seats up front and a folding bench type seat at the rear.

The bench seat folded up and out of the way to increase the load carrying space at the rear. Later SWB models had a wider bench seat that sort of turned up at the ends to negotiate the rear wheel arches, thus allowing 3 rear seats, allowing 5 in all. About '84-'85 the head lights went from round to square and it's this feature that will be asked about if someone is trying to work out if you have and MQ (round) or MK (square). Suspension seating was also introduced in '86 and the resin canopy went metal and non removable in Australia. In other countries, the resin top was still available. Most models had volt meter, oil pressure gauge, tachometer, 4WD indicator, park brake, temperature and speedometer.

The wide wheel packs had a spare wheel carrier mounter at the back that was secured with two catches, metal flares and chrome side steps. The metal flares were all black in early models but later came out color coded, about the same time as the metal canopy.

2. Things to watch for

Rust. These things rust just like any other car, especially now as the average life of an MQ/MK is about 14 years. However rust is not as big a problem as it is with some other cars. The tail gate latches on the wide wheel packs tend to loosen up. To stop this I filed a groove in the locating post and put a rubber washer in it. The groove holds the washer in place as the post tapers. This helps to keep the tail gate tight and it stops rattling. A real plus on bumpy roads as one latch used to pop open. The radio antenna is prone to breaking off when you reverse under things with it extended. I cut the base of one of these metal antenna and jammed a fiberglass whip antenna in it. This is much better and I haven't managed to break it.

Radio reception is awesome and kicks the butt of even the latest model pasenger cars with aftermarket mega steroes.

3. Modifications

Aftermarket seats are popular and provide better support for long distance driving as is recovering, etc. Parts such as GQ center consoles also fit in and I have seen this done, and I'd like to do it myself. Carpet is also a popular addition and several companies offer pre-cut kits. I bought a pre-cut kit and tried to fit it myself. It didn't fit well so I took it back and the guy told me they make them a bit big so you can trim them back (why buy a pre-cut kit then?) Make sure your pre-cut kit is really cut to size and get a guarantee if mail ordering. One thing I'd like to do is change the interior color from baby poo brown to grey. Not easy, but I'll start on the easy bits. I'll swap out what I can with parts from other model Nissans, and cover the rest. The dash and head lining are the real problem areas and will need expert help (cash). The standard radio that came in my Patrol was a single speaker AM radio unit. There are extra speaker holes and I have added an AM/FM cassette unit, two front speakers and the back is in sort of a change at the moment.

I will have one sub woofer right back at the rear, and two smaller speakers behind the front seats. This sounds better than having two at the front and two full range right at the back. You can really notice the distance between the front and back speakers. The two in the middle will fill this sound void. The standard radio is easily removed and a replacement fitted. A CD player skips too much for my liking and tapes are just a little more rugged. Tinted windows make these 4x4s look good. I've also seen the rear canopy with a single piece of glass along the side instead of the normal two piece sliding windows deal. It was in northern Queensland, was tinted and looked really slick.

Electrics

1. Description

The electrical system on the petrol engines is 12 volt negative ground. Early diesels were 24 volt as far as I know, and went to 12 volts at some stage. Wiring looms were made up to cover all options around the world. Austalia didn't get fog lights, but I like to fit them. If anyone could send me some photos on the fog light bits, (the lights F&R, the switch, the loom plugs etc) I'd be very happy. The alternator is a wimpy 50 amps on Australian models, and I think 60 amps was the max available. European models had alternators with internal regulators while Australian models had external voltage regulators.

However the wiring loom should cater for either. The external regulated ones are marked LT and the internal ones are LR. So you get LT150 (50 amp) and LR160 (60 amp). The Wide Wheel Packs had slightly different wiring for the bumper mounted indicators at the back and had simple red tail lights in the place of the standard models indicators lenses. Wiring is also there for fog lights and air conditioning, if you didn't get it fitted from the factory.

2. Things to watch for

Alternators wear out just like any other moving component. I have been through about 4 alternators including a few extra sets of brushes and bearings. I also managed to blow a diode pack as the + lead from it wasn't tight. This allowed movement and this created sparks which slowly arced away at the terminal post until it cut it in half. Then the + lead shorted to ground and blew the diodes. Replacement alternator time. The other thing I have had trouble with is the high beam switch.

I don't know if it was just lots of use or the fact that the wiring has been changed to drive relays instead of globes. I wouldn't expect relays to draw more than the standard 130 watts of high beam load. Anyway, the metal contacts in the switch unit in the steering wheel carbon up and don't work properly. This caused the highbeams to come on by them selves, not turn off when you wanted, even turning all lights off. This came be fixed by pulling the steering wheel off, and the switch unit and cleaning the contacts inside it gently with a points file. I've done this twice.

3. Modifications

I've added relays on the main lights.I did this so that I could run 55/100 bulbs without putting too much stress on the stock wiring system and to eliminate any drops. It also has a trailer plug on the back. I've added a stereo, CB radio and soon I'll add a mobile phone car kit. I'd also like to add a small light for the rear cargo area and a new horn. The stock horn is wimpy for such a rugged looking truck! I've finally got an upgraded alternator. As the factor alternator is Hitachi, parts are expensive and hard to get. I have sourced a Bosch internally regulated alternator from a Nissan Bluebird series II.

It was then modified for higer out put by doing something tricky like joining two of the winding together. The plus of doing this is that Bosch bits are easily and cheaply available, and came out in Australia on other Nissan cars with L series 6 cylinder engines. So, mounting brakes are easily available, and cheap. The alternator cost me $25 from pick-a-part, and the braket was $6. (I broke a bolt off in my braket.) Bosch parts are used in Australian made cars also, so you could be fairly sure that you could get parts in the outback if you break down. The modification to the alternator cost me $100 but I'm sure that you could do it yourself if you knew what to do. from looking inside it looks like about 10 minutes work and no parts needed. It did however measure an output of 110 amps. The downside of this modification is that the output is lower than an unmodified alternator when the revs are very low like at idle. The External regulator must be disconnected and one of the wires from the original plug into the back of the alternator need to be connected to the new alternator, and the other wire is not used. I think it's the fatter wire that is not used, but play it safe and take it to an autoelectrician. Once you've done this, wire your spotlights directly to the output of the alternator so you don't put too much load on the fusable links between the batter and alternator.

References/Bibliography

Thanks to Dennis Lou as I followed his FAQ format, and some of these references. Thanks to the readers that have given feedback and helped to correct me on the errors in the FAQ. "How To Modify Your Nissan/Datsun OHC Engine", by Frank Honsowetz
Nissan Part #99996-M8012, ISBN 0-89586-353-7
"How to Rebuild Your Nissan/Datsun OHC Engine", Monroe
Nissan/Datsun Service manual model 160&61 series
The Honsowetz book is really only useful if you are doing a ground up rebuild and it confusingly refers to the Z engines as the LZ20, LZ22 and LZ24. Nonetheless, it is a helpful resource if you are serious about your engine. The Monroe book is supposed to be a companion to the Honsowetz book, but I have not read it.

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