Towing with a Patrol

Thanks Pinko...unfortunately I don't have the Ultimate until April so can't get onto their forum until then.....but I certainly will. Thanks for the tip.

Thanks for the tips....sounds like commonsense to me.
Cheers

I agree with Stan, but admit to having had some misgivings in the past.

I have a 2000 Patrol (ex- 4.2TD) that had a heart transplant from brand new (naturally aspirated 6.5 Chev V8 diesel with more torque than the 4.2TD).

Despite the truck having now done 240,000klm and most of that has been towing something (or so I believe..... I have only owned it for the past 60,000klm), it's still going strong. I tow our Ultimate in 5th gear most of the time, but not into a headwind or up moderate to steep hills etc.

One arguement which has some validity for towing in 4th relates to EGTs (exhaust gas temperatures). With the turbo engined rigs, it is important to ensure the EGTs stay within specifications.

When I owned my previous vehicle (also a 2000 GU Patrol with 4.2TD, but not the same rig I now own), I had EGT gauge with sensors both above and below the turbo. I was REALLY surprised by how much the temps would DROP when I changed back from 5th to 4th gear under load. It seemed to defy logic....... you're pressing along up a moderate hill in 5th gear, revs and speed are starting to drop and EGT is going up and up. You drop her back to 4th, revs build up, speed starts to hold steady or even increase AND the EGTs would start to drop. This alone is a good enough reason to use 4th gear when towing in "adverse" conditions.

As for the gear box strength, they aren't designed to be heavily loaded in 5th gear as it is a small cog that sits off to the side of the main shaft. But, under moderate and constant loading, it should be quite okay.

The Patrol gear boxes circa 2000/1 did have a defective main shaft, which hadn't been machined for the correct spline length. This resulted in many gearboxes carking 5th gear, but it was rectified by 2002.

Cheers and I'll look forward to seeing you on the Ultimate forum in due course.... We've owned our Ultimate (number 56) since February 1999.... I'm sure you'll be pleased with your decision.

Roachie

Thanks Roachie...looks like an EGT guage may be the go before I do too much towing over to the Kimberely area in June.

Cheers
Ian

Just wondering why is Exhaust gas temps so Important on turbos??

Because if you turn them off straight after running hard and hot they spin

down while still at a high temperature and as the oil is no longer circulating it

can boil and fry the bearings at the same time.

Cylinder and manifold temps can get up towards 700d C at at times.

An EGT is a very good thing to have IMHO

The probe in mine is in the dump pipe and has been up to 510deg coming up

a long hill so I back off and let it cool a bit as the difference in after turbo and

pre turbo is about 200deg.

I believe pistons melt at about 800deg.

Thanks Peter, we're looking forward to finally getting our Ultimate at Easter and then we're heading off to NW Australia in June from Brisbane for 7 weeks. I've had the Patrol turbo tuned and fitted a 3" exhaust...made quite a difference!. I'll take it back to put it on the dyno before we travel to Moruya to get the trailer. Are you happy with your Ultimate? Any issues I should look out for??
Cheers
Ian

Thanks Duncs. After the small mods done to the 4.2, according to the dyno readout, the torque is pretty flat between 1900 & 2700rpm so I try and keep it around the 2000-2200 mark and its quite happy and gives me some in reserve.
Cheers

I'm with you....I've just checked my bank balance and can't afford a gearbox rebuild, so I'll err on the side of caution and stay out of 5th unless going down hill with a tail wind.
Ian

As mentioned above, there are heaps of Posts on this subject.

When I had my manual Cruiser (a TDV8 Trayback) I also had a Scangauge in it.

I tested this theory time and time again to my absolute satisfaction:

Towing in 4th gear is:
more economical than towing in 5th (at the same speed, 90kph)
kinder on the engine and gearbox
more responsive to accelerator changes.

This was with a 2500kg caravan on the back.

cheers