Tranny failiure 69 Patrol

[Gurkha]

Hi,

I am in a peculiar predicament, I have a 1997 Jonga which is based on the 69 Patrol. The version I have comes with a HINO 4009cc diesel engine instead of the original six cylinder Nissan Patrol 4 liter engine. The stock three speed transmission has self destructed three times under 60k and this is the fourth transmission I am currently using. My question would be, it is due to lube failiure, I have been using Castrol ST 80W-90 in the diffs, transfer case and transmission, now because of repeated failiures I have switched to Castrol EP GL-4 140 oil for summers and then switch back to ST 80W-90 in winters, would I be better off using 85W-140 gear lube all year around? Is there any way I can add a transmission cooler, at around 110mph, I can smell the gear oil burning and have to get it replaced.

Also I have a MB based G clone made in India which uses ZF transmission and reccomends ATF, the problem is that I find ATF too thin for 50c summer driving here, is there any other alternative?

I appreciate any feedback from all you experts out here and many thanks in advance.

 

[Lance]

2 questions in one thread.

For the vehicle which you say requires ATF, if you're concerned about viscosity loss, OK. Use a GOOD synthetic ATF. You can go up in viscosity, to something like Redline MTL, but the synchros may stop working.

For the Nissan Patrol, sounds like you need to find out if there is another stouter transmission available. My 1969 Plymouth Barracuda came with the small 7 3/4" ring gear differential, and it was NOT up to the task, paired with the 318 cubic inch V-8 engine. After only a few weeks of teenage burnouts, one of the spider gears just split in two.

 

[Gary Allan]

quote:

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The stock three speed transmission has self destructed three times under 60k and this is the fourth transmission I am currently using. My question would be, it is due to lube failiure,

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Not likely a lube failure issue. Poor design for intended use issue is more likely ...or a "use beyond intened design issue.

That is the trans is a POS ..or you're flogging it into an early death ..repeatedly. I doubt lube would do anything but maybe prolong the the failure interval.

As was recommended ..find a stouter trans. I'm sure another is available.

quote:

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at around 110mph, I can smell the gear oil burning and have to get it replaced.

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In this case ..I'd say that @ 110 mph (not km/h?) you are venting gear oil out the vent and having it spray upon the exhaust ..I can't imagine how you can tax this fluid with speed alone ..unless the trans itself has such sloppy tollerances that this induces heat fatigue on the lube (still doubtful).

This I've done with a fairly reliable Ford 5 speed gear box. Excessive high speed driving without checking the lube level in a timely manner. Next thing I know the input bearing was rumbling away like a muffled diesel (I would imagine that this would be impossible to detect if in fact you have a muffled idling diesel as an engine).

Don't drive 110 mph in a vehicle that lunches gear boxes every 60k ..and check the lube more often ...and lengthen the vent with a tube that extends to a small chamber that will allow any vented lube to return to the trans.

 

[tdi-rick]

quote:

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at around 110mph, I can smell the gear oil burning and have to get it replaced.

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don't you mean km/h ?

I don't think our 4.2 l turbo Patrol would go that fast.

If it's cooking the gear oil, there are serious clearance issues with the box. The G60 Patrol was designed like a tractor, and went forever, so I think there is something fundamentally wrong with how that gearbox has been assembled.

Although......
Something that used to happen to M20 g/boxes fitted to Holdens here years ago was that the oil feed to a number of bearings, which were actually bushes was a problem. If you used a 90w, and at one stage I used an 85w-140 gear oil, it was exactly the wrong thing to do.

Because the oil feed grooves were too small, a better flowing gear oil needed to be used. The heavier oil just didn't flow well enough to provide adequate lubrication. Of course the real fix was real roller bearings, but the lighter weight oil was a good band-aid.

It sounds like you can get Castrol stuff fairly readilly, so I'd be trying something like EPX 75w-80 GL5, or Multitrax, which is a 75w-90 GL5 transaxle oil. they both flow a lot better than an 80w-90, and could help.
If you can afford it, and it's available, Castrol Syntrans is excellent. It is a 75w-85 GL4 full synthetic synchro gear oil. It, and its 75w-90 brother, Syntrans M are used in large trucks like Volvo's and MAN's that use a ZF synchro g/box. If you would prefer a GL5 oil, Syntrax is a 75w-90 transaxle/hypoid/LSD oil that is used in intrstate trucks here. Both of these synthetics generally result in lowerer operating temperatures in the transmission.

Regarding the G-wagon, the Aussie Castrol and Mobil sites only have ATF as the g/box fill, but there are a few dedicated light weight manual gear oils that will give better synchro performance, and less noise in high ambients.
I don't know if any of these are available in India, but here's a link to some tables comparing them and ATF's. click here

Hmm, your gear box has a crash first gear, so I hope your double-de clutching skills are OK.

Good luck.

Rick.

 

[Gurkha]

Hi Guys,

Many thanks for the input, the original Patrol six cylinder developed 145bhp and the HINO develops close to 138 but the torque in the diesel HINO is much higher and available at much lower RPM, maybe one of the reasons the gearbox cant take it.

My speedometer goes to 160Km/ph and I have gone way past it on occasions so I estimated 110mph, could be the speedo is not correct.

So from all your advices I gather that using SAE 140 gear lube would be a wrong idea for the transmission, I am better off using SAE 90 oil. How about using a 85W-140 oil, would that be a proper compromise?

As for the ATF issue, while I was in the US, it was easy to get synthetic ATF but here in India, synthetic ATF is the exclusive domain of Mercedes dealers who use Mobil-I, they charge US$25 per liter. I guess I am stuck using regular ATF and changing it every year. I don’t exceed more than 12000Km with the regular ATF.


Rick, thanks a lot for the informative link in gear lubes.

 

[cryptokid]

a 3 speed manual transmission in a wheel drive diesel? do i understand that correctly?

 

[Gurkha]

Just wanted to add that this vehicle can easily out accelerate other diesel vehicles in its category like the Land Cruiser and Pajero so the top speed cant be that far off from what is indicated on the speedo.

I also double clutch on every gear and try and match the revs as much as possible.

 

[Shannow]

Gurkha,
I don't think I've ever seen a 6 cylinder 69 Patrol go any where near 120km/hr, let alone 160km/hr.

Do they still have the crappy 4 wheel drum brakes ?

The three speeds that they had down here lasted forever, with little to no maintenance.

If yours is consistently failing after rebuild, there could be an alignment issue, and a new box might fix it.

If it's been new boxes each time, then it's something that you are doing that causes the problem (high speed, load, lubrication etc).

If you want, there's one for sale around the corner with a good gearbox (well it's gone 300 and something thousand km without failing). It's only $450 Oz also (about the price of a sixpack in USD)

 

[Gurkha]

The Patrol I have has the HINO diesel 6000cc six cylinder engine and can go over 120 with ease, dont know about older Patrols though.

The alignment issue sounds logical to me, I have seen maximum damage occur to the input shaft. The input shaft is modified as the HINO engine needs a spline with wider diameter.

Yes they still have the fade special drum brakes, only this time they have been bolstered with a booster thankfully but still not that effective especially with the HINO engine.