4.8 GRX Auto - Torque Converter Lockup

[KOOS BEST]

Daar is net 2 diesels wat my excite. Die een was in die SAS Tafelberg en was 'n straight 8 wat 5 verdiepings hoog gestaan het en net 110rpm gedoen het. Die ander is 'n 6.6L V8 Duramax wat in stock vorm 'n GU in 12 sekondes die kwartmyl laat doen. Met 'n bietjie electricary doen hy dit in 11 en met nog bietjie massage onder 10. frans kan vir jou se wat dit vat om 'n 10 sekonde kar te bou. Die duramax kan dit vir jou in die Patrollie doen.

Hy is volgende op my shopping lys.

Pierre was jy op die Tafies? Ek was vir n paar dae uit op sy nuwe refit in 84 om skiet oefeninge te doen saam met daai tyd teen die nuwe refit Mirage Cheetahs van Langebaanweg en met 4VR Langebaan die nuwe landing crafts te toets. Sy het n lieflike enjin ,en onthou jy nog jy moes haar aan die brand skiet met n 76mm blank in een van die silinders af. Jy kon ook dmv n venster binne in die enjin inkyk, maw na die crankshaft se beweging.Ek was daai tyd in die mynveer flotilla.
Koos

[Freakazoid]

Was net kort op haar. Maar my tyd was eers hier 89-94 in die vloot. Was baie korter op die bote. Het studeer deur die vloot. Maar daai enjin was net mooi. Die Strike Craft se MTU's was ook impressive maar die Tafies se 8 silinder was net so blerrie groot. Die blowers was 2 meter hoog.

[Clem]

An old thread but a useful one. This weekend I also could not work out whether my GRX was locking up or not. As soon as I touched the accelerator pedal the engine revolutions climbed much faster than the increase in engine speed and as soon as I released the pedal, the transmission would go into "free-wheel" mode so that revs dropped quite low (1500 or thereabouts) while the machine rolled forward unimpeded by engine braking. It seemed strange to me and very, very different my other automatic which locks up very solidly indeed and revolutions and vehicle are exactly related. I found it very strange and wondered why Nissan would design and build the primary transmission this way. Would be interested in hearing any views on it.

Yet for all that, when using engine braking going downhill in first or second gear (and whether low range or high range), it locks up solid as a rock and the engine brakes the machine beautifully.

[dieselfan]

Clem having just got my 4.8, I can say it's a Nissan thing. My BIL bought a Pathfinder and it too behaves in a similar fashion. To be honest I prefer the Nissan route to what I had with the 330D and Disco3 which would feel more sluggish despite being "locked" and although the Patrol doesn't seem to have any engine braking in 2wd slowing down towards a robot it does make the car somehow feel lighter. With the disco it would engine brake but when you get closer actually "push" you making the car feel heavy and slow to stop. I often felt my self overshooting the lines. As a result I used to go to Neutral as I approached 30. The car would stop MUCH faster and "lighter" in N.

When I test drove my BIL's pathy it felt SO light braking as the revs were almost idle. I suspected the Patrol AT would totally suck in the offroad compression department, but on Saturday night I tested it down some steep slopes - NOT bad at all. Berakah will be the best test though, there the D3's HDC was hopeless (too fast and sliding) and my boets manual diesel was amazing barely using any brakes one the worst declines.

If the Patrol AT's 1st holds those hills then this car is more than just amazing. Can't wait for a Berakah outing.

[Clem]

Many thanks for that post dieselfan. At least we know it is consistent. I did find it a little bit strange at first as my other automatic locks up completely in every gear and only unlocks briefly to change gears. But, as we both have noticed, it seems to work very well in the Patrol. I have wondered whether it would not result in the transmission oil overheating when working for very long periods of time in heavy sand but I must assume that the Nissan engineers know what they are doing and that it is not for me to second-guess their engineering skills.

Concerning using the engine braking for hill descent, please note that while it does work very well indeed, the manual also says that there is a mechanism to protect from damage. I have not pushed it that hard but I assume what it means is that it will shift up a gear if necessary to protect the engine from revving too high. This could have unfortunate consequences if one is not aware of the possibility of that happening. It is probably best to be quick on the brakes in such circumstances. :-)

[dieselfan]

Clem if anything the BIG difference is in "manual" mode the Patrol does NOT change up a gear. It's the only auto I've EVER driven that does not change up when redlining. The reason I assume, makes sense...if on a long sand dune (as the arabs love the Patrols SOOO much - check you tube) it will hold the gear YOU choose even so much as riding on the governor this means holding third instead of dropping to 4th when you really can't afford it. Although being an auto this means that the manual mode is a true manual mode - although it wont stall should you select 4th etc. I does put a big smile on both my boets faces

The patrol 4.8 is one of the few cars designed to sit on redline all day in the dunes. Although I wouldn't recommend you doing that yet (running yours in). Once you have you will hear how relaxed it is at 6000rpm. Very unstressed and smooth.

[Clem]

Clem if anything the BIG difference is in "manual" mode the Patrol does NOT change up a gear. It's the only auto I've EVER driven that does not change up when redlining.

Thank you. That is something I did not know and was wondering about. It is good to know that it will not shift a gear.

as the arabs love the Patrols SOOO much - check you tube

By all accounts they upgrade some of the engines to 2000 hp – how I do not know but apparently it is done.

The patrol 4.8 is one of the few cars designed to sit on redline all day in the dunes. Although I wouldn't recommend you doing that yet (running yours in). Once you have you will hear how relaxed it is at 6000rpm. Very unstressed and smooth.

Well, good to know that it will do it if I ever need to get there! :-)