KL TH gear changes on sand

[ColinH]

Hi All,

I've got a question about the TH 4wd system on sand and am interested in your experiences.

I'm running upgraded tyres Yokohama 245/70R17 119R G012 AT's that give me a bit of extra lift and so far no evidence of rubbing.

The problem I have is that in "sand" mode and in auto/ drive the car seems to stick in 1st gear and is very reluctant to go into a higher gear like 2nd or 3rd. It really revs up quite high before it will change (3,000+ RPM to shift up).

Then if I drive it in manual even if I move the gears up and can see the number switch up to 3, 4, 5 etc it is not really switching up at all.

Note that if I run it in "snow" mode on the beach and turn off the ESC it switches up/ down gears just fine. It's only in sand that it seems stuck.

Has anyone else had this experience? Is it some sort of learning issue?

Thanks in advance for you feedback and suggestions.

Colin

[SeaComms]

Cant answer the questiin though as mine will be used in sand I am very interested in the answer.

The manual shifting though is not actually manual shifting. All it does is limit the maximum gear it will shift to. So if you select 3rd it will use first second and third but not shift past third.

It could just be the shift patterns programmed to use higher revs before shifting assuming that sand is harder to drive in and when shifting not letting the revs drop too low.

[wjlimited]

It would be software, to stop it cooking the tranny fluid when the converter isn't locked. At 3000 revs there is no heat being generated because the converter is locked.

That's my guess haha.

[ColinH]

Thanks guys I think that you're right that it is a software thing. I've seen in a few of the American forums that the gearbox software has had several updates to improve performance but I do believe mine has had them.

I'm interested in what you said SeaComms about the manual shift function. I didn't know that it worked that way so I will do some reading up in the manual and practice a bit to see if I can figure it out. At the moment I do think it is meant to shift up and down manually as when I run it in "snow" mode the gears do go up/ down as I move the stick backwards and forwards.

I was wondering if there's any other source reference manual for how the gears are programmed to work other than the manual that comes with the car?

Cheers - Col

[DebAth]

In sand mode it will hold the gear for way longer than seems logical, until you actually get into soft sand and then it makes sense!

[ColinH]

Hi All,

I've been doing a bit more research based on what Dave said and now I understand what you are saying and think that's right. I found a good thread (http://jeepcherokeeclub.com/33-engine-technical-discussion/47441-shifter-manual-mode.html) that discusses the situation and how the car is meant to behave.

All in all just another excuse for me to go to the beach and have another muck around to make sure I get it right :-)

Thanks all for your feedback.

Cheers - Col

[Trailfirst]

I'll make the observation here that we've used "Snow" as our normal driving mode since getting our TH - that's on bitumen, offroad, wherever. Altho we haven't been anywhere that's needed rock/mud or use of the locker - that's not to say we haven't been in some pretty lumpy or soft crap - but Snow so far has just got the job done without fuss - ie. the need to think about using the more specialised modes. It seems to be the only mode that really behaves like a "normal" transmission. I have noticed recently that Auto isn't as bad as it used to be - perhaps some learning has happened - but its still squirrelly and makes you go "wtf" every now and then - whereas with Snow selected you don't even think about what its doing.

[pantsman]

My first service included the transmission flash???? fortunately when I put my car in to get a paint defect rectified, they loaned me a replacement limited. I noticed a huge difference in the dynamics of each of the different modes from my car, so I made sure they re-flashed my transmission before returning it to me. End result, in Sand/mud mode it should not change gear until about 4000 revs, originally I could not tell the difference between Auto/Sand/mud and snow mode (sport mode was working OK). If your car is not revving out to approx. 4000 in sand/mud mode I would suggest taking it back in and getting them to reflash it. I drive on Blacksmiths beach in Newcastle (probably one of the worst in NSW) and it drives brilliantly as long as the Tyre pressure is down (15-20).

[pantsman]

PS I've also left it in Auto mode on the beach and it seems to work well in some situations as well....it will take a bit of trial and error in different conditions to work out whats best.

[ColinH]

I agree with what your saying. With my new transmission (2015 hardware and software flash now) I've noticed that sand and snow modes are very different and yes on sand mode it's revving up very high (3,500 - 4,000) before a gear change. Seems to be working very well now.

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