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Neutral in auto not quite neutral?


WesBrooks
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Hi All,

Is neutral in the auto boxes not quite as neutral as a manual?

Been pushing the project in and out of the garage with auto in neutral. Was surprised that things didn't get easier when most of the body was removed. Had a moment of clarity and thought to knock the transfer box into neutral and now find it much easier! The autobox is currently drained of fluid, just wanted to be sure that the difficult push into the garage wasn't anything to worry about - and just me being a bit embarrassingly clueless on autos.

If this is normal what causes the drag? Presuming it's the wheels that are seeing the drag and not also the engine?

Why I'm on the topic if your going downhill in 1, 2, or 3 can the vehicle cause the torque converter to slip reducing engine braking or does it fully lock up? So compaired to a manual when rolling down hill it might roll a little easier initially due to torque converter slip but lock up once the engine speed builds up?

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There's just more drag in the inside of the autobox I'd guess? My merc box I can spin by hand with it in neutral, but there is a fair bit of drag on it.

On the lock up issue.... it depends entirely on what box it is. For example the LR boxes in the disco and RRC lock up only in 4th over about 45/50mph I think it is. Some of the more modern boxes will lock up the TC in other situations now to save fuel.

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No fluid? Good way to damage the box!! You were probably okay running around the shop. Never move any distance in neutral with the engine off though. The oil pump is powered from the input shaft and does not work with the engine off.

It has got no engine, wiring loom, drivers seat...

Appreciate the warning but in this case other than perhaps a long term corrosion risk I don't think it will cause any damage being pushed in and out of my garage. Need to service it at somepoint and it was leaking so dropped the oil.

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For example the LR boxes in the disco and RRC lock up only in 4th over about 45/50mph I think it is. Some of the more modern boxes will lock up the TC in other situations now to save fuel.

Interesting. I think some of the newer ZF boxes had electronic controls for gear shift? Any idea if the torque converter lock up can be forced either electronically or physically?

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Interesting. I think some of the newer ZF boxes had electronic controls for gear shift? Any idea if the torque converter lock up can be forced either electronically or physically?

The P38 ZF box has electronic control, and also electronic control of the lockup.

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Park while transfer box is in neutral is a good shout, will do.

I'm guessing the P38 box isn't a straight swap? Mounts in the same place with a different prop or would I have to weld mounts on? P38 is the same/similar suspension geometry as the D2 isn't it?

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you wont do any damage to the auto box pushing it around with the oil dropped, but if its easier to push with transfer neutral then do that. TCL can be at what speed is required down to engine power, torque rise etc , in the jatco box on the freelander TCL is prevented when cold to allow faster warm up down to slippage , and relies on a temp sensor in the box. Using the engine resistance when going down hill is limited compared with a manual gearbox.

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...hmm electronics issues aside it looks like the output into the transfer box is different. Think the P38 had some sort of fluid centre diff, rather than mechanical with locker.

Doesn't sound like the effort would be worth the hassle.

The D2 box is the same, albeit the slightly weaker 4HP22E instead of the 4HP24E fitted behind the 4.6 in the P38. The D2 had an LT230 behind it.

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Doesn't look like there is much between the D1 and D2 for economy and if anything it favours the D1. Also interesting is there isn't much betwen the manuals and autos.

Model Urban Extra Urban Combined

1 12.4 22.8 17.3

2 12.3 21.6 16.9

If anything the D1 is better on economy, but I realise the D2 also has a significantly revised engine inlet, ignition & ECU, and longer body rendering comparing the figures next to useless to get an idea of the relative performances of the gearboxes!

I'll service (oil and filter, rather than rebuild) what I've got and read more into what could be done to increase the strength of the D2 box to P38 standards.

Thanks for the information. Food for thought!

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As an aside to this, the autobox models get through front brake discs and pads quite a bit quicker, because of the lack of engine braking. Indeed given the risk of damage if the hand brake is applied while the vehicle is mving, if the brakes fail on an auto there is not much one can do about it, except steering for something soft.

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As an aside to this, the autobox models get through front brake discs and pads quite a bit quicker, because of the lack of engine braking. Indeed given the risk of damage if the hand brake is applied while the vehicle is mving, if the brakes fail on an auto there is not much one can do about it, except steering for something soft.

The autobox engine brakes just fine, you just have to shift it.

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Thanks for the link. I'd just emailled them to see if I'd understood their pricing right and asked a few other questions. As the original vehicle had 140,000 on the clock I'm assuming the autobox is likely to be tired anyway. It all boils down to how long I can hold off getting it on the road to save many pennies!

Indeed given the risk of damage if the hand brake is applied while the vehicle is mving....

Another thing for me to read up on!

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As an aside to this, the autobox models get through front brake discs and pads quite a bit quicker, because of the lack of engine braking. Indeed given the risk of damage if the hand brake is applied while the vehicle is mving, if the brakes fail on an auto there is not much one can do about it, except steering for something soft.

If its applied gently in a controlled fashion it won't damage it. Yanking it on would however.

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Mostly because the auto's first gear is rather high. That is truly the biggest disadvantage of an auto off-road IMO.

I'm looking forward to using my merc box, as the ratios are almost identical to the LT77 :D, including being a 5 speed. The merc 1st is either 3.951 or 3.595 depending on the box variant and the LT77 is 3.585 :D

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That sounds nice. The 2.48 first in the ZF is quite annoying at times... especially with larger tyres.

Which reminds me that we've got a broken LT230 sitting on a pallet... that might be worth another look :P Just need to find a way to mount and drive it through the PTO hole, can't be that hard, can it?

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