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Old automatic gearbox off road. Suicide?

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Well, these days I have been reading a bit about torque converters and auto boxes.

As far as I have undersood, older non computer controlled boxes will lock up the converter only in 4th gear above 50mph.

So, at low speeds, it will never lock and will "slip". 

Now imagine: off road, downhill. Torque converter slipping and offering no engine braking. Brakes cause wheels to lock. 

Is this what actually ocurs or automatics aren't that bad?

 

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Slip isn’t freewheel, you set the gear box to hold lower gear and you get a bit less engine breaking bit it isn’t none.

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As above, there is some braking, not as much as manual.

Brakes do not lock if you have human feet with feelings in them, and a buttock that senses motion of the vehicle.

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Ok, thanks. The only auto vehicle I have droven off road was a Freelander. Really nice, I was able to complete the same course I made previously with a Defender. But that Freelander relyed in HDC for going downhill.

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I have driven both off road. Up hill and in the mud auto is awesome. Down can be buttock clenching, cadence braking is the key. As stated above they're not that bad and lots of people prefer them as they break traction less. Personally give me manual any day.

Mike

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I hate autos for road driving but my rrc v8 auto was a fantastic gearbox for offroad. It could shift up and down on hills without losing drive at the wheels, you could left foot brake over obstacles which meant you didn't have the lurching and stopping then trying to start again as you go from clutch to brake to accelerator and you cant stall it. The above also means you dont need to spend a fortune lowering hearing provided you dont cook the oil which I never had any problems with. 

For the downhill I used to lock it in first, as you went over the edge youd get a bit of a lurch which was disconcerting but then it used to hold it back pretty well. Not as much as a manual but it could still get a wheel to slide on loose ground. Braking is fine so long as you dont just slam on and feather it if required. Relying on the engine to brake without difflocks in means if one wheel slides you'll speed up anyway. The brakes are on all wheels. 

The biggest downsides were you did lose some power to it and you couldn't really bump start it if the starter failed.

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I was a regular passenger in a RRC with a V8 and automatic gearbox. I am now a regular passenger in a D2 with a V8 and automatic gearbox (Only the driver has changed!!).
Both vehicles were / are on All Terrain tyres on standard wheels, no lifts or other 'enhancements'.

Driving in the Peak District I experienced no qualms as the drivers tackled slopes, up or down.
A big benefit was being able to take a very slow approach to a hazard knowing there was no possibility of a traction breaking gear change required when the route out was shown to be clear.
During one downhill stretch I asked the driver about 'lack of braking' and locking it in a low gear. He demonstrated the effects of manually selecting a low gear. The result was very very slow! I didn't bother to ask again.

Neither driver indulged in Pay and Play sites, nor even TYRO trials, just BOATs and UCRs.

If such an option was available I wouldn't hesitate to use an automatic.

Regards

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1 hour ago, David Sparkes said:

I was a regular passenger in a RRC with a V8 and automatic gearbox. I am now a regular passenger in a D2 with a V8 and automatic gearbox (Only the driver has changed!!).
Both vehicles were / are on All Terrain tyres on standard wheels, no lifts or other 'enhancements'.

Driving in the Peak District I experienced no qualms as the drivers tackled slopes, up or down.
A big benefit was being able to take a very slow approach to a hazard knowing there was no possibility of a traction breaking gear change required when the route out was shown to be clear.
During one downhill stretch I asked the driver about 'lack of braking' and locking it in a low gear. He demonstrated the effects of manually selecting a low gear. The result was very very slow! I didn't bother to ask again.

Neither driver indulged in Pay and Play sites, nor even TYRO trials, just BOATs and UCRs.

If such an option was available I wouldn't hesitate to use an automatic.

Regards

The D2 should be locking the torque converter up when in low range, so will offer engine braking. Older models will not and will be very different on down hills.

The p38 has a 'manual/sport' button. When in low it allows you to lock up the converter.

Auto's have some advantages off road but also some disadvantages. They don't crawl very well at tickover, as even a small bump can stop them, where a manual would likely continue. This means you often need to be more active on the throttle with an auto and oddly this makes them slightly less smooth on some terrain.

The ability to upshift on a hill can be useful, although I can count the number of times I've needed to do this in a manual on one hand.

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I was reporting my experiences, which you quoted in full.
I did not venture into the technicalities of different auto boxes, partly because I did not have that knowledge, instead I focussed on my experiences from the passenger seat.
I never experienced any concern because an auto box was in use, nor did I detect any unease by either driver because an auto box was in use.
I did not comment on the 38A with auto box because I don't have that experience.

As your comments reflect your views rather than comment on my quoted experiences I would have preferred that you didn't quote me at all.
I will appreciate it if you edit your post accordingly.

Regards.

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If you need more engine braking from an auto you can always pop it in reverse and feather the throttle :ph34r:

I don't like them much personally, but there are benefits in other conditions, so some good some bad. I find with an auto in the conditions here, in soft ground where you need quite a lot of power it is very hard to judge when the TC is slipping and when the wheels are spinning in slippery heavy going, but that's a different problem.

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As Mike said, Cadence Braking is your friend. Although young folk today haven't got a clue what that means

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I learned all about cadence braking from a bloke who calls himself Nonimouse when I was a mere boy 😉

Mo

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2 hours ago, David Sparkes said:

I was reporting my experiences, which you quoted in full.
I did not venture into the technicalities of different auto boxes, partly because I did not have that knowledge, instead I focussed on my experiences from the passenger seat.
I never experienced any concern because an auto box was in use, nor did I detect any unease by either driver because an auto box was in use.
I did not comment on the 38A with auto box because I don't have that experience.

As your comments reflect your views rather than comment on my quoted experiences I would have preferred that you didn't quote me at all.
I will appreciate it if you edit your post accordingly.

Regards.

wow, overly sensitive are we?? Well apologies. I only quoted you as you said RRC and D2. So thought I'd share some knowledge that they operate differently.

 

:)

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4 hours ago, Chicken Drumstick said:

The ability to upshift on a hill can be useful, although I can count the number of times I've needed to do this in a manual on one hand.

I think the ability to downshift on a hill without loosing momentum is more useful. Particularly on climbs where you need a good run up, but then get steeper.

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Two feet, three pedals, I know which I would choose!

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4 hours ago, Chicken Drumstick said:

The p38 has a 'manual/sport' button. When in low it allows you to lock up the converter.

That's not entirely accurate. The P38a autobox does have a different shift strategy in low and high, and will use lock-up when possible in all gears when in low, instead of just in 3rd and 4th.

The manual mode allows you to hold a gear, preventing the box from shifting down while in low. In high you can only limit the upshifts. This can be quite useful as you often want to hold a gear while crossing some sections.

I can also echo @BogMonster in that with an autobox I sometimes have a hard time to determine if the wheels are spinning (and digging) or it's just the torque convertor. Never ran out of power though, and the upside is you can load the torque convertor to get a better start. Still prefer a manual, which is why I'm going through the (considerable) trouble of converting my P38a...

Filip

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16 minutes ago, landroversforever said:

I think the ability to downshift on a hill without loosing momentum is more useful. Particularly on climbs where you need a good run up, but then get steeper.

I can see the technical merit for it. Just not so much the practical one. Especially in anything modern'ish with enough power. Low 2nd in a manual Tdi/V8 is usually slow enough for a lot of things and enough whee lspeed for the majority of climbs.

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3 hours ago, BogMonster said:

I don't like them much personally, but there are benefits in other conditions, so some good some bad. I find with an auto in the conditions here, in soft ground where you need quite a lot of power it is very hard to judge when the TC is slipping and when the wheels are spinning in slippery heavy going, but that's a different problem.

I didn't find that a problem in the range rover as it was on aggressive tyres and if they were spinning you could see the mud flying up and hear it landing on the roof. :lol: I have had that confusion a few times in the pickup which is only on ATs, but that's 95% road car 5% muddy construction sites so I wouldn't class it as offroading and I would much rather have a manual in that if I could. It also has traction control, hill decent, it slows the abs so mud / snow builds up infront of the tyres etc etc so frankly I haven't got a clue what's going on!

As for them coming to a stand still easily at idle, very true, I found left foot braking so you can hold the revs up slightly worked wonders. I think if you try that you will find it can be smoother than a manual over uneven terrain. 

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I find it makes it all rather relaxing. D low everywhere except downhill 😄

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2 hours ago, Escape said:

That's not entirely accurate. The P38a autobox does have a different shift strategy in low and high, and will use lock-up when possible in all gears when in low, instead of just in 3rd and 4th.

The manual mode allows you to hold a gear, preventing the box from shifting down while in low. In high you can only limit the upshifts. This can be quite useful as you often want to hold a gear while crossing some sections.

 

Filip

Thanks. Although it must do more than just limit downshifts. If I lock the selector in Low 1st, so it won't shift up or down. Pushing the 'Manual/Sport' button alters how it engine brakes on descents.

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2 hours ago, Cynic-al said:

I didn't find that a problem in the range rover as it was on aggressive tyres and if they were spinning you could see the mud flying up and hear it landing on the roof. :lol: I have had that confusion a few times in the pickup which is only on ATs, but that's 95% road car 5% muddy construction sites so I wouldn't class it as offroading and I would much rather have a manual in that if I could. It also has traction control, hill decent, it slows the abs so mud / snow builds up infront of the tyres etc etc so frankly I haven't got a clue what's going on!

As for them coming to a stand still easily at idle, very true, I found left foot braking so you can hold the revs up slightly worked wonders. I think if you try that you will find it can be smoother than a manual over uneven terrain. 

 Hard baked ground with deep ruts, an auto will generally be more stop/start in terms of motion in my experience. But yes, they can be smooth too and very nice on slick mud or sand. And of course no need to slip the clutch for rocky terrain.

 

If I'm honest I really liked how my 4.0 litre Jeep Cherokee XJ auto went off road. I do still prefer a manual, but it really did win me over. Not sure how the box worked exactly as you couldn't manually put the selector in 1st, just 1 / 2. But it would hold first really well and never felt like it was running away downhill. A classic Range Rover on the hand with the 4 speed ZF box was much more butt clenching at times.

 

 

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10 hours ago, BogMonster said:

need more engine braking from an auto you can always pop it in reverse and feather the throttle :ph34r:

Have thought about that, but aparently will make the box to explode ;-).

I'm not thinking about auto conversion for my 88. I have a bmw m51 engine, ex Opel Omega, with non electronic Bosch ve6 pump. Not fitted yet, as I have not decided what box to use. A Bertone Freeclimber box/transfer has nearly the same gearing as a Series stock box.

My 88 left the Santana factory with 2.25D, LT85, LT230 and 3.54s. Previous owner fitted 4.7 diffs. That combo is lower than stock, but not as much as I would have expected.

So, for my convesion I'm considering a torque converter with manual! TC will emulate an underdrive and will avoid stalling the engine. Nothing new. Used today by ZF for heavy haulage. In lighter applications was popular between 30 to 60s. Plymouth HyDrive, Porsche Sportomatic, VW Autostick...

A manually locking TC will be the best, but I don't know If I could make the lockup work when not used as expected with an auto box.

 

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Engine braking is overrated.   I regular offroad in non standard class in my rangerover....its been a 3.9 v8 auto and its now a 300tdi auto....I only every use D and R :)  If its steep downhill I brake with the brakes...if it slides a bit then let the brakes off a bit...if it slides a lot...give it throttle :)  

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If you’re worried about the loss of engine braking, and selecting 1 doesn’t do enough, then you could partially apply the hand brake - it’ll do the same thing, giving equal retardation to the diffs and not locking any wheels as long as it’s used gently.  Heat generation could be an issue if overused, but as a last resort backup, used in addition to the engine braking obtained in “1”, having been judicious in descent planning, it should be OK, especially if you have any kind of locking, LSD or ATB diffs.

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