6 speed + 4L driving Advice

[fdFifty]

I'm not terribly new to 4 low / trail driving, but I'm completely new to the ways of the third pedal.

The ability to choose the exact gear I was in while on the trail was a huge factor in deciding to go this route. I've read and understand that "skip shifting" this (or any transmission really) isn't such a good idea. Does operation in 4wd low range alleviate or increase risk of damage while doing this? My main concern isn't necessarily the act of "skip shifting" itself but instead with the ability to start from 3rd or maybe even 4th while in low range. Is doing so ill-advised?

I absolutely love having the 6 speed so far, and want to keep the clutch/synchros healthy and smooth. Any advice on how I can use the transmission to its full potential offload while not introducing unnecessary wear and tear would be greatly appreciated!

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[Jeepjunkie]

In 4-lo I often start in 3rd, although it’s obstical dependant. I also skip shift all of the time in 2-hi, for example accelerating in 2nd, I may shift directly into 4th. The trick is to not rush skipped shifts and let the input shaft decelerate appropriately. The sycros will have to work extra hard on a rapid & skipped up shift.

 

[vavaroutsos]

There is no issue with starting in 3rd (or any other gear) when in 4 low. The issue is with the syncros as mentioned by @Jeepjunkie. When you skip gears the amount of change required in input shaft speed to match the new gear is large. This requires heavy work from the syncros and can wear them out prematurely.

 

[iklln6]

Wouldn't double-clutching avoid damage to the syncros? I double-clutch at low speed (parking lot speeds in 2H) going from first to second, which avoids the loud THUMP, but honestly never thought about it in 4L until reading this post and responses @Jeepjunkie @vavaroutsos

 

[MadDog27]

Subbed.

I also bought the 6 speed for this reason. Ive had a blast off roading the last few times with mine. I take off in 2nd or 3rd in 4lo and it seems fine but glad to hear from others that it isn't hard on it. Like someone already said, it depends on the terrain. If I’m approaching a steep hill/climb, ill kick it in 1st.

Love my 6 speed.

 

[Amaruq]

Is skip shifting really that bad? If I’m in 5th, and slowing down with rpms dropping below 1500, it seems pretty natural to go ahead into 3rd. This is bad?

 

[Jeepjunkie]

I’m not an expert, but I’ve driven multiple vehicles with manual transmissions without syncros (tractors, trucks and a Model A fords).

Double clutching
When upshifting, the transmission input shaft has to spin/slow down (just like the engine does) to match the next gear speed/rpm). Even without syncos this happens naturally as long as the driver gives the input shaft time to spin down. Unless the input shaft takes a long time to spin down, double clutching isn’t necessary. If the input shaft takes a long time to spin down though, and if the syncros are weak (old Saab 900s come to mind) double clutching on the up shift can help shift faster.
Downshifting is a whole different matter. When going to 5th to 3rd for example, the transmission input shaft has to increase its speed (just like an engine does on a downshift) and this can only happen in two ways: 1) the syncros engage during the downshift and spin up the input shaft, or 2) the driver double clutches, that is put the vehicle in neutral and releases the clutch (matching the engine and input shaft speed together) and raises the engine (and hence the input shaft) speed to what the lower gear needs for an rpm, depress the clutch and select the lower (in this case 3rd) gear. This is why a model A ford can upshift without double clutching but not downshift.

Skipping gears
I skip gears all of the time but I don’t rush the shift so the syncros have time to spin up or down the transmission input shaft over those larger RPM changes. Sometimes I double clutch the JL when downshifting, but not often and mostly for practice.

HTH
Someone with more expertise may have better insight to the above.
Sorry for the long post, I didn’t have time to write a short one.

 

[iklln6]

I’m not an expert, but I’ve driven multiple vehicles with manual transmissions without syncros (tractors, trucks and a Model A fords).
...
Double clutching
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Skipping gears
...

Somebody buy this man a beer

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