Downshifting in 4Lo (MT)

I drove over 450 miles on the WABDR late this summer, and spent 90% of the time in 4LO without issue. I was in 4HI for maybe...30 minutes on a really smooth section of gravel road, and used 2HI on paved sections. Spent a lot of time cruising at 30-35MPH in 4th gear. If you're going faster than that you should be in 4HI.

Zero issues outside of being the guy holding everyone up a little longer whenever we had a quick pavement section and I needed to get into 2HI.

 

I was up above 7k feet going up a pretty steep trail. Tried to stop and start back up in 4hi, not happening. “Shifted” to 4lo and the truck takes off up the hill pops into 2nd with a big jump. I ended up back in 4hi while someone else was coming down the trail. With no room to pass he throws his f-250 United rentals truck into reverse and scorches up the hill to a pull off. I was dang. This truck ain’t doing that, shifted back into 4lo and went by him in 2nd gear. Left in 4lo quite a bit on the twisted steep stuff after that. Never hit 5/6 gear or nothing. The truck handles great in 4lo. It’s unreal how easy the clutch responds. I don’t know why anyone would ever need the clutch start cancel switch. I mean, I would get rid of mine if I could just delete the clutch having to be engaged to start.

 

Not directed at you, but I'll just leave this here:

 

Have any pics or links to that? I've never heard of it before but I definitely know what you mean. If I hit a large enough bump the same time I shift, there is some grinding so I wonder if the CORE shifter will fix both of those issues

 

Here you go!
https://core-shifters.com/products/...tick-for-toyota-tacoma-2016-2019-v6-4x4-rc62f

here’s the thread where I found it:
https://www.tacomaworld.com/threads/core-shifter-for-3rd-gen-v6.589705/

Just for anyone considering, these things go out of stock fast, on their website the owner/operator posts the current lead time on parts. Don’t ask him when they’ll be in stock, he’s a little short tempered with less-than-intelligent questions.

 

Have a Jeep (4.0L Cherokee, AT) and a 6MT Tacoma. I run 4Lo in many places in WV at speeds up to ~25mph. Both of them don't engine brake well downhill in 2hi (or 4hi). Even in 1st in the Tacoma it rolls out more than I like downhill in high range. Easier on the clutch and makes the locker available too!

 

My Sport manual has no issues shifting while in 4 low

 

The bumpiness of the trail and the wobbliness of the shifter are definitely contributing factors I'd say.
There is a bump in the road on my way leaving work just before a right turn. It's exactly the distance away from the turn that I want to downshift to 2nd. First week or so after getting my truck it crunched into 2nd every time I went over the bump, but eventually I learned to wait until after the bump for a smooth shift.
The first time I tried shifting while in 4lo offroad I felt the familiar crunch and thought "Oh yeah, just like that bump by work." Now I try to wait for a smooth-ish section to shift to 2nd or 3rd on a rough trail, but I'll definitely shift gears before stopping and switching to 4hi if I'm revving up too high in 1st gear.
Downshifting in 4lo, yeah I find it just takes a little more patience and finesse with the rev matching along with also being aware of gnarly the terrain in that particular spot is.

 

MT in low range + rev match and/or double clutching = smooth, non-grinding shifts.

 

Old thread revival. But lots of incorrect answers in the 1st few pages. You may not NEED low range, but at those slow speeds it won't hurt a thing. It's better to be in low and not need it than to have to stop and shift back and forth all the time.

 

Have you driven a MT 3rd gen taco at slow speeds off-road? From what you said, I doubt it. As soon as you encounter hills, or anything technical, you must be in 4lo otherwise you will fry your clutch.

 

Yeah, OP basically got rid of that BS verbatim in the third page. And what you’re saying is correct.

I simply tried to revive an old thread to throw some helpful advice out there RE the shifter and replacing with a better short-shifter. To my knowledge this is the only issue that can’t be solved with a driver-mod

this thread has been answered and beat to death at this point.

 

At risk of beating this thing into the ground, I don't think rev matching is the end all be all of this. Rev matching is always a good practice and vital for clutch longevity, but it's not going to make life much better for your synchros on a downshift. In order to get the input shaft up to proper speed, double clutching is necessary. Otherwise the synchros are doing it. Normally I wouldn't dream of bothering with it, but double clutching does seem to alleviate the grinding in low range.

I never considered that a core shifter might help, but that's a great point to bring up. I think harshness of terrain has a lot to do with it.

 

You bring up a good solution here, and I guess it violates an assumption I had. I assumed that we were trying to shift as quickly as possible, whilst not getting the gears to grind. I’m personally all good on wearing the synchros, and am fine rebuilding the trans as-needed. For me, double clutching is an extra shift, and would take longer to perform than just just rev-matching and hope that it’s not the 0.01% of the time that the synchro misses.

to each is own.

Not saying you’re wrong, and I do double clutch occasionally downhill in low, but doubling uphill downshifting? Not a chance, I’ll be stopped by the time I am in the needed gear .

 

Yeah double clutching is for big rigs and super race cars mang. And yes, double clutching uphill = probably rolling backwards

 

In 4 low , when you mash your clutch to the floor as you are downshifting , you remove the power from the engine from turning the input shaft of the transmission , However , all 4 tires are turning .
Those 4 tires are pushing the weight of the vehicle through both differentials during deceleration .
Both differentials drive the driveshafts during deceleration
Both driveshafts drive the transfer case output shaft during deceleration
The transfer case input shaft drives the transmission output shaft during deceleration .
They call this" Reverse Power flow " because the transmission is being driven from the output shaft rather than the input shaft
This is why rev match is important and also why some people grind while downshifting .