Need help diagnosing 4Lo transmission problem

[bluduk15]

When I shift into 4low all it does is beep. The VSC light use to come on, but does nothing now.

Also, I was once on a slight grade and tried to shift into 4low and it made a loud clicking/grinding noise. I quickly stopped that.

No other problems or noises in 4Hi.

Thanks for your help.

 

[03L4RUNNER]

When I shift into 4low all it does is beep. The VSC light use to come on, but does nothing now.

Also, I was once on a slight grade and tried to shift into 4low and it made a loud clicking/grinding noise. I quickly stopped that.

No other problems or noises in 4Hi.

Thanks for your help.

My 03 has always beeped in low also, i think thats the just what its supposed to do, that clinkin noise might of been the 4WD ingaging or disingaging,

 

[CJ3Flyr]

Try this, if you have a V8 skip the 1st step...

1) While moving shift to 4HI. Wait until the green 4wd indicator is solid (not flashing).
2)Stop. Place the vehicle in 'N' then rotate the switch to the 4LO position. I find that stopping on a slight incline may be helpful. If the 4LO light doesn't illuminate steady the let the vehicle creep forward or backward with the transmission still in 'N'. ('N' NOT any other gear!)

For the V6 guys: You must select and complete one mode change at a time. That means 2HI to 4HI then to 4LO. The same is true of center diff lock/unlock. Unlock it prior to driving on hard surfaces or switching to 2HI.

How do you know if a mode change is complete? Steady vs flashing dash lights; steady = complete.

I think you'll be pleasently surprised and may even say, "Wow! I have never really had it in low-range:bigok:" It is ok to use 4LO on the pavement just don't lock the center diff.

:cheers:

 

[bluduk15]

Re: Re: Need help diagnosing 4Lo transmission problem

My 03 has always beeped in low also, i think thats the just what its supposed to do, that clinkin noise might of been the 4WD ingaging or disingaging,

I very well may have done it incorrectly. The manual blows, thanks for the info.

 

[5adat]

Thanks guys, one mystery solved for me too! Always thought getting around the grinding in 4Lo had more to do with my magic touch, not stepping down the gears.

as for the beeping, while shopping for my used 4th Gen one dealer told me it was so I know when I'm in Lo. Bull! Understandable to assume that, but not if you're trying to sell the product and need to inform buyers! Anyway if it's beeping, you're not in lo gear.

 

[CJ3Flyr]

:bigok: glad it worked out and yes, the manual is tough to decifer (sp?) sometimes.


:cheers:

 

[bluduk15]

So, it shifts in to 4lo pretty easy now. The first time I tried it, I had a trailer hooked up and was at a steep incline and it didn't work.

I've been using it in my parking garage to test it on the inclines now, but there is another strange problem...

When I am slowly coming to a stop or stopped, it surges and wants to jump forward a bit, almost like something hits the gas, but the brake pedal is engaged.

Any ideas?

 

[CJ3Flyr]

So, it shifts in to 4lo pretty easy now. The first time I tried it, I had a trailer hooked up and was at a steep incline and it didn't work.

I've been using it in my parking garage to test it on the inclines now, but there is another strange problem...

When I am slowly coming to a stop or stopped, it surges and wants to jump forward a bit, almost like something hits the gas, but the brake pedal is engaged.

Any ideas?

My guess is you're feeling the bump associated with the transmission downshifting from 2 to 1 as you slow to a stop. The torque multiplication due to the low ratio is greater. (You'll also feel the compressor cutting on and off more.)

I would suggest putting it in 4lo and L (1st gear) accelerate a bit and stop. My guess is the bump will be gone. That'll confirm that you are feeling the transmission downshift to 1st as you come to a stop.


:cheers:

 

[bluduk15]

My guess is you're feeling the bump associated with the transmission downshifting from 2 to 1 as you slow to a stop. The torque multiplication due to the low ratio is greater. (You'll also feel the compressor cutting on and off more.)

I would suggest putting it in 4lo and L (1st gear) accelerate a bit and stop. My guess is the bump will be gone. That'll confirm that you are feeling the transmission downshift to 1st as you come to a stop.


:cheers:

Ahh, good advice. Deductive reasoning, I'll look in to that...

 

[CJ3Flyr]

So, it shifts in to 4lo pretty easy now. The first time I tried it, I had a trailer hooked up and was at a steep incline and it didn't work.

I just focused on this point:

The trailer and the hill shouldn't affect it. As I alluded to earlier try the rolling slowly trick (forward or backward) while in 'N' if it doesn't change modes. That should help and I have never had to roll more than a foot. Now (if you have the V6), to go from 2HI to 4HI will take more than a foot or two but can that can be done at any speed under 62.5mph (100km/h).

:cheers: