V8 jerks in 4Lo when shifting gears.

[chronicanomaly]

I bought a 2003 V8 SR5 4x4 in December, and never really tried 4Lo before, since I never did anything that needed it. Occasionally when I would test it, it would jerk when shifting from 1st to 2nd and 2nd to 3rd, but I never paid any attention to it since I was at school.

Now that I am home, I tried it last night with my dad in the car, and definitely think something isn't right. After putting the car in neutral, stopping, and changing into 4Lo, when I accelerate the Revs seem unnaturally high, and when the Runner shifts from 1st to 2nd gear, the car jerks forward like something is slipping. The same thing happens when shifting from 2nd to 3rd. I have never had a 4x4 before, so I wouldn't know for sure, but I really don't believe this is normal behavior. Any ideas?

 

[joshik]

unaturally high revs... like what kind of rpms?

since u said u have never had a 4x4 before... if u didnt know... in 4lo... your gear ratios drop dramatically. thats so you get more power and torque to climb hills, rocks, and what have you.

your suv shifts at a lower mph than normal...so by the time you are at like 10mph, you may be in 3rd gear. (not sure of the actual numbers but you get the point).

when your suv jerks forward, how hard are u stomping on the gas? when shifting at higher RPMs, your car will "jerk" during a shift even when in 4hi but maybe not as dramatically as in 4lo. if you stomp on the gas in 4hi u will shift at a higher rpm than normal. same thing in 4lo, you will shift at a higher rpm and since the gears are lower, when it shifts from 1st to 2nd, you will feel that jerk. try to ease the gas. 4lo is not really meant for hi speeds.

sorry my explanation may not be technical but i get how it works but have a hard time expressing it. lol maybe someone else can chime in and explain in greater detail. but i think what you are experiencing is actually normal.

 

[chronicanomaly]

Seems to be revving to about 2500-3000 with very light acceleration before shifting, whereas in 4Hi and the same amount of acceleration it shifts at 1500-1700. Not sure if that is normal with 4Lo, was more concerned with the jerk/slip when shifting.

 

[joshik]

icic, hm, mine usually shifts before 2krpms... and i can have a slight jerk but i dont have any "slipping" not sure what youre experiencing. maybe someone else knows.

 

[chronicanomaly]

Thanks joshik, I appreciate the response.

I'm going to call the dealer today and see what they have to say, although I'd rather have an experienced opinion from someone on here!

 

[mole177]

that's normal.

i hope you didnt go faster than 25mph in lo.

 

[chronicanomaly]

never got above 20.

A pretty bad jerk when shifting is normal?

 

[mole177]

do you get whiplash?

from 1-2 there's a nice thump and jolt when im in 4lo and center diff locked.

 

[chronicanomaly]

nope, no whiplash, nice thump and a jolt is a better way of describing it.

Talked to the dealer, said his tacoma does the same thing, just said theres so much torque in 4lo that it causes a jerk when shifting, said as long as there is no noise there is nothing to worry about, so hopefully its alright.

 

[mole177]

it will make sense when you're on terrain that really needs 4lo and diff lock.

 

[TheBlueWave]

When I've used 4 lo I pretty much keep the tranny in first gear. If I'm in a situation where I want to go faster, I use 4 hi rather than expecting the tranny to shift a bunch in 4 lo.