Binding then "pop"

[zcruiser]

Posted this over on the 4Runner forum but thought maybe I could get some local help here.

My 2000 SR5 4WD has developed a very disturbing behavior. It has a CDL button on the dash (left of the steering wheel), but I've never used it or really tested it out at all.

The truck is being used by my daughter @ App State. She has been shifting between H2 and H4 this past winter as the conditions there have changed from snow/ice to dry surfaces and back to snow/ice. (This truck does not have the automatic 4WD button on the side of the 4WD shifter because it is an SR5 not Limited.) She has not used the CDL button at all, and I'm pretty sure it is OFF.

What happens is that when she puts the truck in Drive, the transmission will drop into gear, but when she presses on the gas pedal, it doesn't move until the rpms get up to about 1500 then something "pops" and it will lunge forward. Even when moving forward it seems like there is resistance. Also will do this in Reverse.

I visited her this weekend and verified this strange behavior. I checked the shifting from 2WD to 4WD and it doesn't always disengage the front driveshaft when in the 2WD position (and the green 4-wheel symbol on the dash will stay lit).

Is my transfer case blown?

If so, can anyone recommend a good transmission shop in Boone?

 

[strong_toy]

I have no experience with the auto tranny and t-case in your year of 4Runner, but will try to help what little I can. My experience with Toyota auto trannies, is limited to dropping the pan and replacing solenoids, so here goes...

Based on the info you provided, I assume this 4Runner (2000 SR5 in your sig) has an automatic transmission and part time (2Hi, 4Hi, 4Lo) t-case. With a part time t-case, I'm not sure why it would have a CDL switch. Seems like the CDL switch would only be used with full-time 4WD t-case to lock a viscous coupler. Probably not important, but just trying to decipher info you provided to help solve this. If there is a viscous coupler on the t-case, that could be the culprit to the lag (slip) when in 1st gear or reverse.

The other possible culprit could be the shift solenoids in the transmission. You might move the lever to drive, or 2, or L, but the transmission may not be actually shifting into the correct gear. Maybe the same issue with reverse? I had issues with clogged shift solenoids in an 89 4Runner years ago.

Another cause could be the torque converter.

Does the lag or slipping in D and R happen when the t-case is in H2, H4, and L4? When in D, 2, or L on transmission will the truck drive fast enough to upshift or what is your maximum speed?

Have you checked the fluid level in the transmission?

 

[lt1fire]

Simple things first.

Make sure the converter has enough fluid in it.



Never heard of a CDL in a runner though.

 

[dbenke]

That will happen with low fluid. It has to build up enough pressure to engage in gear. That would would be the easiest/cheapest fix,but where is the fluid going?

 

[zcruiser]

Sorry, not CDL, but Rear Diff Lock (the truck's in Boone and I have never actually tried activating that part of the diff).

After messing around with it in the parking lot, I think I got it solidly back in 2WD mode and it hasn't misbehaved since. I have not tried putting it back in 4WD just because of lack of access.

The J-shifter on the TC looks like this:

So, when it's in H4 or L4, it's locked, and not good for driving unless the surfaces are slippery.