Binding then "pop"

[Martinjmpr]

There is a button on the dash left of the steering wheel that says 'DIFF LOCK' or something similar.

If your 4runner is a 2000 SR5 then that's a rear diff lock, not a center diff lock. Rear diff lock will only work with the T-case in 4lo unless you (or the previous owner) have done the "green wire" mod.

The rear diff lock is a highly sought-after option, so make sure you take it into account if/when you decide to sell. :

As for shifting, on my 4runner I have to put the Transmission in neutral to go from 4Lo to 4hi. And I always come to a complete stop when shifting in or out of low. 2hi to 4hi and back can be done up to 60mph.

 

[Nelsonmd]

I think you misread. My FRONT ds is spinning freely (as it should) when I am in 2WD mode.

No, I understood just fine, but my wording wasn't great. If you can turn the rear DS without it binding like you described, then it seems to me that the binding wouldn't be in the TC if the TC is being directly driven by the DS.

Not sure that made sense, but I promise it makes sense in my head.

 

[BrianSD_42]

I had the truck on a level spot in neutral, 2WD, no parking brake (front driveshaft spinning freely by hand). I could turn the rear driveshaft by hand and the truck would move forward and reverse (as much as I could make it move by hand), so I don't think it's the brakes binding. Rear parking brake has always worked fine.

After this experiment, I got in the truck, started it up, dropped it in drive, and when I pressed on the gas it stayed put for a couple seconds, then the "pop" before moving forward.

Hmmm. based on the above statement, I wonder if your problems have anything to do with 4WD at all. You are in 2WD, you stay in 2WD and then hear a loud surge and pop. This is a classic transmission symptom.
.

 

[t4r4life]

change the oil in your diff and transfer go with synthetic

 

[Singtoe]

change the oil in your diff and transfer go with synthetic

Don't ruin your diffs and transfer case using synthetic oil. It is too thin, and doesn't stay where it needs to be. Use Lucas gear oil. It is tacky, thick and stays on the gears. It is the best product you can buy.

 

[athlon450]

Sounds like a sticking shift solenoid. When you shift it doesn't shift until is builds enough pressure to trigger the solenoid and jumps in gear. Just like revving up the engine and dumping it into drive.

 

[athlon450]

Or wore out clutch band pressure solenoids.

 

[zcruiser]

Sounds like a sticking shift solenoid. When you shift it doesn't shift until is builds enough pressure to trigger the solenoid and jumps in gear. Just like revving up the engine and dumping it into drive.

It actually tries to move forward. You can feel it drop into drive, build up pressure, then comes the pop. If the tranny weren't dropping into gear right away, I think the engine revs would come much easier and there would not be the mild bump you feel when it drops into drive at the get-go.

I think I'll change out the TC for cheap via Singtoe, and if that doesn't fix it I'll go from there. The transmission was rebuilt by the PO, and I'm pretty sure it was due to pink milkshake. Fortunately the TC has a different reservoir.

 

[zcruiser]

No, I understood just fine, but my wording wasn't great. If you can turn the rear DS without it binding like you described, then it seems to me that the binding wouldn't be in the TC if the TC is being directly driven by the DS.

Not sure that made sense, but I promise it makes sense in my head.

Ah, now I get what you're saying. Makes sense now.

 

[AddictedOffroad]

If this is only happening when you shift from 2hi to 4hi, then its definitely not the tranny.

Its likely an accuator issue in the front diff binding and no engaging or in the Tcase.

 

[BrianSD_42]

I think I'll change out the TC for cheap via Singtoe,

I don't think it makes financial sense to spend ANY $ buying 4WD parts when you don't even know if the problem is a 2WD or 4WD problem.

I had the truck on a level spot in neutral, 2WD, no parking brake
........
After this experiment, I got in the truck, started it up, dropped it in drive, and when I pressed on the gas it stayed put for a couple seconds, then the "pop" before moving forward

Does the issue occur when you are in 2WD only; moving from a stop to drive?

:frog:

 

[zcruiser]

If this is only happening when you shift from 2hi to 4hi, then its definitely not the tranny.

Its likely an accuator issue in the front diff binding and no engaging or in the Tcase.

It's not happening during the the shift, it's happening while in 2HI. My daughter hasn't had it in 4HI for quite a while now (ever since the snow left the NC mountains where she drives). I made sure she wasn't running 4HI in the SR5 on dry surfaces, since it runs with front/rear driveshafts locked in that mode.

 

[sandy4runner]

rev it up, dump into Drive or Reverse, tranny problem

Hi,
I have a similar problem, like described below,
1) I need to rev up the engine, in order to shift in D or R, car has about 100k miles only. --Solenoids? Which ones?
2) It seems like, it takes a lot of effort to accelerate and doesn't go much faster than 70 miles, what could that be?

3) I am new here, is there a free repair manual available online here?

Thanks,
Seb

Sounds like a sticking shift solenoid. When you shift it doesn't shift until is builds enough pressure to trigger the solenoid and jumps in gear. Just like revving up the engine and dumping it into drive.

 

[zcruiser]

Seb -

Check the link in my sig for lots of bookmarked resources:

http://www.toyota-4runner.org/3rd-gen-t4rs/69744-tutorial-documentation-reference.html

Mysteriously, my problem went away (for now). I'm thinking the 2WD/4WD shifter position wasn't quite in the right spot, and after I shifted back and forth and settled on 2WD mode, the problem has not returned. Next time I have access to the vehicle I may try a few shifts on loose gravel to see if I can reproduce.

 

[zcruiser]

Ok, problem is back with a vengeance. Had my daughter trade 4Runners, and I got a replacement set of rebuilt Tundra calipers from AdvanceAuto and installed them, then had Toyota do a brake line flush.

It's worse than ever and now I'm suspecting the ABS system. I'm taking it to Toyota tomorrow to have them diagnose it before I swap back to the stock 4Runner calipers / rotors.

Example of how bad it is.... My daughter was on a friend's flat driveway that is made of pea gravel. She could not move forward. The back wheels were spinning and pushing the front wheels that were locked in place. Once the "pop" occurred, the front wheels started moving.

 

[cordrayj1]

Ok, problem is back with a vengeance. Had my daughter trade 4Runners, and I got a replacement set of rebuilt Tundra calipers from AdvanceAuto and installed them, then had Toyota do a brake line flush.

It's worse than ever and now I'm suspecting the ABS system. I'm taking it to Toyota tomorrow to have them diagnose it before I swap back to the stock 4Runner calipers / rotors.

Example of how bad it is.... My daughter was on a friend's flat driveway that is made of pea gravel. She could not move forward. The back wheels were spinning and pushing the front wheels that were locked in place. Once the "pop" occurred, the front wheels started moving.

have you checked the FSM for the proper troubleshooting?

http://www.ncttora.com/fsm/index.html

 

[zcruiser]

have you checked the FSM for the proper troubleshooting?

Toyota Tacoma/ 4Runner/ Tundra/ FJ Cruiser Factory Service Manual Page

Read through that but none of the symptoms match.

I had a brilliant idea to just pull the ABS fuse and take it out of the equation but can't get the durned thing out.

:gun4:

 

[techno]

Example of how bad it is.... My daughter was on a friend's flat driveway that is made of pea gravel. She could not move forward. The back wheels were spinning and pushing the front wheels that were locked in place. Once the "pop" occurred, the front wheels started moving.

Sounds like a good set up for burn-outs!

I think you are on the right track with replacing front brake components. A sticky caliper or loose pad might cause this kind of behavior.

 

[zcruiser]

Sounds like a good set up for burn-outs!

I think you are on the right track with replacing front brake components. A sticky caliper or loose pad might cause this kind of behavior.

Well I have replaced the first set of Tundra calipers with a 2nd set of rebuilt Tundra calipers and the problem didn't go away.

I disabled the ABS (cut the fuse, couldn't get it pulled), no difference.

Loosened up the rear emergency brake like the Toyo tech suggested, and there was a slight improvement but it didn't make the problem go away.

I think I'm at the point of reversing this mod back to stock 4Runner caliper & rotors and see what happens next.

 

[LittleCaesar]

Sticking caliper piston? I had one on a Pontiac once. When cold, it would not release and the car would dive to the right.

I'd jack the 4runner up and see if you can freely turn both wheels to see if you can hear and/or feel anything. Front diff may be on its way out. Drain the fluid to see if there is a large amount of metal shavings in it.