Broke shift fork in transfer case

[fishnbas2]

Last year I had a broke shift fork in the transfer case. Figured it was fatigue on the part or something since the vehicle had 180,00 miles on it. Well now at 200,000 miles I believe the fork has broke again. I have the same symptoms as last time. Im getting ready to tear it down. Any ideas on why this has happend again or what should I look for as a cause. Im gonna use the sticky to open it up but just wondered if anyone had a similar issue and maybe a shortcut to fix this. We did have a rough winter and used 4X4 a lot more this year. Could the Auto 4X4 be doing this? Im thinking that possibly the Auto 4X4 kicking in might be putting a strain on this part. Brown wire mod will get done if this seems to be the problem. Let me know. Any help is appreciated.

Thanks

:exp:

 

[Joe Dirt]

What were your symptoms? Just curious...

 

[fishnbas2]

You start hearing a grinding noise under the vehicle. Usually round 40 mph+ when you let off the gas. Put pressure on the gas pedal and it will quit until you let off the gas again.

 

[IZwack]

That doesn't necessarily mean the shift fork - a loose pinion gear in the rear axle could make the same noise difference between accelerating and coasting.
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[KPT]

Could the Auto 4X4 be doing this? Im thinking that possibly the Auto 4X4 kicking in might be putting a strain on this part.

The shift fork has nothing to do with 4WD. All it does is shift between high and low.

Did you use your old case halves when you did the last repair? The shift rail bore is probably wallowed out.

 

[fishnbas2]

I opened it up and replaced the fork and replaced the halves.

 

[fishnbas2]

How can I tell if this is the issue?

 

[IZwack]

How can I tell if this is the issue?

If you are asking about the loose pinion gear I mentioned:

To check for a loose pinion gear in the rear axle
1) Disconnect the rear driveshaft from the rear axle. There are four (4) bolts, each of them takes a 12-point 12mm socket.
2) With the rear driveshaft disconnected from the rear axle, push on the rear axle's yoke side/side and up/down. If there is any lateral play on the yoke, then the pinion gear is loose.

 

[fishnbas2]

Ok, broke down the transfer case today and to my suprise it looked fine inside. Fork was not broke. I checked the rod holes and they seem tight. I put it back in the exploder and still have the issue. I took the actuator off the outside of the case and had some one working the switch and it would not turn. Iput it back on and it finally broke loose and started working. I noticed 1 thing when putting it back on. that the actuator was actually set more towards high than neutral. Im feeling that possibly the transfer case actuator is keeping the case slightly out of neutral and almost engaged in 4X4 high. Is this possible and can this be adjusted? I dont know im trying anything now. Im for sure the sounds in the transfer case. I tried IZwacks pinion gear check and it was tight. Thanks dude. Any ideas??????????

 

[fishnbas2]

Grinding noise has slowed. It doesnt happen as much but the problem seems to be in the transfer case for sure.

 

[gijoecam]

Ok, broke down the transfer case today and to my suprise it looked fine inside. Fork was not broke. I checked the rod holes and they seem tight. I put it back in the exploder and still have the issue. I took the actuator off the outside of the case and had some one working the switch and it would not turn. Iput it back on and it finally broke loose and started working. I noticed 1 thing when putting it back on. that the actuator was actually set more towards high than neutral. Im feeling that possibly the transfer case actuator is keeping the case slightly out of neutral and almost engaged in 4X4 high. Is this possible and can this be adjusted? I dont know im trying anything now. Im for sure the sounds in the transfer case. I tried IZwacks pinion gear check and it was tight. Thanks dude. Any ideas??????????

It should be in high any time the truck in in 4auto or 4high. It should never be in neutral (unless you have a neutral tow kit installed, of course).

 

[fishnbas2]

I dont think I have that installed. Im starting to think the motor actuator is not acting right.

 

[gijoecam]

Not likely. Motor failures in second-gens are notoriously uncommon. If you pull the motor off and the shaft is pointing at high, it's perfectly fine.

The whizzing noise is caused by something allowing the planetary gearset to slide out of position on deceleration. That's usually either a shift fork issue or a shift rail bore issue. I've seen pics on here of the fingers that ride in the shift rail wearing out, the fingers that engage the gear set wear out, the shift fork itself get bent or broken, and several others. The most common cause is the shift rail bore issue, but that's not usually a problem after replacing both case halves with rebuilt ones. (were they rebuilt halves, or just junk yard specials?)

Good luck!

 

[fishnbas2]

when i take the motor off it is pointing almost neutral. On mine the high is at 9oclock and neutral at 6oclock and low at 12oclock with the motor turning counter clockwise. When i remove my motor it points at about 7oclock.

 

[fishnbas2]

Should I change just the top or bottom half of the case or just do both???

 

[neallea1]

im also having that problem, after replacing the shift fork about 5 thousand miles ago I started having your problem but mine also does it in reverse at times but in reverse it wont move till I put it back in park then in reverse.

 

[Lazerskull]

Last year I had a broke shift fork in the transfer case. Figured it was fatigue on the part or something since the vehicle had 180,00 miles on it. Well now at 200,000 miles I believe the fork has broke again. I have the same symptoms as last time. Im getting ready to tear it down. Any ideas on why this has happend again or what should I look for as a cause. Im gonna use the sticky to open it up but just wondered if anyone had a similar issue and maybe a shortcut to fix this. We did have a rough winter and used 4X4 a lot more this year. Could the Auto 4X4 be doing this? Im thinking that possibly the Auto 4X4 kicking in might be putting a strain on this part. Brown wire mod will get done if this seems to be the problem. Let me know. Any help is appreciated.

Thanks

:exp:

Any updates on your transfer case?

I had the same exact grinding noise when decelerating above 40 mph.

At first it would go away by accelerating however, it became to the point when you let your foot off the gas and the whole thing would loose power, engine still running but no power from gas to the drive train. It happened while I was on a major highway and luckily coasted to the side. When I stopped the car put it in park, then drive again, it drove again but only a few feet. I managed to coast to the off ramp and I had it towed to a nearby transmission shop. The transmission shop was able to drive it but only in 4x4 low. His computer told him to change the shift motor. He changed it and said it is still not working right. He then opened the transfer case and found a broken shift fork, broken input shaft, and broken range slider. He wants 1,300 bucks for the whole thing, to fix and reinstall.

Before this happened. The pinion on the rear drive shaft was leaking oil. I put some in the rear differential hoping it might do something. Nothing happened. Another weird thing was my lights for the AC / Heater went out a few days before. Is that related?

My question is after I pay this guy 1,300 dollars for fixing the transfer case is it just going to break again?