Cent Diff will not lock

[GregGimbert]

2005 V8 full time 4x4. Usually center diff locks with touch of a button after 3 dash light flashes. Tonight just flashes in perpetuity. Tried searching for info but it is 1 in the am and it has been a long off road night. If you know anything about such a problem, especially common problems/solutions I would so appreciate your input.

Thanks,

G.

 

[NJshadow93]

2005 V8 full time 4x4. Usually center diff locks with touch of a button after 3 dash light flashes. Tonight just flashes in perpetuity. Tried searching for info but it is 1 in the am and it has been a long off road night. If you know anything about such a problem, especially common problems/solutions I would so appreciate your input.

Thanks,

G.

Was your truck in gear when you were trying to lock it? Or neutral or park? Try locking it while in Drive, will help if you're rolling too.

 

[LTDSC]

i had the same thing happen. If it doesnt stop flashing its not going to engage. Mine engaged partially and was stuck. I had to get a new actuator which was very costly.

 

[GregGimbert]

I have used it extensively in the past. Always in neutral and at a stop when I did. Today I tried it stopped as per usual tactic, then rolling out of frustration. Manual was not specific as to whether I should be stopped or rolling so I was always did it stopped till tonight. Will try it again in the am. So disgusted right now. Just going to bed and pull covers over my head.

 

[NJshadow93]

I have used it extensively in the past. Always in neutral and at a stop when I did. Today I tried it stopped as per usual tactic, then rolling out of frustration. Manual was not specific as to whether I should be stopped or rolling so I was always did it stopped till tonight. Will try it again in the am. So disgusted right now. Just going to bed and pull covers over my head.

Mine just seems to lock much faster in drive while rolling than any other method. It may take up to 30 seconds sometimes if I'm in Neutral. When rolling in Drive it locks up immediately.

 

[JB.]

Yes, by all means while driving (straight), that's the easiest way. If it doesn't work, give it some gas and then let off. Keep trying.

If that doesn't work, get into a parking lot and try various combinations. Drive, then neutral -- then try reverse, then neutral. Try stopped. Try rolling a little. (all while it's flashing and trying to engage).

If you get it working use it frequently (daily for a while) to keep it working. It's an advantage of the V8 that exercising the diff lock is easy to do just about any time you think of it. It needs to be done while driving straight, but don't let the prospect of an impending mild, rolling street turn after it's locked worry you. Just make the turn and then disengage when straight.

 

[scw1991]

I'd slightly loosen the three actuator bolts and give it a wiggle. Hopefully the extent of this problem is just a gummed up shift rod.

 

[GregGimbert]

I'd slightly loosen the three actuator bolts and give it a wiggle. Hopefully the extent of this problem is just a gummed up shift rod.

Thanks for the advice everyone. Any chance someone has a picture of this 'actuator' or some advice on location? I would love to try this. Again, thank you all. I will update when I have tried actuator as well as reverse, ect tactics.

 

[scw1991]

Actuator is big plastic box bolted to back of transfer case right next to rear drive shaft. Use 12mm socket and or wrench to loosen the 3 bolts

 

[JB.]

I'd probably also make sure the truck was really warmed up well before making all the attempts.

 

[GregGimbert]

OK, I "fixed it". Sort of...

After finding all kinds of threads outlining removal of the box with the gears in it and all the potential problems messing with that could yield I decided to try some shock therapy.

Started the truck, set parking brake, put in neutral, hit diff lock button and dash light flashes with no engagement and no VSC off light.

Went under truck and gave it some whacks with a rubber mallet. Went back and checked dash, VSC off light now lit (yay!!) but diff lock light still flashing. Hmmm


Hit diff lock button again, VSC light goes off and diff light goes off. OK.

Repeat process again with same results. Darn.

Leave to go pick my kid up from school and when return home tried the diff lock on a WTF and the darn thing worked!!

Retried it in 4h, 4l, several times and works flawlessly and engages as quickly as ever, like in three light flashes or less.

Anyway, before anyone else tries taking the thing apart or paying cash money break out the rubber persuader and give that a try.