hate to post 4x4 prob here,but

[shadetree]

sorry to bring other problems to the engine side, but i didnt find any similar problems. I had a rusted reese hitch and was trying to remove it using a large chain and matching tree. needless to say i got it a part but discovered that my front tires did not dig into the yard as did my duallys did. so my ? is how do i test it. iam assuming the actuator on the front axel is what controls the locking in and out of 4x4.

this is the truck that i just put a new motor in and have only owned for a month or so. still need to do tdc learn on the computer. i am just glad that it is running and moving on its own power(so is the wife). have other problems but gotta pick witch gremlens to kill first. 4x4 is important thats why i bought the truck

thank in advance love this site

 

[packratt]

Sounds like the actuator. There have been a couple threads in this forum in the last month or so that I believe have diagnostic info.

 

[ShawnR]

If you pull the actuator out of the front housing and stick 12 volts to it, it should "extend" as the fluid inside it heats up. If it is bad, replace it with an updated one as indicated in the other threads. You won't regret it.

 

[mattthebrat]

It could also be the button, if it had the push button 4X4, 95 was an intermediate year for that kind of crap.

 

[shadetree]

thanks my trucks got the lever on the floor. does the shift linkage have a switch? am planning on doing all the test this weekend.

 

[Bullseye240]

Theres a switch on the lever that sends power to the to the problimatic TLA. They sometimes go bad but the TLA is more likely. But it always makes sense to check the free stuff first, after all it's free.

 

[trouttrooper]

I'd say with 90% certainty that it's the actuator. They were a bad design to begin with, and yours is 14 years old.

 

[Missy Good Wench]

There is a unit called POSI LOCK and is a cable system that replaces the probelmatic thermal actuator.

The T A on my 94 Burb died last winter and a trip to the parts house to get a fresh one solved the issue quickly.

There is an electric servo motor replacement and associated wiring harness but it is Spendy.

I would Opt for the Posi Lock and not worry any more.

best

MGW

 

[nvmtnlion]

+1 for the Posi Lock. I had it on all 3 of my S-10 Blazers, and when my actuator went bad on my K2500, it was my first stop.

 

[Chevylover]

Missy is right. The TLA (Thermal Linear Actuator) is prone to failure on these models.
You can replace it and wait till the next time it fails again. You could uprade to the later style electrical actuator (expensive incl. some electrical work) or go with the posi-lok system. Works manually and works if needed ant any time AND as a benfit, you'll get 2Low for manouvring trailers, etc. on tarmaq.

I AM REALLY SATISFIED WITH THE POS-LOK SYSTEM ON MY TRUCK !


Cu,
Sven

 

[Matt Bachand]

Easy test for 4x4 is put it in 4x4 and turn the wheel sharp while rolling forward slowly. If it is working, you WILL notice it.

 

[kojo]

if original has lasted 14 years how you can say it for bad design? I was working for one big japanese car company in old life and they told me that they plan cars to last 6 years...

 

[fastjohnny]

if original has lasted 14 years how you can say it for bad design? I was working for one big japanese car company in old life and they told me that they plan cars to last 6 years...

Just cause it worked doesnt mean it worked well. Too slow to engage IMO.

That said, I have a used one on the shelf from a broken diff I'd sell cheap if interested.

 

[Chevylover]

Just cause it worked doesnt mean it worked well. Too slow to engage IMO.

That said, I have a used one on the shelf from a broken diff I'd sell cheap if interested.

AND if locked with the posi-lok, it will be engaged also after shutting the igniton off. The OEM actuator (both thermal and the newer electric) will disengage the 4WD.

Cu,
Sven

 

[DieselSlug]

There is a unit called POSI LOCK and is a cable system that replaces the probelmatic thermal actuator.

The T A on my 94 Burb died last winter and a trip to the parts house to get a fresh one solved the issue quickly.

There is an electric servo motor replacement and associated wiring harness but it is Spendy.

I would Opt for the Posi Lock and not worry any more.

best

MGW

I am going to get one of those posilocks, only a few bucks more than a thermo jigger....

 

[Bullseye240]

if original has lasted 14 years how you can say it for bad design? I was working for one big japanese car company in old life and they told me that they plan cars to last 6 years...

It most likely lasted that long because it never got used before. Most of the vehicles never had the lever moved or button pushed to engage the 4X4 that most of the previous owners most likely never knew they had let alone what it was for.

 

[Missy Good Wench]

My 94 went from new until 2007 (winter)
As mentioned its not if it will fail its when.
The big issue is they usually fail wen you need it most.
The design issue was that it was prone to more failures than should happen to a "Mission critical part"

I like our 91 Burb with Warn "you twistem" Hubs and a lever on the foor

During cold snowy weather OR ??? I hate the fact that you dont always know if its gonna work.

The fact that it always disengages when the rig is off is also of concern too.
I replaced my original with a NAPA part and just let it go. I dont use the rig in 4x4 enough any more to justify the $$$$ for the POSI LOCK.

Back in December we had the most snow in 40 years here with over 3 feet on the ground by Christmas time.

The Burb got its butt run off in 4x4 during that time and I was nervous every morning with temps in the teens or below that the thing would work.

If you use your rig a lot the POSI unit is great.

Best

MGW