Suburban dilemma

We had to have the rear end replaced on our 'burb, but it was coming down Pikes Peak that did for it. It ran for years after that. You may want to look for a place that specializes in electrical problems we have one here in this area and you may have one where you are.

I had a Florida Highway Patrol officer tell me that in his opinion the 'burb was the safest vehicle on the road. He bought one for his wife. Weighing two and a half tons might have something to do with that. That was after responding to hundreds of car crashes.

those were known for the ignitions going bad. As far as the rearend take a look at 5he pinion yoke nut probably alittle loose

I had to have the differential rebuilt on my Burb. Apparently it's very common on GM light trucks. I had mine done at a local garage that does really professional work with high end parts, so it was expensive IMO but, it should be good to go for 100,000 miles. It cost me $1,400.00 but, everything was replaced including the half axles.

As to the ghost.. I wish I had a suggestion. I can't imagine what would reset the computer like that. Maybe there's something overheating and cutting the circuit till it cools down. That would be a big deal for me. I can't know that I will be broken down on the side of the road. Wonder if there's a grounding issue..?

This is really neither here nor there, but I wonder if the original owners didn't follow proper break in procedure for the differential. 2500 burbs are almost always bought for the purpose of towing heavy. They could have hooked up to a heavy trailer and headed down the road with 50 miles on the clock.

The electrical problem would concern me much more than the rear differential, as you will never know when you will be stranded, and you will not know if it's fixed unless you find the "smoking gun" which is not easy on these newer vehicles.

Ah...the good old BAD GM battery side post issue...if GM still has side post batteries in your year Suburban...

There is a one time use, lead, crush washer in the stack of stuff on the positive side post

One time usage, as once it is used and crushes to provide the proper contact pressure...it will "NO LONGER" provide proper contact pressure if reused.

Not many believed that on my old Suburban/SUV forum, but those that actually cut apart their positive lead lug end plastic...they found that crush washer

What happens is that the next time the positive post bolt is tightened...there is NOT enough lead washer thickness left to provide proper contact pressure...so everyone...me include till discovered this...cranked the bolt down a bit harder...

what then happens is that the bolt pokes into the battery case and cracks it. Just a bit, or lots if cranked hard enough

That then setups this failure mode:

• Acid leaks out ever so slightly and slowly
• That then corrodes the contact stack of lugs
• That then has the acid wick down the Positive Cable
• That some times corrodes the starter electrical post and sometimes the solenoid
• That then has the positive connection at the battery become intermittent
• That then cause all kinds of gremlins that is almost impossible to diagnosis
• That then load dumps the alternator numerous times to kill the alternator diodes

One of the question I ask is how many times have you had your alternator go bad...also if you have ever jump started another vehicle with your vehicle's engine still running...these two things kills many alternators

This become a vicious cycle chasing ever failing components seemingly associated

Solution is to either switch to top terminals, but few have the room between the hood metal and positive post

Bests solution is to toss that lead washer and replace the custom GM bolt with either a regular bolt of the right thread and LENGTH. That also is long enough to poke out to have a second jam nut between the bolt hex head and the stack of cable lugs. Gotta also have a brass/copper washer interface with the lead connection land on the battery. As that landing sits below the plastic case area

You can keep that stupid lead crush washer with the below image solutions...but was so PO'd that tossing it was the best for my mood at that time...

Not able to take a picture of mine, but found these pictures of what you can buy. I'll take a picture later and post back, but for now here are the pics found on line...such a common gremlin...

As far as the electrical problem goes I would have a really, really good look at the battery terminals and wires coming off of the batteries. I've seen wires that look good but when you strip the insulation back there is nothing but corrosion.

As stated above I would find a really good shop that specializes in electrical problems. Big difference between a general mechanical shop and a shop that specializes in electrical problems.

Good luck!

(On edit) Looks like Ben had the same idea I did! Great minds think alike. :)

Well, I have replaced all the battery cables with new cables, I have had the main fuse box checked, cleaned and dielectric greased. I have added a new ground strap from the body to the engine block. I have done, or had done every suggestion I have read or found to try. Nothing fixes it. It will seem fine for a while, long enough to make you think it’s fixed. Long enough to start to trust it again and then BAM. On that day you really need it, when if it acts up you are going to be in a whole heap of trouble, that’s when it won’t start, or it will die.

Any sign of it having been flooded in the past? Clean title?

austingta wrote:
Any sign of it having been flooded in the past? Clean title?

Really good question. ^^^^

I would clean up all the battery connections and look for ground bolts around the eng compartment that connect wires to the body. Remove all of them, wire brush threads and reinstall.