Community Forums

UFO Pilot · 01-06-2018, 10:22 AM

On our way South on Thursday, a strange vibration or shudder started and I pulled over on the side of the Interstate. The battery light came on and the water temp shot up. I knew from past experience that the serpentine belt was the problem. I carry a spare so I crawled under and removed what was left of the serpentine belt. In looking it over for a seized pulley it was obvious that the pulley on the harmonic balancer had moved about 1/2" to the rear.

After the tow service from hell

( a story for a different time) I was towed to a shop in Turlock, CA. We arrived about 9 PM and on Friday morning they confirmed my diagnosis and ordered a new harmonic balancer. It will arrive on Monday morning. Workhorse informed them that the part was Workhorse specific so it could not be bought locally.

Two questions:
1. Is this possibly an indication of a bigger problem or does this just happen. Am I looking at more trouble down the line?

2. Why would Workhorse use a different balancer than was used on 8.1 engines in GMC and Chevrolet trucks? The shop said it might be because my Chassis is a R26 UFO.

Bolander GMC Truck repair in Turlock has been fantastic so far. The shop manager gave me his cell number and told me to call with any questions or problems. I called him 3 times Thursday evening due to the towing service problems. I will right a review when this is all over.

70ChevelleSS · 01-06-2018, 12:23 PM

Ultra RV Products, the go to place for Workhorse parts, lists part# 12555140 as the balancer for a 2008 R26. Workhorse specific part numbers usually start with a W. So I googled Workhorse 12555140. Seems it's a standard GM part, not Workhorse specific.

Haven't heard of any problems with balancer before, good luck.

F4Gary · 01-06-2018, 12:33 PM

$145 on Amazon. (above part number) ^^^^^^^

UFO Pilot · 01-06-2018, 12:42 PM

I think the problem is they could not locate it locally at a GM dealer and it wouldn't cross reference to any other brand. I called Napa myself and they couldn't cross reference.

I found online it fits the following GM products:
Chevrolet Express 3500 2002 8.1L V8
Chevrolet Express 3500 2001 8.1L V8
GMC Savana 3500 2002 8.1L V8
GMC Savana 3500 2001 8.1L V8

Probably just an error in communication, my error not theirs.

Alan_Hepburn · 01-06-2018, 03:29 PM

Workhorse will ALWAYS want to sell you a Workhorse part. We broke down last summer due to water in our differential and the repair shop called Workhorse for parts. The rear axle bearings were marked with a Workhorse number and there was no cross-reference available. The shop was able to find a cross-reference by measuring the bearings and comparing the numbers to their own books. Similarly, Workhorse wanted to charge almost $12K for their 3rd member, with a 6 week wait for shipping. The shop was able to get a 3rd member from a local shop for under $5K, and we were back on the road in under 3 weeks.

Motor7 · 01-07-2018, 07:58 AM

Another good cross reference is the Chevy Kodiak w/8.1.

That is how I found the idler, tensioner & pulley in stock at O'Reilleys. Nothing was listed at all for the Serp parts under "Workhorse" at AutoZone, Oreillys or Advance.

CJ7365 · 01-07-2018, 10:51 AM

Quote:

Originally Posted by UFO Pilot

On our way South on Thursday, a strange vibration or shudder started and I pulled over on the side of the Interstate. The battery light came on and the water temp shot up. I knew from past experience that the serpentine belt was the problem. I carry a spare so I crawled under and removed what was left of the serpentine belt. In looking it over for a seized pulley it was obvious that the pulley on the harmonic balancer had moved about 1/2" to the rear.

After the tow service from hell

( a story for a different time) I was towed to a shop in Turlock, CA. We arrived about 9 PM and on Friday morning they confirmed my diagnosis and ordered a new harmonic balancer. It will arrive on Monday morning. Workhorse informed them that the part was Workhorse specific so it could not be bought locally.

Two questions:
1. Is this possibly an indication of a bigger problem or does this just happen. Am I looking at more trouble down the line?

2. Why would Workhorse use a different balancer than was used on 8.1 engines in GMC and Chevrolet trucks? The shop said it might be because my Chassis is a R26 UFO.

Bolander GMC Truck repair in Turlock has been fantastic so far. The shop manager gave me his cell number and told me to call with any questions or problems. I called him 3 times Thursday evening due to the towing service problems. I will right a review when this is all over.

My question would be, why/how did the harmonic balancer move?

When you say it moved to the rear, is that the rear of the engine or MH?

UFO Pilot · 01-07-2018, 10:54 AM

It moved toward the motor. I also wonder why it moved and if that is an indication of a bigger problem?

exrench · 01-07-2018, 12:36 PM

Quote:

Originally Posted by UFO Pilot

It moved toward the motor. I also wonder why it moved and if that is an indication of a bigger problem?

I would not try to second guess this one. Harmonic balancers move on their own." Back in the day" setting ignition timing became somewhat of an adventure if the timing mark is on the part that moved.

mfire1339 · 01-07-2018, 01:01 PM

There may still be re-builders for them. I have had that done a couple times.

Mike

vettenuts · 01-07-2018, 01:38 PM

I am assuming only the "pulley" portion of the balancer moved, not the hub. Likely there is an elastomeric compound between the hub and the pulley, which aids in harmonic damping, and it sheared and the pulley moved out of alignment. If that is the case, and it didn't damage the timing cover, you should be set with a new one.

If it's any comfort, see this failure a lot on Corvettes and Camaros with the later Gen III and Gen IV motors. Unfortunately, sometimes on the Corvette they walk forward and destroy the steering rack in the process.

UFO Pilot · 01-07-2018, 02:08 PM

There appears to be rubber between the balancer and the pulley. The pulley moved back on the balancer about 1/2". I started the motor while waiting for the tow truck for a few minutes. After the driveshaft was reinstalled I started the motor and drove it to the spot the shop wanted it stored until repaired. Everything sounded and seemed normal other than the obvious warning lights.

CJ7365 · 01-07-2018, 07:42 PM

Quote:

Originally Posted by vettenuts

I am assuming only the "pulley" portion of the balancer moved, not the hub. Likely there is an elastomeric compound between the hub and the pulley, which aids in harmonic damping, and it sheared and the pulley moved out of alignment. If that is the case, and it didn't damage the timing cover, you should be set with a new one.

If it's any comfort, see this failure a lot on Corvettes and Camaros with the later Gen III and Gen IV motors. Unfortunately, sometimes on the Corvette they walk forward and destroy the steering rack in the process.

Quote:

Originally Posted by UFO Pilot

There appears to be rubber between the balancer and the pulley. The pulley moved back on the balancer about 1/2". I started the motor while waiting for the tow truck for a few minutes. After the driveshaft was reinstalled I started the motor and drove it to the spot the shop wanted it stored until repaired. Everything sounded and seemed normal other than the obvious warning lights.

OK, now I can picture that.

It would be great if you could get the old balancer and post a couple of pictures of it.

Where did you get a replacement?

UFO Pilot · 01-07-2018, 07:53 PM

The shop found it, it is coming out of Reno. If they will give me the old one I will take pictures. I started to take some pics while I was under the RV but got side tracked and forgot.