Bent crankshaft
05-06-2021, 07:36 PM
#1
Thread Starter
Join Date: 03-21-2021
Location: Omaha, Nebraska
Posts: 9
Bent crankshaft
Hello everyone. I made a post about a month ago about having a broken keyway in the crankshaft sprocket of a 2008 HHR SS. Long story short I put a new timing set and gears in. Upon starting up I seem to have the same balancer wobble as before. I put a new balancer and new bolt it. Has anyone had a similar issue before? I assume the crank is bent now and have no option but to use the vehicle. Thanks in advance!
05-06-2021, 08:22 PM
#2
Senior Member
Join Date: 02-01-2006
Location: lockport,ny
Posts: 1,378
How much wobble is there?
A crankshaft is very hard to bend. If it's really bent enough to visually wobble the balancer, then it's also wobbling the timing chain crank gear. Which means the timing chain isn't going to last long. Also, the oil pump drive is going to take a beating.
The only way to tell if the crank is bent is to put a dial gauge on the crank snout and rotate the engine to see how much side-to-side runout there is.
Steve
A crankshaft is very hard to bend. If it's really bent enough to visually wobble the balancer, then it's also wobbling the timing chain crank gear. Which means the timing chain isn't going to last long. Also, the oil pump drive is going to take a beating.
The only way to tell if the crank is bent is to put a dial gauge on the crank snout and rotate the engine to see how much side-to-side runout there is.
Steve
05-06-2021, 08:48 PM
#3
Platinum Member
Join Date: 01-09-2007
Location: SE USA
Posts: 15,884
How much wobble is there?
A crankshaft is very hard to bend. If it's really bent enough to visually wobble the balancer, then it's also wobbling the timing chain crank gear. Which means the timing chain isn't going to last long. Also, the oil pump drive is going to take a beating.
The only way to tell if the crank is bent is to put a dial gauge on the crank snout and rotate the engine to see how much side-to-side runout there is.
Steve
A crankshaft is very hard to bend. If it's really bent enough to visually wobble the balancer, then it's also wobbling the timing chain crank gear. Which means the timing chain isn't going to last long. Also, the oil pump drive is going to take a beating.
The only way to tell if the crank is bent is to put a dial gauge on the crank snout and rotate the engine to see how much side-to-side runout there is.
Steve
05-06-2021, 09:06 PM
#4
Thread Starter
Join Date: 03-21-2021
Location: Omaha, Nebraska
Posts: 9
It is definitely a noticeable wobble. If I had to guess it looks like maybe an ⅛ inch of play. The old balancer had a cracked keyway so I was thinking someone didn't torque the balancer bolt properly and it had came loose and sheared the key.
05-07-2021, 06:12 AM
#5
Administrator
Join Date: 10-13-2011
Location: Welland,Ont Canada
Posts: 36,598
I think, that at one time the timing chain and balance shaft chain where changed and the crankshaft sprockets for the LNF were replaced by the sprockets in the new chain kit, which are very different, that would explain the harmonic balancer not being able to seat correctly, and wobble.
watch the video, he shows the difference in the sprockets
https://www.chevyhhr.net/forums/how-...in-kits-60394/
watch the video, he shows the difference in the sprockets
https://www.chevyhhr.net/forums/how-...in-kits-60394/
05-07-2021, 07:39 AM
#6
Thread Starter
Join Date: 03-21-2021
Location: Omaha, Nebraska
Posts: 9
I watched that video before assembling everything. I did put a new crankshaft sprocket on but it wasn't the one supplied in the kit that is thinner. Has anyone ever experienced a faulty new balancer?
05-07-2021, 09:05 AM
#8
Platinum Member
Join Date: 12-06-2009
Location: Alabama
Posts: 11,112
Let me take a guess at this one.
1. The car was wrecked before and got hit in the passenger front side. Damaged the crank or balancer.
2. Engine was replaced at some point. Donor engine was damaged previously.
1. The car was wrecked before and got hit in the passenger front side. Damaged the crank or balancer.
2. Engine was replaced at some point. Donor engine was damaged previously.
05-07-2021, 09:39 AM
#9
Administrator
Join Date: 10-13-2011
Location: Welland,Ont Canada
Posts: 36,598
That crankshaft snout looks very stout and not easy to bend
https://zzperformance.com/products/ecotec-crankshaft
https://zzperformance.com/products/ecotec-crankshaft
05-07-2021, 10:29 AM
#10
Platinum Member
Join Date: 12-06-2009
Location: Alabama
Posts: 11,112
My reasoning is from back in my "mechanic for a living" days. Have changed out many engines before. Almost all came from our local wrecking yards. Every now and then they would drop one off with some obvious damage that occurred when the donor car was wrecked.
Have seen bent pulleys, dented valve covers, cracked exhaust manifolds, etc.
Just wondering if the OP knows of any engine swap history for this car.
Have seen bent pulleys, dented valve covers, cracked exhaust manifolds, etc.
Just wondering if the OP knows of any engine swap history for this car.