"CLUNK" sound

[PattBlue]

\"CLUNK\" sound

Ok..here's what I got. 90 Blazer 350 th700-R4 all standard stuff. I recently bought this and the last owner said the "CLUNK" sound you hear/feel may be from the pinion in the rear-end going bad. It only happens when I stop like at stop sign (completely) the go again. Nothing else just alittle vibration 40 to 50 MPH then all clears up. Any ideas?? Does the pinion sound right. It also happens if I sit and shift from "D" to "R". 1 guy told me we could try to just tighten it instead of replacing. Thanks in Advance

 

[mudfanatic]

Re: \"CLUNK\" sound

before you go spending dollars on the pinion take it to a reputable shop and have them check the U-Joints, unless you know what you're looking for. check slop side to side, up and down and foreward and backward- both joints.
If everything is tight then get ready to spend dollars rebuilding the rearend... In fact just replace the rear end with a good 12 bolt that's been rebuilt, in the long run you'll be better off
Dan

<font color=red>get involved with land issues or lose the land</font color=red>

 

[Eagle86K5]

Re: \"CLUNK\" sound

Don't forget the motor mounts and the tranny mount....

<font color=green>

Eagle86K5

<font color=red>
Masonry...It's a Good Thing
2B1ASK1

 

[Truckfan2]

Re: \"CLUNK\" sound

do check the u-bolts... that's what was happenind with my '89 Jimmy

NEVER been stuck... *yet*

 

[rich]

Re: \"CLUNK\" sound

Hey. I have exactly the same model Blazer that you do. It has always had a clunk or "slack" in the drivetrain that can be felt when shifting into gear from Park or Neutral, and even when getting back on the gas after coasting or decelerating. My parents bought this K-5 new, and it has always been that way. We took it in for warranty work, and almost everything in the driveline was worked on - rebuilt trans, replaced driveshaft, new rear axle gears, but the clunk never went away.

It has never caused any problems, but it does worry me when I think about it - so I just try to ignore it

Seriously though, everyone is right - you should check all the driveline parts they have suggested, especially U-joints and torque converter bolts. But I have never been able to get rid of my clunk, and it has 123,000 miles on it now.

Later!

Richard
'76 K-5 Blazer
'90 K-5 Blazer

 

[1TUFF89]

Re: \"CLUNK\" sound

I have an 89 Blazer and do feel a "clunk" when I shift from drive to reverse or vice versa. It doesn't make any noise when I stop though. I have recently been hearing a loud "clunk" when I shift gears especially if I'm on an incline. I just had heavy duty u-joints installed after going through two sets of regular u-joints in two years. The two totaled $50 for the joints plus labor. Now there is no noise and rides great. Make sure you have the u-joints checked really good before going into the rear end!!

Chevy's RULE!

 

[BurbinOR]

Re: \"CLUNK\" sound

The guys are right, it COULD be your u-joints. Sounds more likely to be the "elusive" GM driveline clunk. I have read more posts and opinions on this over the past two years that I can imagine - seems it is also possible to be in the slip joint of the driveshaft. Apparently GM knows about this problem, always has, and has a (VERY expensive) lube you put on the splines. Have heard it works for a while, then you have to re-apply. Hard to believe not many of you guys have it (meaning the "leaving a red light"), I had it on all 5 of my K5's.............

'79 - 406 w/IROC TPI - K5#5 - a <font color=orange>sickness

<font color=blue>you never get enough of!!

 

[bablazer73]

Re: \"CLUNK\" sound

above and beyond all the great idea's everybody has, here's 2 more from my life's experience. If you have an open carrier, check the spider gears. had one that had worn gears causing play in the diff. also have had leaf springs break. usually on the rear half, loosened up the u-bolts that held the axel in and let it slip back and forth. I have never seem anybody "tighten" a pinion. if a pinion is loose, the bearing is damaged.

your right. I don't understand the jeep thing!

 

[Can Can]

Re: \"CLUNK\" sound

I just solved the exact same problem by using Eagle86's advice......Check that tranny crossmember and the rubber dampener that sits between the bracket and the tranny. I still have a bit of vibration, but the clunk is gone. All I had to do was tighten up the crossmember that supports the tranny and it was fixed.

 

[DMK]

Re: \"CLUNK\" sound

I had an 89 blazer doing the exact same thing did this for about 3 years. Finnaly the rear end went out. Clunk when starting or stopping is the pinnion adjusutment. u-joints
make a clunk when putting into gear.