Metallic “Clang!” Noise Shifting From Reverse To Drive

[Sonofaskipper]

i sometimes hear a clang type noise when shifting from drive to reverse, and vice versa. Any ideas as to where it might be coming from. No play in the shafts front or rear. It’s rather metallic sounding, not really a “clunk,” more of a ringing “clang.” No issues or aberrant sounds when driving, only hear it when shifting.

I drive a ‘91 HDJ81.

 

[Technician1985]

Have you greased all of the slip joints and u-joints with moly grease? I'm guessing you'd hear a similar noise if you abruptly let off the gas in 3rd gear with all the windows down. I'm not an expert but from what I've read that's normal.

 

[Sonofaskipper]

I have greased the u and slip joints. Still hearing it. I’ve indeed heard/felt the lash from coming off throttle abruptly, wondered if the sound was correlated. I’ve not ridden in other 80’s, so I have no frame of reference. Thanks for the input.

 

[Sonofaskipper]

@Technician1985 amaze balls avatar btw.

 

[-Spike-]

Tap the dust ring on the pinion and see if it sounds familiar.

 

[nukegoat]

Go outside and tap on the rear driveshaft tube. If it sounds the same then there you go.

 

[Technician1985]

@Technician1985 amaze balls avatar btw.

Makes me laugh every time I see it. Also as said above mine makes the same noise and I believe it's the rear driveshaft tube, mine has a TINY amount of play and on occasion it can make a loud ping like hitting something with an aluminum baseball bat. It quieted down a lot after heavy greasing but before adjusting the kickdown cable on occasion if it upshifted with no throttle it would clang and I'd get a WTF from the passenger.

 

[LS1FJ40]

There shouldn’t be play in the drive shaft. Lock your center diff. Pull the rear drive shaft. If the noise goes away you found your culprit. U joints on the rear drive shaft.

I’ve had the same noise on all of my 80s. Always freaks me out. It’s always been the u joints.

 

[joey.w]

Same here. Just did mine.

 

[BILT4ME]

i sometimes hear a clang type noise when shifting from drive to reverse, and vice versa. Any ideas as to where it might be coming from. No play in the shafts front or rear. It’s rather metallic sounding, not really a “clunk,” more of a ringing “clang.” No issues or aberrant sounds when driving, only hear it when shifting.

I drive a ‘91 HDJ81.

You state no play in the shafts.

How did you check it? Pull up, stop, slide under and twist and rattle and nothing moved?

If so, that's the wrong way.

The driveline needs to be UNLOADED for a proper diagnosis.

Chock the wheels.
Put the truck transmission in neutral.
You CAN yank the parking brake, but not necessary.
Slide under and grab one end of the driveshaft.
Move it up/down and side/side to check for movement in either axis. If movement, U-Joints are bad.
Repeat this with both ends of both driveshafts.

Do a twist on the driveshaft both directions. If you get a lot of play (1/4 turn or more) you are having bearing problems in the differential.

You should always grease them in the same manner in order to place the grease on the wear areas instead of the non-wear areas.

 

[Tools R Us]

Another place for slop on the early rigs is the short spline drive plates/birf. Pop the caps, watch the birf ends as it's shifted back and forth, if excessive, can cause drive line clang. Overall, the non-VC rigs are much more prone to clang/clunk than the VC rigs, so somewhat normal.

 

[Sonofaskipper]

Another place for slop on the early rigs is the short spline drive plates/birf. Pop the caps, watch the birf ends as it's shifted back and forth, if excessive, can cause drive line clang. Overall, the non-VC rigs are much more prone to clang/clunk than the VC rigs, so somewhat normal.

I’ll be in there to inspect and tighten up the bearings when I get home. I’ll have the wife shift it back and forth for me before I begin.

 

[Technician1985]

Another place for slop on the early rigs is the short spline drive plates/birf. Pop the caps, watch the birf ends as it's shifted back and forth, if excessive, can cause drive line clang. Overall, the non-VC rigs are much more prone to clang/clunk than the VC rigs, so somewhat normal.

The drive plates are softer than the axles right? I need to get some new drive plates because mine aren’t totally tight, sometimes I think I can feel them shift if I am on the brakes and put it in reverse when the car is warmed up but maybe I’m imagining it. It seems like a different feeling and noise than the rear clunk.

 

[-Spike-]

The drive plates are softer than the axles right? I need to get some new drive plates because mine aren’t totally tight, sometimes I think I can feel them shift if I am on the brakes and put it in reverse when the car is warmed up but maybe I’m imagining it. It seems like a different feeling and noise than the rear clunk.

If you do this, get the newer, thicker ones from the later models (might be '94+, but definitely '95+) and use a fender washer and bolt to secure them to the stub axles. Or get new style birfs too, with longer stub axles.

 

[VETTE60]

that sound can be commonly commonly attributed to the viscous coupler, and not really a big deal.

 

[RFB]

I have greased the u and slip joints. Still hearing it. I’ve indeed heard/felt the lash from coming off throttle abruptly, wondered if the sound was correlated. I’ve not ridden in other 80’s, so I have no frame of reference. Thanks for the input.

is this a new development? or ongoing from a while back?

 

[Technician1985]

If you do this, get the newer, thicker ones from the later models (might be '94+, but definitely '95+) and use a fender washer and bolt to secure them to the stub axles. Or get new style birfs too, with longer stub axles.

Hmm I didn’t know you can use the new ones, I’ll look into that for sure, thanks!

 

[jaymar]

Another vote for u-joints here.

 

[Sonofaskipper]

If you do this, get the newer, thicker ones from the later models (might be '94+, but definitely '95+) and use a fender washer and bolt to secure them to the stub axles. Or get new style birfs too, with longer stub axles.

I guess I’ve got to disassemble everything to get an idea about what you’re describing. Where does one fit the fender washer and bolt?

 

[Sonofaskipper]

is this a new development? or ongoing from a while back?

I’ve only had the truck since mid March. I’ve only really driven it a handful of times, so I honestly can’t say. I didn’t notice it during the initial test drive, but that doesn’t really mean anything. I didn’t see anything to glaringly obvious crawling around under the truck before I bought it. I’m underway for Hawaii right now, so I really won’t have a chance to really look at things until late July when I get home. Being away from home for protracted periods means time with my wife and kids trumps time to baseline and turn wrenches. There’s a lot I want to do, but I’ve got to be patient, and take it one project at a time.