[ZonMatsukai]

I've had this problem with the driveline clunking when I step on the gas, let off of the gas, and shift into drive and reverse. It only happens occasionally, so I didn't think much about it.

I've also seen threads made by others that have the same problem. Well, I just went over drivelines and the such in class today, and saw an article in my book that pretty much explains it all.

This is directly out of my book, so, if the information seems incomplete or missing some stuff, don't complain to me, direct your complaints to CCi, which ordered the books. >.<

Spline Bind Cure

Driveline "clunk" often occurs in RWD vehicles when shifting between drive and reverse or when accelerating. Often the cause of this noise is excessive clearance between the teeth of the ring and pinion in the differential. Another cause is called spline bind and occurs when the changing rear pinion angle creates a binding in the spline as the rear springs change in height. For example, when a pickup truck stops, the weight transfers toward the front and unloads the rear springs. The front of the differential noses downward and forward as the rear springs unload. When the driver accelerates forward, the rear of the truck squats downward, causing the driveshaft to be pulled rearward when the front of the differential rotates upward. This movement on the spine often causes the spline to bind and make a loud clunk when the bind is finally released. The spline bind is not to be confused with "launch shudder," which is the vibration felt during acceleration when the front and rear driveshaft angles are not equal. Weak rear springs or an overloaded vehicle usually causes launch shudder.

The method recommended by vehicle manufacturers to solve this noise is to follow these steps:

1.) Remove the driveshaft.
2.) Clean the splines on both the driveshaft yoke and the transmission output shaft.
3.) Remove any burrs on the splines with a small metal file (remove all filings).
4.) Apply the manufacturer recommended (often synthetic) grease to the spline teeth of the yoke. Apply grease to each spline, but do not fill the splines.
5.) Reinstall the driveshaft.

I hope this helps anyone who was wondering what caused this, and how to remedy it.

 

[1BADI5]

Could also be caused by bad U-joints too.

Jeremy

 

[laidflat]

^^^ yea that. i had to have all of mine replaced at 50,xxx. two had broken caps and the one at the carrier bearing was like welded shut lol. and i baby my truck so it was a surprise to me.

 

[ZonMatsukai]

Never said that's the only reason that it might do that. It's just one thing that could be the cause.

 

[1is2many]

my friend had the same problem in his blazer and it was the linkage in
his transfer case. it was 4wd there was a chain in there that had streched.

 

[ZonMatsukai]

OK, so I got bored while I was in the shop today. So, I got on AllData and was browsing through some TSB's for my truck. I happened to stumble on one concerning the driveline clunk.

A/T - Clunk When Shifting From Park/Drive/Reverse

Some owners of vehicles equipped with automatic transmissions may comment that the vehicle exhibits a clunk noise when shifting between Park and Drive, Park and Reverse, or Drive and Reverse. Similarly, owners of vehicles equipped with automatic or manual transmissions may comment that the vehicle exhibits a clunk noise while driving when the accelerator is quickly depressed and then released.

Whenever there are two or more gears interacting with one another, there must be a certain amount of clearance between those gears in order for the gears to operate properly. This clearance or freeplay (also called lash) can translate into a clunk noise whenever the gear is loaded and unloaded quickly, or whenever the direction of rotation is reversed. The more gears you have in a system, the more freeplay the total system will have.

The clunk noise that owners sometimes hear may be the result of a buildup of freeplay between the components in the driveline.

For example, the potential for a driveline clunk would be greater in a 4WD or AWD vehicle than a 2WD vehicle. The is because in addition to the freeplay from the rear axle gears, the universal joints, and the transmission (common to both vehicles), the 4WD transfer case gears (and their associated clearances) add additional freeplay to the driveline.

In service, dealers are discouraged from attempting to repair driveline clunk conditions for the following reasons:

- Comments of driveline clunk are almost never the result of one individual component with excessive lash, but rather the result of the added affect of lash present in all of the driveline components.

- Because of all the components in the driveline have a certain amount of lash by design, changing driveline components may not result in a satisfactory lash reductions.

While some owners may find the clunk noise objectionable, this will not adversely affect durability or performance.

 

[1BADI5]

Never said that's the only reason that it might do that. It's just one thing that could be the cause.

Its all good Bro, no one was implying you were wrong. Just adding more informetion.

Jeremy

 

[FMRJPR]

A quick check for bad ujoints is to liberally spray the bearing area with WD40, Go for a short run, take a peak, if you see rust ooozing out of the bearing it's a bad joint.

 

[1BADI5]

A quick check for bad ujoints is to liberally spray the bearing area with WD40, Go for a short run, take a peak, if you see rust ooozing out of the bearing it's a bad joint.

Damn you have all kinds of useful information. Good tip!

Jeremy

 

[rangerbob]

Even older thread - but my driveline was clunking. Then it turned into a horrible squeaking in reverse. Was a blown out u-joint. So bad that I had only 3 needle bearings left in one cap. The rest were rust.