99 yukon/tahoe clunk
Question:
GM recommends the PTFE Grease, However I found that adding Tuffoil to the Txfer case oil ( according to the instructions) has the same affect. It appears that the Txfer case output shaft ( the later version 96+ ) binds with the drive line yoke. Tuffoil $9 Martin
– Hide quoted text — Show quoted text -> mks, > Mobil 1 universal synthetic grease cured the problem once and for all > with my Suburban. > Dean >My 99 Yukon 50,000 mi. [just bought it last month] has a clunk when stopping >and accelerating from a stop.It’s coming from the rear. I don’t think it’s >in the differential. >U-joints check out good.I heard it could be the splines at the trans output >shaft and the driveshaft. >Manually by hand it slides good. > I lubed the shaft with clean grease—worked fine for 2 days–now today >it’s back. >It kind of feels like the rear end housing twists back when stopping then >goes back when accelerating. >Is anyone else having this problem? What’s the cure?
Response:
Hello- I bought a new 99 Tahoe, and remember a clunk at about 17000 miles- took it in, sevice dept. wrote on the repair order- checked suspension and body mounts, noise seems to be coming from driveline, flushed transfer case per bulletin and installed new fluid per bulletin 990421004. Had another problem at 7000 miles, noise in driveline when slowing down- repair was- remove driveshaft, cleaned splines lubed spline, reinstall and roadtest. After both those, the noises/clunks/etc went away. Hope this helps. Carl – Hide quoted text — Show quoted text – > What exactly do you need? Looks like you found the TSB alright, there > are at least 2 listed on www.alldatadiy.com (I only have access to > titles) with the word "clunk" in the title, both numbers I found are > listed in your post. Take it to the dealer and ask them to perform the > TSB… >NOTE: >IF anyone can get me the TSB listed below, I would be thankful. Post >to here please. >Important: The condition described in this bulletin should not be >confused with Driveline Stop Clunk, described in Corporate Bulletin >Number 964101R (Chevrolet 92-265-7A, GMC Truck 91-4A-77, Oldsmobile >47-71-20A, GM of Canada 93-4A-100) >Driveline Clunk >File In Section: 04 – Driveline Axle >Bulletin No.: 99-04-20-002 >INFORMATION >Driveline Clunk >Models: >2000 and Prior Chevrolet and GMC Light Duty Truck Models >This bulletin is being revised to update the models section and add >information to the Important statement. Please discard Corporate >Bulletin Number 56-44-O1A (Section 4 – Drive Axle and Section 7 – >Transmission). >Important: The condition described in this bulletin should not be >confused with Driveline Stop Clunk, described in Corporate Bulletin >Number 964101R (Chevrolet 92-265-7A, GMC Truck 91-4A-77, Oldsmobile >47-71-20A, GM of Canada 93-4A-100) or Bump/Clunk Upon Acceleration, >described in Corporate Bulletin Number 99-04-21-004. >Some owners of light duty trucks 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 known as 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 (lash) between the components in the driveline. >For example, the potential for a driveline clunk would be greater in a >4-wheel drive or all-wheel drive vehicle than a 2-wheel drive vehicle. >This is because in addition to the freeplay from the rear axle gears, >the universal joints, and the transmission (common to both vehicles), >the 4-wheel drive 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 freeplay (or lash) present in all of the driveline >components. >Because all of the components in the driveline have a certain amount >of lash by design, changing driveline components may not result in a >satisfactory lash reduction. >^ While some owners may find the clunk noise objectionable, this will >not adversely affect durability or performance. > — > Reach me by ICQ. My ICQ# is 8023912 or, > * Send me E-mail Express directly to my computer screen
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Response:
Next question. Will it eventually hurt anything if the part is not replaced? Thanks! Kevin
– Hide quoted text — Show quoted text -> There is a TSB for a nickel plate slip yoke for this problem, see: > http://www.geocities.com/crackeregg/bulletins/01-04-17-004.html > : My 99 Yukon 50,000 mi. [just bought it last month] has a clunk when > stopping > : and accelerating from a stop.It’s coming from the rear. I don’t think it’s > : in the differential. > : U-joints check out good.I heard it could be the splines at the trans > output > : shaft and the driveshaft. > : Manually by hand it slides good. > : I lubed the shaft with clean grease—worked fine for 2 days–now today > : it’s back. > : It kind of feels like the rear end housing twists back when stopping then > : goes back when accelerating. > : Is anyone else having this problem? What’s the cure? > : > : > :
Response:
What exactly do you need? Looks like you found the TSB alright, there are at least 2 listed on www.alldatadiy.com (I only have access to titles) with the word "clunk" in the title, both numbers I found are listed in your post. Take it to the dealer and ask them to perform the TSB… – Hide quoted text — Show quoted text – >NOTE: >IF anyone can get me the TSB listed below, I would be thankful. Post >to here please. >Important: The condition described in this bulletin should not be >confused with Driveline Stop Clunk, described in Corporate Bulletin >Number 964101R (Chevrolet 92-265-7A, GMC Truck 91-4A-77, Oldsmobile >47-71-20A, GM of Canada 93-4A-100) >Driveline Clunk >File In Section: 04 – Driveline Axle >Bulletin No.: 99-04-20-002 >INFORMATION >Driveline Clunk >Models: >2000 and Prior Chevrolet and GMC Light Duty Truck Models >This bulletin is being revised to update the models section and add >information to the Important statement. Please discard Corporate >Bulletin Number 56-44-O1A (Section 4 – Drive Axle and Section 7 – >Transmission). >Important: The condition described in this bulletin should not be >confused with Driveline Stop Clunk, described in Corporate Bulletin >Number 964101R (Chevrolet 92-265-7A, GMC Truck 91-4A-77, Oldsmobile >47-71-20A, GM of Canada 93-4A-100) or Bump/Clunk Upon Acceleration, >described in Corporate Bulletin Number 99-04-21-004. >Some owners of light duty trucks 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 known as 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 (lash) between the components in the driveline. >For example, the potential for a driveline clunk would be greater in a >4-wheel drive or all-wheel drive vehicle than a 2-wheel drive vehicle. >This is because in addition to the freeplay from the rear axle gears, >the universal joints, and the transmission (common to both vehicles), >the 4-wheel drive 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 freeplay (or lash) present in all of the driveline >components. >Because all of the components in the driveline have a certain amount >of lash by design, changing driveline components may not result in a >satisfactory lash reduction. >^ While some owners may find the clunk noise objectionable, this will >not adversely affect durability or performance.
– Reach me by ICQ. My ICQ# is 8023912 or, Download ICQ at http://www.icq.com/download/ For adding similar signatures to your e-mail go to: http://www.icq.com/email/emailsig.html
Response:
NOTE: IF anyone can get me the TSB listed below, I would be thankful. Post to here please. Important: The condition described in this bulletin should not be confused with Driveline Stop Clunk, described in Corporate Bulletin Number 964101R (Chevrolet 92-265-7A, GMC Truck 91-4A-77, Oldsmobile 47-71-20A, GM of Canada 93-4A-100) Driveline Clunk File In Section: 04 – Driveline Axle Bulletin No.: 99-04-20-002 INFORMATION Driveline Clunk Models: 2000 and Prior Chevrolet and GMC Light Duty Truck Models This bulletin is being revised to update the models section and add information to the Important statement. Please discard Corporate Bulletin Number 56-44-O1A (Section 4 – Drive Axle and Section 7 – Transmission). Important: The condition described in this bulletin should not be confused with Driveline Stop Clunk, described in Corporate Bulletin Number 964101R (Chevrolet 92-265-7A, GMC Truck 91-4A-77, Oldsmobile 47-71-20A, GM of Canada 93-4A-100) or Bump/Clunk Upon Acceleration, described in Corporate Bulletin Number 99-04-21-004. Some owners of light duty trucks 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 known as 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 (lash) between the components in the driveline. For example, the potential for a driveline clunk would be greater in a 4-wheel drive or all-wheel drive vehicle than a 2-wheel drive vehicle. This is because in addition to the freeplay from the rear axle gears, the universal joints, and the transmission (common to both vehicles), the 4-wheel drive 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 freeplay (or lash) present in all of the driveline components. Because all of the components in the driveline have a certain amount of lash by design, changing driveline components may not result in a satisfactory lash reduction. ^ While some owners may find the clunk noise objectionable, this will not adversely affect durability or performance.
Response:
There’s a TSB on this exact issue from what I recall. Something about the fluid in the t-case, not 100% sure though… – Hide quoted text — Show quoted text – >Perhaps you want to look at the suspension instead. A sticky shock or a >torsion bar or maybe a spring. Look at everything. I test drove a truck a >99 Tahoe and didn’t buy it for that very reason. I never found what was >causing it. It really sounded to me like a suspension issue. U-joints >usually have a ringy, tinny, bell, sound to them, this was a dull thump. >Hope it helps. >My 99 Yukon 50,000 mi. [just bought it last month] has a clunk when >stopping >and accelerating from a stop.It’s coming from the rear. I don’t think it’s >in the differential. >U-joints check out good.I heard it could be the splines at the trans >output >shaft and the driveshaft. >Manually by hand it slides good. > I lubed the shaft with clean grease—worked fine for 2 days–now today >it’s back. >It kind of feels like the rear end housing twists back when stopping then >goes back when accelerating. >Is anyone else having this problem? What’s the cure?
– Reach me by ICQ. My ICQ# is 8023912 or, Download ICQ at http://www.icq.com/download/ For adding similar signatures to your e-mail go to: http://www.icq.com/email/emailsig.html
Response:
mks, Mobil 1 universal synthetic grease cured the problem once and for all with my Suburban. Dean – Hide quoted text — Show quoted text – >My 99 Yukon 50,000 mi. [just bought it last month] has a clunk when stopping >and accelerating from a stop.It’s coming from the rear. I don’t think it’s >in the differential. >U-joints check out good.I heard it could be the splines at the trans output >shaft and the driveshaft. >Manually by hand it slides good. > I lubed the shaft with clean grease—worked fine for 2 days–now today >it’s back. >It kind of feels like the rear end housing twists back when stopping then >goes back when accelerating. >Is anyone else having this problem? What’s the cure?
Response:
Is it in 4×4 mode or 2 wheel drive. Could be the transfer case if in 4×4 mode or the switch that puts it in 4×4 mode.
– Hide quoted text — Show quoted text -> My 99 Yukon 50,000 mi. [just bought it last month] has a clunk when stopping > and accelerating from a stop.It’s coming from the rear. I don’t think it’s > in the differential. > U-joints check out good.I heard it could be the splines at the trans output > shaft and the driveshaft. > Manually by hand it slides good. > I lubed the shaft with clean grease—worked fine for 2 days–now today > it’s back. > It kind of feels like the rear end housing twists back when stopping then > goes back when accelerating. > Is anyone else having this problem? What’s the cure?
Response:
Perhaps you want to look at the suspension instead. A sticky shock or a torsion bar or maybe a spring. Look at everything. I test drove a truck a 99 Tahoe and didn’t buy it for that very reason. I never found what was causing it. It really sounded to me like a suspension issue. U-joints usually have a ringy, tinny, bell, sound to them, this was a dull thump. Hope it helps.
– Hide quoted text — Show quoted text -> My 99 Yukon 50,000 mi. [just bought it last month] has a clunk when stopping > and accelerating from a stop.It’s coming from the rear. I don’t think it’s > in the differential. > U-joints check out good.I heard it could be the splines at the trans output > shaft and the driveshaft. > Manually by hand it slides good. > I lubed the shaft with clean grease—worked fine for 2 days–now today > it’s back. > It kind of feels like the rear end housing twists back when stopping then > goes back when accelerating. > Is anyone else having this problem? What’s the cure?
Response:
There is a TSB for a nickel plate slip yoke for this problem, see: http://www.geocities.com/crackeregg/bulletins/01-04-17-004.html
: My 99 Yukon 50,000 mi. [just bought it last month] has a clunk when stopping : and accelerating from a stop.It’s coming from the rear. I don’t think it’s : in the differential. : U-joints check out good.I heard it could be the splines at the trans output : shaft and the driveshaft. : Manually by hand it slides good. : I lubed the shaft with clean grease—worked fine for 2 days–now today : it’s back. : It kind of feels like the rear end housing twists back when stopping then : goes back when accelerating. : Is anyone else having this problem? What’s the cure? : : :
Response:
My ‘99 Suburban has always done this and my ‘95 Yukon does it a bit as well. The Yukon had grease put in the yoke while under warranty. This fixed it for a while and then it started maybe six months later. Hasn’t hurt a thing and I haven’t been concerned enough to beat myself up trying to figure it out. It doesn’t cause any performance issues at all that I’ve seen.
– Hide quoted text — Show quoted text -> My 99 Yukon 50,000 mi. [just bought it last month] has a clunk when stopping > and accelerating from a stop.It’s coming from the rear. I don’t think it’s > in the differential. > U-joints check out good.I heard it could be the splines at the trans output > shaft and the driveshaft. > Manually by hand it slides good. > I lubed the shaft with clean grease—worked fine for 2 days–now today > it’s back. > It kind of feels like the rear end housing twists back when stopping then > goes back when accelerating. > Is anyone else having this problem? What’s the cure?
Response:
My 99 Yukon 50,000 mi. [just bought it last month] has a clunk when stopping and accelerating from a stop.It’s coming from the rear. I don’t think it’s in the differential. U-joints check out good.I heard it could be the splines at the trans output shaft and the driveshaft. Manually by hand it slides good. I lubed the shaft with clean grease—worked fine for 2 days–now today it’s back. It kind of feels like the rear end housing twists back when stopping then goes back when accelerating. Is anyone else having this problem? What’s the cure?
