Clunks when starting and stoping

[navyjoe]

I have a 2006 2WD 60K miles with the auto trans. Every time I start off there is a light clunk and just before I com to a stop another clunk. I think it does it between 1st and 2nd shift but Thats hard to pin down.



I've tried checking the drive shaft for play but it seems solid (did not drop the drive shaft though). I did measure the temps on all 3 u-joints and they are running about 115 to 120 degrees after a long trip pulling a light load.



I read one post that it could be the slip joint behind the transmission and that lubing it might help. In the old days with a one piece drive shaft that was easy to check. Just unbolt the rear u-joint slide it out and squirt some oil on it.



With mine there is that center carrier bearing too. How do you slip out the yoke at the transmission? It also has a rubber boot covering the spline at the back of the transmission. Also what do you lube it with? Lithium grease?



One more question. How do you get a u-joint off these days. Mine has no clips. Some kind of injected plastic must hold it in.



I just need to know where to get started. This klunk is getting worse

 

[navyjoe]

I had just climbed into bed and remembered that the rear of an automatic has a seal because the slip joint is lubricated with automatic transmission fluid! Correct?

So that leaves me with only the u-joints, carrier bearing, or rear end as the cause. Right?

 

[TCDiesel]

Drop the rear Diff cover and check the slop in the pinion and ring gear, My guess is the Pinion bearings are gone (pinion bearings).

 

[rscurtis]

Wouldn't that give you a terrible gear whine before you felt any play?

 

[TCDiesel]

Wouldn't that give you a terrible gear whine before you felt any play?

NO/Maybe. Also you cannot feel it in the drive line,Put rear wheels in the air (Block front tires) Place In (N) and have some one move them back an forth (Wheels),You will see the movement in the pinion gear.

 

[navyjoe]

Drop the rear Diff cover and check the slop in the pinion and ring gear, My guess is the Pinion bearings are gone (pinion bearings).

By movement in the pinion gear do you mean sideways movement ie wobble or an in/out movement.



Wish I had posted this several days earlier. 4 days ago I just replaced the diff cover with a PML cover and put $50 worth of new lube in it.



Can this also be checked by measuring the degrees of rotating of the differential yoke or does that just check gear lash?

 

[TCDiesel]

You will see the wobble, the Pinion and Ring gear will look good, its a PITA to replace the crush sleeve, You will need a 3/4 Impact to do it correctly, if things go that far. Just save the lube if possible...

 

[navyjoe]

I guess I should be able to catch it now. The PML cover has a drain. I will have to find a container that holds 5 quarts.



If it is the pinion gear bearing I guess that is a job for a pro. The trick is finding a pro. It seems like I rarely hear of work done on a rear end that went well.



If this pinion bearing is bad will I have to also replace the ring and pinion gears?

 

[TCDiesel]

I guess I should be able to catch it now. The PML cover has a drain. I will have to find a container that holds 5 quarts.



If it is the pinion gear bearing I guess that is a job for a pro. The trick is finding a pro. It seems like I rarely hear of work done on a rear end that went well.



If this pinion bearing is bad will I have to also replace the ring and pinion gears?

No... ... ... .

 

[rscurtis]

When my '03 was new, it had a slight deceleration whine, which was common in the AAM axles at the time. I greatly reduced it just by tightening the pinion nut less than a 1/16 of a turn. I can't believe you wouldn't hear gear noise if you could see physical movement in the pinion gear. You'ld hear that truck coming from three blocks away. If you want to look for play in the rear end, which doesn't seem to be an issue in these trucks, look for someting in the differential, or worse, the ring gear loose on the carrier.

 

[TCDiesel]

When my '03 was new, it had a slight deceleration whine, which was common in the AAM axles at the time. I greatly reduced it just by tightening the pinion nut less than a 1/16 of a turn. I can't believe you wouldn't hear gear noise if you could see physical movement in the pinion gear. You'ld hear that truck coming from three blocks away. If you want to look for play in the rear end, which doesn't seem to be an issue in these trucks, look for someting in the differential, or worse, the ring gear loose on the carrier.

I agree,and that’s why I was so confused on MY 03,after much investigation the clunk was related to bearing failure. I thought for sure the ring & pinion were bad (I replace the entire Unit) I still have the ring & pinion . I had 3 experts check them, ALL come back with the same report, “Like New Condition" the Clunk got so bad People in Parking Lots would jump when I put it in gear. What really wired if you engaged 4X4 it was lessen the noise.

 

[navyjoe]

What would make a unit like mine go bad so quickly? I only have 60K on it and its not been driven hard at all.

 

[TCDiesel]

You need to check it,so far its only Post broken... ... .....

 

[Tejasdge]

Is that like your give-a-dang being busted?

 

[TCDiesel]

Is that like your give-a-dang being busted?

You lost Me?

 

[navyjoe]

You need to check it,so far its only Post broken... ... .....

Ha! You're right. I'm on vacation at the beach this week until next wed. I'll have to get on it after that.

 

[navyjoe]

I have a 2006 2WD 60K miles with the auto trans. Every time I start off there is a light clunk and just before I com to a stop another clunk. I think it does it between 1st and 2nd shift but Thats hard to pin down.



I've tried checking the drive shaft for play but it seems solid (did not drop the drive shaft though). I did measure the temps on all 3 u-joints and they are running about 115 to 120 degrees after a long trip pulling a light load.



I read one post that it could be the slip joint behind the transmission and that lubing it might help. In the old days with a one piece drive shaft that was easy to check. Just unbolt the rear u-joint slide it out and squirt some oil on it.



With mine there is that center carrier bearing too. How do you slip out the yoke at the transmission? It also has a rubber boot covering the spline at the back of the transmission. Also what do you lube it with? Lithium grease?



One more question. How do you get a u-joint off these days. Mine has no clips. Some kind of injected plastic must hold it in.



I just need to know where to get started. This klunk is getting worse

I found a good local shop and they identified the problem. The splines on the slip joints were dry. They dropped the driveshaft and lubed the one at the transmission and also at the center carrier. Only charged $63 with tax. So much for the splines being lubed by at transmission fluid! I keep you posed if this does NOT fix the problem.