and no its not the taco bell i had last night! haha, when i come to a stop something in the rear end is binding up cause when i go to start up again i hear a honking like sound and it feels like the whole rear of the truck drops just a little, somethings definetly shifting either in the drivetrain or suspension. ive checked my ujoints and they seem fine and theyre less than a year old also and i just greased them 2 weeks ago. was thinking about checking the ubolts next, maybe one has loosened up and a lift block is shifting? other than that im not really sure what else could be causing it, any ideas on what else to look at?

wow, 31 views and not one reply! this place used to be the place to get answers, now its hardly worth posting, what a shame...

Have you pulled the diff cover to inspect? Just a thought since you said it feels like the rear end itself.

I'd first check the u-bolts like you said since your lift may be causing axle wrap. It may be hard to diagnose.

Sorry I did not see your thread yesterday.

Although the sound you describe does not equate to the "typical" description, the other symptoms could be indicating the drive shaft splines need lubed. More often it's described as a "pop" or "clunk", but there are always exceptions to the rule.

Search this drivetrain forum for such as you'll find many suggetions for remedies.

Have you changed or had others change the oil in the rear diff? Did they add or you add the friction modifier to it? If you can't smell the modifier then they didn't put any in? Was it mixed properly? You could always add more, I put in another bottle in the Dana 80 and have very good traction on mud and snow. I very often ask questions and have few responces so not to worry most of us won't answer if we don't think something might help. Good luck and let us know what it was.

Friction modifier reduces the clamping capacity of the clutches in the rear diff in trucks with synth. fluid, it should not be used.

Some gear oils have the modifier in it and some don't I have always bought Mobil 1 75W/90 syn and it doesn't have it in! Over the years watching the gravel roads on corners most of them look like the rear diffs lock and unlock as they travel around the circle. So this tells me that the diffs are not working the way that they should be! Hence me adding more modifier 1 bottle for the Dana 80 then reccomended I have never had a problem in mud ( 4to 5" up a ?? 20% grade for hunting) or in snow.:D

our differentials dont use friction modifiers because there are no clutch packs in them. just straight synthetic gear oil if i remember correctly

have you checked brakes

thanks for the replys guys, havent had much time to mess with it but im planning on lubing the drive shaft splines for one. also keith, i know the back brakes are shot and need to be replaced, maybe the slide pins are stuck and causing the brakes to not release? that thought had run through my head. also still need to check the ubolts, been busy with other things so i just havent gotten around to it yet.

oh, and one other thing, i think my rear shocks need replacing also as ive seen some fluid leaking from one, any chance one could be sticking?

wow, 31 views and not one reply! this place used to be the place to get answers, now its hardly worth posting, what a shame...
Ye of little faith...We're all still here...
thanks for the replys guys, havent had much time to mess with it but im planning on lubing the drive shaft splines for one. also keith, i know the back brakes are shot and need to be replaced, maybe the slide pins are stuck and causing the brakes to not release? that thought had run through my head. also still need to check the ubolts, been busy with other things so i just havent gotten around to it yet.

oh, and one other thing, i think my rear shocks need replacing also as ive seen some fluid leaking from one, any chance one could be sticking?
Read post #7 here http://www.dieselplace.com/forum/showthread.php?t=146597&highlight=another+soft+brake

Even if it isn't your problem, you being in the snow/ rust belt, like me, It needs done..... Just did the rears on two 07.5s, under 24k miles each, and they weren't pretty.

Ye of little faith...We're all still here...

Read post #7 here http://www.dieselplace.com/forum/showthread.php?t=146597&highlight=another+soft+brake

Even if it isn't your problem, you being in the snow/ rust belt, like me, It needs done..... Just did the rears on two 07.5s, under 24k miles each, and they weren't pretty.


haha, sorry to doubt!

and i have read that thread before as well as just about all of your posts on brakes and other tech stuff. thanks for all the good info! like you said even if thats not what this problem is i know the pins are not sliding. the backs are original as far as i can tell and have been feeling pretty spongy lately. seems like every car or truck i do brakes on the pins are just about dry every time, guess those crappy rubber boots dont really do much good in keeping the water/salt out.

My truck made the noise that you are describing and I found that on of the 1.5" lift blocks had broke in half. Very rare but it did happen. Hope you find what you are looking for.

i would check the splines in the slip yoke out of the transfer case, there is a tsb for changing the slip yoke to a new nickle plated one, but lubing the splines works just as well but not quite as long

I lubed my splines a couple thousand miles ago and it made the noise go away instantly. The only pain in the ass thing was getting the rear u-joint broke free from the yoke
Brandon