So I got tired of paying for people to work on my truck and started learning to do things on my own. I have a 2005 GMC Duramax. I’ve changed some switches, instrument panel cluster, fuel and oil filters, changed the oils in the transmission/both diffs and done the rotors and brakes. Also changed out the brake fluid and power steering fluid.

This Wednesday, I drained and replaced the fluid in the transfer case and noticed the rear output seal was leaking. So, I jumped on utube and learned how to replace it and did so. After, I took it for a short drive around the neighborhood in 4H at low speeds (15mph tops) and got home to check the T-case and seal to check for leaks. Nothing there and I thought I was in good shape.

Later I had to take my son somewhere and while driving it (I put it back in 2WD), it feels like there is vibration when driving about 40mph and up. I marked the front slip yoke and and at the rear u joint/universal when I replaced the seal. Everything came off and went back on smoothly.

I guess my question is...Could something I did in in reattaching the driveshaft cause the vibration? Or could the universal joint be bad and just acted up after the driveshaft was taken off and put back on? I don’t know if I’m imagining the vibration or not to be honest. Being new to working on the truck I always get nervous after doing something new, thinking I screwed something up.

Thanks for any help.

CT

Is the vibration constant, or only under acceleration/ throttle?

I had a vibration under throttle on my AWD Chevy Express van, and it was my transfer case failing. After replacement, I did notice a regular vibration, but it's calmed down (approx 1500 miles).

So in short, yes it could be from reassembly. I'd keep an eye on it, but hopefully it calms down for you like it did me.

While the drive shaft was out, did you check the U-joints for binding? Also be sure the rear U-joint is completely seated and tight in the pinion shaft yoke. If I remember my GM truck U-joints right, two of the bearing cups have retaining rings on the outside. These must face the right direction and be seated fully on the inside of the yoke. If either or both cups are out of position, the drive shaft will be off center and will vibrate. Remember that a RWD drive shaft rotates at nearly four times the speed of the wheels, so it doesn't take much.

quote:

Originally posted by Gibb:
Is the vibration constant, or only under acceleration/ throttle?

I had a vibration under throttle on my AWD Chevy Express van, and it was my transfer case failing. After replacement, I did notice a regular vibration, but it's calmed down (approx 1500 miles).

So in short, yes it could be from reassembly. I'd keep an eye on it, but hopefully it calms down for you like it did me.

It’s constant. But I only notice it at speeds around 40mph and up. Not noticeable at speeds under that or while accelerating.

Thanks.

quote:

Originally posted by egregore:
While the drive shaft was out, did you check the U-joints for binding? Also be sure the rear U-joint is completely seated and tight in the pinion shaft yoke. If I remember my GM truck U-joints right, two of the bearing cups have retaining rings on the outside. These must face the right direction and be seated fully on the inside of the yoke. If either or both cups are out of position, the drive shaft will be off center and will vibrate. Remember that a RWD drive shaft rotates at nearly four times the speed of the wheels, so it doesn't take much.

I didn’t notice any binding in the u joints. I actually thought about the universal not being seated completely. I’m going to take it off and make sure it seats fully in the morning.

Thanks.

At any point in reassembling the driveshaft did you re-use the existing crush washer?

Check the drive shaft for the balance weight. Maybe it came off. If it came off, look for a shadow where it was located.

quote:

Originally posted by ChasinTails:

quote:

Originally posted by egregore:
While the drive shaft was out, did you check the U-joints for binding? Also be sure the rear U-joint is completely seated and tight in the pinion shaft yoke. If I remember my GM truck U-joints right, two of the bearing cups have retaining rings on the outside. These must face the right direction and be seated fully on the inside of the yoke. If either or both cups are out of position, the drive shaft will be off center and will vibrate. Remember that a RWD drive shaft rotates at nearly four times the speed of the wheels, so it doesn't take much.

I didn’t notice any binding in the u joints. I actually thought about the universal not being seated completely. I’m going to take it off and make sure it seats fully in the morning.

Thanks.

Also make sure to use locktite red on the bolts.

quote:

Originally posted by jimmy123x:

quote:

Originally posted by ChasinTails:

quote:

Originally posted by egregore:
While the drive shaft was out, did you check the U-joints for binding? Also be sure the rear U-joint is completely seated and tight in the pinion shaft yoke. If I remember my GM truck U-joints right, two of the bearing cups have retaining rings on the outside. These must face the right direction and be seated fully on the inside of the yoke. If either or both cups are out of position, the drive shaft will be off center and will vibrate. Remember that a RWD drive shaft rotates at nearly four times the speed of the wheels, so it doesn't take much.

I didn’t notice any binding in the u joints. I actually thought about the universal not being seated completely. I’m going to take it off and make sure it seats fully in the morning.

Thanks.

Also make sure to use locktite red on the bolts.

Red locktite is permanent. It has to be heated to 500 degrees to break it loose. It’s not suitable for what he’s doing. Blue is fine for driveline work.

quote:

Originally posted by PowerSurge:

quote:

Originally posted by jimmy123x:

quote:

Originally posted by ChasinTails:

quote:

Originally posted by egregore:
While the drive shaft was out, did you check the U-joints for binding? Also be sure the rear U-joint is completely seated and tight in the pinion shaft yoke. If I remember my GM truck U-joints right, two of the bearing cups have retaining rings on the outside. These must face the right direction and be seated fully on the inside of the yoke. If either or both cups are out of position, the drive shaft will be off center and will vibrate. Remember that a RWD drive shaft rotates at nearly four times the speed of the wheels, so it doesn't take much.

I didn’t notice any binding in the u joints. I actually thought about the universal not being seated completely. I’m going to take it off and make sure it seats fully in the morning.

Thanks.

Also make sure to use locktite red on the bolts.

Red locktite is permanent. It’s not suitable for what he’s doing. Blue is fine for driveline work.

I know Ford was using red from the factory (OEM) in the late 90's and through the 2000s. Blue would be fine also. It is fine to secure a driveshaft, which has lots of vibration. You can break red loose if you want to. Or, if you heat it (locktite), it releases completely.

quote:

Originally posted by jimmy123x:

quote:

Originally posted by PowerSurge:

quote:

Originally posted by jimmy123x:

quote:

Originally posted by ChasinTails:

quote:

Originally posted by egregore:
While the drive shaft was out, did you check the U-joints for binding? Also be sure the rear U-joint is completely seated and tight in the pinion shaft yoke. If I remember my GM truck U-joints right, two of the bearing cups have retaining rings on the outside. These must face the right direction and be seated fully on the inside of the yoke. If either or both cups are out of position, the drive shaft will be off center and will vibrate. Remember that a RWD drive shaft rotates at nearly four times the speed of the wheels, so it doesn't take much.

I didn’t notice any binding in the u joints. I actually thought about the universal not being seated completely. I’m going to take it off and make sure it seats fully in the morning.

Thanks.

Also make sure to use locktite red on the bolts.

Red locktite is permanent. It’s not suitable for what he’s doing. Blue is fine for driveline work.

I know Ford was using red from the factory (OEM) in the late 90's and through the 2000s. Blue would be fine also. It is fine to secure a driveshaft, which has lots of vibration. You can break red loose if you want to. Or, if you heat it (locktite), it releases completely.

Ford uses a lot of yellow loctite nowadays. So does Honda. Red needs to be heated to release. If not, you take a HUGE risk in breaking bolt heads off.

I replaced some u joints a long time ago on a high mileage car I drove during and after college. I changed them because of a lot of lash and clunking and worried about dropping the drive shaft at highway speed. After my "fix" it vibrated like a banshee. But I couldn't afford to pay a professional shop to fix it so I kept it and just drove it into the ground. Someday I should start a thread about the worst pos you ever drove but kept it anyway.

quote:

Originally posted by jimmy123x:

quote:

Originally posted by ChasinTails:

quote:

Originally posted by egregore:
While the drive shaft was out, did you check the U-joints for binding? Also be sure the rear U-joint is completely seated and tight in the pinion shaft yoke. If I remember my GM truck U-joints right, two of the bearing cups have retaining rings on the outside. These must face the right direction and be seated fully on the inside of the yoke. If either or both cups are out of position, the drive shaft will be off center and will vibrate. Remember that a RWD drive shaft rotates at nearly four times the speed of the wheels, so it doesn't take much.

I didn’t notice any binding in the u joints. I actually thought about the universal not being seated completely. I’m going to take it off and make sure it seats fully in the morning.

Thanks.

Also make sure to use locktite red on the bolts.

Or tighten them, as usual and not worry about it.
They are not going anywhere.

I would NEVER put red locktite on them!

Thanks all for the replies. My hunch and egregore’s affirmation were correct. One side of the universal wasn’t seated completely. Put back together correctly now....with no loctite as there was none on when I took it off.

Thanks again,
CT

quote:

Originally posted by Excam_Man:

quote:

Originally posted by jimmy123x:

quote:

Originally posted by ChasinTails:

quote:

Originally posted by egregore:
While the drive shaft was out, did you check the U-joints for binding? Also be sure the rear U-joint is completely seated and tight in the pinion shaft yoke. If I remember my GM truck U-joints right, two of the bearing cups have retaining rings on the outside. These must face the right direction and be seated fully on the inside of the yoke. If either or both cups are out of position, the drive shaft will be off center and will vibrate. Remember that a RWD drive shaft rotates at nearly four times the speed of the wheels, so it doesn't take much.

I didn’t notice any binding in the u joints. I actually thought about the universal not being seated completely. I’m going to take it off and make sure it seats fully in the morning.

Thanks.

Also make sure to use locktite red on the bolts.

Or tighten them, as usual and not worry about it.
They are not going anywhere.

I would NEVER put red locktite on them!

Agreed!!

Easily some of the worse advice possible (red loctite) - and from the same source, again. Likely some "well I thought...", "I once heard..." or, "well I thought I saw..." advice (also again).

OP - make sure the threads are clean and always, always, always use new locking washers where applicable. (If lock washers are not used and you're concerned about it, use blue loctite if the manufacturer doesn't specify)

quote:

Originally posted by LS1 GTO:

quote:

Originally posted by Excam_Man:

quote:

Originally posted by jimmy123x:

quote:

Originally posted by ChasinTails:

quote:

Originally posted by egregore:
While the drive shaft was out, did you check the U-joints for binding? Also be sure the rear U-joint is completely seated and tight in the pinion shaft yoke. If I remember my GM truck U-joints right, two of the bearing cups have retaining rings on the outside. These must face the right direction and be seated fully on the inside of the yoke. If either or both cups are out of position, the drive shaft will be off center and will vibrate. Remember that a RWD drive shaft rotates at nearly four times the speed of the wheels, so it doesn't take much.

I didn’t notice any binding in the u joints. I actually thought about the universal not being seated completely. I’m going to take it off and make sure it seats fully in the morning.

Thanks.

Also make sure to use locktite red on the bolts.

Or tighten them, as usual and not worry about it.
They are not going anywhere.

I would NEVER put red locktite on them!

Agreed!!

Easily some of the worse advice possible (red loctite) - and from the same source, again. Likely some "well I thought...", "I once heard..." or, "well I thought I saw..." advice (also again).

OP - make sure the threads are clean and always, always, always use new locking washers where applicable. (If lock washers are not used and you're concerned about it, use blue loctite if the manufacturer doesn't specify)

FORD uses red locktite on their driveshaft bolts as OEM. They use 12 point, 12 MM bolts as well. This is fact. When you buy new bolts, they come with red Loctite on them. The AC DELCO 26036835 bolts that are for the OP's truck, come with red locktite on them from the factory. As does the GM shop manual's recommendation for the installation of driveshaft bolts on an HD2500. SO, until YOU actually know what the hell you are talking about, please stop calling me out.

https://www.partsgeek.com/zr27...ord+Drive+Shaft+Bolt

Chevrolet 2500HD driveshaft bolts
https://www.napaonline.com/en/...put=driveshaft+bolts



Secondly, you normally use an impact wrench on driveshaft bolts to take them off, and they still come right off with red Loctite 98% of the time. Have you ever removed and installed driveshafts? I've done a 100 of them, when I used to work in a mechanics shop. I only had to heat the bolts on 1 or 2 of them with a torch on old cars that were severely corroded from salt and up North.

OP- if you still have vibration issues, the longer HD 2500's have a carrier bearing that goes bad in the driveline and causes vibration. This needs to be done by a shop as the bearing is pressed into the carrier. Or you can buy the entire carrier assembly for only a little more and it's an easy change rather than trying to change only the pressed in bearing.

Edited to add: on cars a lot of times you don't see thread locker (OEM) on drive shaft bolts. Trucks, almost always at least with U.S. brands. I don't know about foreign trucks as I never worked on those.

You are confusing Dri-loc (red) with Loctite Red.

They are completely different uses and "lock" ability.

"Red Loctite" required for permanent fastening and requires greater than 500F to break the bond.
(Yes, it can be broken with torque, but the torque may likely damage components in the process).

Drive shaft U-bolt nuts only require about 12-24 foot lbs, max. (depending on small to large c

Over torque will often crush the caps enough to cause vibrations as well as not fully seating the cross.

Once things are assembled and snugged, whacking with dead-blow hammer helps settle and relieve stresses before fully torquing.

I'm not familiar with your specific vehicle. If it has a driveshaft with splines near one end that allow the universal joints on each end to have the alignment changed by reinstalling in a different position, that can be a problem. That's called being out of phase and will give a vibration at some speeds.
Here is a video explaining how to align.
https://www.youtube.com/watch?v=uRkYhI1afHk

quote:

Originally posted by sigmonkey:
You are confusing Dri-loc (red) with Loctite Red.

They are completely different uses and "lock" ability.

"Red Loctite" required for permanent fastening and requires greater than 500F to break the bond.
(Yes, it can be broken with torque, but the torque may likely damage components in the process).

Drive shaft U-bolt nuts only require about 12-24 foot lbs, max. (depending on small to large c

Over torque will often crush the caps enough to cause vibrations as well as not fully seating the cross.

Once things are assembled and snugged, whacking with dead-blow hammer helps settle and relieve stresses before fully torquing.

Dry Loc red, is made by Loctite, and has the same adhesion properties as locktite red, it is just in a dry form until it is assembled.

Here is the data sheet, just in case you don't believe me.
www.threadlocking.co.uk/loctite-dri-loc-2045.html

"Dri-Loc® 2045™ is a high strength pre-applied thread locker with good substrate compatibility specially designed to meet the automotive specification requirements. It is suitable for use on plain and passivated metal surfaces. Dri-Loc® 2045™ has good hot strength, heat ageing and solvent resistance properties. This product meets the environmental resistance and performance requirements of DIN 267, part 27, GME151 and Ford Worldwide standard WX200 October 1996."

Here is the actual chart of the different colors of dry-loc and their adhesion properties. Red is HIGH (adhesion).

www.longlok.com/s.nl/it.A/id.42696/.f

Wow jimmy you have done it again. Another off topic pissing match with fourteen chapters.

To back things up a bit here “Does the Op GMC need loctite/thread loc on it drive line bolts”?

Not every bolt needs to be secured with thread locker and to make a blanket statement to apply it to every application without knowing is simply bad advice and this is generally what gets all these pissing matches started.

Per the op no thread locker was seen so none was applied on re-assembly.