weird vibration at speed 60 plus

[75chev4x4]

Originally Posted by y5mgisi

That is interesting. Its further interesting to do those runup tests tho isnt it? I had a good time doing that "investigating". Im going to venture to bet you and i both have two issues. Out of balance drums and drivelines. I am contemplating just going to disc brakes in the rear since its so cheap. And then then getting the drive line rebuilt and balanced up at sixstates here in Portland.

Exactly I think your right on the money. Is sixstates any good? I was thinking that or go grab a junkyard ds and try that. I kind of like the drums, they r heavy and a pain but they stop a freight train. The disc option looks cool too.

[y5mgisi]

Six states is arguably the best. They do all things drivetrain related. From building driveshafts for big rigs to golf carts and doing axle re-gearing, transfercase rebuilds etc. Certainly at least worth a call! No harm in trying a junk yard shaft. I just never had the will to try and find one. However, if you search this phone number on Craigslist you will find a guy that parts countless chevy trucks and would most certainly have a drive line to choose from. 360-852-7608

About the discs, its hard for me to say which are "better". The drums do stop well. But i like the idea of discs in all other aspects. And they do stop well too. THink about this, all new trucks have 4 wheel discs. The only sucky thing about swapping to discs on our trucks is you loose the parking brake unless you do it up a different way.

[y5mgisi]

Also, this fella on pirate4x4.com sells a complete swap kit for $315 shipped. You can probably do it cheaper by piecing it together but i like one stop shopping.

http://www.pirate4x4.com/forum/axles...5-shipped.html

[y5mgisi]

My end goal for my truck is to swap over to an NP241 transfer case with a slip yolk eliminator and use one of the driveline parking brake kits on it. along with a drive shaft that uses a CV joint at the transfer case side. Problem is, thats around $800 or more all said and done!

[75chev4x4]

Originally Posted by y5mgisi

Six states is arguably the best. They do all things drivetrain related. From building driveshafts for big rigs to golf carts and doing axle re-gearing, transfercase rebuilds etc. Certainly at least worth a call! No harm in trying a junk yard shaft. I just never had the will to try and find one. However, if you search this phone number on Craigslist you will find a guy that parts countless chevy trucks and would most certainly have a drive line to choose from. 360-852-7608

About the discs, its hard for me to say which are "better". The drums do stop well. But i like the idea of discs in all other aspects. And they do stop well too. THink about this, all new trucks have 4 wheel discs. The only sucky thing about swapping to discs on our trucks is you loose the parking brake unless you do it up a different way.

Thats very good to know about six states ill prob go there. I think I know which guy I craigslist u mean. Yea I have gone back and forth on the disc swap myself. Would be fun to try anyway.

[75chev4x4]

Just hoping the wobble is from the driveline and not the transfer case or rear end.

[y5mgisi]

Chances are that if the pinon and transfercase out put feel tight by hand, then its probably not them. Are all of the alignment tabs on your yolks present? The ones whuch center the u-joint in the yolk.

[75chev4x4]

Yea still have all the tabs.

[y5mgisi]

Ok thats good. I have know of problems caused by that. We could always try trading shafts for the day?

[y5mgisi]

After all, mine does look an awful lot like yours!

[75chev4x4]

Haha yea thats an idea. Wow I like yours beauty. Looks like original paint? Very nice truck, definitely my trucks twin.

[y5mgisi]

No no. That pic does it a bit much of a favor. That was right after i repainted the white stripe. Also that front fender is not original. The rest of it is a mixed bag. I just am wrapping up my budget resto on my Suburban and when its done, this is getting a similar treatment.



Now the 78 has some origianl style white wheels and hub caps (yet to be installed) and the aluminum wheels are back on the suburban. You can also see in this pic i have yet to repaint the white stripe on the passenger side. Also shows how not perfect it is!

[75chev4x4]

Looks really good, I like the white steelies. If I could find a decent set of hub caps I would do the white steelies. Can u put the hub caps on the 16" wheels or do they only fit the old 16.5" wheels?

[y5mgisi]

You can put them on the 16's no problem. What i have now is the something like 75-86 style but i want to get the 67-72 style. But they are EXPENSIVE for a nice set.

Here is the set while they were on the burb.



And here is the ones i want to run on the gmc, but with open fronts obviously for the hubs.

[75chev4x4]

The style you have on your burb is what I was thinking of running. Glad to hear they will work on the 16" wheels. I like the older style like you are looking for, you never see those much anymore. Gonna hit the junkyard tomorrow after work see if I can find another gm drum in good shape and maybe a driveshaft if im lucky.

[y5mgisi]

Good luck! Which one do you usually go to?

[75chev4x4]

The picnpull on 111th and foster in portland, not really my favorite but they usually have our trucks. Just moved out to estacada so ill have 2 see if they have any good ones out this way.

[y5mgisi]

They have one in damascus too.

[75chev4x4]

Yea they closed people from going in, you can have them pull your stuff for you but I have had problems getting the right part before. I liked damascus when you could go in and pull your own parts.

[y5mgisi]

What?! Lame! Its been a while since i have been to that one. Thanks for saving me the time!

[75chev4x4]

Sure np

[cedens]

My experience if it shows up over 60 its a tire/wheel issue, i have had that problem a lot with getting the Red Sticky Peanutbutter like mud all over my wheels, its nasty and tough and just spend a $1 at a car wash and clean the insides of the rims, if that still happens any small tire shop can ballance them for you.

That being said on my 06 jimmy i hit a nasty mud hold and got that same red ok clay on the fans which were off .... from then when fans kicked on it was like you broke something.

[75chev4x4]

I ran it without the wheels and tires and still had the vibration. Im thinking its in the aftermarket drum and the driveshaft.

[Keith Seymore]

Originally Posted by 75chev4x4

I ran it without the wheels and tires and still had the vibration. Im thinking its in the aftermarket drum and the driveshaft.

Those drums are huge, so it's not unreasonable to think they could be way out of balance.

When you mentioned checking the shaft with a sharpie marker and it was skipping (only hitting part way around) - that indicates a dimensional problem to me. Either a bent/dented driveshaft or rear axle companion flange runout (bent pinion).

A bent pinion will swing that driveshaft like a jump rope...

K

[75chev4x4]

Yea I could see the ds wobble just a bit. Its tight at the rear diff so I hope its not that. Im thinking it has to be partly that drum that I replaced from the junkyard. I thought it was original gm but it is an aftermarket drum. Im gonna find another original gm drum to replace with.