Update on Driveshaft

[farmtruc]

Just my luck, i get the shaft in (i wasn't ina rush) and the damn thing vibrates at about 60mph. I'm not sure if the shaft or if the orig. shaft messed something up.

I swear i hate shops, if it's the shaft i'm going to be pissed and beat someone to death. Why can't anyone do the job right the first time. I'm going to be forced to buy every damn tool in the world.

I'm done ventalating,

I'll keep ya'll updated,

btw, anyone have any ideas, like domes said, i'll jack the truck up and find out if it vibrates at 60 without the shaft in, if it don't hurt it. That will tell me if it's the shaft or rearend.


later,

allen

[br1ev8]

This sounds too familiar. let me share my experience here. my vibration started right after i had 3.73's installed. it vibrated around 80mph. I thought it was a problem with the gears. I ignored it and ended up throwing my ds going down the road just like you. i got a new one made at a local shop using thicker walled tubing and upgraded to 1350 u-joints. put it in and it vibrated at ~60mph. i inspected the ds and found it to be too short. had the shop re-tube the shaft a little longer. put it in and it vibrated ~70mph. i was pissed. so i drove 2 hours to jacksonville to get it professionally balance because the local shop didnt have the equipment to do it. on the drive back still vibrated. now i was really pissed. at this point i thought maybe it is the gears after all, so i ordered some new gears (4.10's) and had them installed. vibration still there. so i thought maybe my axels are bent. so i had the whole rearend rebuilt with new parts (axels, bearings, seals,). got the truck back and still have the mf'ing vibration. I continued to drive it at loss as to the cause until the vibration wore out the tranny output shaft bushing and started leaking tranny fluid. took it to a tranny shop and had them replace the bushing. when they did that they told me my ds was too short and that was why my bushing wore out. so i had another ds made a little longer. put the new shaft in and had the vibration still. went back to jacksonville to get the thing balanced again to no avail. at this point i pretty much eliminated all possibilities except for the tranny. so i went to a shop that speciallizes in t56's and they found my output shaft to be bent, which i found happend when i threw my ds going down the road. so i had the shop replace the output shaft in the tranny thinking this was the problem. put the tranny back in and guess what, yep, i still had the vibration ~ 70mph. the people at the tranny shop told me the bent output shaft would cause the ds to warp, so i went back to jacksonville again to have the shaft balanced yet another time. and of course the shaft still vibrates. only on this last visit to the ds balancing shop, one of the techs there told me that ds was borderlining being too long for the diameter/gauge of tubing used and really should be of stronger gauge and diameter. so after all this, i STILL have a vibration at 70mph. ive done some major thought over the past months and have come to the conclusion that the cause of my vibration is still the driveshaft. my reason is this: my ds is steel; my original axel gear ration was 2.73. this combination didnt cause the ds to spin too fast going highway speeds. my new combination of 4.10s and steel driveshaft causes the driveshaft to spin very fast at highway speeds. here is where the problem lies IMO...at high rpms, the steel shaft will warp or become imbalanced causing vibration. solution: aluminum baby! aluminum is less rotational mass therefore allowing higher rpms without distorting. and think about it--gm uses this same principle with its f-bodies. f-bodies that come equiped with 2.73's from the factory come with steel ds's. f-bodies that come equiped with 3.23's and 3.42's come with aluminum ds's. so, one of these days, when i can come up with a spare ~ $325 im going to get an aluminum ds from someone like http://www.iedls.com/
so--alan im not saying for sure that this is your problem, but it is a huge possibility. also, did you check your tranny output shaft? just unbolt your driveshaft and crank up the engine and put the tranny in drive and have a look at the output shaft to see if it is going around in a wobbly motion. what is your gear ratio?

[Sleeper]

yup. thats why i said go aluminum in the first thread he started about the driveshaft....hmmmm that makes 3 threads on the driveshaft, allen you postwhore

and i think he's got 4.10's now.

[br1ev8]

Originally posted by 1500Sleeper@May 21 2003, 12:55 AM
yup. thats why i said go aluminum in the first thread he started about the driveshaft

well gee, where were you when i had all this trouble? oh yeah, you were here there whole time just as stumped as i was. :flipoff:

OT--you call mr. chan about the 6th and 7th?

[farmtruc]

i thought i was the only one with those kind of problems, lol, isn't it funny how you end up being on your own with sht like this? once you eliminate one or two possibilities, that is where all shops loose interest, or they just don't know anymore than you do, and they do this sht for a living. come on shops, get it together and get with the program, if you're going to be doing something for a living, damnit, learn and live it, or go find something else to do.
I've had it with shops and their dumbass techs.

Ok, so on with the post.

I have 4.10's and ya the vibration is at 60mph or so. It's really bad too. Also i don't want to drive it without a driveshaft loop. I was lucky that big ass thing didn't hit someone.

In one of my super chevy mags the editor was trying to hunt down a vibration also. He replaced everything like you did, finally he found this company that make a vibration detector. The way is works is your car is jacked up or on a dyno (man i wish i had one now) and a few light beams projected from these little stands point at the shaft, they can detect movement and vibrations anywhere on the driveshaft. The editors problem was an improperly balanced driveshaft, even though he had it done a few times.

I would pull the driveshaft (i'm tired of typing this so it's "ds" for now on) and check out the trans shaft but joe said that the ds yoke centers that trans yoke and it will wobble if i do that. Plus i have the chance of hitting that reluctor ring on the tailend of the tranny. So, once i start the truck up and put it in gear, it will go, but as soon as i pass thru reverse then drive it will force the trans to spin the other way and he suggested i don't do this.

However, he did say if i jack up the rearend and take it to 60mph and if the leaf springs get shaky and wobble, it's more than likely it's my ds. I'll try this today, i'm so pissed i don't want to fix it. Do i hear a camaro being added to my list., doh not yet, but i wish.

Well, i'm going to call the shaft place today and find out what they say, i may just break down and get them to take their pos back and build me an aluminum one and credit the one i already payed for. Maybe this will save me some headaches, like what you've already been thru.

Back to yours, i think it's the ds too, there are few companies that can balance them correctly, and then they say the balance them up to 2500 or 3000 rpms, that is sht, unfortunately not many shops have one that can do that. I understand that the shaft will probably not spin this fast anyway, but super chevy had their shaft balanced higher and gave some math forumla that explained why it should be spun faster when being balanced.


good luck,

allen

[Sleeper]

Originally posted by farmtruc@May 21 2003, 09:04 AM
I have 4.10's and ya the vibration is at 60mph or so. It's really bad too. Also i don't want to drive it without a driveshaft loop. I was lucky that big ass thing didn't hit someone.

some of us werent as lucky

[Sleeper]

Originally posted by br1ev8+May 21 2003, 02:04 AM--><div class='quotetop'>QUOTE(br1ev8 &#064; May 21 2003, 02:04 AM)</div>

<!--QuoteBegin-1500Sleeper

@May 21 2003, 12:55 AM
yup. thats why i said go aluminum in the first thread he started about the driveshaft

well gee, where were you when i had all this trouble? oh yeah, you were here there whole time just as stumped as i was. :flipoff:

OT--you call mr. chan about the 6th and 7th? [/b]

i was there stumped as well and wondered about that but didnt really know if the lighter substance spinning faster made that big of a difference, i mean if its balanced true then the steel one should work...is what i was thinking...i figured it had something to do with tha DS angle being altered, even if it was by like 1 millionth of an inch

and no not yet :flipoff:

[GMCwantsLS1]

I&#39;m with 1500Sleeper if it is ballanced it should run true. There are pleanty of trucks and cars out there with steel drive shafts and low gears with no vibrations. Hell the cars from the 60s came with 4.11 gears steel drive shafts and smooth as hell. Check both of your u jounts the should move back and forth witn no binding. Check your drive line angle ( this is very important ). Aheck this out&#33; http://www.drivetrain.com/driveline_angle_problem.html