Topic: 1st Gen Vibes

[Yoat Goat]

Back story, I purchased the truck to be a project, got it without motor/trans/case/ drivelines for $600. Got a 20R/L-52/t-case and put it all together, 4" RUF's in front with like 7.5* shims i think, 2-3" lift stock S-10 rear springs, 4.38's and 35" bfg's. Custom front driveshaft and stock rear shaft btw...

My truck has a vibe right around 40mph and stays the same upto 60(as fast as i have gotten it too...). I changed things on it like front spring bushings, alignment is close to what i can get it too(slight toe in, 1/8"ish), rear driveshaft(used, original might have been better spline wise, but jump roped it seemed...), u-joints seem good, I thought the vibe was my old tires and rims i had but I replaced those with some 35" bfg's on rims, 1 rim and tire doesnt have balancing weights on it(doubt that is causing it cause the vibe was there with old tires in back where the "unbalanced" combo is...).. Now some things i have noticed, T-case flange in rear has small amount of play in it, d-shaft spline has play in it, upper shackle bushings are old and worn out i bet, havent found any to replace em with, When I put the clutch in fast with load on the motor it seems to unload hard, not a banging neccessarily, just unloads hard. Some things I have came up with, T-case bearings for rear output flange are shot, pinion bearings may be shot, worn upper shackle bushings bad, or caster is F-ed(it isnt a death wobble, just vibes), and just my luck. Seems it does it the most accelerating, still does it coasting down hill but not as bad...

[79coyotefrg]

drive shafts out of phase

[Yoat Goat [OP]]

Driveshaft is in phase, or its 180* off, but my old shaft did the same thing, what are the odds they are both off 180*?...

[crawlerdad]

Mine did that and the problem was that I had spun the bearing race in the rear third.

[Yoat Goat [OP]]

Ok man, thanks!

[Yoat Goat [OP]]

So an update, like i said before i replaced the rear drivehaft with another used one, replaced the stock 4.38 diff with a V6 diff, replaced the trans case with another used one cause of the rear output play, re-did the front wheel bearings, specs are within the range both times, the vibration is still there! Also if there isnt a vibration, it sounds like something is cavitating... Im tired pissing money away and wasting time. Help me so i dont sell this thing! Suggestions?  

I might replace the rear shafts with other ones cause i think it might be a bad wheel bearing or bent shaft or something, seems the cavitation may be coming from the rear end...

Maybe I should start replacing things with new items...  

[Yoat Goat [OP]]

And the unloading hard when I clutch fast I have found out is axle wrap. I get quite abit out of the stock S-10 springs.

[crawlerdad]

Is it all the time or just certain speeds? I have one at certain rpm. I got bigger tires so I can't feel it as much. You should try that.

[crawlerdad]

Is it all the time or just certain speeds? I have one at certain rpm. I got bigger tires so I can't feel it as much. You should try that.

I just saw your post in another area. Did you try wheel bearings yet. I think I am going to throw some in this weekend.

[Yoat Goat [OP]]

Well Im pretty sure its all the time but it starts coming on pretty bad at about 40 mph. I havent done the wheel bearings yet, just trying to get enough motivation to do this... I just took the axles out to change the diff, and i absolutely hate taking the break lines off and putting them back in.

[OOPS]

The only thing I do not see in your list of things that you have done is to make sure your D-shaft/pinion angles are right. Need to check that since you changed the rear springs.

Here is a good basic 101 on driveline basics:

http://www.4crawler.com/4x4/CheapTricks/Driveline-101.shtml

[Yoat Goat [OP]]

The only thing I do not see in your list of things that you have done is to make sure your D-shaft/pinion angles are right. Need to check that since you changed the rear springs.

Here is a good basic 101 on driveline basics:

http://www.4crawler.com/4x4/CheapTricks/Driveline-101.shtml

I have measured the angles once, here is what i came up with.

5* down at the t-case
4* up at the pinion flange
11* driveshaft angle. 

[Yoat Goat [OP]]

Sound good to anyone?

[Yoat Goat [OP]]

Bueler...

[crawlerdad]

Sounds good to me. The only problem I see is that I have no clue. I have a vibration that seems to be similar to yours. I cut off my spring hangers and rotated the axle to straiten the drive angle and the vibration didn't change. I am going to try rear wheel bearings.

[Yoat Goat [OP]]

Let me know what happens...