ricky

*UPDATE* 2-24-2012
THIS HAS BEEN FIXED!!! Go to post 55.
https://www.yotatech.com/forums/f2/d...l#post51853782

Hey guys, I'm having an issue that I think is more than one issue, so I thought I'd bring it up here and see what you guys think. I've also done some searching, that has given me a few ideas.

Recently swapped out the gears on my truck from the stock 3.57's to 4.88's. They are awesome, and feel great. I also lifted the truck 3" with a toytec lift. No blocks. New leafs in the rear, and new springs up front with bilstein suspension all around. Also new 33x12.5 tires on new 15" wheels.

Before getting any of this work done, I noticed a cold-shudder from the clutch in the truck. During the first few cold miles of the day, the clutch would shudder on takeoff. I assumed this was a warping flywheel, and that it's probably just its time after a couple hundred thousand miles. I assume this is the stock clutch, as I've had the truck since 128k miles, and it was in great condition when I bought it. But I'm not positive.

Problem 1: After the gear swap, all was fine. It even felt like the gear swap helped reduce shudder on cold takeoffs because there's less friction time required. Then I lifted the truck, and only had the small tires on for about 5 days before getting the new ones. After finishing it all, I started noticing that the cold takeoff is WAY worse now. Violently shaking the truck on a takeoff, and even with clutch slippage from 1st to 2nd gear, you can feel the extra fast vibration, making me still think it's the flywheel. But, I keep reading other things that say it could be motor mounts or tranny mounts? I'm not so sure...

Problem 2: After all was upgraded, I started feeling like one of the u-joints was going out, from a mild low-speed vibration (after full clutch engagement) The guy that did my gears said my splines were going bad, and I should get the driveline rebuilt. I notice this at higher speeds with mild vibration now that the driveline is spinning faster. I ripped out the driveline thinking it'd be no big deal to just swap out u-joints. I had done the rear one once before, and assumed it was its time again. After removing the rear u-joint on the rear driveshaft, I found that it wasn't bad at all... I replaced it anyway. Then I started ripping apart the 2 front joints only to find out that absolutely nobody in the world sells them, including toyota. Non-serviceable part. WTF?? So I go to the Yota Yard here in town, and pick up a used driveshaft from a 1996 Tacoma. Identical part. I take it home, check the joints, all of them seem fine, gave them a good greasing, and I popped it in place. Absolutely zero difference from the old driveline. Splines feel tighter, but I still have high speed vibration, and I still feel the low speed vibration.

Now, I'm not positive what the problems are here, but here are my thoughts:

-Possible warped flywheel
-Leaking rear main seal onto clutch (I've never seen a drop of oil leak out of my truck EVER)
-Bad motor/tranny mounts
-Driveline must be rebuilt due to bad u-joints, worn splines, or balance

I'm not sure what I may be leaving out. It's just that the combination of these problems make me think it's both clutch and mount issues. And that my high speed vibration is all the driveline splines going bad. I'm going to take a good look at the motor mounts and see if they look bad. I have checked the transmission and transfer case fluid levels, and they seem normal from the last flush.

mylittletacoma

it might be the carrier bearing, or if you have lifted it get the carrier bearing drop kit to align the angle

ricky

No carrier bearing in this truck. It's a double-cardon joint up front, and the angle definitely isn't drastic. Also, the rear has the angled shims, so the rear u-joint is almost perfectly straight, lessening the angle on the double-cardon.

ricky

Anyone???

Checked the motor and tranny mounts, and they look fine.

Another tidbit of info: It does not do any of this in reverse. Only when moving forward.

ZUK

iTrader: (1)

not in reverse.....maybe a tranny mount or passenger side MM. It takes 2 people to check them out properly.....1 behind the wheel and the other doing the eyeballing.

az_eaglescout_pilot

iTrader: (1)

i have a vibration shudder on take off...i thought it might be the fact that my drive shaft is rotated 90* lol i haven't had time away from my brake problem to go under it and turn it right...but i don't know if this would actually make a vibration bad enough to be felt throughout the truck...

montoyotana

I had a similar problem and it was because one of my spring seats had a fracture in it which was enough to throw things off kilter but being that you got a lift put in you'd think that would have been caught. Might try jacking up the rear and have someone go through gears to see if you cant catch anything irregular.

ricky

See, I don't think I know enough about the mounts to say whether or not they are good. I looked very closely at the tranny mount last night, after looking at pics of a new one, and it looks (at a standstill) to be in ok shape. The outer pieces of rubber still keep the middle piece of rubber suspended above the base of the mount...

I had a talk with Scott from Addicted Offroad last night, and he's convinced it's something in the clutch, but damn, that thing just feels SO solid! It's quiet, always grabs, never has any issues. And the fact that it doesn't do it in reverse, at all... no matter how long I try to ride that clutch... smoooooooooooooth like it should be, in reverse. I then had another convo with a guy at a shop down the street, and he said that can happen when a pilot bearing goed bad and the input shaft starts to wobble. But I doubt that's this case... This is a VIOLENT shake. I also noticed this morning (kinda chilly, and a bit of snow) that the effect was lessened by the time I got to work and the truck was warm. This makes me think that there is still an issue with the clutch, but it's just minor. And that there's also something else causing the bigger problem.

Maybe I'll have someone who knows what they're doing, physically check all the mounts.

Thanks for the input!!

ricky

Another set of notes. I just had this bright idea to block the wheels of the truck, and try to take off in first gear and drag the clutch to replicate the shake. I did this after the truck was warm, and there's absolutely no shake from the clutch... it's not until the vehicle actually starts to move more than foot or so, that the shaking starts... That says to me that it's absolutely NOT the clutch. Am I right in that assumption?

ZUK

iTrader: (1)

I don't think you can make that assumption....you still need to have a 2nd person watch the motor mounts when the shake starts....

ricky

Fair enough. How I can do that without getting the truck on a dyno or something?

Maybe I'll put my gopro down there on the passenger side, and see if I can't catch it on video. Hell, that just opened up a whole slew of possibilities. Not sure why I didn't think of it before.

JDlikesgunsntrucks

mine is an 87 with auto tranny sittn on 36x14.50's with 5.11's. when i let off the gas,i hear a grinding or steel rubbing sound. Sounds like maybe the driveshaft??

ricky

OK, I took a quick video from under the truck The mount looks fine to me. Maybe this is related to the clutch pressure plate and not the flywheel??

Watch in 720p full screen for the best view.

http://www.youtube.com/watch?v=_3KHx1fkkmQ

ZUK

iTrader: (1)

wow....that was an interesting ride. Not related to the shudder but check that upper bolt/nut on the rack and pinion bushing capture plate....it looked loose....sloppy steering could result.

justin_4runner

i had a car do something like this and it ended up being the clutch disk it had sections of it broke out and would chatter or shutter like this.

ricky

Sounds like it may be new clutch time.

troopa4life

Man I understand your frustrations. I too have the same issue with my 3.4 manual 4runner. During the morning when I start of in first I get this really nasty judder but it only happens in first and when the truck is cold. I too have check my mounts and everything else you mentioned except the clutch. I think I need to do my clutch as well. Let me know if it solves your problem. Good luck with the issue.

ricky

Nope, not in 4wd, the hubs are locked, so the diff is turning the front driveline. Doesn't make any difference if they are unlocked. Tires are brand new. Probably fewer than 500 miles, but I noticed this with the old tires. Just not as badly because they were quite a bit smaller.

ricky

That's one thing I have yet to do, but I'm thinking I may not feel it due to the lack of load on the drivetrain. I guess we'll see... easy enough to do.

ricky

Sorry, I lost track of everything. Many important things going on, and since the truck isn't my primary vehicle, it's no hurry.

Anyway, today I jacked up the rear by the rear diff and let the tires run a bit with a load of the parking brake. It's hard to create that same load with the brake, but I can still feel it jumping a little.

If I put the truck in 5th, and let the tires spin at idle, you can feel and hear a rumble (heavy rattle). If you hit the gas in 5th, from idle (no load), the vibration is quite noticeable. I took a vid from the ground, looking up at the rear driveshaft, but I don't see any vibration. Even looking at it with my own eye, I just don't see it.

I'm uploading a video I'll post in a few.