4x4Wire TrailTalk

Tranny Clunk backing up!

Posted By: allochris

Tranny Clunk backing up! - 03/23/12 03:08 PM

Ah, I can't believe i'm back already!

I've been experiencing a bit clunk suddently while down shifting from 3rd to 2nd slowing down for red lights. It happened about 4 times now. The other day I had to back up a steep driveway, & a loud clunk was heard clunking at each revolution. No clunk/vibration if I coast/slow down with brakes in neutral. I can feel vibration also whenever tranny is in gear while letting off gas pedal to slow down. Vibration is easily felt at slower speed than high speed.

What could this be? Maybe I should have put in a decent brand name clutch 3 yrs ago? Something came loose?

FYI: My mechanic back in Quebec put in a seco korean made clutch about 3 yrs ago. While I had my engine replaced last fall, I had to put in a new input bearing to replace the one that already had play in it.

<img src="/forums/images/graemlins/confused.gif" alt="" />
Posted By: ephwang

Re: Tranny Clunk backing up! - 03/24/12 01:28 AM

Sounds similar to when one of my main transmission bearings went out.
Posted By: oldsub86

Re: Tranny Clunk backing up! - 03/24/12 04:37 PM

Check out the easy things first.

Have a good look and pry on the universal joints.

Randy
Posted By: 4Crawler

Re: Tranny Clunk backing up! - 03/24/12 04:45 PM

Yes, check all the drive line for play. I usually find that vibrations when letting off the gas are due to something being loose. Common source is a loose pinion or t-case flange or a slip yoke that is out of grease or pulled out to far that it is loose. Could also be u-joints. Basically the checking is all the same, climb under the truck and then just grab each part of the drive shaft and give it a tug and feel for any play up-down or side-side. You want to have it out of gear so things are free to move. And you an also unbolt the shaft at either end and feel the u-joint motion by hand as some times the joints get loose as they wear but they may also feel too tight and bind up as they rotate.
Posted By: allochris

Re: Tranny Clunk backing up! - 03/24/12 10:30 PM

Could I also try removing the whole rear drive shaft & drive in front wheel drive to try pinpointing the noise/vibration source?

It surely feels like it's coming from near my right foot pedal.

I soon have to drive/move to Saskatoon in April, I wonder if it will make it there if I can't fix this problem in time... <img src="/forums/images/graemlins/rolleyes.gif" alt="" />
Posted By: Bent_85

Re: Tranny Clunk backing up! - 03/25/12 06:43 PM

A while a go I too had a clunk somewhere in my drive line of my 91 Toyota. I hunted around for loose components and never ended up finding it until I made the swap from my standard 4:10 differentials to 4.56. After I replaced the rear diff, the gears where still good but there was a lot of play in the carrier bearings holding the ring gear. The noise I had was an irregular "warbling" when going +120km/hr with neutral gas. If I let up or put gas down, the noise would go away. That source of the noise was hard to pin down. I also had drive line clunk/bang when I when I threw the truck into reverse in the mornings when first going to work. When it was getting bad I had to use a bit gas to "break" the rear into position, as the ring gear was so loose that it was binding up between the ring and pinion gear. That noise sounded like it was coming from the transmission but since it was fine going forward I started contemplating a transmission swap. Both noises when away after swapping differentials. At that time the truck had about ~450,000kms on it. If all else fails it might be the rear end.
Posted By: kewlynx

Re: Tranny Clunk backing up! - 03/26/12 02:20 AM

IIRC, you've got an xcab don't you?

I'd give that carrier bearing and the ujoints a good physical inspection. DO NOT OVERTHINK THIS. You've got a lot of miles on the ol gal; if you haven't worked over the ujoints since you've had the truck, it might be time. Start with the basics, as oldsub suggests.

The carrier bearings are $$$ and sometimes hard to find. The workaround for that is to take it out of the equation, and have a longer one piece DL fabbed up. This wouldn't be the first time it's been done.
Posted By: KiwiCowboy

Re: Tranny Clunk backing up! - 03/28/12 08:23 AM

Check your transfer case too. I had the same sound in a Jeep Cherokee and the drive chain was jumping the gears in the transfer. <img src="/forums/images/graemlins/kewl.gif" alt="" />
Posted By: allochris

Re: Tranny Clunk backing up! - 03/31/12 06:44 PM

Ok,

Last weekend, I hand-checked the drive shaft & noticed that the pinion at the differential could be rotated about 1/4" freely, while truck was parked in gear. Since then, I parked the truck as-is & went back to work in Vancouver.

Yesterday (Friday), my gf used the truck & the noise/vibration continued and got worse. The sound began as soon as she started driving and progressively got worse.
It sounded like a wrench banging on a metal pipe. The more gas she put, the faster & louder it got. As it became worse, it got louder with a stronger vibration.

On the way home, at a yield stop, after she put it in 1st & let off the clutch very gently, the whole truck shook violently upon acceleration.

She clutched in a second time and kept adding gas until the truck got going. Banging noise & shaking continued.

At the next intersection (before calling the tow truck), she experienced the big bang and shaking again, but the truck wouldn't go forward. She tried again & the truck was just revving with the gear engaged. She then gravity backed-up onto half of someone's driveway and reversed the latter half of driveway. No noise/vibration was observed when backing up.

Today:

I just traced down (visually) some slipping action at the pinion/driveshaft. I really hope this is just my pinion/rear 3rd causing all these problems & not anything else? <img src="/forums/images/graemlins/cyclops.gif" alt="" /> Thanks!

FYI: My current rear 3rd is a 94' V6 Auto 4.88 modified with 87 Supra LSD.

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Posted By: allochris

Re: Tranny Clunk backing up! - 03/31/12 08:00 PM

All right, I got right into it today!

I just finished pulling the rear 3rd out. And guess what? Broken tooth, loose pinion, metal shaving at the magnetic plug. See pics.

I hope this is my only problem! I'm going to replace my rear 3rd with the easiest/quickest method. That is to find another junkyard/used 94 v6 auto 4.88 3rd and drop into my existing 91 rear axle housing.

If I were to rebuilt my existing 3rd, would it be safe to re-use any of the existing components such as supra LSD, supra carrier bearing & outer race, (except new ring, pinion, and V6 bearing kit?)

Thanks,

<img src="/forums/images/graemlins/cheers.gif" alt="" />



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Posted By: kewlynx

Re: Tranny Clunk backing up! - 04/02/12 01:45 AM

Zuk hasn't been around in awhile. Might see if he's got some inspection specs for your locker, or knows where you might find 'em.

www.gearinstalls.com Give him a holler.

I am also going to STRONGLY suggest you get that driveline balanced after replacing the U-joints. I've had my wheel/spline depart a truck a few years back; found out my main D/L had gotten bent somewhere along the line, as the ujoints were fine.

Keep in mind that you had a lot of twisting torque on that thing, so get it looked at to make sure it's still true, or you'll be back under there in about 6 months.
Posted By: Greg_Canada

Re: Tranny Clunk backing up! - 04/02/12 02:08 AM

I would replace the bearings.
As for the LSD, pull it apart and rebuild it. Would not want to find more particles inside it!!
Posted By: kewlynx

Re: Tranny Clunk backing up! - 04/02/12 03:37 AM

Yep that at least. Stuff didn't get that way entirely on its own. Chris, was that a pull-n-play LSD perchance?
Posted By: allochris

Re: Tranny Clunk backing up! - 04/02/12 05:41 AM

Ok, yesterday it took me like 1 hour to wipe "clean" the inner housing. The tiny metal flakes were just everywhere!

The old supra LSD was directly pulled from a supra & implanted with v6 auto 4.88 ring & pinion & 1 side carrier bearing. As for performance wise over the last 6 yrs, it didn't grab as much as I wanted to on slippery gound. I should have added more shims/washers inside the LSD.

My friend (heavy duty mechanic, not car mechanic though) helped me 6 yrs ago to setup the pinion/carrier bearings preload. It was our first time & following fsm instruction, at least it did lasted about 105000km though.

Too bad i'm in a rush to get the truck running by next weekend. I won't deal with my old 3rd for now. I'm just going to find a replacement 3rd from junkyards locally on Vancouver Island and Vancouver. If I don't have any luck, I might have to bite the bullet & buy the drop-in unit from Marlin at $650!!! We'll see, lots of phone calls tomorrow.
Posted By: allochris

Re: Tranny Clunk backing up! - 04/02/12 05:46 AM

Quote
www.gearinstalls.com Give him a holler.
Will do!

Quote

Keep in mind that you had a lot of twisting torque on that thing, so get it looked at to make sure it's still true, or you'll be back under there in about 6 months.


Are you refering to the driveshaft getting unbalanced on its own from wear & tear? or from my diff gear slipping?
Posted By: allochris

Re: Tranny Clunk backing up! - 04/02/12 06:12 AM

Can anyone please confirm the year range of the rear 3rd that comes with 4.88?

-92'-95' 4runner v6 auto with 31" tires?

-There's a VIN/gear code for that gear ratio identification right?

-Pinion nut has a pink mark?
Posted By: allochris

Re: Tranny Clunk backing up! - 04/02/12 06:28 AM

Quote
Can anyone please confirm the year range of the rear 3rd that comes with 4.88?

-92'-95' 4runner v6 auto with 31" tires?

-There's a VIN/gear code for that gear ratio identification right?

-Pinion nut has a pink mark?


Found my info from: Erik's Toyota Differential Info

The FACTORY 4.88 V6 diff is unique!
- Axle code G144, white pinion paint code,
- generally came in 92-95 trucks/4runners with V6, auto tranny, 31" tires, and tow package.
- Housing offsets pinion towards ring gear, allowing ring gear to be thinner
- OEM Toyota gears are the ONLY gears that fit this diff due to the thinner ring gear. All other gear sets have thicker ring gears and do not fit.
- The carrier (case) is the same as the V6 diffs, so normal V6 lockers, LSD's, etc. will work in this diff

Posted By: kewlynx

Re: Tranny Clunk backing up! - 04/02/12 06:35 AM

Quote
Are you refering to the driveshaft getting unbalanced on its own from wear & tear? or from my diff gear slipping?


In my case, I might've bent the D/L on an obstacle without realizing it. The D/L doesn't 'wear/tear' quite as your u-joints do. Ever see one grenade before? It's pretty gnarly, esp if the front of the D/L hits the ground while you're in motion <img src="/forums/images/graemlins/zombie.gif" alt="" /> Glad that didn't happen to your girlfriend.

Either way, they can't/won't balance your D/L without new ujoints installed; takes the slop out of it so they can set it up properly for you. Science in action.
Posted By: Greg_Canada

Re: Tranny Clunk backing up! - 04/02/12 04:10 PM

Trail-gear is pretty close to you http://trail-gear.ca/default.cfm?fa=products&prodcategoryid=30
Posted By: allochris

Re: Tranny Clunk backing up! - 04/03/12 04:25 AM

ya, i sourced a used rear a 4.88 diff from Nanaimo on the island today. $20 shipping to the door where my truck is sitting! It got pulled out today, i'll find out tomorrow about its condition. <img src="/forums/images/graemlins/cheers.gif" alt="" />
Posted By: allochris

Re: Tranny Clunk backing up! - 04/05/12 06:43 AM

Alright, the yard on the island didn't work out. (pinion seal was leaking)

But I got hold of one here in Vancouver finally this afternoon. Tomorrow I just gotta lug this 80lbs+ anchor-way back with me (on foot!) on the ferry to Victoria!

It came off a 4runner, about 240k. Hope it will last a while...<img src="/forums/images/graemlins/rolleyes.gif" alt="" />

Friday, I'm planning to plug the 3rd in, refill, run for a couple mins around the block, then drain the fluid to remove left-over metal shaving in the housing. Then refill afterwards. Good plan?
Posted By: kewlynx

Re: Tranny Clunk backing up! - 04/05/12 07:13 AM

Good plan. A better one would be to call NAPA quick and see if they offer a magnetic plug to put in there. If not, will be a good mini-mod later on.

Take your time and set it up right. I'd be callin' a taxi. <img src="/forums/images/graemlins/ignore.gif" alt="" />
Posted By: allochris

Re: Tranny Clunk backing up! - 04/07/12 07:54 PM

All right, it's done!

Yesterday i cleaned the new to me 3rd, about 240k on it. Plugged everything back it. Filled with gear oil, ran it for 5 mins with the truck on jackstand, drained gear oil. Refill again, test drove. Felt good. No more clunk or excessive backlash play felt while letting gas pedal off.

Hope this one will last another while...

Thanks everyone.

My original drain plug already has a magnet built in. Just too bad it doesn't sit directly at the bottom of the housing though... <img src="/forums/images/graemlins/cheers.gif" alt="" />
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