LuckyStrike

Hi everyone, just bought a 98 Tacoma ext. cab 2.7L 5 speed TRD with 88k miles, and there is a noise in the rear end.

When I am driving highway speed and let my foot off of the accelerator, there is a high pitched whirring sound in the rear end... push in the clutch and the noise stops. The noise is only there when I let off the accelerator with the clutch engaged, and its more noticeable at higher speeds. It doesn't sound nasty, but its loud enough. Just topped off the differential fluid and the noise is still there. Any ideas on where to start looking would be great.

This is my first post to the forums, looking forward to learning from everyone!

95yoter8

Rear diff. carrier bearings. When the truck is under load it doesn't make noise as you said. That is a tell tale sign that it's the bearings. When you let off the gas and still in gear it will have play which makes the noise you are describing. Happened to my 92' 2 wheel drive. I just put in a whole new diff. Not worth rebuilding to me. You can find the whole carriers fairly cheap plus i have toyota parts trucks everywhere. Not sure how hard it is to find tacoma diffs though

LuckyStrike

Thanks. If it may only be the carrier bearings that need to be replaced, why do you recommend changing out the entire differential?

95yoter8

Because If you don't have the proper tools (i.e. an air compressor and a press etc.) then it is kind of a pita and it's much easier to unbolt the old carrier from the axle, slide axle shafts out, drop new carrier in and slide the axles back in place and bolt the new carrier in. Rather than having to tear the diff apart..but everyone is different, that's just what I would do because I have spare axles... You can always build it later after you put another diff in it...

95yoter8

I guess it's just personal preference but yes, it is definitely fixable but you will be down a truck unless you can do it in a day or weekend or whatever. Or you can just run your truck in 4wd and keep the driveshaft off till' you finish building the diff...

waskillywabbit

iTrader: (-1)

Could be rear dshaft u joint too.

:wabbit2:

Team420

Depending on how many miles are on this rig... I would have to agree with wabbit!

I would start by checking out the u-joints, Jack the rear of the truck, and place securly on jack stands, put truck in neutral, then get under there and start shaking that shaft... ANY side to side or up/down movement indicates worn u-joints....

If not the u-joints, then I would move on to inspecting the diff, but... always start simple...

4Crawler

iTrader: (3)

Might also check the pinion flange on the rear diff. I usually find that vibes/noise when letting off the gas can mean that the pinion flange is a little loose. I've had good luck with just un-staking the flange nut, torquing the nut to about 90 ft.lb. and re-staking the nut. You don't want to go much over 90 as you might deform the crush sleeve (if you have one) in the pinion bearing.

And you can tell the flange is loose by the above "shaking" test. Just feel the flange for any up-down or side-side play. And check the t-case flange as well, same test, same fix.

LuckyStrike

Alright I'll check all those and let ya'll know what I find. Turns out the rear axle seal has been leaking gear oil into the right break drum, so I'll have to fix that, may go ahead and put in all new bearings just to be safe if its not too expensive.

rokblok

iTrader: (1)

Maybe Wabbit and 4crawler can comment also, but isn't the accel/decel whine sometimes caused by pinion bearings or pinion-to-ring gear pattern?

LuckyStrike

Well I finally got around to taking the axles out to change the seals. I took the backing plate off with the axle, and I noticed that it had a little play in it, I could wiggle it where it sits on the axle.

This has me a little worried that the wheel bearings need changing, is this wiggle normal? Also, how would I remove the backing plate from the axle, it seems pretty stuck on there. Thanks.

4Crawler

iTrader: (3)

Backing plate/wheel bearing replacement, use a press and jig or below:
- http://www.4x4wire.com/toyota/mainte...wheel_bearing/

I think the FSM lists a radial run-out spec on the bearings.

LuckyStrike

Mechanic I took it to says he thinks all the bearings in the rear end are shot, his best guess is water got in there, probably from putting boats in the water. I know the previous owner had boats and jet skis so this would make sense, and it might explain the surface rust on the lower parts of the frame and leaf springs too.

Rebuild - $1000. Its an e locker so i guess that some extra labor. Dealership wont even touch it, they want to charge $2700 to put in a new one. I don't have the tools to rebuild it myself.

Seems worth it to me, another rear end would be a little cheaper than that but who knows what I would be getting. If anyone has any thoughts I would love to hear them!

badattitude

A diff leaking past the axle seals can "wash out" the wheel bearing's grease and of course when the diff is low on gear oil the carrier and pinion bearings will suffer. Somtimes the diff breather becomes clogged, then the internal pressure pushes gear oil past the axle seals through the wheel bearings.

Check/replace the diff breather
check/replace the axle seals
check the wheel bearings, some play like you mention is ok
check the pinion and carrier bearings in the diff/third member

Also, call east coast gear supply. Many times it is the same cost to just buy a new diff and install it yourself as it is taking it to a diff shop and asking them to rebuild it. Plus finding a good diff shop is difficult. ECGS are pros and the new diff you get will be grade A.

http://eastcoastgearsupply.com/

I had the clogged diff breather, leaking axle seals, ruined pinion bearing. I had to replace the breather, diff bearings and axle seals. My wheel bearings were ok. I had a local "diff shop" do the work. If I had to do it again I would have ordered a new diff from ECGS. MY labor cost was $650 plus pinion and carrier bearings were $160ish.

this is a fairly common issue with Toyota axles. It all starts with a clogged diff breather most of the time. Of course getting water in the diff breather will cause problems too.

GuitarMike

What he said!

Heck, you can find a used diff easy enough...a little more research if you want the elocker, of course.
We redid the oil seal on mine last fall, as a sort of "make it last" proposition. Just did rear wheel bearings (<$200 by me doing the rip down/reinstall)....I should've changed the diff then (dummy!), since i now have shavings in the oil.

Gonna have to make some time in late summer to take the axles out AGAIN, and put in a spare diff my buddy gave me...if only he'd given it to me 2 weeks ago! LOL

Rebuilding them just buys SOME time, in my humble, noob opinion. Cheaper in the long run, and time-wise, to just find another.

LuckyStrike

Thanks for the advice fellas. Anyone have any opinions on an elocker 3rd member from ECGS? Their 3rd member is just under $700, half the price of the 3rd member quoted by the dealership. With that price difference, am I getting the same quality?

ZUK

iTrader: (1)

Hey LuckyStrike---
I'm winding down on the gear installs here due to the hot weather picking up but the early morning hours are still sorta cool so I can do a nice pro bearing replacement with a solid collar upgrade if you are willing to go to the trouble of sending your e-locker to me.... ZUK

edit---The whine on de-accel is usually loose pinion bearings....you can try what 4Crawler recommended to see if that helps. You can check for a sloppy pinion yourself also....just put the parking brake on for safety and tranny in neutral....crawl under there and shake the heck out of the pinion flange and see if it has slop in it. Good time to see if the uj's have any visual rotational play.....if you can see it then the uj is bad.

LuckyStrike

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