Frustrating Toyota noise.

wentz912 · Jul 15, 2012

Let me start with a little back story. My 80 short bed started making what sounded like transmission noise a while back, it had an old L series 5 speed in it, So I dug around and found a cheap G series with a case attached to it and threw that in the truck after making up a quick new crossmember.

Still noisy.

Bummer. Must have got a bit of a lemon, always a mystery buying a used transmission from CL. So, figured I'd deal with it a bit while sourcing another transmission in better shape.

Ended up finding a freshly rebuilt W56 top shift at one of the local transmission shops, get it thrown in and guess what? Still got the noise.

All clutch components are BRAND new, rear d-line just got brand new joints in between the g and w series, I wouldn't think that a shop rebuilt trans would end up making the same noises as an old mystery trans...

Noise can only really be heard on decel, and REALLY sounds like bearing/gear chatter.

Since everything between the back of the engine and the rear diff has been replaced with new or rebuilt, I'm running out of ideas. Could the noise from a rear wheel bearing failing or a chattery ring gear be transmitted up through the drive shaft and be audible in the cab?

WHITE TRASH1 · Jul 15, 2012

Rear diff is probably needing bearings.

wentz912 · Jul 15, 2012

Thanks trashy. I'll throw a set of bearings in it while I have it out to stuff it into a IFS housing.

CarnationSensation · Jul 16, 2012

If you havent found your answer yet i know if your backlash is off your rear end can be quite noisy on the decel, sounds good when puting power to the gears but once you let off there is that play that can create noise, A LOT of noise in some cases.
My buddy just installed his rear gears a little off and they sounded great for the first 500 miles, Wore in a bit and then started sounding like the rear end was gunna blow at any moment.
Just another thing to look at and rule out.
Good luck.

TreeClimber · Jul 16, 2012

Another 'odd' noise is caused by too steep of a driveline angle, which gives a 'rattle' noise, which seems to be coming from the transmission. I had it occur on my CJ5. It's easily solved by switching to a CV style shaft. That noise would not occur under power, or under hard deceleration. It would occur in that 'middle ground', typically when you just get off the power, but hadn't quite started slowing down. I noticed it worse while coasting down hills. I thought for sure it was transmission, but it wasn't.

Good luck,
Tony

WA-Wheeler · Jul 16, 2012

Rip apart the rearend after and only after you have verified it is the rearend.....no need to hthrow more money in the wrong area!!

zukkev · Jul 17, 2012

Sounds to me like the pinion flange is loose, allowing the pinion gear to contact the carrier when under decel...

wentz912 · Jul 17, 2012

It should probably also be noted that my driveline angle did change a lot putting in the G/W series.

Between the tranny being significantly longer and me shoving the tranny WAY up against the body...did I go too far for my u joints to handle in a shortbed?