The problem:

I have a whining noise that has been going on for months ever since I redid my rear suspension/rear driveshaft/rear diff. All was done at once, so there isn't really a way I can separate the specific mods.

Rear diff was re-set up with the same gears and locker due to original install using the wrong bearings. Same gears, but they have a new wear pattern.

No noise prior to that.

Rear driveshaft angles are perfect (ie 0deg) at the diff.

The noise ONLY occurs with slight acceleration above about 40 mph, or at least that is when its noticeable.

The way to get the noise is to accelerate up to 40-45-50 ish, let off the gas completely, and then just BARELY put my foot back on the accelerator. Roughly enough on the gas to maintain speed on flat ground. Hard acceleration and the noise goes away, coasting, the noise goes away.

Here are the stats:

4.88 gears with an ARB diff. CV style (double cardan) driveshaft, .120 wall.

CV was USED out of a 96 taco shortbed. Its the rear joint, so it has plenty of flex.

There are no wear marks on the shaft from grease fittings rubbing, etc...

What I've done:

Pulled the diff to inspect the gears. New pattern seems to be wearing in well.

Changed the diff oil twice. No abnormal shavings/chunks of metal.

Checked the driveshaft: No play in Ujoints that I can see or feel.

However, I DO have some play in the splines where the shaft slips. Maybe a 16th of an inch or so.

Axle housing is straight, wheel bearings seem solid.

No abnormal play in the diff flange or tcase flange.

Noise does not seem to occur in front wheel drive only, leading me to think its possibly not the tcase, or if it is, its the tcase output bearing on the rear.

It is very hard to determine the location of the noise. Half the time it sounds like its coming from the rear end, and the other half from the tcase. This leads me to suspect the driveshaft.

Anyone else have this issue before, and/or know if the little bit of play in the splines would cause this noise?

 

How did you check the ujoints? You won't see it if you just do it by hand - need a prybar and really reef on it

 

Oh. I just tried to move stuff by hand.

Where do you reef on the u-joints at?

 

Get a thin(ish) prybar into the yoke.

Molly has a prybar that fits perfectly

 

yea its hard to tell if there is any play when the shaft is in(unless you do as tc described).

could it be the R&P making a lil noise because of the pattern being changed? how many miles were on the rnp before the new pattern was set?

 

Sounds like classic u-joint noise to me with letting off the gas description. Cheap thing to eliminate regardless.

My 85 ext cab did the same thing and replaced the u joints and that stopped it. They didn't have any play by hand either but when removed they were shot.

Update when you figure it out please.

 

Wabbit,

Did you have the noise when coasting, or just barely on the gas, as I do? Mine does not make noise when coasting.

I'm looking into the ujoints as we speak. Toyota has the single cardan end for 51 bucks, and it looks like High angle drive line carries the double cardan end for 30 each. Napa carries them too, but everything I've read suggests Napas are garbage.

 

20-30k on the R&P before the new set up. 2k or so on the new set up. 2 oil changes.

 

The guys at AllPhase swear by the NAPA "Super strength" u-joints.

Longfield has high strength ones too I think

 

Check the pinion bearing, it can cause the noise your having when it goes bad.

 

If I could hear it I could tell you. I have had enough with the problem that I can hear it a mile away on a Toyota, but you are a bit far.

Mine never made noise accelerating fully, just in the intervals between being fully in the gas and getting out of it. Seems as long as the joint was under constant velocity it was fine, but once it changed, made that dull bone jarring noise.

Keep us posted.

 

So just to clarify my understanding, you changed your suspension. I'm assuming lift. You rotated your pinion, to go to a cv rear driveshaft. Did you install dual cases? You changed the gear pattern because but the install is good and the new pattern is good.

X2 on the noise being to do with changing gear pattern, seems ZUK has something on one of his builds about reusing a ring and pinion and noise afterwards.

Maybe it is a ujoint, who built the shaft? You mension HAD and Jesse does awesome work.

If you have dual cases did you check if the cv end of the shaft is it interfacing with the horsecollar crossmember. I had to clearance mine, did a trick little job with a piece of steel pipe, I got an archway like a roman bridge

You say 0degrees and the pinion flange, how did you measure it? 4crawler describes a nice method for doing so. I compensated for axle wrap under acceleration, when doing mine.

just thought I'd through somethings out there.

 

Responded in the quote with red.

 

Sounds like yours was similar. I'll certainly update as I go.

 

It could be, but I don't think so, simply because it would have had to be going bad from the moment of install since its a brand new bearing from Toyota.

 

All I've read about the NAPA ones online is that they are garbage. Since the High angle driveline ones are virtually the same price, and people seem to like them in heavy duty rock rigs, I'll go with those on the CV side and an OEM one on the single cardan side.

I'll order them up tomorrow.

Oh, and Longfield carries U joints for Danas, but not the toyotas as far as I can tell.

 

Got me I've never messed with a link setup. You fab your own or get a kit? Good luck with the noise

 

fabbed my own.

 

Purchased an OEM ujoint for the single cardan end and Miatsu joints (2) from High Angle Driveline for the CV end today.

 

nice.. keep us updated.