Rhythmic Rear End Noise

Fingers · Post by **Fingers** » Fri Apr 21, 2006 9:07 pm

Hey Arch,

I might have a spare here in the next week or so, depends on the condition of the one on the driveshaft I am getting. If it is good, i will shoot it to you.

I will let you know next week if all goes well this weekend.

Fingers

Post by **ARCHINSTL** » Fri Apr 21, 2006 10:31 pm

Fingers -
Great !
I will be in St. Chuck (OK- St. Peters) in a subdivision near Birdie Hills & Ohmes Saturday, 0429, and also the following Saturday, 0506, g-kidsitting. Just let me know - you have my email address and we can call.
Thanks,
Tom M.

Soutthpaw · Post by **Soutthpaw** » Fri Apr 21, 2006 10:42 pm

Eventually the vibration will wear out other parts of the driveline like u joints (any play) in a u joint means it is shot. also if the knock/ vibration chages at different speeds or occurs at certain speeds or accell/decell etc then its a good indication of driveshaft problem. actually there is abearing attached to the rubber bushing that is then attached to the shaft.

Post by **ARCHINSTL** » Sat Apr 22, 2006 1:51 am

Soutthpaw -
Thanks for the comments.
As previously mentioned, the frequency of the omnipresent rhythmic rapping varies with speed.
Also as previously mentioned, there is a rubber bushing which surrounds the bearing (which is pressed to the shaft).
While it seems unlikely, it would be nice if the vibration vamoosed with the installation of all new rear brake internals - we shall see...
Tom M.

Post by **ARCHINSTL** » Fri Jun 09, 2006 1:04 am

Well -
My rhythmic rapping disappeared, it seems. After doing a complete brake job front & rear (all is new save the steel lines and the MC and drums which were turned), I think what the cause of the problem was - was me.
When I installed the new stud on the right front, I simply put my shoulder to the lug wrench and put on a lot of pressure. While I have a nice torque wrench, I did not bother with it. After using the wrench this time with the new stuff, it seems like the OE setting of 76 foot pounds is a lot less than what I originally applied.

So - I think I may have warped the original rotor.....

At least, that is what I think. As a point of interest, my '88 Dodge Ram 50 2WD/Mitsu Mity Max, which has 6 studs, has a recommended torque of 87 to 101 foot pounds.

The center drive shaft bearing support still has some slop - about 1/8" or so in all directions, but since the rapping stopped, this replacement will have to wait until I do the struts and tie rods.

Thanks to all for their advice.
Tom M.

Typrus · Post by **Typrus** » Fri Jun 09, 2006 12:06 pm

I doubt that would've warped the rotor... I regularly put the equivalent of maybe 100ft/lb on all my lugs. Remember, the pressure goes to the pad in behind the rotor, and unless you had one at 120 and the opposite at 50, I doubt that enough stress to warp anything would be there.
Maybe you did have a warped rotor or out-of-round drum...
I hate the idea of turning rotors or drums... I fear warping. The less material the more likely a warp is.

I dunno if I mentioned it, but my carrier bearing is so out that I have maybe 3/4 inch total slop, side-to-side. Well, if my dads is out at 100,000 on his truck, then I can see how mine would be fried at near 200,000.
Someone indicated that the baering can fly apart and allow for the driveshaft to seperate... How valid is that?
At $240*-ish for Toy-brand parts... I think I may wait for that sucker.

*I use USD $ when I quote currency, unless otherwise stated.

Post by **ARCHINSTL** » Fri Jun 09, 2006 9:54 pm

Well -
The rapping is back. Actually, it would seem it never left - my previous report was based on driving on roads that had more ambient noise - and I think I sorta wished it away, too...
So - I guess the center shaft support bearing will be in line after the other items.
Sure wish there was a way to confirm that it was the bearing, though. Incidentally, while doing the brake job, all of the wheel bearings seemed fine, in that there was no shaking, they did not feel loose, and there was no lubricant leakage at all.
Tom M.
EDIT----
typrus - I guess I gave my arms too much credit - I thought all of that spinach I've been eating recently gave me some Popeye-Power.
Also, AZ and Advance have the center bearing for $104 to $112 for Anchor and BCA, and $138 for Timken (and $220 for Pioneer-quite a disparity).

takza · Post by **takza** » Sat Jun 10, 2006 5:18 am

Just had my driveshaft out doing the trans....have only slight slop in the bearing itself & no noise turned by hand...you might check to see if it's the bearing or the rubber around it?

I think you could "bolster" the rubber surround using something or other if that's where it's loose.

When I tighten wheel lugs I use a cross pattern to do it.

Post by **ARCHINSTL** » Sat Jun 10, 2006 2:14 pm

takza -
I would have to take it out, I think, to confirm, but your suggestion is exactly what I was considering if it is indeed the rubber surround that is the culprit - kind of a shim/spacer/encirclement of some material.
It's kinda hard to check if it is the rubber or the bearing if inspecting in situ.
I do use a cross-pattern in tightening the lug nuts - as much as one can do with only 4 lugs, that is.
Thanks,
Tom M.

Gasoline Fumes · Post by **Gasoline Fumes** » Sun Jun 11, 2006 12:59 am

ARCHINSTL wrote:takza -
I would have to take it out, I think, to confirm, but your suggestion is exactly what I was considering if it is indeed the rubber surround that is the culprit - kind of a shim/spacer/encirclement of some material.
It's kinda hard to check if it is the rubber or the bearing if inspecting in situ.

3M Windoweld should do the trick. I've used it to stiffen engine mounts. It dries to about the same hardness as the rubber. I got a tube of it at Advance Auto for around $10.

Post by **ARCHINSTL** » Sun Jun 11, 2006 2:36 pm

Gasoline Fumes -
Say, now that stuff certainly sounds like it's worth a try. It would act as a spacer, and not subject to a lot of motion/pressure,
Might also have a number of other uses.
Thanks,
Tom M.

Logbear · Post by **Logbear** » Thu Aug 17, 2006 5:31 am

I've been having the same noise with my Tercel. I checked the wheel bearings for play and noise and they seem fine.
I disconnected the driveshaft from the rear diff and I could feel that the U-joint isn't moving completely freely. My suspicion is that this is what's causing the noise.
Is there any reason I can't remove the driveshaft and drive the car. I just wouldn't have 4WD right? That would prove to me that the driveshaft was the noise. Then I'd just swap the driveshaft with one off one of my parts cars.

takza · Post by **takza** » Thu Aug 17, 2006 5:43 pm

You'd lose the oil from your trans...not good.

You could remove the driveshaft and soak the stuck universal in oil to loosen it up....but doubt if it would last.

This works for steering universals.

Might be able to drill a hole in the cap or center and force some grease in...then seal the hole someway. Otherwise...new driveshaft?

Post by **ARCHINSTL** » Thu Aug 17, 2006 8:14 pm

Maybe Logbear meant "...to disconnect and remove the rear driveshaft only..."?
Upon cursory examination of the shaft and the FSM, it would seem that this is possible, as the front appears to be still held up and into the transmission by the center support bearing - but I do not know - anyone tried it?
Perhaps Logbear could pull on the front shaft's mating flange to the rear and see if it pulls out/moves rearward? If found to be tight, then perhaps drive it gently before trying it at speed? If the noise disappears, then at least the rear two U-joints would be the culprits; if not, then there is still the one on the front shaft or___.

Since the U-joints are integral with the driveshaft (BIG Bucks), would it be possible to cut them out and weld in a replacement? That seems like a naive question, given probable rotational issues/balancing issues, but I just did not know. I figured someone, somewhere, must have tried it with some car....

My noise is still there, as noted. After resolving some more pressing items, I plan to try the Windo-Weld procedure on the center support bearing; I've been reading quite a bit about some real successes with it, and even bought a tube at Advance (Thanks, Gasoline Fumes!).
Tom M.

Logbear · Post by **Logbear** » Thu Aug 17, 2006 10:38 pm

Well I went ahead and removed the rear drive shaft only this afternoon. I talked to a local shop and they said it would be OK to drive with it off. I have driven 50 miles at highway speed with no ill effects. But the noise is still there.

I've checked: Wheel balance, wheel bearing, brakes, and driveshaft.

I'm afraid the only thing left is the rear differential.