Hey all-
This is the first "weird noise" question I've ever posted.

Every once in a while, I hear a sort of grinding sound from under my truck. The best way I can describe it is like this:
On front wheel drive cars, if the CV joints are worn or failing, they make noise when going around a corner.
My truck is making that noise only when accelerating in a straight line. At first I thought it was the supercharger. But, if I drop the tranny into neutral and rev the engine, the noise disappears. The noise stops when the truck stops. I can't tell for sure, but it sounds like it might be either from the driveline or the rear diff.
In either case, I'm having the diff fluids changes and driveline lubed next weekend.

Anyone else have any other ideas?

It's a 96 4Runner Ltd 3.4L V6

Thank you!

 

Did I stump all of you?

 

I was waiting to see what happened when you changed you fluids. I've got no ideas so far.

Mike

 

Could be your muffler bearings going out, if so you're in big trouble, they're a b!tch to replace.

 

:pat: Dammit! I was affraid of that. Which would you recomend...painted or chrome?

I had a chance to look at the turn signal fluid, bumper rebound fluid, and the 710 cap. They all looked fine.

 

Hmmm, painted definitely. . . those chrome won't don't last at all. Have you switched to vented brake lines yet? I'm think of upgrading to those once I save up a little more money.

Good luck finding a fix, I've got a nasty rattle/buzz that I can't locate right now as well sounds like the cat shield is loose.

 

Mine is really weird. It's most noticeable between 2000-2600 rpm. If I hammer the throttle, it goes away (or the exhaust noise drowns it out, I don't know).
Either way, I have an appointment on Feb 15th to have the front and rear diff fluids changed, driveline lubed, and transfer case fluid changed.
I'm going to have them look at the steering components, u-joints, axles, etc.

 

Hey Alan,

I'm not really sure what the situation is on working on your vehicle at your residence, but all of that stuff can easily be done by you - the diffs, transfer case, etc. You seem like you have good technical ability, so this would be a no-brainer for you. However, there may be some other circumstance, and if there is, I'm sorry for this post!

 

Normally I would do that myself. I've read all the tech articles about it and it looks realtively easy. I just don't have the time. It took me almost a month to set aside enough time to replace the starter.
The dealer doesn't charge that much to do it. To lube all the driveline points, replace the front and rear diff and t-case fluids, they will only charge me $100. I'd rather pay $100 than let my rig set for another month.

 

That's cool. Just a friendly tip

 

Well, went to bed last night feeling kind of dumb. Turns out the noise is being made by my exahust system. I have two torn rubber exhaust hangers.
On a brighter note, in the last three weeks my 4Runner has gotten a new timing belt, CV joints, starter (twice :mad: ), front and rear diff fuilds changed, t-case fluids changed, and the headers wrapped. Today was the first time I've REALLY driven it in over a month.
Up next: TJM, Rock Ware rear bumper, new rims and tires (for highway use), CB, and a complete stereo upgrade!