2000 4runner driveshaft/wheel issue

[cash]

I just had my 120k scheduled maintenance done at a Goodyear shop. The maintenance included a transmission fluid change, differential fluid, spark plugs, coolant exchange. The truck was running fine just wanted to get the scheduled maintenance done but after I picked the car up I noticed a buzzing sound/vibration from underneath the car. It happens whenever I press the accelerator. When I brought the car back and told them what was going on they said it was the rear differential (which was replaced) they said to add an additive and it will fix the vibrating, did that and nothing changed.

so i was asked around and i got 2 popular responses:
1.) it could be the driveshaft and would need to be balanced
or
2.) could be the wheel weight getting out of balance or falling off
input on those responses? any advice will help
:shrug:

 

[Big John]

I have never heard of an additive that would cure vibes.
What did they say was wrong with the rear differential, and what did they say the additive would do to fix the problem?
Since they changed the oil in the diff., and now they actually admit there is something wrong with it, I would suspect they forgot to fill it.
I would take it back to them and insist that they fix their mistake. Don't let them tell you they can put anything in your diff aside from a new one that will make the noise go away.

 

[JohnsD90]

If your driveshaft is having an issue you should grease your u-joints, and if 1 doesnt accept grease than it likely is shot and needs to be replaced, if i am correct, the vibrations will get progressively worse until it becomes so f*cking annoying that you can't put it off anymore and you change almost instantly after that.

 

[cash]

they didnt say anything was wrong with the rear differential, they replaced the fluid and then added the additive to it since the fluid they used was not full synthetic. they didnt mention anything about greasing up the u joints, just said the drive shaft needs to be balanced. could the wheel weight being off balance or missing cause the vibrations?

 

[kball]

The only additive that gets put into differentials is a friction modifier for limited slips. 4runners don't have limited slips so no additive is needed. It doesn't matter if the fluid is full synthetic or not. Synthetic or regular dino oil will work fine in your diff so I'm guessing they are bumbling clueless idiots or they are yanking your chain.

 

[1985taylor1925]

The only additive that gets put into differentials is a friction modifier for limited slips. 4runners don't have limited slips so no additive is needed. It doesn't matter if the fluid is full synthetic or not. Synthetic or regular dino oil will work fine in your diff so I'm guessing they are bumbling clueless idiots or they are yanking your chain.

Thats the reason I decided to join this forum and learn to do all the work myself. That and i like working on stuff. But really you cant trust any shops to work on your vehicle any more. Its ridiculous.

 

[RHeld24]

Cash,

I have a 2WD also and have been through a few driveshafts/front u-joints (they're factory welded together). For some reason ours have no grease fittings. One way I knew mine was starting to go again was by feathering the gas on the freeway at speed, I heard this hum for a while and then things got worse. Replace it early (if it is a u-joint problem), as it can mess with the output yoke on the trans.

 

[cash]

Rheld24,

Thanks for the response. I am hoping its not the driveshaft cause I figure it will be expensive to replace. From what they have told me if it is the driveshaft they will balance it instead of replacing..do you think that is ok? I am hoping it is the wheel weight out of balnce and just get that adjusted. Could that be the problem too or most likely driveshaft?

 

[RHeld24]

From my experience, wheels out of balance wouldn't really make the noises (if any at all) that you were speaking of.

The drive shafts we have are welded to the front u-joint and can be picked up from a dismantler for about $100. You can pull your old one out and put in the replacement in about half an hour taking your time (w/ minimal mechanical ability/know how).

If I were you (and I assume no responsibility for your actions), I would put the rear of my truck on jack stands (with the front wheels chocked and the truck on a level surface) and then put the trans in neutral. Get under the truck and turn the drive shaft back and forth by hand to look for any play in the u-joints (this is what I have done to safely diagnose the problem myself). I would hate to have you waste money on a drive shaft balancing when the u-joints were the problem...

 

[Big John]

Rheld24,

Thanks for the response. I am hoping its not the driveshaft cause I figure it will be expensive to replace. From what they have told me if it is the driveshaft they will balance it instead of replacing..do you think that is ok? I am hoping it is the wheel weight out of balnce and just get that adjusted. Could that be the problem too or most likely driveshaft?

1) I'm really confused Cash. You took the car in and it was fine. You get it out of the shop and now it's making noise and vibes that weren't there before the shop. Correct?

2) If it were the D/S, why would it start right after you took it to this shop. That said, let's assume it is. Put the rig in neutral, chock the wheels, crawl under it and check for excessive play at either end of the D/S. If the D/S has a lot of play, it will most likely be a u-joint(s). If that's the case, pull your D/S (8 bolts) take it to a driveline shop and have them replaced if you're not comfortable doing it. You can have them check the balance of it while it's there as well, but having a driveshaft go out of balance without hitting it on something is very rare (I've never heard of it). You will not have to replace the whole D/S.

3) If it were a wheel weight, again why right after you took it to that shop? Only way to check that one is to have your tires balanced. May as well have them rotate them while you're at it.

Unless I'm misunderstanding what you wrote in you OP, I still doubt it's 2 and really doubt it's 3. I would quit taking it to the above shop regardless (unless it's to fix their mistake) as I don't think they know what they're doing aside from taking your money.

 

[Big John]

From my experience, wheels out of balance wouldn't really make the noises (if any at all) that you were speaking of.

The drive shafts we have are welded to the front u-joint and can be picked up from a dismantler for about $100.
.

I have never heard of this practice being done so I HAD to go look.
I have a 2k 4Runner with a double cardan rear D/S and my u-joints are NOT welded in.

 

[AddictedOffroad]

U-jonts on the rear shaft are not welded in place. There is an internal C-Clip that holds the joint in.

Its a slip yoke style on a 2wd. Double Cardan(CV) style on a 4wd.

Still, you can easily replace u-joints without having to replace the entire shaft.

FWIW, if you took the 4runner into the shop and none of the sounds were present prior to taking it in, then they screwed something up. Its that simple. At this point, they know that you are gullible enough to believe what they are saying, so they are just giving you a line. Unfortunately, its a common occurance these days.

If they claim its the driveshaft, then ask them how it came in without a vibe or sound, and all of a sudden its there now after they did the work.

If they claim its the rear diff, then tell them to fix it since it wasn't like that before you brought it in. Just them telling you its the limited slip additive that is the reason means they are a lying through their teeth to cover their ass.

 

[RHeld24]

Didn't mean to misguide anyone, just giving what I've done in the past to remedy the problem effectively and cost efficiently. At the time, replacing the front u-joint/driveshaft assembly was cheaper than old u-joints being pressed out and new ones being pressed in.

Again, my apologies if I sent anyone in the wrong direction.

I agree with the "Addicted" posts that regardless of what is wrong, if you went in fine and came out with problems, that shop did the damage and is responsible for returning your truck to its previous state.

 

[cash]

ok thank you to everyone on their input for this issue. I have to agree that the goodyear shop I took it to messed something up since the truck was running fine until they did the scheduled maintenance. Unfortunately I dont know much about car mechanics so even is the shop was giving me the run around, i took it as if they knew what was wrong. but seeing as if nothing has worked i am suspicious of their work. i just hope they fix the problem without me having to shell out anymore $$. thanks again to everyone who responded to my post

 

[Big John]

ok thank you to everyone on their input for this issue. I have to agree that the goodyear shop I took it to messed something up since the truck was running fine until they did the scheduled maintenance. Unfortunately I dont know much about car mechanics so even is the shop was giving me the run around, i took it as if they knew what was wrong. but seeing as if nothing has worked i am suspicious of their work. i just hope they fix the problem without me having to shell out anymore $$. thanks again to everyone who responded to my post

Cash, you will probably have insist that they fix what they screwed up. Bottom line is that there is no magic oil that they can put in to fix a noise that has developed in the rear end. You don't have to know a lot. If it sounds too good to be true then it probably is. So just stick to the plain fact that when you brought it in it was fine and now it's making a noise FIX IT! I'm still betting they forgot to fill one of your fluids.