1999 4x4 4.0 Explorer vibration over 70 MPH...front drive shaft??

[Zack1978]

Hi everyone,
I own a 1999 Explorer Eddie Bauer 4x4 SOHC V6 with 170,000 miles. I have a vibration that starts at around 7- MPH and is rather strong. The vibration seems to vary a bit with RPM's. I have had the truck up to the vibration speed, threw it in neutral and it was still felt.
To remedy the problem I purchased 4 new Michelin tires, new shocks, and all new u joints. Needless to say the problem is still there.
Since I am at my wits end, I dropped the truck off at a local and well respected transmission and driveline shop. They drove the truck and confirmed the vibration (how could you not!!!) and they confirmed all my new parts. The one thing that he noticed is that there seems to be a lot of play in the front driveshaft. He "thinks" the vibration is coming from the worn front driveshaft. He noted that vibrations are very hard to solve generally, but that his best answer is to replace the front driveshaft.
Does that sound like it could be the problem? Is a worn front driveshaft a common problem on the Explorer's?
If I replace it, what is my best option? I can get a brand new front driveshaft from Detroit Axle for $165.00 (made in China) or I can have my driveshaft rebuilt locally for $350.00. I'm not that concerned with price, I just want it done once and for all.


Any ideas?


Thanks,
Zack

 

[Rhett]

Is your front driveshaft turning all the time? You're not AWD. Wonder why they said front, and not rear driveshaft?

Driveshaft imbalance can definitely cause a vibration, but I would think it would be the rear driveshaft / u-joints.

 

[koda2000]

The front driveshaft is always turning if the truck is moving, unless you have locking hubs. The tires turn the hubs and axles, the axles turn the diff and the diff turns the driveshaft whether your in 2WD or 4WD/AWD.

To see of the front ds is the problem, temporarily remove it and see if the vibration goes away.

 

[Zack1978]

Yes, my truck is AWD/4x4 so the front driveshaft is always turning. The shop said with the front driveshaft removed, I could not drive the truck. So based upon that I can't remove it to verify it that is the issue? Has the front driveshaft been problematic at all? Both driveshaft shop seemed VERY familiar with the Explorer shaft.

 

[MAS Tequila]

You CAN remove it temporarily to check if it changes or eliminates the vibration.

Don't leave it out, as the vehicle uses the front for the PARK detent/function, and it will roll away if your not careful.

 

[Rhett]

The front driveshaft is always turning if the truck is moving, unless you have locking hubs.

Do 2nd gen 4x4's front driveshafts always turn? Obviously the AWD ones do, but do the 4x4's?

 

[koda2000]

Do 2nd gen 4x4's front driveshafts always turn? Obviously the AWD ones do, but do the 4x4's?

Yes. As said, if the front tires are spinning the front driveshaft is turning. What's to prevent it from turning? The transfer case is where the disconnection from the transmission occurs in 4x4's. If AWD you technically don't have a transfer case, instead you have a "center differential" with a viscous coupling. With AWD's the transmission is always supplying a minimum of approx 35% power to the front wheels and 65% to the rears.

Older 4x4's had manual locking hubs which disengaged the front wheels from the axles. This prevented the front wheels from turning the axles, diff and front ds. Newer 4x4's no longer use manual locking hubs. They were a bit of a PITA because you had to climb out of the truck to engage/disengage the hubs.

 

[SupaSwope]

They actually still put manual lockers on their trucks. My boss bought a brand new f250 4x4 6.7 and its got manual lockers.

 

[koda2000]

They actually still put manual lockers on their trucks. My boss bought a brand new f250 4x4 6.7 and its got manual lockers.

Yes. They may still put them on real trucks, but not on mall assault SUV's.

 

[Zack1978]

Does anyone have any experience with this brand? https://detroitaxle.com/shop/drive-...MIhbmU_M3A1QIVCQ9pCh0G2QW6EAQYAyABEgJwLPD_BwE

The transmission said he would advise having my driveshaft rebuilt locally, which is considerably more money than the above.

I don't want to go cheap only to have it bite me.

 

[koda2000]

Does anyone have any experience with this brand? https://detroitaxle.com/shop/drive-...MIhbmU_M3A1QIVCQ9pCh0G2QW6EAQYAyABEgJwLPD_BwE

The transmission said he would advise having my driveshaft rebuilt locally, which is considerably more money than the above.

I don't want to go cheap only to have it bite me.

I'd go with your local guy or DIY. It's not that hard. I've read bad things about Detroit Axle's quality. No matter who rebuilds the CV end I think you're gonna end up with Dorman parts.

DIY will cost you around $100.

 

[Zack1978]

I looked at my truck today, and I don't think I can drive it without the front driveshaft. Without the front driveshaft, there is nothing connecting the engine/trans to the rear wheels. My truck is full time AWD and selectable 4wd.

 

[koda2000]

I'd go with your local guy or DIY. It's not that hard. I've read bad things about Detroit Axle's quality. No matter who rebuilds the CV end I think you're gonna end up with Dorman parts.

DIY will cost you around $100.

Edit: FYI - Checking current eBay prices on DIY front DS CV joint repair kits, it appears the kit prices have dropped to around $45.

 

[koda2000]

If you have the V6, you do not have true AWD. Only the V8 was available in AWD and they had no 4WD switch. There were a number of different configurations on 4WD offered for the V6. What are settings on your 4WD switch say?

 

[Zack1978]

The settings are: Auto
4x4 high
4x4 low

 

[koda2000]

The settings are: Auto
4x4 high
4x4 low

I believe "Auto" means that the front wheels will be engaged automatically if slippage of the rear wheels is sensed. This is not AWD. It's automatic 4WD. Most find this feature annoying, as the engagement of the front wheels is a bit harsh and surprising. The "Brown wire mod" prevents the automatic engagement of the front wheels. Some add switch to the brown wire to be able to control this feature.

Your rear wheels are always driven. I think you could remove the front driveshaft temporarily and drive the vehicle to see if it's the source of the vibration.

 

[Mbrooks420]

Your truck is NOT AWD. It's automatic 4wd and that is actuated used a clutch that 'duty cycles' the front drive. I am confused about your statement of not being able to remove the front shaft. The front shaft will have nothing to do with the rear drive. Any second gen can be driven without the front shaft, regardless if they are 4wd, or true AWD.

 

[Mbrooks420]

Also, I would have the shaft rebuilt locally, or put a quality CV on it yourself. The remans do not last. If you are keeping the truck, it's worth not replacing the shaft, again, in short order. If the front shaft fails it can leave you stranded.