Help - low speed vibration (10 Viewers)

[CDN_Cruiser]

Gang:

I could use some help trying to narrow down a problem that just started (in last day or so). I think I know what the problem is, but I'm in a bit of a state of denial and I may have more than one thing (unrelated?) that may be confusing the problem.

Here is what I know / have done:

- Truck is a basically stock 1997 LX450 (excet for a fog light ) - no lift, stock size tires, OEM suspension (original AFAIK). It has ~126,000KM/78,000 miles. Synth fluids

- I believe (pre this list ) that the bearings were likely repacked on both sides about 2.5 years ago when I had some dealer work done to replace a part that broke in the front end (don't have the job sheet - looked like a large brass tube ==I shape)

- Replaced front brake pads with OEM about 3 months ago (rear were fine at the time)

- I lubed the drive shaft about two weeks ago - not too much

- While under there, I noticed what I didn't want to see - some 'battleship grey', liquidy oil on 'the balls'. This was after a day trip off offroading, including a number of water crossings (diff breather are extended)

- Here is where it starts to get a bit confusing/unrelated. I was talking to my wife today and she told me the brake warning light was on. I asked her to check the fluid level and she confirmed that it was slightly low - thought it was likely a sign the rear pads need to be replaced (light is now off)

- She also mentioned that the truck had a vibration at relatively low (city) speeds

- I just did a test drive and this is what I noticed: No vibration until about 20-25mph. It feels more the like the dash vibrating and a bit in the wheel. I don't hear any 'popping' as I make hard turns, but I do hear a sound of metal rubbing (not when turning - more when going straight). It seems to be on the DS and it isn't constant - nothing when I hit the brakes and nothing when I go over bumps. Maybe a bit more when I'm accelerating.

Based on reading some 'vibration posts' my sense is that (1) low brake fluid is likely rear brake and unrelated to anything and (2) I have a loose bearing and birf soup to deal with and this is causing the vibration.

I don't have a garage to work in, so I'm going to take it to my indi mechanic and see if I can get it on a lift to have a look. If it's the birf, I think I need to air freight from CDan and I'll go to my brother's house this weekend to do the job in his garage (need to buy a jack, stands, torque wrench,....but cheaper than the $2,000 bill I'm sure)

Thoughts?

Things I should look at / test to confirm the diagnosis?

Thanks for any help.

Cheers, Hugh

 

[IdahoDoug]

The large "brass" tube they replaced was almost certainly the spindle, which has a brass inner liner with distinctive spiral cuts in its inner surface. The outer surface is polished steel. If the brass inner liner failed and they replaced only this, then something's a bit odd as the only reason it would fail is that the birf had failed and was banging around in there. So, kinda strange.

This merits a look inside yourself before getting too excited, but does not sound good. First, check on your bearing theory to discount it as I suspect it's not the problem. Do this by seeing if you can rock the tire in any dimension by aggressively yanking on the tire and/or rocking the vehicle laterally to see if there's wheel bearing slack.

Then, pull the center cap off the wheel to expose the 6 nuts with the much ballyhooed tapered washers behind them. No need to jack the truck - just leave it on the ground. These hold on the thick metal cap known as the drive plate. Use a screwdriver or other to pry the smaller center grease cap off (go around and around, don't just pry at one spot). Once it's off, you should see a considerable amount of grease in the area where the now exposed axle tip mates with the splines in the drive plate. If you do not, the mechanic who replaced the spindle forgot to grease it and your problem is a dry spindle. Likely it's trashed.

If you see grease there, then you'll need to open it further to see what's going on. You'll need to refer to the tech pages and have a couple seals and gaskets to disassemble further, but it's not much more work to now pull the wheel, the wheel bearings, and the suspect spindle. From your symptoms it's the spindle, which was likely installed and/or run dry. That is not cheap, but better than a birf. If the spindle comes off and has plenty of grease that does not appear full of brass filings, then it will almost certainly be a birfield about to go.

I'd get the gaskets and wheel bearing grease seals and immediately dive in before you order the big stuff like a spindle or birf. If you find a dry spindle, I hope the previous mechanic is around so you can get some warranty help on the damage.

DougM

 

[CDN_Cruiser]

Doug:

Thanks for the response. It was indeed the spindle that failed (had a look at a post where someone posted a picture - old style) - the guy showed the part to me and it had definately sheared at the collar. IIRC, that was the only part they replaced - at the time there was no noise of anything else banging around, just a strange (not all the time) noise that I'm not sure I can even describe (sort of like a buzzing noise).

I'll do what you suggested - so it's possible that this would take over 2.5 years to show up?

In any case, to be safe, I'll call CDan this AM to get some parts coming my way and go and get some of the tools I need.

Cheers, Hugh

 

[CDN_Cruiser]

Back from the mechanic -

- Put the truck on a lift and there is no visual clue of any problem (eg part falling off)
- Doug, you are correct that the wheel bearings feel fine - no slop on either side
- Manually rotating the wheels does not create any strange sounds or feelings
- Pried of the dust cap and the splines that I can see (about 3-4mm?) seem to have lubrication
- Had a look at the front diff fluid - seems to be relaitvely clear, despite the thin/watery looking grease on the balls

We did a test drive and my mechanic feels that the vibration is across the entire truck vs. front end. It does get worse the faster I go (still not up to highway speed). He had a look at the joints on the shaft and they feel firm. He thinks the rear shaft is out of balance (e.g., weight fell off). When I greased the shaft, is it possible that I put it out of balance (eg too much grease, unbalanced amount of grease in the different zirks?)

I now wonder if I'm chasing two or three problems.

My sense is that I still need to tear into the front end on the weekend and see what's happening.

Any other thoughts or comments? Thanks

Cheers, Hugh

 

[Bob_Garrett]

I've driven my 80 with an unbalanced rear drive shaft (damaged it on the trail) and the vibration did not appear around the dash at all. Felt more like an out of balance rear tire, but with a mch faster rate of vibration.

Do you have a center diff lock switch? If so, you can lock it, remove the rear shaft and see if the problem goes away.

Bob

 

[alia176]

would it help to disconnect both driveshafts (one at a time) and isolating the problem further? You could totally isolate the CVs by removing the drive flanges, remove the front ds and drive it rear 2wd (CDL engaged)? I assume this can be done for a short period w/o any repurcussions?

 

[mabrodis]

I think you're chasing a few things here. The vibes could very easily be tires, some wear wierd, mine did this not long ago, I had a shake in the steering wheel quite bad at about 40-45mph, but above that it was totally gone. I rotated the tires and everything was happy again (rear felt a bit bouncy at times, but even that stopped this past weekend with lots of driving to wear the tires correct again).

So the tires and probably more specifically the balancing of the tires. I would rotate them if you can, see if that changes something/everything/nothing.

The grinding noise is something else I expect, don't know exactly what but Ali's idea makes sense, if you have a center diff lock switch, pull the front driveshaft and the drive plates, so front axle/diff is not turning at all, then drive around, problem still there? Then it's probably front wheel bearing related.

Make sure your knuckle studs are tight (2 top and 4 bottom), those can come loose over time and make the vehicle go all over and do wierd things since it gives the knuckle room to play, which is bad.

I do not think your driveshaft has any part in this at all, from my experience you can't overgrease your u-joints, you might be able to on the slip-joint but that won't cause what you're finding.

Good Luck,
Mark Brodis

 

[CDN_Cruiser]

Thanks guys, I'll add that to my list. I think that I'll drop the rear shaft first and see what happens and then go from there. BIG shipment coming in from CDan - with the ability to do front end, drive shaft, brakes...and radio antenna!

Cheers, Hugh

PS - Start to email me your home numbers so I have someone to call!

 

[CDN_Cruiser]

Quick update

The good news is that I've tracked down the vibration. The bad news is that I think I need a new front shaft

After rebuilding the front end, I also pulled the rear shaft - still a strong vibration. I pulled the front shaft today and noticed that the clip that holds the spider in place was poking out. As I started to clean the shaft I noticed that there appears to be a chip (size of the top of a thumbnail) out of part of the flange where the spider is seated.

I'm assuming that the flanges aren't a seperate part?

I guess I'll check the new prices and see if someone has a used shaft.

I noticed the vibration a few weeks after greasing the shaft - so I'm not sure what happened, but feel like this may have something to do with it. Then it's a bit of 'chicken and egg' - not sure if I had chipped it somehow or the part broke and then chipped - more likely.

I'm just happy that the shaft didn't blow up. The PO of my 60 had the front shaft fail and it took out the front diff, the shaft and a lot of other stuff in the process.

Cheers, Hugh