Uh-oh !! What's making a grinding noise ! (1 Viewer)

[XR-boy]

This doesn't fill me with confidence a couple of weeks before we head of to NSW to do some wheelin' over Xmas........ -----I had my new Tough Dog springs and 45mm adjustable shocks fitted last week, mmm, me very happy. Lift at the front =95mm, at the rear 145mm. Now mind you, that's from a very shagged 10 year old OEM suspension, so the actual lift of approx. 4" at the front and 6" at the rear is about 3" over stock as it was so sagged to begin with. So it's not too radical, just set up nice for my every day driver. We also did swaybar drops and castor bushes as I already had these so it was easier to do it while the car was up on the hoist. -----We put a longer brake hose on the rear as the stock brake line was JUST starting to pull under full droop, didn't need to do the front as even at full shock extension, there's quite a bit of hose flex available. -----So I drove it home from Opposite Lock Preston, about 50 kays, all is well. -----I backed the shocks off as the ride was a bit jiggly in an empty car, and have now got a nice ride with lots of scope to stiffen it up once the kids and camping gear plus trailer get loaded on. -----However, the next day I get this 'grinding' noise from somewhere up the front end, only noticable or able to to happen at about above over 50kph. It only happens in throttle transition from coasting to JUST, and I mean JUST on the power, or, when lifting the foot off the accelerator and transitioning to COAST. It's that 1mm of accelerator load when you just go on or off the throttle that I can hear and sort of feel a high speed grinding noise.... -----I don't even know if it's related to the suspension package, but it started with 24 hours of it being fitted. The only thing that would have changed is my driveline angles, so I got under and gave the front shaft a good shake and twist. No slop in any of the uni-joints and no backlash between the diff and transfer, well bugger all anyway. Certainly the least I've EVER felt in a 4wd. I greased up all the slip joints and unis anyway, nup, no difference. Changed out front diff, gearbox and transfer oils, nup, no difference. I grabbed the shaft at the slip joint and shook it back and forth in case there was slop in the spline that might show under a light or no load condition, nup, nothing. All tight as a drum under there. There's probably 4mm of spline showing outside the tube, now with fresh grease showing, and my original 'dirt' mark is about 10 to 15mm further out than it was, so it's not like the shaft is about to fall out due to lack of spline engagement. -----I had an FJ40 that used to rattle the uni-joints in the front shaft against the front bash plate at full droop when going up steep hills, that created a hell of a din !!! This is nothing like that, but the speed of the noise is the same, a very fast sounding grind, but not overly loud. It almost feels like crownwheel and pinion meshing, but the diff is tight and quiet at every other time, and the suspension fitment would have nothing to do with that either- coincidence ????????????? -----As it seems to be coming from the front, I suppose my next option is to pull the front shaft and drive with CDL engaged to see what happens. If the noise goes away though I haven't really narrowed it to anything though as the noise only happens with the tiniest of loads, which naturally enough I can't duplicate with the front shaft out !!! -----Any ideas out there team ??? -----Cheers,

 

[Brian894X4]

I would still lean towards the U-joints. Not that the joints or splines are bad, but the driveline is out of phase, assuming it's U-joints at both ends and no CV joints. If it's out of phase, it will make noise, sometimes only even at certain speeds or under certain loads.

You're lift might be more than the castor bushings can correct for and this might be affecting the driveline angles.

On my SAS Toyota mini-truck, a modified CV joint added to the T-case end of the driveline allowed for some pretty extreme angles even at speed, with little to no noise, so that might be your ultimate solution.

I noticed that Slee Off Road sells double cardan front drivelines for their 4 and 6" kits, so the front driveline is definately an issue over 2.5 inches and it sounds like your lift is 3" or maybe even higher.

If you guys got a good driveline shop, you might be able to steal a CV joint off of a Hilux driveline and make it work on your stock 80 front shaft. You still got a good month to go.

Good luck.

 

[XR-boy]

The shaft is undisturbed from when Toyota fitted it waay back in '95, so it won't have gone out of phase on it's own, that's what's got me tossed..... My lift is so minor (just under 4" from sagged stockers) that visually the joints don't seem to go through a big angle to me, but you could be right.I don't get much vibration, just noise, and I'd always thought vibration would be the first thing manifested by excessive u-joint angles. If I have to fit a modified shaft, I will, but I'd hate to do it and find that pesky grind noise still there !!!!!

 

[XR-boy]

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[XR-boy]

Double post

 

[96r50]

Changing your truck's ride height by 4-6 inches could bring out vibes in a 12-year-old driveshaft. It's been sitting comfortably at stock height for 12 years where the u-joints have only been working at a small angle. Now with the lift they have to work at a bigger angle where they may never have been before, thereby causing the noise/vibe. Try greasing them a lot and see if the noise changes. Sorry I can't explain this better, hopefully someone else will chime in. Try searching as well, there are a bunch of threads here about lift-induced vibrations and noises.

 

[XR-boy]

I greased 'em up to where you could here the seals 'crack', but I'll pop under again tomorrow morning and squeeze in a bit more. Who knows, they might 'wear in' to the new agles if that's all it is. There is absolutely no play or slop anywhere in the shaft, which means I don't have a smoking gun to aim my silver bullet at !!!!

 

[96r50]

I don't think the u-joints need to have play in them to cause the problem. It's kind of like a door hinge. Say you have a door that you only ever open and close 45 degrees, and for 12 years that's as far as it ever moves (your u-joints, stock height). Then you come along and start opening the door out to 90 degrees (your u-joints, lifted). The door (or your u-joints) are going to be awfully unhappy about this sudden new range of motion. The door hinges would probably squeak or bind, u-joints tend to protest by causing a vibration.

I'm not saying that this is a definite cause of your vibration, but it's worth a shot. 12 years is a pretty good life span on a 5000lb truck, so they might be a candidate for replacement.

 

[knorrena]

I agree with 96r50: Sounds like the cry of worn ujoints to me. With your new lift the ujoints are operating over a larger range of degrees and using more of the race - a part of the race that has never been used before. As well

 

[Beowulf]

Sounds like the classic vibes indicating you need a dual cardan front DS.
-B-

 

[mtkreitz]

I have EXACTLY the same problem with my 96 LX450 with only a 3" OME lift. I am running Man-a-Fre's drop bracket for caster correction but experience the same noise you do. It is only when I lift my foot off the gas at over 50-60 MPH and will go away as soon as I re-apply the gas. I have replaced my U-Joints (which were not bad) and the problem still persists. I really do not think the noise is from the driveshafts and am not willing to spend $700 for DC shafts to find out. I am kicking around the idea of making some primitive "chassis ears" to find the actual source of the noise. Mine came on right after the lift and bothers the crap out of me. There is a good Toyota shop in Mesa, AZ and I am going to talk to them next week about it as well. Please let me know if you figure it out before I do. There are a lot of us having the same problem...

 

[landtank]

using bushings to correct for caster will not alter the axle's position enough to use a DC shaft. However between the lift and the bushings you have altered the operating angles enough to warrant new u-joints. This however only addresses the vib problem and doesn't mean that the suspension is setup right to begin with.

Measure the distance from the hub's center to the bottom of the wheel flare. if it is at or just above 58.5cm then you should go with plates and a DC shaft to properly correct for caster and get rid of the vibs.

 

[XR-boy]

I'm fitting new OEM uni joints next week and converting to part time as well. I reckon I could run all day with the hubs locked in on bitumen (not in 4wd naturally) and not replicate the problem as there's no drive to the shaft in part time. If it spins due the the hubs turning it, no biggie, I won't get the noise as it's only when backing off POWER I get the grind.Anyway, I won't have the hubs in for 95% of the time so I shouldn't get the noise. And on the trail it's very rare that I'd have the hubs in and be in 4WD and be even doing 50kph in the first place to be backing off the power. There might even be enough wind up with no centre diff that I never hear the noise again anyway.Fingers crossed this does the job. I'll do a measurement from the hub centre to the flare anyway- mtkreitz, can you do this as well to see if our set-ups are similar ?I wonder if my noise is getting less this week too. Either I'm getting used to it, driving to avoid it, or the joints are getting used to the new operating range. Could be wishful thinking, but I'm still going part time anyway and the new unis.

 

[XR-boy]

I measure in at about 61.5cm from hub cap centre to lower edge of flare.My lower front uni doesn't seem to be doing a lot of work as it's pointing pretty much at the transfer case. The output on the t/case uni looks like it's got all the angularity.....I'm still going part time next week as it's cheaper than a d/c joint.....

 

[rsmith19]

I had a similar problem after install of OME kit and found that the front sway bar was rubbing against the front drive shaft. Not visible with the truck on the rack but found some groving on the drive shaft.
Used the Slee blocks and problem solved...noise was very bad and eventually caused vibration.

 

[XR-boy]

I dropped my swaybar(s) about 70mm using a locally available kit at the same time as the lift to make sure my DS didin't hit the bar. That said, I pulled the front shaft yesterday and found the diff uni is lumpy in one plane of operation, so this could be 1/2 the problem.Boy, talk about smooth driving with the CDL locked and no front shaft. No vibration, more positive steering, easier gearshifts (how ?) and no dash frizzes.Part time kit and new uni's going in tomorrow. If this fixes it, I'm happy !! I'll post up some pics soon.

 

[GXO]

sounds like DC shaft is in order.

 

[rtony1357]

PLEASE! Have you fixed the problem?

 

[Type-Zero]

My Landy friends had this and it was diff bearing related. FWIW.