| Author | Message | ||
     Hendrik Behrmann (Hendrik) New Member Username: Hendrik Post Number: 1 Registered: 09-2003 |
Hi there, ages ago there was a discussion regarding drivline vibrations of Range Rovers. I think someone even replaced the complete front axle assembly without success. I�d like to share my experience with those who want to ;) If you do not want to read that lot, just go to the end .. When I bought my Range Rover I couldn�t dare to overtake trucks on the highway with 150kg weight in the back � due to the car rolling. I then immediately replaced ALL suspension bushes with Polybushes (from Bearmach � they are junk, should have taken Polybush� but couldn�t get them). I was quite happy for a while but had trouble with vibration at speeds above 75mp/h. That became better between 75 and 80mp/h, driving faster made the car shake like mad. The vibration sometimes (better roads?) were less, but not reproducible. I thought rotating the tires (crossover) made things better, but not for long. I considered the usual things: tire balancing (fairly new tires), steering adjusted, tires rotated, front driveshaft replaced by a DiscoII-type. Steering damper upgraded with Bilstein. All suspension bolt were tight because recently tightened (to more than the specified torque, by �hand�). The axles had been replaced by Discovery items that I had overhauled and fitted same time with the bushes. They came from a crashed Disco. Too, the Borg-Warner transfer gearbox was meanwhile replaced with a LT230. Spings are Rover HD�s (moved the rear springs to the front). Many changes � no way to tell, where to focus on. And some things as you see were replaced by trial and just on suspicion or because it made sense to do so with or without vibration. What almost completely eliminated the vibrations recently was to replace all (BTW I still have to do the panhard rod) suspension bushes again � with Rover OEM ones (The Polybush� might have served just as good, but Polybushes happen to be in disfavour with me since. Rubber vs. OEM has been discussed before. I feel that usually a worn OEM suspension is compared with a then new Polybush suspension and that is part of the good Polybush-reputation. Who replaces a new OEM suspension with them!?. ). I have to admit that one of the two bolts that hold the front axle to the radius arm on each side was a bit loose, was no surprise � a small cracking noise could been heard when breaking for a while. The polybushes had covered 25000 miles. Just try to slacken to big nut on the chassis end on the rear radius arm and rock the Range at the trailer hitch left-right. That allows a lot more movement. I started with the rear axle � this was noticeable, but not too much. The front axle made the difference, lot less nose-diving when braking and sweet cruising at the aforementioned highway speeds now. And this is without new bushes on the Panhard rod � I expect another very noticeable improvement from that. Should make the steering even �tighter� and stop the last vibration the remains at speeds above 95mp/h. In a nutshell: a) I cannot believe after this experience, that other �improvements� like hinged radius arms and some makes of polybushes do anything good to the driving characteristics. b) Sometime one does overlook the obvious, simple things. c) Not in all cases aftermarket improves things, regardless of what adverts say. d) Not sure this cures all the vibrations ;) Something else: Oil loss of hydraulic fluid from the PAS-system can be due to all the well known seals etc. AND the cover of the reservoir. This has a tiny rubber seal that (though I can�t see any rupture) seems to allow oil passing when old. I had a very slow leak and took me quite some time to trace. Regards, Hendrik | ||
| Randall Smith (Mr_smith) Member Username: Mr_smith Post Number: 74 Registered: 04-2003 |
Hendrik First of all let me say that your english is very good. That was probably me who you are refering to.(based on clues in your post). One year ago I posted many times about the hidious vibration which was ruining my truck. No one on this earth could pinpoint my problem. I spent more money on parts last year than the truck is worth, all for the goal of eliminating that vibration. Six months into it and after having replaced every part on the truck that could even remotely been blamed...I realized that replacing parts was never going to end my driveshaft vibration. I have come to the following conclusions: Due to the way the front drivetrain is designed, driveshaft vibration is inherent. LR uses about 5 different "tricks" to eliminate front driveshaft vibration. Mess around with any of these tricks and sooner or later you get front DS vibes. Also the front DS off the D2 is much better balanced than any after market DS. And correctly setting up a superbly balanced D2 DCDS is key to eliminating DS vibration. I also concur that bad bushings can cause vibration. Try lossening one of your panhard rod mounting bolts just a little bit and see what happens. The whole front axle assembly will shake, even at low speed. Every time you try to "improve" on what LR gave us, you're taking a risk, and introducing a new variable. But that's what I do. Engineer new stuff and take risks. Randall | ||
| Hendrik Behrmann (Hendrik) New Member Username: Hendrik Post Number: 2 Registered: 09-2003 |
Very true, what you say. If I were intersted in troublefree (?boring?) motoring I would drive a car of the type all my friends and relatives around do - a common family sedan (that�s how you call it ?.. probably would be a Volkswagen). Working on my Range Rover (or the 88" I had before) is somehow "essential" for me ;) It seems to be more fun to modify the truck rather than to do the maintenance. That�s what I had to blame ME (and I only mean me) for !!! I even got larger tires (will put them on soon) because I thought they would be more forgiving, maybe due to their lower rpm�s per mile and thus produce less vibration. I wanted them anyway. BUT I had neglected the maintenance and consequently my truck punished me with vibrations  Still, every Rover is an individual. I hope you pardon me for using your "tale of woe" (�you say so ?) as an example of how difficult it can be to adress vibrations in our trucks. I think in cases like this (appears very regularly on the BB) every hint you can get is of benefit. That�s why I posted. BTW: has the DC-driveshaft solved the problem for you ? BTW: if I manage, I would like to post some pics of the Polybushes I removed from the Panhard rod. regards, Hendrik | ||
| Geoff 93 RRC (Geoff) Member Username: Geoff Post Number: 97 Registered: 11-2002 |
I have poly's and have been happy so far (about 20K miles). I have found that the radius arm bolts have to very tight or I get more vibration when hitting bumps. I think this is true of the rubber bushings as well. I get some vibration at 75 mph +, but I am almost sure that it's from the driveshaft as it has a rythmic feel to it. Also, watch your tire pressures. I found that when rotating the tires the shop did not adjust the pressure. The rears have to be higher than the front or the handling is downright dangerous at speed. | ||
| Randall Smith (Mr_smith) Member Username: Mr_smith Post Number: 75 Registered: 04-2003 |
Changing to the 4.10 gears was a big part of my vibe problem, as this increased the DS speed by 16%. Also suspect that the new front gears are the actual origin of my vibe, and that the DS angles just amplifies it. There is no practical way to test this because the diff units that I swaped have the same gears. (The vibe problem started the day I change gear ratios.) Puting a Tom Woods DC DS helped a lot, but really did not end the problem. And I had the DS balanced 3 times with no improvement. The DiscoII DS is much better balanced, and it is obvious when you look at the weights on it verses the yahoo brands. Adjusting the pinion angles to point the DC DS straight at the TC made a big improvement. Note that there is more than one angle per u-joint. I am not finished adjusting angles. I also got a remanufactured BWTC witch helped a lot(and eliminated 90% of my driveline "klunking"). I lowered the chassis about 1/2" too. Everybody should retorque all the bolts on their suspension once a year. You might be suprised what gets loose under there, and it costs you nothing. Randall | ||
| Hendrik Behrmann (Hendrik) New Member Username: Hendrik Post Number: 3 Registered: 09-2003 |
Hi there, here�s the pic of the polybush I removed from my track rod. You can see the damaged the chassis mounted arm caused (ok - there are a few cuts that might have been from pushing the panhard rod & bush into the arm); probably this allows more movement than one could desire. I think this is a general problem of polybushes in this particular application because the mounting arm does not cover the entire polybush and does not give it enough support. The arm is designed to hold a sleeve/tube. No such problem on the axle side of the panhard rod. You might have noticed the make is IronMan. But, as said, I humbly returned to OEM�s and I�m not looking back. Hendrik  | ||
| Randall Smith (Mr_smith) Member Username: Mr_smith Post Number: 82 Registered: 04-2003 |
The chassis connection point of the panhard rod recieves many times more wear than the axle end. The axle end is almost stationary. The chassis end is all over the place. Just getting into a Range Rover causes the chassis end to move. And also as I mentioned somewhere above: Just the slightest amount of looseness in the panhard/chassis mount point can cause strange vibrations and the shakes when you hit a bump in the road. Randall |
