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| 4x4abc Date registered: Apr 2006 Location: La Paz, Baja California, Mexico Vehicle(s): 02 G500  | RE: Wobble at 50MPH+ when it's cold. Seen it before, fixed it all, nothing works. I found over time that quality tires are a significant factor (BFG, Michelin etc) fro any front end shaking not painstakingly cleaning the surfaces of wheel and hub after taking a wheel off can cause severe imbalances there is even an MB service bulletin out about this to understand shaking and wobble better: main cause for death wobble is an improper caster angle usually not the cause of stock G aside from off caster wobble/shaking start with something that is out of balance or something that creates harmonics (bad tires, out of balance tires, out of round tires, bent axle, bent drive shaft, warped disks) any lose/worn connection will amplify the movement (wheel bearings, bushings etc) the steering dampener is an instrument to reduce slight, naturally occurring imbalances it is not designed to cure wobble/shaking - it will only mask them | ||
| #224853 - in reply to #224851 |
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| Floobydust Veteran Date registered: Mar 2014 Location: Massachusetts, USA Vehicle(s): 1995 E320 Cabrio, 2003 G500, 2000 SL500, 1980 TR8 Posts: 284  | RE: Wobble at 50MPH+ when it's cold. Seen it before, fixed it all, nothing works. Changes is caster angle will cause death wobble even with perfect tires on almost any solid axle car. This is even more so with a radius arm design like the G because suspension travel causes the caster angle to change as well. The longer the radius arm, the less change there is, but it is still there. The radius arm to axle bushings on the G are particularly important because the attachment design not only allows the axle to move fore and aft, and up and down (bumps), but also allows it to rotate as well as the bushings flex and axle rotation will change the caster. And it doesn't take much flexing to create a significant change. The bushings are positioned about 4 inches (apologies to metric readers) from the center line of the axle which means that a deflection/compression of 1/16 of an inch will change the caster by 1 degree. Compressing the bushings by 5/16" will reduce the caster to zero. This is not a lot when you consider that the bushings are 2.5" in diameter (14% compression). I can move the metal sleeve in the old bushings by nearly that much with a screwdriver! This is why I think these bushings are so important to look after. | ||
| #224854 - in reply to #224813 |
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| chris505 Date registered: May 2007 Location: San Francisco Vehicle(s): '79 280E/'80 280GE/'00 G500  | RE: Wobble at 50MPH+ when it's cold. Seen it before, fixed it all, nothing works. My 280GE beater (with a bent frame) can be an extreme example of severe looseness in all suspension components: Tie rod ends were trashed (their boots fell apart 20 years ago, bone dry and rusty with TONS of play). Radius arms bushings are all essentially metal on metal (rubber quickly cracks/separates from steel sleeves under heavy offroad use/flex, they now allow so much movement Im sure my wheel base constantly shrinks and grows as I drive, pinion angle changes too, which I can feel through t case lever as small load dependent vibration). No steering shock attached. 37/12.50-15 Goodyear MTR on 15x8 ET11 wheels are obviously well balanced, and as a result I enjoy a very smooth ride, even at 90MPH. If the tires spin true and smooth, no amount of suspension/steering component wear will cause DW in my experience. DW when cold that disappears when the tires heat up reminds me of those old bias-ply Interco Super Swamper tires that were notorious for "flat spotting". My brother recently purchased a set of yokohamas and they seem to flat spot when cold. Highest quality tires (Michelin/BFG) should never flat spot. I think a great (and simple) test of tire balance/imbalance is to drive with no steering shock, Im extra curious to see how Flobbydust's G behaves with no steering shock. Edited by chris505 11/1/2014 2:58 PM | ||
| #224855 - in reply to #224813 |
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| Gurukid Member Date registered: Jul 2013 Location: Sarasota, Florida Vehicle(s): 2003 G500 Posts: 21 | Re: Wobble at 50MPH+ when it's cold. Seen it before, fixed it all, nothing works. Hey guys, do you have a part number for the front trailing arm bushings, I'm only able to find it for the rear? Also, I have a brand new transverse bar, I'm assuming the bushing would have been replaced at the same time? I went to the specialty tire shop today, they closed early on me. I guess I'll have to wait until Monday for a rebalance. Looking to order all new bushings for the car this weekend. Thanks, Alex | ||
| #224856 - in reply to #224813 |
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| Floobydust Veteran Date registered: Mar 2014 Location: Massachusetts, USA Vehicle(s): 1995 E320 Cabrio, 2003 G500, 2000 SL500, 1980 TR8 Posts: 284 | Re: Wobble at 50MPH+ when it's cold. Seen it before, fixed it all, nothing works. The radius arm to chassis bushing is 4603520465 (X4 for the front) and the front axle to radius arm bushing is 4603330314 (X4). | ||
| #224857 - in reply to #224856 |
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| DUTCH Administrator Doppelgänger Date registered: Apr 2006 Location: US, GA, Atlanta Vehicle(s): 2015 Audi Q7 3.0 TDI,2018 Sprinter Posts: 9963 | Re: Wobble at 50MPH+ when it's cold. Seen it before, fixed it all, nothing works. Gurukid - 11/1/2014 4:14 PM Hey guys, do you have a part number for the front trailing arm bushings, I'm only able to find it for the rear? Also, I have a brand new transverse bar, I'm assuming the bushing would have been replaced at the same time? I went to the specialty tire shop today, they closed early on me. I guess I'll have to wait until Monday for a rebalance. Looking to order all new bushings for the car this weekend. Thanks, Alex It was posted in the message above. http://pointedthree.com/disc/forums/showthread.php?tid=21965&mid=22... | ||
| #224858 - in reply to #224856 |
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| petermerle Expert Date registered: Apr 2006 Location: Cape Town ( deep south ) Vehicle(s): W460 *1, W123 *2, W124 Posts: 1315  | RE: Wobble at 50MPH+ when it's cold. Seen it before, fixed it all, nothing works. 4x4abc - 11/1/2014 7:12 PM spider gears in the differential usually have quite a bit of play as long as the pinion to ring gear is within spec (if it feels tight, it's good) you are good to go
Spider gear play and pinion-ring gear play are two independent variables - not related at all. Spider ring play is primarily determined by the shims in the differential gear housing - play amount is not specified but preload torque is
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| #224892 - in reply to #224849 |
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| Gurukid Member Date registered: Jul 2013 Location: Sarasota, Florida Vehicle(s): 2003 G500 Posts: 21 | Re: Wobble at 50MPH+ when it's cold. Seen it before, fixed it all, nothing works. Roadforce balance solved the problem...... Un-real, tires were already balanced 3 times at other shops... Stick with your indy, that's all I gotta say. I went to three "mercedes specialists" to have that stuff done, wasted a ton of money. | ||
| #224904 - in reply to #224813 |
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| 4x4abc Date registered: Apr 2006 Location: La Paz, Baja California, Mexico Vehicle(s): 02 G500 | Re: Wobble at 50MPH+ when it's cold. Seen it before, fixed it all, nothing works. out of curiosity - what brand/kind of tires are you using? (sorry if it's buried in the posts somewhere) | ||
| #224905 - in reply to #224904 |
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| Floobydust Veteran Date registered: Mar 2014 Location: Massachusetts, USA Vehicle(s): 1995 E320 Cabrio, 2003 G500, 2000 SL500, 1980 TR8 Posts: 284 | Re: Wobble at 50MPH+ when it's cold. Seen it before, fixed it all, nothing works. I'm glad you got it resolved! At someone is making progress. | ||
| #224907 - in reply to #224904 |
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| Rich Regular Date registered: May 2006 Location: Elkins Park, PA USA Vehicle(s): 1985 280GE cabrio Posts: 75  | Re: Wobble at 50MPH+ when it's cold. Seen it before, fixed it all, nothing works. Gurukid - 11/4/2014 4:51 PM ... Stick with your indy, that's all I gotta say. +1 | ||
| #224909 - in reply to #224904 |
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| Gurukid Member Date registered: Jul 2013 Location: Sarasota, Florida Vehicle(s): 2003 G500 Posts: 21 | Re: Wobble at 50MPH+ when it's cold. Seen it before, fixed it all, nothing works. Hey guys, Sorry for the late response, I wanted to wait a week or so to see if the problem was fixed. Anyways, I got a roadforce balance, all was well, EXCEPT, it was warm that day, so I got excited and assumed the problem was fixed. I just purchased another set of tires 285/35/24 for the G and it still wobbles. On the stock 18" wheels, it wobbles as well, even with new tires as per benz spec. I'm lost now. The only thing I haven't changed were the bushings. @4x4abc I noticed at benzworld (or one of the other forums) you had mentioned you were looking for poly bushings as the damper did not fix the problem. Did the bushings work? If the bushings do not work for me, I will proceed to change the wheel hubs. Also, what damage could the wobble have caused? I ask because, I'm convinced the previous owner drove with the wobble, the shop I took the vehicle to in Atlanta told me they were familiar with the previous owner and that there was a wobble prior to me owning it. I bought new tires and all was well for a year or so, now it wobbles again. @Dutch Aren't you located in the Atlanta area? Are you familiar with the 463 models? Perhaps I can visit you and get some real life advice, we can inspect the car, willing to provide compensation for your time. Thanks, Alex | ||
| #225570 - in reply to #224813 |
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| DUTCH Administrator Doppelgänger Date registered: Apr 2006 Location: US, GA, Atlanta Vehicle(s): 2015 Audi Q7 3.0 TDI,2018 Sprinter Posts: 9963 | Re: Wobble at 50MPH+ when it's cold. Seen it before, fixed it all, nothing works. Gurukid - 12/5/2014 3:17 AM @Dutch Aren't you located in the Atlanta area? Are you familiar with the 463 models? Perhaps I can visit you and get some real life advice, we can inspect the car, willing to provide compensation for your time. Thanks, Alex Alex, If you're in Atlanta, feel free to stop by. I'm in Gwinnett County, a NE Atlanta suburb. No charge for a chat and a look see. I'd love to help, if I can. I just sent you a PM. | ||
| #225571 - in reply to #225570 |
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| Titus Pullo Elite Veteran Date registered: May 2007 Location: Ottawa, ON, Canada Vehicle(s): '90 Wolf 240GD, '06 G270 CDI. Posts: 1010 | Re: Wobble at 50MPH+ when it's cold. Seen it before, fixed it all, nothing works. I had one of my customer that reported problem solved after he changed to my bushings. Just saying. | ||
| #225572 - in reply to #224813 |
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| Floobydust Veteran Date registered: Mar 2014 Location: Massachusetts, USA Vehicle(s): 1995 E320 Cabrio, 2003 G500, 2000 SL500, 1980 TR8 Posts: 284 | RE: Wobble at 50MPH+ when it's cold. Seen it before, fixed it all, nothing works. As most know on this board, I have been vibration chasing on my G for some time now. The vibration was/is definitely a two part affair - one component was a suspension that couldn't keep the tires under control in that there were loose tie rod joints, a worn steering damper, and most importantly, worn suspension bushings. I replaced them all in a serial fashion, and to my great surprise, the single biggest improvement came from replacing the front panhard rod bushings. Yes, those two small bushings, in spite of the time and money spent on the others, totally transformed the driving feel of the truck! The old ones didn't even appear to be worn, but the difference after replacement was amazing. They are easy and cheap to replace - maybe it would help. The other half of the vibration problem, drive train rumble at 59-60 MPH, is still there, but it has nothing what so ever to do with the tires and suspension - there is absolutely no steering wobble or vibration in the steering wheel. Just the low rumble of too much play in a drive train component somewhere. The search continues for this. . . . | ||
| #225593 - in reply to #224813 |
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| Toronto230ge Extreme Veteran Date registered: May 2006 Location: Toronto Vehicle(s): 2002 VW van 1987 230GE, 2002 G500 1965 porsche 911 Posts: 492 | RE: Wobble at 50MPH+ when it's cold. Seen it before, fixed it all, nothing works. This may be obvious , but I have had 6 broken springs in both my 460 and 463, Its isn not always easy to tell if they are broken, The break is usually in the first spool. | ||
| #225597 - in reply to #224813 |
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| Titus Pullo Elite Veteran Date registered: May 2007 Location: Ottawa, ON, Canada Vehicle(s): '90 Wolf 240GD, '06 G270 CDI. Posts: 1010 | RE: Wobble at 50MPH+ when it's cold. Seen it before, fixed it all, nothing works. Floobydust - 12/5/2014 10:53 PM and to my great surprise, the single biggest improvement came from replacing the front panhard rod bushings. Yes, those two small bushings, in spite of the time and money spent on the others, totally transformed the driving feel of the truck!. I kept repeating this year after year on all different forums... people think I am crazy and don't know shit about. | ||
| #225599 - in reply to #225593 |
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| 512bbi Expert Date registered: Jan 2007 Location: North western US and Europe Vehicle(s): 05G55kge,Range rover classic,clk55amg,ML 430 Posts: 1313 | RE: Wobble at 50MPH+ when it's cold. Seen it before, fixed it all, nothing works. 03-Gwagen - 11/1/2014 8:13 AM 512bbi - 11/1/2014 9:45 AM TIRES DONE RIGHT FIRST and then steering shock and bushings. Ditto. What tire size are you running? Is it changed from original? In other words.... what is the wheel size? What tire make/model are you using? I am running 285-65-18s on my stock amg rims The trailling arm to chassis stock bushings are fairly soft and designed to compress a lot even when new. I took brand new ones many years ago and I measured their elasticity, not how soft or hard they are ....and found out after they compress and change shape they take a long time to regain their shape as new ones.....in other words their elasticity is very low and worse when cold. I have removed used ones that looked very sorry with out being broke and after seating on the self for a few days they regained the same shape as new. If you freeze them their elasticity is even a lot worse,which means as they change shape becoming compressed and take a set after you park your G they take a while to regain shape if given the space by the trailling arm as it moves allowing them to constantly be under some compression to a certain shape and then to another dimension that they take the time to regain the shape they can achieve . I had a G parts guy tell me many years ago if he leaves his G parked for a long time he puts it on blocks to avoid the wobble he gets from being parked too long. When installed properly even if you torque the bolts to spec or to the end of the threads you will have the same result.....that space available that they operate with in is specific but it gets smaller as the truck gets driven and the suspension flexes or gets effected by different travel speeds etc from turning or going straight,towing or whatever ways you operated the truck at various moments and the space allowed goes from specific so large, to very little because it changes all the time when the vehicle is operated. All this makes the bushings compress a LOT and then they hold that shape for a while.the length of time that it takes for them to regain shape or swell back up towards original shape depends on how new they are. If one could use bushings that are soft with high elasticity they will have much less wobble ,or if they let them get old and go to pieces then the axle will operate so loose you might have no wobble. Every time there a little play the tire out of round ,balance or road force that is not perfect will create the oscillation on the front axle that in essence is the axle changing direction facing left and right at the frequency and amount that is allowed by the bushings being compressed allowing movement which results in a constant change of axle steering effect left to right.......the total toe stays the same automatically compensating to the axle change in direction as fast as the axle moves left and right. When the axle faces left for a split second the total toe stays the same at zero and the caster effect makes the steering to react and go the opposite direction and then the next split second axle goes the other way and the steering follows through correction and there is the wobble Take of your steering shock and the wobble can get down right scary with really bad tires and bushings and at lower speeds than 60 ....just accelerate hard prior to testing with out a shock to increase the space available at the trailling arm and chassis connection through further compression of the bushings ,with in the available space they operate in. The reason the wobble happens more at around 60mph is because below that speed most tires do not put enough force towards the creation of the wobble and the stock steering shock works more at that speed..... above 70mph the force of compressing the bushings becomes higher together with higher caster effect and the wobble gets to either go away or produce a very tiny movement on the steering left to right or none as the axle now changes direction much faster and with much more force against the already compressed bushings from the higher speed which allow less movement in available space at the arm to chassis connection At higher speed the front end gets taller also in height because the resistance from the tires and force against the axle from the trailling arms increases and this gets the trailling arms to operate at a higher angle which compresses the bushings even more so less or no wobble If you go of road you will exercise and force the bushings to change shape more often than the street and that is why the wobble will decrease or be gone after you go back on pavement from of road for a while. On a long trip on pavement also they wobble might go away for the same reason as the space for the bushings to swell back in shape stays more constant so they pick up the available space easier with heat generated and some help from the elements . Poly that is as soft as stock with higher elasticity than stock might solve this problem with the G but maybe not in freezing weather where poly looses elasticity when cold and even brake.... Another detail that contributes to the problem is the axles are all made to not sit square on the G and the front one is facing left and the rear to the right. That makes left wheel base shorter and right wheel base longer and that is what makes the G leaning to the right as the position of the tralling arms effects the position of the axle. With identical springs the front left corner is taller than the right front, which causes the front left trailling arm to operate at a steeper angle and make the front axle face of center to the left ......thrust angles front to rear on a G are that way, and it must have a reason which I never figured out yet..... The have a name for it with Unimogs and I forget what it is called and what it does! Mario | ||
| #225648 - in reply to #224838 |
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| 512bbi Expert Date registered: Jan 2007 Location: North western US and Europe Vehicle(s): 05G55kge,Range rover classic,clk55amg,ML 430 Posts: 1313 | RE: Wobble at 50MPH+ when it's cold. Seen it before, fixed it all, nothing works. 4x4abc - 11/1/2014 8:47 AM 512bbi - 11/1/2014 7:55 AM The G is build to have play at the axles to protect it self from its best feature ....the lockers. Mario what is play at the axles? The trailling arm to the axle connection at each corner can flex by the two bushings compressing so much that if you could push one corner (say front left) as far as it will go towards the chassis and extend the other (front right) all the way out ,it will equal your steering making almost three quarters of a complete turn while you maintain the same direction as far as steering goes. Now that is some serious flex of the axle being able to move back toward the chassis or change direction that has a profound steering effect! I wonder if it was made that way on purpose to protect the lockers from damage in the following exercise I have been in many times. I come to a point on a rough trail with a very steep section that I can go up very slowly and safely but I can only go up in this fashion if all the lockers are engaged including the front one. As I top the spot I am back on flat surface made out of rock with very high traction and at that point I have to turn sharply to stay on the trail and stay away from a cliff on one side. As I hit the button to release all the lockers as soon as I am on all four tires touching the ground right after I have topped out the tough spot, and with out the lockers needed any more the lockers stay in for a few yards even-though I have hit the button to disangage and I got no choice but to make the turn.....now the high traction available and the vehicle having to recieve enough steering lock to turn while the lockers are still in is with out a choice ...... so the axle compresses very hard against the tralling arms and compresses the heck out of all available travel at the tralling arm to chassis connection. What do you think? How much does that available flex protect the gears from too much strain for a short time? I wish I could have the lockers in or out in zero time or distance traveled after stopping to engage or dissangage If those bushings and connection to the chassis was solid with no flex and that situation would equal turning with half or more steering lock available on locked lockers on pavement.....how good would that be on those components in the diffs and axle internals? Mario | ||
| #225649 - in reply to #224840 |
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