|
Philippe, It's possible that one of the shafts is unbalanced. I know you're in France, but over here in Dallas, TX there are all kinds of places to go to get prop shafts balanced. Perhaps you have at least one around.... I know this because I own a Jeep. If you have 4-wheel drive clubs over there, they are using vehicles that constantly have to have prop shafts "made". Again, over here, those are everywhere, and very reasonable. If you can find one there, you could at least have your shafts checked for balance. Beyond that, have you disassembled them to make sure that all the cups on all the U-joints actually feel very smooth as you rotate them with your fingers? Also, do that with the center bearing. Is it tight, or can you wiggle it around, thus changing the angles under acceleration? And is the rear transmission/engine mounting tight? Remember, it's one thing to measure the angles while you're sitting still and the motor's not running. How they behave under accelleration / decelleration could be a different situation entirely. Beyond that, if you do have to use the shims, I believe you could (here again) get what you need from a 4-wheel drive shop and modify it to fit. Because we lift our Jeeps and things, that changes all the drive line angles. On my own Jeep, I added a 4" lift kit, and after that, I had a vibration in certain ranges and could not keep the rear U-joint in it. I had the rear u-joint changed to a constant-velocity joint (you could have that done too, at the same place that will check/balance the prop shaft) and that fixed that. Other people add shims (sold at 4-wheel drive shops) between the axle and the spring pack, as shown in the FSM references you gave. And like I said, maybe they could be modified to fit the Imperial. Or at least used as a pattern to make whatever you need. I'd also check that front prop shaft angle really good, because it could be corrected pretty easily by adding shims under that rear engine mounting. It's possible it started out like that years ago at the factory, with shims under it, and somewhere along the way, somebody replaced the mount (or the transmission) and didn't notice that there were shims or forgot to put them back, and here you are. Here is a link that shows pictures of the wedge-shaped shims for sale on a 4WD site. There's all kinds of other parts, but search in this page for part # 4529536 and the photos and description are above that part #. One of the shims pictured is standing on its side so you can see what it looks like. http://www.mopartsracing.com/parts/dtrain.html Anyway, good luck, and let us hear back! --Brooks in Dallas Philippe Courant wrote:
|
Back to the Home of the Forward Look Network