Rear subframe bushings

Are you 100% certain the shocks and air pump fit? I see the lucerne is s bit heavier so I guess the shocks are spec'd differently for that reason. Might still be a good option for me since I have a tow hitch and I often carry a lot of weight in the trunk and/or back seats. but I would probably want the lucerne springs too wouldn't I?

I wonder whats different about the air compressor? I saw that the air fittings looked the ssme, but there different parts listed for the 2000-2005 lesabres vs the 2006-2011 lucerne. Why are they not listed as being cross compatible and what are the differences, if you happen to know?

When my air compressor went out, I converted to manual inflation with a shrader valve that I installed because a replacement air compressor was either unavailable or way too expensive. But I see rockauto has them now for a price that isn't too outrageous so I may convert back, it would be nice to have it work automatically again. Especially now since i have new bushings that I dont want to be overstressed. I just need to consider the lucerne options too now, maybe they would be better.

P.s. I still need to get an alignment but the car feels so much better now with all the rear bushings replaced, upgraded moog trailing arms, and the added sway bar. So much stiffer but in a good way, still not harsh. The vibrstion under load is still there so I'm pretty sure thats a cv axle, i will be replacing those next.
 
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An 08. cxl trim. The yard actually had 2 of them side by side that were the exact same year, model, and even color. And both said cxl. So I took 1 from each, they were both the same.
curious, my source lied to me saying it was the same on all examples. were the crossmemebers similar looking?
 
Are you 100% certain the shocks and air pump fit? I see the lucerne is s bit heavier so I guess the shocks are spec'd differently for that reason. Might still be a good.option for me since I have a tow hitch and I often carry a lot of weight in the trunk and/or back seats. but I would probably want the lucerne springs too wouldn't I?

I wonder whats different about the air compressor? I saw that the air fittings looked the ssme, but there different models listed for the 2000-2005 lesabres vs the 2006-2011 lucerne. Why are they not listed as being cross compatible and what are the differences, if you happen to know?
the valving by the compressor manages the height, the shocks behavior and performance is for a heavier car, the RPO on the lucerne your stealing from being SOFT or FIRM ride will determine the shocks being used

Fe1 and Fe3 on the SPID iirc, maybe fe2

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were these over your bushings?

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Yep it was the same setup, just a slightly different design to the bushing but fully interchangeable. I'm guessing this is the latest design, the part number 15237958 that I posted earlier must be what I pulled off the lucerne. But the catalog says that part# 15237958 replaces 25634878, so the one I pulled off my lesabre was probably 25634878.

Looking more closely.at the picture for 15237958, i think it actually is solid on top like the one I pulled from the lucerne. Unlike the picture I posted earlier. It's just hard to tell from the stock photo because that part of it is all black and not under the best lighting so it looks like there could be more detail that isn't visible in the photo
 
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Yep it was the same setup, just a slightly different design to the bushing but fully interchangeable. I'm guessing this is the latest design, the part number 15237958 that I posted earlier must be what I pulled off the lucerne. But the catalog says that part# 15237958 replaces 25634878, so the one I pulled off my lesabre was probably 25634878.

Looking more closely.at the picture for 15237958, i think it actually is solid on top like the one I pulled from the lucerne. Unlike the picture I posted earlier. It's just hard to tell from the stock photo because that part of it is all black and not under the best lighting so it looks like there could be more detail that isn't visible in the photo
tbh the plate i showed looks like a shield but its not above the bushing,i ts below, you would see it on the outside of the subframe from below
 
Are you 100% certain the shocks and air pump fit? I see the lucerne is s bit heavier so I guess the shocks are spec'd differently for that reason. Might still be a good option for me since I have a tow hitch and I often carry a lot of weight in the trunk and/or back seats. but I would probably want the lucerne springs too wouldn't I?

When my air compressor went out, I converted to manual inflation with a shrader valve that I installed because a replacement air compressor was either unavailable or way too expensive. But I see rockauto has them now for a price that isn't too outrageous so I may convert back, it would be nice to have it work automatically again. Especially now since i have new bushings that I dont want to be overstressed. I just need to consider the lucerne options too now, maybe they would be better.
I wasnt clear enough. The compressor, is literally, plug and play to the Lesabre. The compressor from a lucerne would be younger than any lesabre (except a 2005 lucerne) and it would be better built
They function exactly the same, the wiring is the same, the pressure on the system for the shocks is the same, the set point of the pump and the height sensor are all the same etc. The shocks are just improved design after learning lessons from 10 + years from the predecessor days and early deaths. they would also be tuned nicer. if you plan to use the used shocks or pay 250 a shock for new ones (still sold new for both lesabre and lucerne) , theres no harm in the compressor. you just MUST use the bracket from a lucerne because they arent the same in that way. but it will bolt as an assembly to your car and plug in and take the fittings for the lines (advise new lines which can be bought or made too and ran the factory route)

If you plan to use ANY aftermarket shock kit, including ACdelco/GM [made by gabriel] you MUST install a spring in the compressor to raise the residual air left in the shocks for base inflation or youll shorten the life of them. this means they would be too harsh and too much pressure in a stock absorber. The aftermarket ones are notable in that if you look at them, they all air up the opposite direction than the GM ones. Its possible this is partly why. They will fit on the shock mounts and control arm like the originals. The shocks also varied on soft/firm, but a GM original shock will be far more nicer than a cheap one , so its an upgrade. The mileage is a key repeat detail here about getting the used ones if you can see lol.

The shock mount itself has a "soft ride" and firm variancy but its not enough that anyones really noticed.
The springs on the rear, that coil springs that is, are swappable. just you can buy new ones and original ones. the older the spring the more sagging it will have ,but the more miles will be more wear. a low mileage lucerne that sags a bit with 50k would be better than a 2000 lesabre with more miles even with sag being the same or less. the car will take up sag to height or can be modified to the linkage to fix the height.

Firm ride cars had constant rate springs im pretty sure, and soft ride used progressive rates. you can tell which is on a car because the coil spring will change thickness in the coils to the very ends vs the center. the original appear rather thin and widely spaced in this way.


here so I'm pretty sure thats a cv axle, i will be replacing those next.
not so fast hot shot

First the shaft between the car and steering rack, it connects to the end of the shaft of the column below, if that is going bad it could be a source for vibrations you feel in the wheel, id inspect any steering component or the subframe bushings or the engine mount (passenger side) as first things that arent engine running or tire related

if all that were good, then i would check trans mounts and from there your cv axles. The CV axle (right picture) is very simple overall, and unless youre high mileage you should not have huge issues. they can, however, wear out in more than one way which have different symptoms and they normally will have a warning sign before the outer joint (wheel bearing end, as shown) dies or is able to cause that.

Wheel bearings themselves can cause the issue, unbalanced tires. Those two things can also kill a CV axle.
Your alignment not being done yet basically says you should either do on the ground work first or align first.

Since a CV axle IS still on the list of possibilites and you SHOULD align after undoing the removing the struts as good practice, you should check it out first.

if you grab it by the end I shown you here from the back of the wheel bearing with the suspension lifted up (so the jack under the control arm, and a jack stand on the cars subframe or pinch weld lift point) you should be able to grab there on the shaft and wiggle it. the only movement should be the shaft itself is able to move in and out toward the transmission/away (to the wheel) without there being a radial looseness (around a circular axis around the shaft, like a tire is)

If you cant find any there, then try by the joint in the transmission. if you cant get it to do it there, youre most likely not dealing with a cv axle
Checking the torque on the nut is good. they are supposed to be replaced anytime you remove it, but id reuse it and just stake it (new ones dont need to because they have one)
To remove a good CV axle or to install a new one YOU CANNOT use an impact on the axle nut. clean the threads and use a lubricant like Deep Creep/PB blaster and use a breaker bar. if you want to remove it faster, a drill with a socket adapter in the clutch at most. The hammering of a impact is HARD On the bearings.

if you found a loose axle nut on the thing like i recommended checking, the wheel bearing and cv axle are both compromised and need replacement. they will die in short order despite a retorque

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The subframe pictured for reference. the sway bar grounding out on something with a broken end link on one side could cause vibration

The 6 mounts can always be worn or installed in a way they are a ground out too. Same with engine/trans mounts. they need to be centered in brackets and not binding or touching metal to metal other than the bolt /stud
 
Well today while I was driving it seeked like things were getting worse. I was feeling a rhythmic vibration while going straight down a fairly smooth street at around 50mph, which would go away when I let off the gas. I was also feeling a separate, slightly more subtle vibration that did not go away when i let off the gas but was totally dependent on speed, so that seemed like a wheel balance issue. However it seemed odd for a wheel balance issue to be so sudden and so noticeable, as i hadn't noticed the issue at all until maybe yesterday.

Oddly, those 1st two issues seemed to become a lot less noticeable after a couple hours of driving around (I use this car for amazon flex). So I'm thinking that much driving leads to more heat buildup and clearances getting smaller in whatever was causing the issue.

I also noticed a lot of really odd and bad sounding noises from the car today. I heard it clicking while turning for the 1st time, which sounded like what you typically might expect from a bad cv axle. But there were a lot of other odd clunks and crunching noises that I noticed, usually when accelerating from a stoplight. Sounded like it could be from a bad mount or something loose.

I should mention that my transmission definitely has issues and will need to be replaced again probably before long, so idk if that might be the actual source of all this. I installed a used transmission a while ago which was in great condition, and then i decided to install a transgo shift kit but i made a disastrous mistake by reinstalling 2 pipes in the trans the wrong way and then running the trans that way for a little while... Figured it out and fixed the pioes and It has been working without any issue (except maybe this vibration?) for a surprisingly long time since then. I emailed a trans rebuilder who works on these transmissions a lot afterwards and he said he doesnt think it would cause a vibration but, who knows...
 
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Btw does this look normal? This is the gap i see in my front subframe bushing when i have it jacked up with the jack placed under the subframe. When the car is sitting on its wheels, the gap between the rubber and that bottom metal plate disappears.
 

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Btw does this look normal? This is the gap i see in my front subframe bushing when i have it jacked up with the jack placed under the subframe. When the car is sitting on its wheels, the gap between the rubber and that bottom metal plate disappears.
That means they are old and tired. id recommend new ones. But you may have a cv axle if it was clicking and not thumping

but you can still check easily.
Also your vibration at speed is either most likely the trans/engine mounts or the subframe
 
TY. I will check the axles how you described. I tried that once and didnt find much, but the suspension was at full droop so maybe that affected it. I just tested for bad mounts by putting it in drive and accelerating with my foot on the brake and yep, I definitely have bad mounts! I replaced all four mounts when I replaced the transmission, which was about 2 years and 40k miles ago. and they were all bad but I didnt have this much vibration at that time, so maybe theres still an axle or something else going on too.

I can tell the front one is bad, at least. Any tips on how I can be sure about the rest before I order parts? Trying to add the video but not sure why it isn't showing up in my recent files...

Edit - as I think more about this, more details are coming back to me. I installed the new mounts with the used trans, then later after driving it for long enough to be sure the trans was good I decided to install new solenoids and a transgo kit into the it and thats when I made the mistake with the transgo kit I mentioned. And after that job must have been when I first started noticing this vibration, but not as bad as now. I also vaguely remember beign concerned that I may have accidentally damaged the new front mount during that job, by forgetting to fully disconnect it before dropping the subframe. so that probably is what happened and it just has been getting worse since then.
 
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TY. I will check the axles how you described. I tried that once and didnt find much, but the suspension was at full droop so maybe that affected it. I just tested for bad mounts by putting it in drive and accelerating with my foot on the brake and yep, I definitely have bad mounts! I replaced all four mounts when I replaced the transmission, which was about 2 years and 40k miles ago. and they were all bad but I didnt have this much vibration at that time, so maybe theres still an axle or something else going on too.

I can tell the front one is bad, at least. Any tips on how I can be sure about the rest before I order parts? Trying to add the video but not sure why it isn't showing up in my recent files...

Edit - as I think more about this, more details are coming back to me. I installed the new mounts with the used trans, then later after driving it for long enough to be sure the trans was good I decided to install new solenoids and a transgo kit into the it and thats when I made the mistake with the transgo kit I mentioned. And after that job must have been when I first started noticing this vibration, but not as bad as now. I also vaguely remember beign concerned that I may have accidentally damaged the new front mount during that job, by forgetting to fully disconnect it before dropping the subframe. so that probably is what happened and it just has been getting worse since then.
The front mount by the radiator, if it was replaced, could be bad again. Aftermarket ones are short lived
 
Well, maybe I was overreacting to the amount of engine movement I saw. I just looked closely all the mounts and none look bad as far as I can tell.


Also checked the cv axles again with the car on ramps, and cant find any play or looseness. The fact that this vibration happens the worst when everything is unweighted after going over bumps, really makes me lean toward these subframe bushings being the issue. But then that would mean the noises I'm hearing would have to be a different issue....

Does this movement look excessive to you? Apparently i can only upload photos here, so here is a link
 
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Well, maybe I was overreacting to the amount of engine movement I saw. I just looked closely all the mounts and none look bad as far as I can tell.


Also checked the cv axles again with the car on ramps, and cant find any play or looseness. The fact that this vibration happens the worst when everything is unweighted after going over bumps, really makes me lean toward these subframe bushings being the issue. But then that would mean the noises I'm hearing would have to be a different issue....

Does this movement look excessive to you? Apparently i can only upload photos here, so here is a link
This is stationary? To my eyes, the amount of roll back is a little excessive, toward the end of the video, id appreciate a picture of your front mount and your one on the subframe by your steering rack. only those two (and the subframe mounts) would allow such roll.

The CV axle thing, you couldnt get the joints to plunge? you should be able to take the shaft and pull in and push back to the inboard joint
 
This is stationary? To my eyes, the amount of roll back is a little excessive, toward the end of the video, id appreciate a picture of your front mount and your one on the subframe by your steering rack. only those two (and the subframe mounts) would allow such roll.

The CV axle thing, you couldnt get the joints to plunge? you should be able to take the shaft and pull in and push back to the inboard joint
Okay I'll get more pics next time I'm under there

I didn't try the CVs in that direction cuz I know that is normal. I just tried twisting and shaking them. One thing I forgot to do though was to try it with that corner just a little bit jacked up but not all the way up in the air. Cuz that's really when this happens. Either after a bump when the suspension unweights and extends, or when I'm turning right so the weight shifts to the left and the right side extends a little bit. Seems like all the noises are coming from the front right too. But all of this happens only if I'm applying the throttle.
 
Okay I'll get more pics next time I'm under there

I didn't try the CVs in that direction cuz I know that is normal. I just tried twisting and shaking them. One thing I forgot to do though was to try it with that corner just a little bit jacked up but not all the way up in the air. Cuz that's really when this happens. Either after a bump when the suspension extends, or when I'm turning right so there is less weight on the front right corner and it extends a little bit. Seems like all the noises are coming from the front right too. But all of this happens only if I'm applying the throttle.
have you ever touched the cv axles, ball joints, tie rods , or the struts on this car? Aftermarket struts are known to have loose top nuts and the spring will rotate itself and things could happen only on rebound (weight of the car is removed)
 
They are aftermarket struts and when I installed them I just used an impact without torquing... But I double checked the top nut last night, using 2 wrenches so I could hold the shaft to stop it from spinning, and it is still really tight.

I am pretty sure its not a cv axle at this point. Glad I didn't fire the parts cannon at those! When I thought I heard it clicking, I wasn't hearing the sound very clearly over the loud stereo. And I was already suspecting the axles so there was some confirmation bias going on. But now after hearing it more, I think it sounds like something loose is shifting around. A motor mount would make a lot of sense. Or the issue mentioned in that tsb about the #2 subframe bushing also seems like that's very likely to be what I'm hearing. I still think the vibration is separate from the sound, I only hear the sound at low speeds. I'm going to double check my ball joint because I've never checked it with the suspension jacked up, maybe that could be making noise.

I guess I should get my alignment done 1st just to make sure the rear wheels alignment isn't out enough to cause the vibration. But other than that I think my next step will be to order a couple of the dorman subframe bushings for the 2 front positions and see if that makes a difference in the vibration. Cuz the looseness I have there definitely isn't right. If that helps then I'll replace the other 4 and maybe use some epoxy for the 2 mentioned in that tsb. Just dont want to sink the money into all 6 right away if its not necessary. But I might change my mind and just do them all at once... Still thinking on that. I'll probably order another front mount too and if I don't need it I'll just hold onto it til I do.

Interesting that your tsb mentions the #2 mount shifting. In the parts catalog, GM calls for a different part # for the lower portion of the #2 bushing, compared to the #1 and #3 bushings. But dorman says the same part applies to all 3 (at least I think/hope so).

If the loose rubber portion if my #1 bushings up front has been causing the vibration all this time, it would make sense for that to eventually cause the issue with the #2 bushing shifting around and making noise. So my main theory now is that everything comes down to the subframe bushings.

I wonder if jbweld is good enough epoxy to use for that tsb? Its what I already have so I guess I will find out.
 
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They are aftermarket struts and when I installed them I just used an impact without torquing... But I double checked the top nut last night, using 2 wrenches so I could hold the shaft to stop it from spinning, and it is still really tight.

I am pretty sure its not a cv axle at this point. When I thought I heard it clicking, I wasn't hearing the sound very clearly over the loud stereo. And I was already suspecting the axles so there was some confirmation bias going on. But now after hearing it more, I think it sounds like something loose is shifting around. A motor mount would make a lot of sense. I still think the vibration is separate from the sound, I only hear the sound at low speeds. I'm going to double check my ball joint because I've never checked it with the suspension jacked up, maybe that could be making noise.

But other than that I think my next step will be to order a couple of the dorman subframe bushings for the 2 front positions and see if that makes a difference in the vibration. If it does then I'll replace the other 4 and maybe use some epoxy for the 2 mentioned in that tsb. Just dont want to sink the money into all 6 right away if its not necessary. I'll probably order another front mount though and if I don't need it I'll just hold onto it til I do.

Interesting that your tsb mentions the #2 mount shifting. In the parts catalog, GM calls for a different part # for the lower portion of the #2 bushing, compared to the #1 and #3 bushings. But dorman says the same part applies to all 3.
a motor mount can be grounding out if they arent centered properly, are worn, or something is in contact with them.

18mm just so you know
Fyi I wasnt able to get one of mine loose... the big bertha impact with a full battery wasnt able to hammer it even after doing it for a minute. id need to get an air impact out and the big one with a lot of air

Only one of mine did that

doing anti-corrosion coating at the time of removing them, even one by one is a MUST. on both the subframe and the unibody
 
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