problems after rear end work and motor mounts...input please!

[RedSiBaron]

alright, so a few things...just did a lot of fixit/upgrade work on the 1990 s13 hatch with the stock ka24e...

FIRST:

BACKGROUND: i just put in a whole new rear subframe in that i disassembled and cleaned up, checked every bushing, they are good, wheel bearings are good, differential is good, all of it has 90k on it...i replaced the subframe bushings with ES red subframe bushings...i also torqued everything to FSM specs...

http://sphotos.ak.fbcdn.net/hphotos-ak-snc6/hs048.snc6/167866_825778027265_21421248_42983737_3682467_n.jp g

PROBLEM 1: im getting a vibration from what sounds like the right rear, and it sounds like a metal on chassis vibration, it makes the noise when i engine brake and seems to go away when i put it neutral and coast THIS IS MY ONLY REAL REMAINING PROBLEM, I ALREADY RE TORQUED ALL NUTS ON SUBFRAME BUSHINGS, AND THE NUTS/BOLTS ON DIFFERENTIAL

SECOND and THIRD and FOURTH:

BACKGROUND: my engine mounts were toast, and i mean toast as in the drivers side was in 2 pieces. the car came with megan engine mounts uninstalled and the trans mount was already installed. I jacked up the motor and shook it side to side until i could get the engine mounts in both sides, snugged the top nuts incrementally while incrementally lowering the motor back down, and kept shaking the engine to help it settle. once it settled i tightened the bottom nuts up as good as i could get them, then went back and tightened the top nuts.

http://sphotos.ak.fbcdn.net/hphotos-ak-snc4/hs1375.snc4/164776_826153020775_21421248_42989085_856690_n.jpg

PROBLEM 2: strong vibration in the front now NOT WORRYING ABOUT IT, STIFF ENGINE MOUNTS JUST NEED BREAKING IN, THEY ARE GETTING BETTER ALREADY

...do the mounts need to be loosened top and bottom and be resettled, or do they eventually break in?

PROBLEM 3: speedo and odometer arent working anymore and the speedo was already reading wrong over 55 (55 was right, 65reading was 60, 70 was 65, etc, etc, so it was 5 off) FIXED THIS, PLUG WAS DESTROYED

...where do i need to check, obviously there is a wire disconnected, pinched, or has a short, but i just dont know where to look for that...please tell me where to trace it start to finish please

PROBLEM 4: while i was test driving it, the motor cut on me once at 4krpms, didnt do it again after revving it out a few more times...STILL CONCERNED ABOUT THIS, BUT NOT TOO CONCERNED, CAR HAS BEEN DRIVING FINE

this one is probably going to be impossible to trace, but i figure we might be able to trace it since the motor was jacked up in the front an so something may have been stretched or pinched...also since i was using my fathers garage he came out and was helping me push and pull on the motor (plus ive never done mounts on a FR car before) and i saw him pulling with his hand multiple times at the TPS/throttle body area, so maybe that could be it...also the wiring/plugs that runs at the rear of the valve cover was getting pushed against stuff mounted on the firewall pretty good


SO i know that was a lot of information and questions, but heres where im at after working on the road warrior s13 for the last few days

this is how i felt before the test drive
:bigok: :hsdance: :naughty:

this is how i feel now
:2f2f: :-/ :tweak: :confused: :aw:

THANKS!!

[S-Nation S13]

vibrations in the rear could be possibly worn out wheels bearings, but if the problems in the rear didnt happen before, then its something you did, in the pic you rear sub looks either really clean out your took it apart and painted it, so recheck EVERY SINGLE BOLT. You also stated it goes away when in neutral or coast, could be a tranny issue, gear issue? did you remove the internals of your diff? if so did you check for backlash?

[RedSiBaron]

vibrations in the rear could be possibly worn out wheels bearings, but if the problems in the rear didnt happen before, then its something you did, in the pic you rear sub looks either really clean out your took it apart and painted it, so recheck EVERY SINGLE BOLT. You also stated it goes away when in neutral or coast, could be a tranny issue, gear issue? did you remove the internals of your diff? if so did you check for backlash?

Wheel bearings were checked, no play or noise from them, the subframe is clean because it only had 90k on it and I cleaned it before putting it in, no paint...I don't think its a bolt, I double checked every one when I assembled it and double checked it was torqued tio spec...tranny is fine, worn and old, but not whining, plus noise is new tranny stayed there...I did not open up the diff since it sounded and turned smooth and no play...plus the new one had 90k on it...I havnt gone outside and checked the subframe mounts now that the car has settled, ill try that first and go from there...

[RedSiBaron]

Any other ideas? Somebody?

Before I left today I backed off the subframe bolts a full turn, shook the hell out of the rear end, and then re-torqued the nuts to fsm specs while it was on the ground, and the rear chassis noise is still there

Im thinking possibly my chassis vibration noise has to do with my diff...I tightened/torqued it on the subframe off the car and then installed...thinking that could be it since it clunks when I nail the throttle...

Also my car cut out at 6k rpms today in 3rd and was dead until I shifted it to 4th...what's that about? Hrrm

[underground_army]

ok heres my idea for the who speed things go under your car and its i think the last sensor. it only has one bolt on it follow that wire and see if theres no nicks on it. Since the ecu reads the volts from the sensor it might think you are just revving it so its cutting it off. it happen to me. as for the noise in the back you should recheck the whole transmission/diff for loose things or maybe check your yolks for damage or something like that.

[RedSiBaron]

ok heres my idea for the who speed things go under your car and its i think the last sensor. it only has one bolt on it follow that wire and see if theres no nicks on it. Since the ecu reads the volts from the sensor it might think you are just revving it so its cutting it off. it happen to me. as for the noise in the back you should recheck the whole transmission/diff for loose things or maybe check your yolks for damage or something like that.

Cool thanks! Ya, im gonna trace the speed sensor, its the last one on right side of the tail shaft right? If its connected and I can't find a break ill just cut and re-wire it all the way to the cluster...I already tightened the trans mounts on the car, so im thinking its the diff...when I put the rear end in, I checked out the driveshaft U-joints and they are good, no excess play.

[Ali 556]

IIRC megan mounts are stiffer than stock, so REASONABLE vibration is ok, you also go to the local sup forum and ask 4 help, pay'em in beer :)

[RedSiBaron]

IIRC megan mounts are stiffer than stock, so REASONABLE vibration is ok, you also go to the local sup forum and ask 4 help, pay'em in beer :)

My mounts are softening up, and vibrations got slightly better, im thinking they just need to break in and take a set...plus its winter so cold urethane doesn't flex nice...

I don't need help working on my car, I need info to diagnose a problem

Really at this point I think the only info I need is how to fix my speedo problem...does the wiring for it run anywhere near the back of the motor or near the mounts?

[sickturbo]

Ok here's what I think. You say when you down shift it makes the noise, and when you put it in neutral?

-When in neutral driveshaft doesn't move therefore no noise.
-When down shifting you have the car on gear, and then the noise is there.

Also removing the sub frame requires do drain transmission fluid. Did you fill the trans with Gl-4 trans fluid? Which gear oil did you use?

Did you change the fluid on your diff? or maybe you dumped it and forgot to fill it up .....

Just my thought tho, good luck.

[RedSiBaron]

Ok here's what I think. You say when you down shift it makes the noise, and when you put it in neutral?

-When in neutral driveshaft doesn't move therefore no noise.
-When down shifting you have the car on gear, and then the noise is there.

Also removing the sub frame requires do drain transmission fluid. Did you fill the trans with Gl-4 trans fluid? Which gear oil did you use?

Did you change the fluid on your diff? or maybe you dumped it and forgot to fill it up .....

Just my thought tho, good luck.

No, I said when I engine brake it makes noise not downshift...

Why would removing the rear subframe assembly require doing the trans fluid when all I needed to do was unbolt the rear driveshaft from the diff and it it up and out of the way...plus the noise isn't coming from the trans...

I changed the fluid in the diff...

Sooooo....ya....I think its the diff mounts...I torqued them off the car, im going to loosen them today and shake the diff about and re tighten the bolts

[RedSiBaron]

ok, fixed the speedo issue, found that the plug had disintegrated, so i did a temp fix on it should be good for years haha...

i loosened up the nuts/bolts on the diff and shook it about then retightened and torqued, it did not solve the engine braking noise...hmm

[underground_army]

glad to hear about the speedo but the noise hhmm. Like what kind of noise does it make? any grinding or whining? Does it still shake when you engine break?

[RedSiBaron]

Thanks! Ya im glad ive debugged a couple things...

It sounds like a metal on chassis vibration...not to say that's what it is but that's the way the noise sounds...it doesn't vibrate, just makes the noise plus a clunk...its almost as if something is loose...also it makes more noise in 1st 2nd and 4th but less in 3rd and 5th...my friend just drove it and thought it sounded like it could be the diff, but thought it was weird it only did it in more in certain gears and only in engine braking...also there is no whining...I have a hard time thinking its the diff when the one I just put in has 90k on it and came out of an auto...

[underground_army]

doesnt matter if it came from the dealer or other places. remove the panel for the diff and check that theres is nothing wrong with it or maybe the previous owner might of weld it. Heres what i always think (it didnt come in my car and im not the original owner so dont know the history of it and i dont trust it, double check).

[az_240]

Did you torque the rubber bushings with the car flat on the ground (car on bricks so you can access the bushings)????

If not the rubber bushings get destroyed from twisting apart when the car is lowered.

Try jacking the rear up and look around for anything that could have come loose or is riding against the chassis. Could also disconnect the shock and try jacking each wheel slightly to check for contact. put the car in neutral and try turning the driveshaft.... also check the diff bushings.

[S14DB]

What kind of exhaust do you have?

[RedSiBaron]

doesnt matter if it came from the dealer or other places. remove the panel for the diff and check that theres is nothing wrong with it or maybe the previous owner might of weld it. Heres what i always think (it didnt come in my car and im not the original owner so dont know the history of it and i dont trust it, double check).

Oh I understand, I know for a fact its not welded haha, that would be very obvious when I sat there and turned it when I had the subframe taken apart...im just trying to rule other things out before dropping the diff...

Did you torque the rubber bushings with the car flat on the ground (car on bricks so you can access the bushings)????

If not the rubber bushings get destroyed from twisting apart when the car is lowered.

Try jacking the rear up and look around for anything that could have come loose or is riding against the chassis. Could also disconnect the shock and try jacking each wheel slightly to check for contact. put the car in neutral and try turning the driveshaft.... also check the diff bushings.

Are you talking about the subframe bushings or the suspension geometry bushings? The car isn't lowered so im not expecting anything to be contacting or do you mean suspension pieces on each other because of a bad bushing? I've turned the driveshaft plenty of times, nothing weird there and its an s13 so no diff bushings

What kind of exhaust do you have?

Just some 2" muffler shop welded up thing the previous owner had put on...the exhaust is the same as before I swapped out the subframe assemblies and I have the noise now, and didn't before...plus I would expect it to make noise even when I wasn't engine braking...

[az_240]

^Exhaust could be hitting the subframe or chassis.

I mean the OEM upright/control arm bushings. Car does not need to be dropped to destroy them.

You are supposed to torque those OEM rubber bushings with the car flat on the ground to put the bushing in its optimal range of motion.

If you torqued them while the subframe was out of the car the bushings are more than likely twisted beyond their range making them twist/shred apart. This happens when you take the car off the jack stands.... the suspension compresses and the bushings twist because the rubber is connected to the inner sleeve.

[RedSiBaron]

^Exhaust could be hitting the subframe or chassis.

I mean the OEM upright/control arm bushings. Car does not need to be dropped to destroy them.

You are supposed to torque those OEM rubber bushings with the car flat on the ground to put the bushing in its optimal range of motion.

If you torqued them while the subframe was out of the car the bushings are more than likely twisted beyond their range making them twist/shred apart. This happens when you take the car off the jack stands.... the suspension compresses and the bushings twist because the rubber is connected to the inner sleeve.

Ok I totally know what you're saying...torquing suspension components whille under load is my worst habit of forgetting to do, and thats after working on my own cars for 11yrs, I always end up having to go back and do it...maybe I've finally fucked something up because of my mistake and ill finally learn and remember...I think this may indeed be where the problem lies, luckily I have spare suspension arms I can use if I screwed up, or I just bite the bullet and buy the press I've been putting off buying and get some energy suspension rear end bushings to put in all the arms...

[S14DB]

Just some 2" muffler shop welded up thing the previous owner had put on...the exhaust is the same as before I swapped out the subframe assemblies and I have the noise now, and didn't before...plus I would expect it to make noise even when I wasn't engine braking...

You removed the exhaust to install the subframe right? Also, the subframe sits at a different height with the new bushings.

When you accelerate the engine torques in one direction and when you engine brake it torques in the opposite direction. This translates through the whole exhaust system.

Just something to check while going through everything that has changed.


I tend to think it's something driveline related. Ether the Diff, axles or hubs. Maybe the caliper is sticking. I don't think it's a suspension arm because it would be as it goes through travel not with engine/driveline load.

[RedSiBaron]

You removed the exhaust to install the subframe right? Also, the subframe sits at a different height with the new bushings.

When you accelerate the engine torques in one direction and when you engine brake it torques in the opposite direction. This translates through the whole exhaust system.

Just something to check while going through everything that has changed.


I tend to think it's something driveline related. Ether the Diff, axles or hubs. Maybe the caliper is sticking. I don't think it's a suspension arm because it would be as it goes through travel not with engine/driveline load.

Actually that's the halarious part about the exhaust, I just bought this car about a month ago, its a disaster of a vehicle in some ways, the previous owner had a muffler shop weld the exhaust as one solid piece including the header...so I just cut it off before the subframe to create an axleback, then luckily I had some of the real nice band clamp exhaust fittings so I put it back together that way...

You make a good point that the subframe is now sitting slightly lower, and that the exhaust may be torquing. I did notice today that if I push the exhaust tip with my foot it hits the tow hook, which might explain the clunking...I mean it could be something as stupid as this pos exhaust vibrating...ill pull out my wire tensioner and spin a quick wire tie pulling the muffler in a direction that seems to secure it the most and see what happens...

My thoughts do keep going back to the fact that the noise only happens during engine braking, id expect to still hear a noise under accel or coasting if it were in the suspension arms

[underground_army]

well when you engine break, the engine does move so the exhaust will move as well creating the vibration which will make it hit the subframe.

[RedSiBaron]

well when you engine break, the engine does move so the exhaust will move as well creating the vibration which will make it hit the subframe.

Ya...that's what we were saying...I just did some fiddling and checking for clearance, doesn't look like the exhaust is actually hitting anything...

im going to jack up the car and go through the suspension geometry again as soon as the rolex daytona 24hr race is over...if its not in there im thinking maybe an axle...my experience is problems in diffs clunk and howl constantly, and this isn't like that...its not the wheel bearing that would change under cornering and would be present under accel and neutral conditions...I've had bad axle cv joints make noise under accel only on my 86civic si, and engine braking is the same sort of load rotational forces, just in the opposite direction...maybe that would explain the clunk as well...

Are axles L/R specific on the s13? I have 2 spare axles on the old subframe, but I don't know if both are good, or either for that matter

[upsdude]

now when you put in the new ES bushings, did you keep the old "cups" from the old bushings? the metal stuff left behind once you burn out or remove the old OE ones? i remember having those bushings and they didn't come with instructions, so i didn't know i had to keep the old metal cups. because other than that it sounds like you've done everything else in terms of double checking your work.

there are a bunch of long winded posts so i didn't read through all of them..but a general rule is re-check your bolts after 5-10k of driving, so with your motor mounts i think they are going to be stiff just 'cause they're new-but no need to loosen and all that just to help them settle. besides from what i've seen most motor mounts are stiffer than OE anyways.

[RedSiBaron]

now when you put in the new ES bushings, did you keep the old "cups" from the old bushings? the metal stuff left behind once you burn out or remove the old OE ones? i remember having those bushings and they didn't come with instructions, so i didn't know i had to keep the old metal cups. because other than that it sounds like you've done everything else in terms of double checking your work.

there are a bunch of long winded posts so i didn't read through all of them..but a general rule is re-check your bolts after 5-10k of driving, so with your motor mounts i think they are going to be stiff just 'cause they're new-but no need to loosen and all that just to help them settle. besides from what i've seen most motor mounts are stiffer than OE anyways.

ya i left the metal sleeves in, the bushings fit just perfect in there...im going to do my last double-checking of work today, then ill have to settle for the fact that something in the diff, axle(s), or wheel bearing(s) is bad...luckily i have another diff, axles and hubs i can press bearings into/rebuild, etc, etc...

...ill recheck the bolts/nuts on the bushings and suspension come spring when the weather warms up and the urethane will flex a little better, though my garage was around 60degrees when they were installed, so...we'll see...

ya the engine mounts are no biggie, ill just double check them in spring, just give a retorque, they probably wont even be vibrating anymore come spring

[upsdude]

Are axles L/R specific on the s13? I have 2 spare axles on the old subframe, but I don't know if both are good, or either for that matter

For sure on a 5 bolt pattern vlsd one axle is shorter than the other.

[RedSiBaron]

For sure on a 5 bolt pattern vlsd one axle is shorter than the other.

ya i just have the open dif with the 6 bolt...



ALRIGHT SO HERES THE DEAL i just checked the suspension geometry for damaged bushings, nope no damage, then i re-torqued everything with pre-load...i also checked for clearance on the exhaust, fine there, and i also made sure the ebrake cables were clearing everything (i noticed one of them could make a "thunk" on the chassis so i fixed that...only thing i havnt checked is to see if there is something wrong with the shock top hat, but i doubt thats it since i tightened it (found it was loose, stupid previous owner) and it didnt change the noise at all...
:wtf:

alright next, check axles, diff, and center bearing...

OR my transmission is actually making the noise and it is translating to the rear end...but that seems like a stretch

[upsdude]

uh hmm...bad carrier bearing? did you check the bolts that connect the shaft to the diff? jeez what els...you running stock rear brakes? oh and are you using the same rotors as before or did you get new ones? sometimes the rotors are warped out the box (especially the cheaper ones). other than that i stumped :confused:

if you could somehow get a camera under the car and tape it when you're driving that would be reeeeeaaaallly helpful lol

[RedSiBaron]

uh hmm...bad carrier bearing? did you check the bolts that connect the shaft to the diff? jeez what els...you running stock rear brakes? oh and are you using the same rotors as before or did you get new ones? sometimes the rotors are warped out the box (especially the cheaper ones). other than that i stumped :confused:

if you could somehow get a camera under the car and tape it when you're driving that would be reeeeeaaaallly helpful lol

I am thinking the carrier bearing, but the thing is it sounds further back and I didn't change out the bearing, but then again the rear doesn't have trashed mounts anymore and the the trans is properly bolted down now so the carrier might be taking up the runout or showing its worn out for the first time...

I've re checked the driveshaft to the diff bolts multiple times, they are good, and I realigned and bolted it up per fsm proceedure...

I have stock rear brakes, and re-used the same calipers, pad, and rotors as before, so im ruling that out for now...

Well see what I can come up with tomorrow

[upsdude]

if anything drive around and have a friend stick his head out the window and listen lol...good luck man, sounds like you're close to smacking your head against a wall :P

[RedSiBaron]

if anything drive around and have a friend stick his head out the window and listen lol...good luck man, sounds like you're close to smacking your head against a wall :P

Hahaha...I've actually been driving around in winter weather with the window down, hanging my head out the window or moving it around the interior trying to see if the noise is anywhere but the passenger side...im probably going to have my father help me on this one, he's been building race cars since the 50s and built formula cars in the 70s, im sure he'll know instantly...

Im not upset, I know every bolt is tight and no dangerous play in anything, so if the diff or axle takes a shit I have spares I know will atleast work for a few minutes, and if its a trans I can get another for $50-$100 locally...id just like to know something isn't wrong haha

[jchrisw85]

i did an install on my car about last winter.

dropped the subframe and burned the old bushings out blah blah and replaced them with the pbm solid subframe bushings. put everything back together and torqued down to spec and i have the same noise you're talking about.

it gets more apparent in 4th as soon as i let off the throttle then goes away once the tach reaches around 2300 rpms. not as loud when im on 3rd or 5th.

its been making this noise for about a year now and there is no damage to any of my suspension links. i have all aftermarket adjustable suspension arms and the car sits on stance gr+ coils. Every month or so i torque down the subframe bolts as well.

i dont think you have anything to worry about honestly. its just REALLY annoying. lol blast the music in the car.

[mr.man.performance]

It may be nothing to worry about like the guy before me said. Especially since you put those poly bushings in. Vibrations that were natural might just be more apparent now.

Do you have any adjustable arms in the rear? The lock nuts on those vibrate loose sometimes.

Also, what kind of vibration is it? High pitched rattle-probably the aforementioned lock nuts or a loose bolt/nut elsewhere (but you've been over the standard stuff several times it seems, haha). Clunking? Probably exhaust or loose subframe/diff (but you've probably checked both of those already). A bad drive axle will emit a subdued vibration but mostly in turns or engine braking. Improperly backlashed diff or a diff low on fluid will make a similar sound.

[mr.man.performance]

I know when I did my rear suspension bushings and solid subframe risers there was a shit ton or vibration noise. I also have adjustable control arms with lock nuts that just want to be freed...I'm very familiar with that noise...feck.

[rcdad123]

i have the same condition on my 89 hatch. it`s the exhaust hitting the chassis. drove me nuts for a while. took out the trunk and back panels to find out where the rattling noise is coming from when engine braking. did not find anything inside. then one day i was changing my oil on my car lift and noticed the rubbing marks on the right side of the chassis behind the rear right bottom of the fender. at that time, the muffler is a good 1.5 inches away from the rub marks. the exhaust twists that much under engine braking. so i just loosened the connection on the rear part of the cat and twisted my exhaust clockwise and the noise went away. mine has stock engine and tranny mounts, so the engine twist a lot. i would say it`s a 99.9% chance that it`s the exhaust.

[jchrisw85]

any updates?

[nike2991]

I also had this problem. I thought it was a right rear wheel bearing because it of the location of the driveshaft noise. It would only happen at ~3k in 1st and ~2k in 2nd. Yesterday The driveshaft vibrated so badly it broke the bolts connecting the two pieces of the shaft and ripped the carrier out of the chassis