Loud shuttering noise from transmission after installing Zuk coils?
11-18-2010, 08:01 PM
#1
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*Edit:Installed Zuk coils with pics!
Hey fellas, just installed the Zuk coils to my 4Runner today and it was a breeze to install! Measured 10.25 inches in the rear and after the install, measured it to 14.50! I purchased the 14 inch #125 Black magic springs. It does give it a bit of a "rake" look but that will be taken cared of once I adjust the torsion bars cause it sits at 13.25 inches in the front. Anyways, to the problem, after the install, I took it for a drive, going from 1st, 2nd, 3rd, and so on is fine, its when I down shift from 3rd to 2nd is where I get a loud vibration (sounds like metal contacting or rubbing) coming from the transmission. It seems to only do that at higher RPMs. What could be the potential problem that is making that noise? My transmission shifts just fine but the new foreign noise is bugging me cause when I down shift, it sounds like the truck is "farting" and people turn to look at what and where the noise is coming from, Lol...please help provide some potential answers so that I can avoid the humility! Thanks in advance.
As per requested ZUK, Pictures are up.
The truck has a bit of rake to it but more significant when the top is off:
Ride height was originally 10.5 inches from the lip of the rim to the fender from the rear. Don't have any pics of the before but the picture above can generalize it up. The new lift from the coil springs; Front at stock height:
Rear:
The ride is absolutely remarkable! It rides way better than it did before and I never will have to worry about it bottoming out ever. I'll be cranking the T-bars tomorrow to try and even it out so I'll take some more pics.
As per requested ZUK, Pictures are up.
The truck has a bit of rake to it but more significant when the top is off:
Ride height was originally 10.5 inches from the lip of the rim to the fender from the rear. Don't have any pics of the before but the picture above can generalize it up. The new lift from the coil springs; Front at stock height:
Rear:
The ride is absolutely remarkable! It rides way better than it did before and I never will have to worry about it bottoming out ever. I'll be cranking the T-bars tomorrow to try and even it out so I'll take some more pics.
Last edited by 4runner_guy; 11-22-2010 at 05:05 PM. Reason: Fixed
11-18-2010, 08:12 PM
#2
Check exhaust system for loose parts? Did you have to and or unbolt any exhaust components during installation? Header/exhaust manifold rubbing the side of the trans on Deceleration?
Video?
You said coils? What kind of runner you have? And are your suspension components secure and all tight? One of your new coils break? Crawl under and look and check...
Video?
You said coils? What kind of runner you have? And are your suspension components secure and all tight? One of your new coils break? Crawl under and look and check...
11-18-2010, 08:29 PM
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Check exhaust system for loose parts? Did you have to and or unbolt any exhaust components during installation? Header/exhaust manifold rubbing the side of the trans on Deceleration?
Video?
You said coils? What kind of runner you have? And are your suspension components secure and all tight? One of your new coils break? Crawl under and look and check...
Video?
You said coils? What kind of runner you have? And are your suspension components secure and all tight? One of your new coils break? Crawl under and look and check...
11-19-2010, 02:33 PM
#5
Exhaust pipe hitting the leafpack or similar?
Are the shocks topped out or broken?
bad tranny mount allowing the upper CV joint on the driveshaft to rub on frame cross-brace? Inspect CV for scrape marks. Never mind the CV scraping as I was thinking of my old modified truck when I thought of this one.
ZUK
Are the shocks topped out or broken?
bad tranny mount allowing the upper CV joint on the driveshaft to rub on frame cross-brace? Inspect CV for scrape marks. Never mind the CV scraping as I was thinking of my old modified truck when I thought of this one.
ZUK
Last edited by ZUK; 11-20-2010 at 05:15 AM.
11-19-2010, 03:26 PM
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After careful observing and reving, the culprit turns out to be the exhaust pipe hitting the leaf pack. Just found this out this morning. So you're right on that part ZUK. Shocks are not topped out. Just debating if I want to adjust the torsion bars, which I understand the consequences if I do try this method to try and make it somewhat even with the stance or if I should shell out for a set of 1.5 BJ spacers...decisions...decisions..
11-19-2010, 04:17 PM
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check your U-joints, if they've never been replaced it would be a good time to do it. you increased your pinion angle, and might have some axle wrap or wheel hop which will wear on your prop shaft and u-joints...
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11-20-2010, 04:52 AM
#8
As you know...it seems one mod leads to another...and more money thrown at it 
You can do a number of things....you can also chopsaw off 2 inches of coil to reduce the lift by 1 inch. You could try cranking the bars like I did on my old 87 Runner. I cranked mine for 1.5" of lift ....I think I measured 14.0" from rim to wheel lip factory length and turned the bars about 10 counted full turns and that gave me close to 15.5" from fender to rim. I did this of course with all the weight off the tires and some lube on the torsion bar bolt threads and all went well. I personally didn't think it was that much stiffer for the modest 1.5" of lift gain.
The BJ spacers would sound tempting though. ZUK
You can do a number of things....you can also chopsaw off 2 inches of coil to reduce the lift by 1 inch. You could try cranking the bars like I did on my old 87 Runner. I cranked mine for 1.5" of lift ....I think I measured 14.0" from rim to wheel lip factory length and turned the bars about 10 counted full turns and that gave me close to 15.5" from fender to rim. I did this of course with all the weight off the tires and some lube on the torsion bar bolt threads and all went well. I personally didn't think it was that much stiffer for the modest 1.5" of lift gain.
The BJ spacers would sound tempting though. ZUK
11-20-2010, 05:11 AM
#9
So 4Runner guy....how about posting some pics of the new rake? 
I would imagine with the large amount of coil lift you have...which means the leafpacks are not supporting the weight that much, that the ride quality is better than it's ever been. You'll probably never bottom it out, also. Later on, you could get somewhat longer shocks to get the wheel travel back in the center of the shock's chrome rod.
The coils will likely stay at whatever ride height you set them up for...for a decade or more. Seems like coils don't have the sagging issues that ALL softriding leafpacks do...especially when the coil is working in tandem with a support leafpack that's sharing the load.
Probably best to leave the factory short shackle as is. It will act as a "flex monster" limiter of sorts and keep the wheels from hyper-extending even with longer shocks and it should keep the coils from loosening up and keep them tightly in place even on flexy trails.
Enjoy the ride ZUK
I would imagine with the large amount of coil lift you have...which means the leafpacks are not supporting the weight that much, that the ride quality is better than it's ever been. You'll probably never bottom it out, also. Later on, you could get somewhat longer shocks to get the wheel travel back in the center of the shock's chrome rod.
The coils will likely stay at whatever ride height you set them up for...for a decade or more. Seems like coils don't have the sagging issues that ALL softriding leafpacks do...especially when the coil is working in tandem with a support leafpack that's sharing the load.
Probably best to leave the factory short shackle as is. It will act as a "flex monster" limiter of sorts and keep the wheels from hyper-extending even with longer shocks and it should keep the coils from loosening up and keep them tightly in place even on flexy trails.
Enjoy the ride
ZUK
11-22-2010, 04:32 PM
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So here is the results after adjusting the T-bars from 13.25 inch to 14.50 inch in the front:
Although, I still get the same noise coming from the truck after fixing the exhaust pipe. I believe that the noise is coming from the bracket (which is bolted to the tranny)and down pipe. They may be rubbing each other under a certain weight so I'll check that out later. Other than that, the ride is great and the truck is now leveled.
Although, I still get the same noise coming from the truck after fixing the exhaust pipe. I believe that the noise is coming from the bracket (which is bolted to the tranny)and down pipe. They may be rubbing each other under a certain weight so I'll check that out later. Other than that, the ride is great and the truck is now leveled.
Last edited by 4runner_guy; 11-22-2010 at 04:35 PM.
11-22-2010, 08:55 PM
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I understand that it's suppose to be there, but the noise is more prominent from that region, I'll have to conduct a couple of tests and see where the noise is coming from.
11-22-2010, 09:41 PM
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i wonder if cause your leafs are fatigued that when you are deceleratign the axle is twisting, pulling the pinion down which would change that joint angle and thats causing a vibration up at the back of the trans. and maybe the ujoint at the trans is needign replaced.
can you get pics of the rear pinion flange and trans output shaft angles?
can you get pics of the rear pinion flange and trans output shaft angles?
I can certainly try as long as it doesn't rain tomorrow. You could be right, but then again I may not even know where to start so I'll be taking a lot of pics to see if you guys can determine if it is what it is that you are saying that it is. Thanks, it sounds like that could be the problem and if so, is it a big one?
11-25-2010, 07:43 PM
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check out these pics. I added some arrows to maybe help you see.
the yellow arrows are the part of the driveshaft the u-joint installes in, the red ones are the transmission output and rear diff input.
Transmission end. notice the yellow arrow is pointing down tand left:
Axle end. notice the yellow arrows are pointing up and left / down and right:
both ends of the driveshaft should be the same, yellow arrows pointing both the same way. looks like you'd have to unbolt one end of the driveshaft, slide the slip yoke out, rotate it so both ends of the shaft are the same then slide it back in and bolt it back up.
make sense?
the yellow arrows are the part of the driveshaft the u-joint installes in, the red ones are the transmission output and rear diff input.
Transmission end. notice the yellow arrow is pointing down tand left:
Axle end. notice the yellow arrows are pointing up and left / down and right:
both ends of the driveshaft should be the same, yellow arrows pointing both the same way. looks like you'd have to unbolt one end of the driveshaft, slide the slip yoke out, rotate it so both ends of the shaft are the same then slide it back in and bolt it back up.
make sense?
I'm trying to make it make sense but its difficult to follow what you're saying. From what I "think" you are saying is that both drive shaft should be in sync? So you're saying that I can slide any part of the driveshaft either from the transmission or the axel end?
11-25-2010, 08:02 PM
#16
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the slip yoke up by the transmission can be slid out of the drive shaft. so if you unbolt it from the trans, you can lower the shaft, slide the yoke out and turn it so the ujoints are timed the same at each end of the shaft then reinstall. looks like you need to turn the yoke about 90 degrees / 1/4 turn
Please don't flame too much.
11-25-2010, 08:17 PM
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the slip yoke up by the transmission can be slid out of the drive shaft. so if you unbolt it from the trans, you can lower the shaft, slide the yoke out and turn it so the ujoints are timed the same at each end of the shaft then reinstall. looks like you need to turn the yoke about 90 degrees / 1/4 turn
Oh, I think I understand what you're trying to tell me. I'll try this tomorrow and see where it takes me. I'll make sure that both shaft are in the same angle and same position. Hopefully that'll eliminate the noise from downshifting. Thanks and I'll keep you updated.
11-29-2010, 06:56 AM
#19
razed- That could possibly be the cause of the noise you were getting....the slip splines could have been chattering. There's probably a weight on the upper end of the driveshaft piece....so there are 2 different positions to get that DS back in phase....one will be balanced and one might not. May not be an issue.
05-19-2011, 09:22 PM
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Sorry to bring this thread back up but didn't want to make a new thread when I could continue with this one I originally made.
So I am going to pull the slip yoke out and align it with the other end of the u-joints to try and fix the problem. I've been reading a lot and most have said that it could be a bad rear u-joint. I have the option of getting my hands on a set of used rear u-joints for $30 for the pair, is that a deal or should I get new ones instead and what costs am I looking to pocket out for a new set?
**Edit** Or should I just look out for a whole new (used) drive shaft?
So I am going to pull the slip yoke out and align it with the other end of the u-joints to try and fix the problem. I've been reading a lot and most have said that it could be a bad rear u-joint. I have the option of getting my hands on a set of used rear u-joints for $30 for the pair, is that a deal or should I get new ones instead and what costs am I looking to pocket out for a new set?
**Edit** Or should I just look out for a whole new (used) drive shaft?
Last edited by 4runner_guy; 05-19-2011 at 10:22 PM. Reason: add
