Driveline backlash/ deceleration backlash
07-22-2016, 09:19 PM
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Driveline backlash/ deceleration backlash
My 1999 s2000 has some pretty heavy driveline backlash. The clutch is a HD Excedy. I have one bad engine mount and hard diff mounts.
On deceleration around 2,500-3,000rpm in gears 1,2 3 the car backlashes/ or otherwise understood as bounces backward and forward once and continues decelerating. It happens on acceleration also but not soo pronounced. There is a light clunk (u can hear it though) on the decleration or acceleration. Its also more pronounced if u are using light throttle and lifting offf the throttle the car will bounce back and forward. It doesnt matter what temeprature it is. Parking the car or driving in car parks are hard as hell because in first gear/second the bouncing/clunk noise is more pronounced.
My diff makes no howling/growling/clicking noise when turning/accelerating/decelerating. Something in the driveline makes the clunk noise - dno if its the diff haha.
Here is what I think it could be in order:
1. Engine mounts
2. Diff mounts and/or other driveline mounts - or they could be worn out?
3. Axle related stuff
4. TPS - throttle position sensor/ throttle adjustment
5. New diff oil/greasing
6. Bad differential - doubt it though - my mechanic said there was play in the diff
My car goes into the mechanic in 5 days from today haha will post back what mechanic says
What do you guys think?
On deceleration around 2,500-3,000rpm in gears 1,2 3 the car backlashes/ or otherwise understood as bounces backward and forward once and continues decelerating. It happens on acceleration also but not soo pronounced. There is a light clunk (u can hear it though) on the decleration or acceleration. Its also more pronounced if u are using light throttle and lifting offf the throttle the car will bounce back and forward. It doesnt matter what temeprature it is. Parking the car or driving in car parks are hard as hell because in first gear/second the bouncing/clunk noise is more pronounced.
My diff makes no howling/growling/clicking noise when turning/accelerating/decelerating. Something in the driveline makes the clunk noise - dno if its the diff haha.
Here is what I think it could be in order:
1. Engine mounts
2. Diff mounts and/or other driveline mounts - or they could be worn out?
3. Axle related stuff
4. TPS - throttle position sensor/ throttle adjustment
5. New diff oil/greasing
6. Bad differential - doubt it though - my mechanic said there was play in the diff
My car goes into the mechanic in 5 days from today haha will post back what mechanic says
What do you guys think?
07-22-2016, 10:10 PM
#2
It could be an aftermarket flywheel that's already lighter than the OEM. It get's a little jumpy for me in the lower RPMs, especially when there's heat soak present after being stuck in traffic.
07-23-2016, 04:48 AM
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Your right, that has something to do with it. However I feel that something is loose, the car bounces forward like 3cm (30mm) from what it feels like to me. On the scale of 1-10 on how much backlash there is, on the worst occassions (2500rpm) its a 6-7/10. Also does urs bounce back and forward once on decel and accel around 2500k?
Its worth noting that the clutch buzz follows the bouncing respectively. For example if the car bounces forward the clutch buzz will silence momentarily and then continue on the deceleration.
I think that because of the age if the car and the clutch - there are a number of factors working together to Pronounce the issue more than it should. I think that if I repair engine mounts it will remove some backlash, the diff mounts and so on and that will bring the play down - maybe im wrong haha
Its worth noting that the clutch buzz follows the bouncing respectively. For example if the car bounces forward the clutch buzz will silence momentarily and then continue on the deceleration.
I think that because of the age if the car and the clutch - there are a number of factors working together to Pronounce the issue more than it should. I think that if I repair engine mounts it will remove some backlash, the diff mounts and so on and that will bring the play down - maybe im wrong haha
07-23-2016, 07:46 AM
#4
Your right, that has something to do with it. However I feel that something is loose, the car bounces forward like 3cm (30mm) from what it feels like to me. On the scale of 1-10 on how much backlash there is, on the worst occassions (2500rpm) its a 6-7/10. Also does urs bounce back and forward once on decel and accel around 2500k?
Its worth noting that the clutch buzz follows the bouncing respectively. For example if the car bounces forward the clutch buzz will silence momentarily and then continue on the deceleration.
I think that because of the age if the car and the clutch - there are a number of factors working together to Pronounce the issue more than it should. I think that if I repair engine mounts it will remove some backlash, the diff mounts and so on and that will bring the play down - maybe im wrong haha
Its worth noting that the clutch buzz follows the bouncing respectively. For example if the car bounces forward the clutch buzz will silence momentarily and then continue on the deceleration.
I think that because of the age if the car and the clutch - there are a number of factors working together to Pronounce the issue more than it should. I think that if I repair engine mounts it will remove some backlash, the diff mounts and so on and that will bring the play down - maybe im wrong haha
07-24-2016, 03:49 AM
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It happens in all gears actually, altough early gears make it more pronounced. I think its torque related because light throttle around 2.5k rpm and off throttle causes it more.
Could be the propeller shaft?
Could be the propeller shaft?
07-24-2016, 04:37 PM
#7
My '06 started doing something very similar, right after I changed the clutch.
I went with oem FD, release bearing, pilot bearing, guide, Act pp, and act streetlite 11lbs flywheel.
I have driveline lash I can feel in propshaft. Not sure if it was there before the clutch work. The lash is felt with car in neutral, so its either internal to diff or the yoke.
What seems odd is when I drive at light throttle, around 2500-3000, I can hear and feel what I could swear seems like the exhaust banging against something. Except all the hangers are intact, and the whole exhaust system (stock) feels solid and tight. I cant yet figure out if the banging due to the lash or not.
Sent from my SM-G920P using IB AutoGroup
I went with oem FD, release bearing, pilot bearing, guide, Act pp, and act streetlite 11lbs flywheel.
I have driveline lash I can feel in propshaft. Not sure if it was there before the clutch work. The lash is felt with car in neutral, so its either internal to diff or the yoke.
What seems odd is when I drive at light throttle, around 2500-3000, I can hear and feel what I could swear seems like the exhaust banging against something. Except all the hangers are intact, and the whole exhaust system (stock) feels solid and tight. I cant yet figure out if the banging due to the lash or not.
Sent from my SM-G920P using IB AutoGroup
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07-25-2016, 01:47 AM
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I dont know if I am allowed to link to another forum ( if I am
Not allowed to then im prepaired for the notification). Nonetheless this guy in this forum describes what I am going through perfectly - http://www.evolutionm.net/forums/evo...-bouncing.html
We have different cars to this guy although his symptoms are exactly what I am feeling (so im not making this up haha).
I think the non oem clutch has alot to do with it, although for some reason it recently got worse. Ontop of this on higher revs 3.5k rpm+ it sortof dissappears or becomes smoother? Like as if when i lightly let off the throttle (from being on light throttle to off throttle) the car takes a softer approach to letting off the gas and "aids" itself into deceleration (ECU/throttle off WISE). When its at -2.5k rpm letting off light throttle lightly causes the BOUNCE FORWARD like as if the car shuts off all gas completely abruptly and the car throws itself forward in addition with the play making things more annoying and amplified.
Might be the solution(s):
I think all of you are right. To me it seems the excedy HD clutch, worn mounts, spastic TPS (or a needed adjusted throttle cable) are working together to cause this annoying bounce. Perhaps a simple solution to 60-80%.rectify this issue would be new mounts engine/tranny/diff wise and a look at the TPS/throttle section? The clutch I cannot justify repairing because it feels perfect and bitey (huge clutch buzz tho) when it dies it will be replaced. What I hope is that the drive train (diff/propeller shaft/transmition) is not the culprit of this because that stuff is srsly expensive.
Btw the clunk happens at 2k rpm more often - goes like this 0% throttle driving to stop light (2nd gear) then turns green - 20% throttle *clunk* straight away lightly off throttle back to 0% *clunk/bounce forward then back (back bounce silenced clutch buzz) and decel (clutch buzz return)* still at 2k rpm. When the car is in the bouncing back and forward faze the car clutch buzz silences momentarily. This is my attempt at monitoring my car.
Unless anyone else mirrors my situation haha
Thanks all
Not allowed to then im prepaired for the notification). Nonetheless this guy in this forum describes what I am going through perfectly - http://www.evolutionm.net/forums/evo...-bouncing.html
We have different cars to this guy although his symptoms are exactly what I am feeling (so im not making this up haha).
I think the non oem clutch has alot to do with it, although for some reason it recently got worse. Ontop of this on higher revs 3.5k rpm+ it sortof dissappears or becomes smoother? Like as if when i lightly let off the throttle (from being on light throttle to off throttle) the car takes a softer approach to letting off the gas and "aids" itself into deceleration (ECU/throttle off WISE). When its at -2.5k rpm letting off light throttle lightly causes the BOUNCE FORWARD like as if the car shuts off all gas completely abruptly and the car throws itself forward in addition with the play making things more annoying and amplified.
Might be the solution(s):
I think all of you are right. To me it seems the excedy HD clutch, worn mounts, spastic TPS (or a needed adjusted throttle cable) are working together to cause this annoying bounce. Perhaps a simple solution to 60-80%.rectify this issue would be new mounts engine/tranny/diff wise and a look at the TPS/throttle section? The clutch I cannot justify repairing because it feels perfect and bitey (huge clutch buzz tho) when it dies it will be replaced. What I hope is that the drive train (diff/propeller shaft/transmition) is not the culprit of this because that stuff is srsly expensive.
Btw the clunk happens at 2k rpm more often - goes like this 0% throttle driving to stop light (2nd gear) then turns green - 20% throttle *clunk* straight away lightly off throttle back to 0% *clunk/bounce forward then back (back bounce silenced clutch buzz) and decel (clutch buzz return)* still at 2k rpm. When the car is in the bouncing back and forward faze the car clutch buzz silences momentarily. This is my attempt at monitoring my car.
Unless anyone else mirrors my situation haha
Thanks all
07-27-2016, 02:13 PM
#10
You have a known bad engine mount, and you started this thread? Get that replaced and then report back if you still have a problem you feel is beyond the normal backlash. I will tell you that putting stiff/hard mounts on one end of the car will put more strain on the other end. The shock load just gets transferred. Do them all or dont do any.