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-   -   Transmission knock (https://www.ft86club.com/forums/showthread.php?t=108095)

tofurun 07-07-2016 10:01 PM

Transmission knock
 
After doing the dss aluminum driveshaft and changing over to the motul 300 75w-90 sometimes I notice a knock coming from the transmission. It only happens on start up after it's been sitting. Once it warms up after a minute drive it is gone and when I put the car away it isn't there. Is it just the motul being cold and needing to warm up or some other weird noise this car makes? Shift perfect no grinds or anything unusual .

humfrz 07-08-2016 02:15 AM

Quote:

Originally Posted by tofurun (Post 2699620)
After doing the dss aluminum driveshaft and changing over to the motul 300 75w-90 sometimes I notice a knock coming from the transmission. It only happens on start up after it's been sitting. Once it warms up after a minute drive it is gone and when I put the car away it isn't there. Is it just the motul being cold and needing to warm up or some other weird noise this car makes? Shift perfect no grinds or anything unusual .

Well, now @tofurun ........ you REALLY messed up this time ......... :slap:

First off, you replaced a TWO piece driveshaft with a ONE piece driveshaft. So, when it cools and contracts, it PULLS on the gears of the transmission apart, thus when they are started up they SLAM together, causing that KNOCK.

Of course this sends a SHOCK through the drivetrain, which is transferred to the differential and will eventually knock a tooth off of the ring gear.

In addition, the SHOCK wave will be transmitted through the shafts in the transmission into the clutch assembly and will, in time, put the pressure plate out of balance and not only scar the flywheel, but will BLOW up the clutch disk and FREEZE the throw out bearing.

Next, you will hear the dreaded "neutral rollover" ask @Ultramaroon for details, which is nothing more than the inability of motul gear oil to deal with the shock waves ....... leaving the gears and bearings to grind themselves to oblivion.


I'm sorry for your impending disaster ....... :cry:


humfrz

Ultramaroon 07-08-2016 02:23 AM

Quote:

Originally Posted by humfrz (Post 2699765)
I'm sorry for your impending disaster ....... :cry:

well, that was painful. :slap:

chaoskaze 07-08-2016 03:46 AM

:lol:


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tofurun 07-08-2016 07:27 AM

Quote:

Originally Posted by humfrz (Post 2699765)
Well, now @tofurun ........ you REALLY messed up this time ......... :slap:

First off, you replaced a TWO piece driveshaft with a ONE piece driveshaft. So, when it cools and contracts, it PULLS on the gears of the transmission apart, thus when they are started up they SLAM together, causing that KNOCK.

Of course this sends a SHOCK through the drivetrain, which is transferred to the differential and will eventually knock a tooth off of the ring gear.

In addition, the SHOCK wave will be transmitted through the shafts in the transmission into the clutch assembly and will, in time, put the pressure plate out of balance and not only scar the flywheel, but will BLOW up the clutch disk and FREEZE the throw out bearing.

Next, you will hear the dreaded "neutral rollover" ask @Ultramaroon for details, which is nothing more than the inability of motul gear oil to deal with the shock waves ....... leaving the gears and bearings to grind themselves to oblivion.


I'm sorry for your impending disaster ....... :cry:


humfrz

Why you gotta make my life so difficult.... :mad0259:

humfrz 07-08-2016 05:28 PM

Quote:

Originally Posted by tofurun (Post 2699846)
Why you gotta make my life so difficult.... :mad0259:

Sorry ..... :(

How about this:

In the driveline, between the back of the crankshaft and the wheels are many moving parts (like for example, the clutch, TOB, pressure plate, transmission gears and bearings, universal joints, ring & pinion gears and real axle universal joints).

So, for the car to move, they must all "tighten up" ...... thus the "knock" sound. Quite normal.

Now, you fell better ??......;)


humfrz

Apoc 07-08-2016 06:32 PM

I liked the first answer

tofurun 07-08-2016 06:45 PM

Quote:

Originally Posted by humfrz (Post 2700308)
Sorry ..... :(

How about this:

In the driveline, between the back of the crankshaft and the wheels are many moving parts (like for example, the clutch, TOB, pressure plate, transmission gears and bearings, universal joints, ring & pinion gears and real axle universal joints).

So, for the car to move, they must all "tighten up" ...... thus the "knock" sound. Quite normal.

Now, you fell better ??......;)


humfrz

TY lol

Quote:

Originally Posted by Apoc (Post 2700359)
I liked the first answer

Yea i knew it was coming. I read a few posts before posting and it sounded like the same issue I was having. I just didnt notice it until after the Fluid and DSS change, wasnt sure if it may be something different. Been discussed 100 times :)


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