Non-BMW Stuff on a BMW Forum

[gilber33]

GunMetalGrey said:

A clunk like your describing has typically been worn U-joints in the driveshaft (for me).
Easy to check if it's in the air. 

How do I check this? 

Also, found a rocker that was way out of adjustment. Will fix that and hope that cures my problem. And then move on to driveline.

[YoungCR]

gilber33 said:

How do I check this? 

Also, found a rocker that was way out of adjustment. Will fix that and hope that cures my problem. And then move on to driveline. 

With the driveshaft removed you just physically move the yoke in both directions on each axis. As long as it moves freely the U-joints are fine. The Center Support Bearing (CSB) will cause drive line vibrations before the u-joints. The csb can be checked without removal. As long as there isn't any cracks in the rubber bushing around the bearing and no significant play its good.

[gilber33]

YoungCR said:

With the driveshaft removed you just physically move the yoke in both directions on each axis. As long as it moves freely the U-joints are fine. The Center Support Bearing (CSB) will cause drive line vibrations before the u-joints. The csb can be checked without removal. As long as there isn't any cracks in the rubber bushing around the bearing and no significant play its good. 

I don't necessarily have vibrations, it's a clunk after shifting and engaging the next the gear. Unless I shift delicately then there is no clunk. 

Picture of it sitting in the garage. Did a short drive today and it was good. Minus the shift clunk. 

[B C]

Noisy lifter all better?

I always wanted to try some shockproof gear oil in the trans and diff to see how it helps cushion the lash noise

in the E46 world, that drivetrain noise is referred to as the “M Clunk”. The LSDs really can be that noisy

https://www.zpost.com/forums/showthread.php?t=166867

https://www.6speedonline.com/forums/bmw-m/173049-e46-m3-driveline-clunk-what.html

[Boris3]

I forget you did replace subframe bushings?

[gilber33]

B C said:

Noisy lifter all better?

Yup. Found one that was probably all the way out of adjustment. 

Boris3 said:

I forget you did replace subframe bushings? 

I have not touched the driveline at all - including rear subframe bushings. I'm treating everything in this car as if it's never been replaced.

[Boris3]

Reason I asked is that if these are shot it can also cause the clunk.

Differential bolts to the subframe are all tight?

[SteelBlue]

B C said:

in the E46 world, that drivetrain noise is referred to as the “M Clunk”. The LSDs really can be that noisy

Or when the subframe is tearing the floor out of the car 

[gilber33]

Boris3 said:

Reason I asked is that if these are shot it can also cause the clunk.

Differential bolts to the subframe are all tight? 

They should be. My hope is to pull the driveline out and do new guibo, CSB, diff mount bushing, and rear subframe bushings. 

SteelBlue said:

Or when the subframe is tearing the floor out of the car 

Ew

[gilber33]

Love comparing the size of older cars to newer ones. 

Also started cleaning up the head from the next engine. I should have taken some before pics because it was very gross. 

[gilber33]

I am probably going to take this block in to get honed, but in order to do so I need to remove these things. I believe one drives the oil pump and the other is the oil pressure sending unit. I know the gear for the oil pump can not just be remover and reinstalled, but can this little piece pop out? And how do I remove the oil pressure unit? 

[B C]

That aluminum bit is an oil pressure relief valve. You can remove it, no problem, with a 22 or 24 mm wrench or whatever it is. Theres just a loose spring on the other side.

the oil pump drive shaft can be removed via the recessed cap with the bmw logo on it. Make sure you do not forget to put that part in! Ive read a couple threads of people anxiously firing up the engine and quickly realizing they forgot a part. You should also use a drill and a 6/8mm socket on the other end of the shaft (the end under the bmw cap) to prime the oil pump and preoil the engine before startup

[jc43089]

Do NOT remove the intermediate shaft bearings unless there is something wrong with them.  Replacement is not an easy task.  They need to be honed to size after installation.

[gilber33]

jc43089 said:

Do NOT remove the intermediate shaft bearings unless there is something wrong with them.  Replacement is not an easy task.  They need to be honed to size after installation.

I'm not removing that. I just need to know if it's okay to remove this rod without doing anything crazy to reinstall it.

[jc43089]

gilber33 said:

I'm not removing that. I just need to know if it's okay to remove this rod without doing anything crazy to reinstall it. 

It should just pull out.  But it's been a while since I built an M20.  

You can take the intermediate shaft out for cleaning and stuff just the bearings should stay in place.

[gilber33]

Cars and Coffee in Cedarburg. Fit both car seats in the back seat! They fit much better than I thought they would.

[Jdesign]

Looks great!

[gilber33]

Jdesign said:

Looks great!

Thank you! 

Started assembling the head last night. Got a bunch of dremel buffing pads which made cleaning the valves and head pretty easy work. Dusty and dirty. But easy. 

[gilber33]

Looking for some insight here. Pulled the pistons out last night. My plan was have the block honed and then do new rings and bearings. There's some light scratches on the side skirts - you can't feel them. There's also no vertical scratches on the cylinder walls and the cross hatching is still very visible. 

I've read to take an emery clutch or scotch Brite pad or something to clean up the pistons. Think I'm okay to move forward with my plan? 

[B C]

The one side of the piston is a bit more scuffing that I have usually seen on an M20. When I asked the machinist/engine builder about it he said it is no concern/as long as the cylinder bores are clean.