gaspam

so my bearings went out on my s/c pulley so i replaced them myself and since i didnt see a diy on here i thought i would throw one up...

pretty easy job and no specialty tools needed.

the offending bearing



get your new nachi bearing Nachi part no. 45BG07S5AIG-2DL
got mine from ebay for $70 http://www.ebay.com/itm/171143893370...84.m1439.l2649



then put the bearing in the freezer for a few hours ( i put mine in for 8hrs)
** ice cream and chocolate highly recommended- and no , im not gay lol



then bust out your 24mm wrench and strap wrench if you got one to hold the s/c clutch from spinning while you loosen the bolt holding the pulley on.... i didnt have a big enough strap wrench so i used 2 metal clamps on the clutch to keep it from spinning as there is a piece of metal that they will stop against when you are torquing on the pulley bolt







pulley is now off



then i had to get the old bearing out of the pulley... for this i made a little tool to pound out the old bearing





remove snap ring on front of pulley and now hammer it out like thor would.... mine came out without too much drama



then i cleaned up the inside of the pulley with some mineral spirits and then took it upstairs and put it in a 215f oven for about 45 minutes to slightly expand the pulley



then i put the pulley on the floor and quickly got the chilled bearing out of the freezer and dropped put it in the pulley and it slide right in like butter

all cooled off and set in just like from the factory



now reintsall the snap ring in the front of the pulley and just slide it back on the supercharger snout( place a little lube on it) , put red loctite on the bolt and torque down to 60ft/lbs

grab a beer and be happy that you saved around $1500 vs going to the dealer

AutoLuxury

i followed this technique and it worked!

AgSilver

Very nice

berti_00

Good job bro, you didnt even have to lift the motor at all?

Toadster

wow - yah, no joke?!

that's pretty nice! must have popeye forearms though

BagMan

I need to pick up a box wrench. What size do I need? 24mm or 15/16?

turbo97se

Very nice! Thanks for sharing ... missed one step though ...

Drive past the dealer showing them the finger and waving 15 $100 bills

I probably need to do this soon, my S/C pulley is starting to look like that

Great straightforward DIY

gaspam

no need to lift engine, dont even need to remove fan shroud if you use a wrench like me... if you wanted to use a ratchet or breaker bar then you would need to take fan shroud out to get the ratchet in there

i do workout lol

technically its a 24 since german car = metric, but a 15/16 will work too

haha true i forgot that step and if your bearings look like mine did then better change them sooner than later as you dont want your bearings seizing with the belt on still trying to turn it as could damage you s/c or your crank pulley

slownrusty

Awesome thread, does the heat from the oven and the cold from the fridge really make a difference in the respective metal expansion and contraction to facilitate the bearing install?

gaspam

thanks and yeah it makes a huge difference... without doing that, there is no way you are getting the bearing in the pulley housing without a press.... with doing the pulley in oven and bearing in freezer the bearing just slides right in with no resistance an within 10 seconds the bearing has warmed up enough from the hot pulley that there is no way its coming out

also same to be said about getting the pulley back on the s/c shaft without grease/oil... if you dont lube the s/c shaft then the pulley wont slide back on

slownrusty

Great thanks for the clarification, I appreciate it.

gaspam

on a side note- the car feels a lot stronger after putting in the new bearing... would not think there would be enough friction in the old bearing to cause such difference... that old bearing must of been really dragging as the new one feels like i added 50hp lol

allenjdmb

question...is there a particular symptom that I should be on the lookout for? My car only has 32k miles, but I think I hear a bit of bearing noise. Thoughts?

gaspam

well mine was easy as you see in the first pic the bearings were exposed, which they shouldnt be as they should have plastic piece that keeps dirt out and keeps the grease in as you can see on the new bearing.

another symptom is grease all over the underside of the plastic engine cover where the mercedes star is

also if is sounds chattery like a diesel truck in that area while running

you can also take the s/c belt of and spin the s/c pulley with your hand and if it sounds like skateboard wheels with sand in them then probably need replacing... but if you can spin it and no sounds or at least smooth sound then bearings are ok.

Toadster

here's a quick video on the bearing sound



so - how did you torque it down with the 24mm wrench?

gaspam

turned it to the right righty tighty, lefty loosy

torque specs are only 60 ft/lbs w/red loctite

Toadster

yes, but how did you get a torque wrench (or what kind) in there without moving things around?
that's usually the tougher part since you have to either move the fan shroud or lift the motor to get to that bolt

BagMan

I jacked up the motor and used a torque wrench

Toadster

yes, but I thought the cool part of this replacement was that he used a 24mm box wrench and improvised the strap wrench method with those two metal clamps

BagMan

That works fine if you can guesstimate the torque with a box wrench.

I can get pretty close by feel.

gaspam

^^this... plus its only 60ft/lbs.... its not like a torque to yield bolt like the crank pulley where hitting the exact torque spec is uber important

Yacht Master

+1500

Denroll

What's the trick for making sure you don't get the fake Nachi knock-off bearings? Last I heard, them crafty Chinese were even copying the box art on their fake bearings.

Toadster

my fake one is blue - not red - we'll see how long it lasts

my tech said well, if the red (real) Nachi lasted 18k miles, expect about 9k out of the fake one

berti_00

if i knew they were fake i would not even bother...