1994 Q45 idler pulley dimensions? I mixed them up? please help

[Overcamber]

Hello..I replaced the 3 idler pulley bearings(originally NTN 6301LU) last august on my fathers Q45 with new NSK6301DU bearings..not sure if they are an inferior bearing or not but with only 800 miles on them they were making noise..I thought it was timing chain noise because the bearings had been replaced but to my disbelief this morning it is the bearings that are sloppy when the center if held tight?..anyways I know the wide pulley is for the altenator belt but the other 2 are different diameters?...one is 89 mm outside diameter and the other a a bit smaller at 84 mm across....hopefully someone can tell me which pulley is for the A/C and which is for the power steerring/water pump?....thanks in advance .by the way 70,000 miles on the car.any comments on the bearings is appreciated as well

[maxnix]

Read TexasOil's post on various grades of idler bearings.

Is the FSM no help? I don't think I can measure mine. Actually, I have new one in bag. I'll measure and post part number.

[Overcamber]

thanks Maxnix...yes i've read Texasoil's thread on this and send him an email..wasnt sure if he would respond or not but am counting on it...the FSM doesnt really specify anyhting on the pulley size?

my small pulley is stamped 3225

and the larger one is stamped 3209

if you know what # yours is and where it goes I can figure out mine through process of elimination thanks again

[goody90q45]

anyways I know the wide pulley is for the altenator belt but the other 2 are different diameters?...one is 89 mm outside diameter and the other a a bit smaller at 84 mm across....

They should be different widths also. The power steering pulley has two bearings.

[maxnix]

Damn, initial search was a bust. I know I bought all three and only installed one. I'll keep looking. I thought I checked all the boxes though.

[Overcamber]

my altenator looks the same as yours but the other 2 are the same width as the A/C..just different diameters and the car was bought new so I know its never been altered but those are great pics none the less..thanks

still hunting for the answer

[Overcamber]

They should be different widths also. The power steering pulley has two bearings.

maybe we're onto something here goody94q45? ...one of mine are the identical diameter to the altenater?..is your p/s tthe same diameter just different width?

[maxnix]

PS looks a little taller in the picture.

[Overcamber]

do you think they both look taller than the altenator?...then that blows that theory....lol

[maxnix]

PS looks a little taller in the picture.

OK, AC looks larger than ALT. Difficult to tell about PS.

A different view would be great, or I could find my spares.

[Overcamber]

really appreciated the effort Maxnix...hopefully someone else will chime in with the answer..

[goody90q45]

maybe we're onto something here goody94q45? ...one of mine are the identical diameter to the alternater?..is your p/s the same diameter just different width?

Here's the dimensions:

AC pulley 90mm X 18mmAlt pulley 84mm X 25mmPS pulley 84mm X 29mm (2 bearings)

The NTN 6301LLU is OEM and is a double shield contact bearing.The NSK6301DU is aftermarket and is listed as a sealed contact bearing which I believe is the same as the OEM version.

I think you're right that the bearing's early demise may be due to the wrong pulley size and not the NSK bearing itself. Just in case, if you can get your hands on NSK bearings (you found out they're not available from the stealership?) you can probably get the NTN's also. Go with OEM for the next set. Good luck.

[Overcamber]

words cant describe how appreciative I am of you taking the time to help me out like this..you guys are a class act!

my sincerest thanks

[maxnix]

Thanks, Mike. Still can't find my pulleys, so there must be another box somewhere in my garage.

[goody90q45]

Mine happened to be sitting on the workshop countertop (for the last 6 months) so I didn't have to go searching bins to find them.

[maxnix]

Wish I had a workshop or even just a counter top.

[elwesso]

Fabulous information Mike.. thanks!!!

[Overcamber]

Read TexasOil's post on various grades of idler bearings.

Is the FSM no help? I don't think I can measure mine. Actually, I have new one in bag. I'll measure and post part number.

Hi..I've read Texasoil's post on idler bearing grades but be damned if I could find it again..would it be possible for anyone to post the link?..thanks again

[maxnix]

zerothread?id=99448

BTW all ball and roller bearings ARE metric. These are 12 M IDx 32MM ODx 10MM wide. The industry standard ID is '301SS' (ss for stainless steel side plates) or just plain '301' for 'rubber' side plates--either work in our application.

[Overcamber]

thx buddy..someone had another thread link posted were Texasoil explained the ones he sells were used in aeospace applications?..

[maxnix]

thx buddy..someone had another thread link posted were Texasoil explained the ones he sells were used in aeospace applications?..

Yes, actually manufactured by same one who supplies submarine fleet.

[Overcamber]

Just installed 3 brand new SKF Explorer bearings w/C3 clearances. Still getting loud noise from alternator idler pulley, but can no longer hear the other 2.Does anybody know what the bearing clearances are for these idler pulleys.....are they standard clearance? C3? C4?

[qship96]

Considering all 3 of my factory pullys/bearings made it past 200K, replacing the pully assembly with a brand new one from Infiniti at around $50 seems the easiest and safest route as far as expecting them to last

[Overcamber]

Sounds like I may end up doing that, however, my dealership wants $117 each, which makes it a bit pricey

[maxnix]

http://www.infinitipartsusa.com

Joe is our friend.

[Overcamber]

thx maxnix..that site is great!

[xmateo]

What is the difficulty level of replacing belts, pulleys and/or bearings?

Any specialty tools I need or tricks to completing correctly?

The only time I've played around with belts was on an engine with a serpentine belt - that was pretty easy.

Also, if the pulley looks fine and the bearing is the suspected problem, what is the recommendation - replace the whole thing or just the bearing?

[maxnix]

Not really, but it is nice to have a lift to get at it from underneath.

Be sure to use the best grade of bearings you can obtain, and replace all the belts at once.

[YELLOW S13]

Yes I know this is an old post rather not make a new one. Ok want to make sure I got all this right did all my belts hasnt fixed the squeal and still lags when i gun it. I hope and assume its the bearing sooo I found this:

http://www.ebay.com/itm/300384295460?ru ... 3D1&_rdc=1

IMO Great price and says 6301LLU right on there.

Thing that concerns me is the below vs what texasoil has posted:
12-MM ID
37-MM OD
12-MM Width

From Texasoil:
"BTW all ball and roller bearings ARE metric. These are 12 M IDx 32MM ODx 10MM wide. The industry standard ID is '301SS' (ss for stainless steel side plates) or just plain '301' for 'rubber' side plates--either work in our application"

sooo 12 ID
32 vs 37 OD
12 vs 10 WIDTH which is correct?
The ebay item claims to be 6301LLU which is supposedly correct but texas oil says sizes are different?

[goody90q45]

.....Great price and says 6301LLU right on there.

Thing that concerns me is the below vs what texasoil has posted:
12-MM ID
37-MM OD
12-MM Width

I measured a couple of old bearings and 12 x 12 x 37 is the correct size. 6301LLU is the correct # so I'm thinking the seller is confused.