well, i didn't see any info on this, so i figured i would put it out there.

i was hearing horrible noises from my idler/tensioner pulleys on my s4, so i decided to replace the bearings. you can get high quality SKF or NSK units from local industrial suppliers for under $10.00 a piece. there are also ceramic versions and all kinds of clearance variants, etc you can get.

the bearing dimensions for both tensioner pulleys are the same (P/S and A/C):

40mm OD
17mm ID/journal
12mm width

***the part number is usually 6203 RS. the 6203 is the size and the RS designates the seal type. on NSK bearings it is DU instead of RS. all you really need to remember is 6203 with a seal on each side.

here are the two i bought:


Installation:

*the P/S pulley was very tight and was a press in/out fit. be very careful pressing in the new one because you can bend/damage the seal. use a proper size adapter to press the new one in and only press on the face of the outer metal ring. i don't recommend using a socket, but it can be done if you are careful. when using a socket, use an oversized one to drive the bearing in initially (to avoid hitting the seal), then use one that just clears the bore (just under 40mm socket)

*the A/C pulley had an internal snap ring and a slightly looser press fit. again, be careful with the seal.

it only takes a few minutes to do this and you only have to loosen the belts and unbolt the pulley nuts, which are 17mm and 22mm IIRC. this is also a good opportunity to bead blast and repaint the pulleys.

 

hey thanks for the write up man....i'll have to look into that.

 

I know I'm bringing this thread back from the dead but I need to replace my bearing too (and the PS pump eventually) but I've been searching for 6203du bearings for a while and can't find anything. I wasn't sure if they were the same bearing but was gonna look into it. All I knew was what was written on the bearing seals. I really appreciate this cause I sure didn't want to buy the pulleys from mazda because they were 60 bucks a peice even with my discount, and no auto parts stores sell them. I'm also a bit drunk and am rambling so ya, thanks.

 

Search for "bearing" near your address and call around asking for 6203 sealed bearings. There are lots of industrial supply companies with them.

There is also ebay.

I would get the tightest clearance you can while still at a reasonable price. I get some minor vibration from mine and I suspect they have a little too much clearance.

 

Take the old bearings to a bearing supplier and ask them to find a suitable replacement.

 

I just replaced my tensioner bearings and wanted to contribute to this thread.

As mentioned earlier, you can get this bearing at an industrial supply house. You can also get it at almost any auto parts store.

It's used for pulleys, pilot bearings, alternator bearings, and so on. Since it's a very common bearing, they can be obtained from any auto parts store. If you ask them for a 6203 bearing they may not know what you're talking about. A very common use for this bearing is a crankshaft pilot bearing.

The bearing may also carry these part numbers:
-6203 (sometimes there will be a prefix or a suffix)
-9-00090-679-0 (Nachi)
-394 25010 331 (IMC)
-035-903-221 (SKF)
-0680035 (Beck/Arnley)
-303SS (timken)

This is a list of the vehicles that use the 6203 as a pilot bearing (copied from my parts catalog.) Just go to an auto parts store and ask for a pilot bearing for any of the vehicles listed. Most of the time they'll have SKF or Nachi. Both are good quality bearings. Try to avoid cheap Chinese bearings, such as FIT. Timken bearings are also very good quality but are generally 3-4 times the cost of SKF and Nachi.

CHEVROLET LUV PICKUP
year Type liter del. asp. vin designation where used position notes
1982 L4 1.8 CARB N N Crankshaft Pilot Bearing
1982 L4 2.2 FI N S Crankshaft Pilot Bearing
1981 L4 1.8 CARB N N Crankshaft Pilot Bearing
1981 L4 2.2 FI N S Crankshaft Pilot Bearing
1980 L4 1.8 CARB N N Crankshaft Pilot Bearing
1979 L4 1.8 CARB N N Crankshaft Pilot Bearing
1978 L4 1.8 CARB N N Crankshaft Pilot Bearing
1977 L4 1.8 CARB N N Crankshaft Pilot Bearing
1976 L4 1.8 CARB N N Crankshaft Pilot Bearing
1975 L4 1.8 CARB N N Crankshaft Pilot Bearing
1974 L4 1.8 CARB N N Crankshaft Pilot Bearing
1973 L4 1.8 CARB N N Crankshaft Pilot Bearing
1972 L4 1.8 CARB N N Crankshaft Pilot Bearing

DODGE RAM 50
year Type liter del. asp. vin designation where used position notes
1993 L4 2.4 FI N G Crankshaft Pilot Bearing
1992 L4 2.4 FI N W Crankshaft Pilot Bearing
1991 V6 3.0 FI N S Crankshaft Pilot Bearing
1991 L4 2.4 FI N W Crankshaft Pilot Bearing
1990 V6 3.0 FI N S Crankshaft Pilot Bearing
1990 L4 2.4 FI N W Crankshaft Pilot Bearing

HONDA PASSPORT DX
year Type liter del. asp. vin designation where used position notes
1996 L4 2.6 FI N 4ZE1 Crankshaft Pilot Bearing
1995 L4 2.6 FI N 4ZE1 Crankshaft Pilot Bearing
1994 L4 2.6 FI N 4ZE1 Crankshaft Pilot Bearing

ISUZU AMIGO
year Type liter del. asp. vin designation where used position notes
2000 V6 3.2 FI N 6VD1 Crankshaft Pilot Bearing
1999 V6 3.2 FI N 6VD1 Crankshaft Pilot Bearing
1998 V6 3.2 FI N W Crankshaft Pilot Bearing
1994 L4 2.6 FI N E Crankshaft Pilot Bearing
1993 L4 2.6 FI N E Crankshaft Pilot Bearing
1993 L4 2.3 CARB N L Crankshaft Pilot Bearing
1992 L4 2.6 FI N E Crankshaft Pilot Bearing
1992 L4 2.3 CARB N L Crankshaft Pilot Bearing
1991 L4 2.6 FI N E Crankshaft Pilot Bearing
1991 L4 2.3 CARB N L Crankshaft Pilot Bearing
1990 L4 2.6 FI N E Crankshaft Pilot Bearing
1990 L4 2.3 CARB N L Crankshaft Pilot Bearing
1989 L4 2.6 FI N E Crankshaft Pilot Bearing
1989 L4 2.3 CARB N L Crankshaft Pilot Bearing

ISUZU I-MARK
year Type liter del. asp. vin designation where used position notes
1984 L4 1.8 CARB N B Crankshaft Pilot Bearing
1984 L4 1.8 FI N B Crankshaft Pilot Bearing
1983 L4 1.8 CARB N B Crankshaft Pilot Bearing
1983 L4 1.8 FI N P Crankshaft Pilot Bearing
1982 L4 1.8 CARB N B Crankshaft Pilot Bearing
1982 L4 1.8 FI N P Crankshaft Pilot Bearing
1981 L4 1.8 CARB N B Crankshaft Pilot Bearing
1981 L4 1.8 FI N P Crankshaft Pilot Bearing

ISUZU IMPULSE
year Type liter del. asp. vin designation where used position notes
1989 L4 2.0 FI T F Crankshaft Pilot Bearing
1989 L4 2.3 FI N L Crankshaft Pilot Bearing
1988 L4 2.0 FI T F Crankshaft Pilot Bearing
1988 L4 2.3 FI N L Crankshaft Pilot Bearing
1987 L4 2.0 FI T F Crankshaft Pilot Bearing
1986 L4 2.0 FI T F Crankshaft Pilot Bearing
1985 L4 2.0 FI T F Crankshaft Pilot Bearing

ISUZU PICKUP
year Type liter del. asp. vin designation where used position notes
1995 L4 2.3 FI N L Crankshaft Pilot Bearing
1994 L4 2.6 FI N E Crankshaft Pilot Bearing
1994 L4 2.3 CARB N L Crankshaft Pilot Bearing
1993 L4 2.6 FI N E Crankshaft Pilot Bearing
1993 L4 2.3 CARB N L Crankshaft Pilot Bearing
1992 L4 2.6 FI N E Crankshaft Pilot Bearing
1992 L4 2.3 CARB N L Crankshaft Pilot Bearing
1991 L4 2.6 FI N E Crankshaft Pilot Bearing
1991 L4 2.3 CARB N L Crankshaft Pilot Bearing
1990 L4 2.6 FI N E Crankshaft Pilot Bearing
1990 L4 2.3 CARB N L Crankshaft Pilot Bearing
1989 L4 2.6 FI N E Crankshaft Pilot Bearing
1989 L4 2.3 CARB N L Crankshaft Pilot Bearing
1988 L4 2.6 FI N E Crankshaft Pilot Bearing
1988 L4 2.3 CARB N L Crankshaft Pilot Bearing
1987 L4 2.3 CARB N L Crankshaft Pilot Bearing
1987 L4 2.2 FI N S Crankshaft Pilot Bearing
1987 L4 2.2 FI T U Crankshaft Pilot Bearing
1986 L4 1.9 CARB N A Crankshaft Pilot Bearing
1986 L4 2.3 CARB N L Crankshaft Pilot Bearing
1986 L4 2.2 FI N S Crankshaft Pilot Bearing
1986 L4 2.2 FI T U Crankshaft Pilot Bearing
1985 L4 1.9 CARB N A Crankshaft Pilot Bearing
1985 L4 2.2 FI N S Crankshaft Pilot Bearing
1984 L4 1.9 CARB N A Crankshaft Pilot Bearing
1984 L4 2.2 FI N S Crankshaft Pilot Bearing
1983 L4 1.9 CARB N A Crankshaft Pilot Bearing
1983 L4 2.2 FI N S Crankshaft Pilot Bearing
1982 L4 1.8 CARB N N Crankshaft Pilot Bearing
1982 L4 2.2 FI N S Crankshaft Pilot Bearing
1981 L4 1.8 CARB N N Crankshaft Pilot Bearing
1981 L4 2.2 FI N S Crankshaft Pilot Bearing

ISUZU RODEO
year Type liter del. asp. vin designation where used position notes
2000 L4 2.2 FI N X22SE Crankshaft Pilot Bearing
1999 L4 2.2 FI N X22SE Crankshaft Pilot Bearing
1998 L4 2.2 FI N X22SE Crankshaft Pilot Bearing
1997 L4 2.6 FI N E Crankshaft Pilot Bearing
1996 L4 2.6 FI N E Crankshaft Pilot Bearing
1995 L4 2.6 FI N E Crankshaft Pilot Bearing
1994 L4 2.6 FI N E Crankshaft Pilot Bearing
1994 V6 3.2 FI N V Crankshaft Pilot Bearing w/ BM Trans.
1993 L4 2.6 FI N E Crankshaft Pilot Bearing
1993 V6 3.2 FI N V Crankshaft Pilot Bearing w/ BM Trans.
1992 L4 2.6 FI N E Crankshaft Pilot Bearing
1992 V6 3.1 FI N Z Crankshaft Pilot Bearing
1991 L4 2.6 FI N E Crankshaft Pilot Bearing
1991 V6 3.1 FI N Z Crankshaft Pilot Bearing

ISUZU TROOPER
year Type liter del. asp. vin designation where used position notes
1991 L4 2.6 FI N E Crankshaft Pilot Bearing
1990 L4 2.6 FI N E Crankshaft Pilot Bearing
1989 L4 2.6 FI N E Crankshaft Pilot Bearing
1988 L4 2.6 FI N E Crankshaft Pilot Bearing
1987 L4 2.3 CARB N L Crankshaft Pilot Bearing
1987 L4 2.2 FI T U Crankshaft Pilot Bearing
1986 L4 2.3 CARB N L Crankshaft Pilot Bearing
1986 L4 2.2 FI T U Crankshaft Pilot Bearing
1985 L4 1.9 CARB N A Crankshaft Pilot Bearing
1984 L4 1.9 CARB N A Crankshaft Pilot Bearing

MITSUBISHI MIGHTY MAX
year Type liter del. asp. vin designation where used position notes
1994 V6 3.0 FI N H Crankshaft Pilot Bearing
1993 V6 3.0 FI N H Crankshaft Pilot Bearing
1992 V6 3.0 FI N S Crankshaft Pilot Bearing
1991 V6 3.0 FI N S Crankshaft Pilot Bearing
1990 V6 3.0 FI N S Crankshaft Pilot Bearing

MITSUBISHI MONTERO
year Type liter del. asp. vin designation where used position notes
2000 V6 3.5 FI N R 6G74 Crankshaft Pilot Bearing
1999 V6 3.5 FI N 6G74 Crankshaft Pilot Bearing
1998 V6 3.5 FI N R 6G74 Crankshaft Pilot Bearing

MITSUBISHI MONTERO SPORT
year Type liter del. asp. vin designation where used position notes
1999 V6 3.0 FI N 6G72 Crankshaft Pilot Bearing
1999 V6 3.5 FI N 6G74 Crankshaft Pilot Bearing

MITSUBISHI MONTERO SPORT LS
year Type liter del. asp. vin designation where used position notes
1998 V6 3.0 FI N P 6G72 Crankshaft Pilot Bearing
1997 V6 3.0 FI N P 6G72 Crankshaft Pilot Bearing

MITSUBISHI MIGHTY MAX SWB
year Type liter del. asp. vin designation where used position notes
1992 V6 3.0 FI N S Crankshaft Pilot Bearing

MITSUBISHI MONTERO SPORT XLS
year Type liter del. asp. vin designation where used position notes
1998 V6 3.0 FI N P 6G72 Crankshaft Pilot Bearing
1997 V6 3.0 FI N P 6G72 Crankshaft Pilot Bearing

 

Just did this. Thanks a bunch to the OP and contributors.