sha4000

iTrader: (1)

Even if you press the 6301 bearing into the idler pulley it wont sit on the shaft of the engine because it wont have the small recess in the back of the pulley like the OEM bearing has.

RA40

iTrader: (6)

Interesting, I'll have to check engine fitment on the one I did last week, my pulley had an NSK 6301 in it. I wonder if Toyota had some variations in model years.

sha4000

iTrader: (1)

The problem is that the ID of the 6301 comes from the extra bushing in the middle of the OEM bearing. In my case I would have to get the measurements of the OEM bearing without that bushing, find that bearing, press that bushing out of the OEM bushing and then press it into the new bushing.

RA40

iTrader: (6)

Looks like Toyota has some slight variations. The most recent assembly that is in the car uses a different bearing, the 6301 bearing is from the original idler.

sha4000

iTrader: (1)

That last pic looks like the tensioner pulley. Which pulley are you using in YOUR car? And does it sit on the lip of the shaft that's on the engine? That lip is what balances the pulley.

RA40

iTrader: (6)

Both those are the idler pulleys for the mount pictured. Both fit without clearance issues. The 98+ looks to have that bushing, IDK what the 90-94 has.

sha4000

iTrader: (1)

They one in the right in your second picture looks just like my OEM bearing, the one in the left looks like the 6301 bearing minus the bushing. The lip on the engine side fits inside the space on the back of the bearing. I can mount the 6301 but it would be spinning against the lip instead of spinning around it. Can you see what I'm talking about. You have the same thing on your engine.

RA40

iTrader: (6)

I get it. Looking at Lexus South Atlanta part #s idler #2 for the 97 which should be same for the 95-96 as well.
166040F010 ; 1660450010; 1660450030

These are listed for idler #2 for the '99 and should carry over to the 98 and 00.
166030W010 ; 1660350010; 16603-50010; 1660350020

They used different bearings in the two idlers I have on hand. Can't go out and buy a bearing until the bearing in the pulley is verified. Toyota doesn't make it easy for us in this instance.

Tom57

I'm trying to solve the same bearing replacement question for the serpentine belt idler pulley for the '01 - '06 LS430, and found this thread.

The replacement idler pulley for the LS430 comes up on Lexus parts diagram as the same number 16604-0F010 (which supersedes the prior 50010 and 50030 numbers) as the '95 - '97 LS. The OE idler pulley bearing in a '01 LS is NSK BD20-15DUL. The complete replacement pulley with bearing is listed by Lexus as Dayco brand (#89154 - available for ~$40+). However, I cannot domestically source the high-quality OEM bearing - BD20-15DUL for the idler pulley.

The OE tensioner pulley bearing in the '01 LS is NTN 6203LU. I was able to source this bearing locally. The complete replacement tensioner pulley with bearing for the LS430 (16603-0W030) is listed by Lexus as a Dayco brand. NOTE: Dayco website and all online sites show Dayco #89026 pulley as the compatible OE replacement tensioner pulley for the 430, but that pulley is NOT the correct fitting pulley. The Dayco #89006 is the correct replacement, with all of the correct dimensions.

RA40

iTrader: (6)

Wow, interesting that Toyota carried the pulley over for the 3-LS's and we'd be able to use the Dayco #89006 in the 95-97's. Wonder if Nachi or Koyo has a fitment for the NSK BD20-15DUL? I'll call the local bearing shop tomorrow and see what they have.

sha4000

iTrader: (1)

I spent a lot of time online about a year ago trying to locate NSK BD20-15DUL with no luck. Glad to have another mind trying to solve this issue.

YODAONE

Anyone have comments on the imprecision on the idler pulley bolt diameter In relation to the idler pulley bearing.

The bearing is centered on one end by the fan bracket boss, and held in place by friction on bolt head torque on the other....not exactly Perfect

Lexus should have used a precision shoulder bolt...





Too much tolerance between bolt and tensioner bearing



This is what positions the bearing...soft aluminum



Mind the gap....



This application calls out for a shoulder bolt...



Another angle of shoulder bolt

sha4000

iTrader: (1)

If you put too much torque on the bolt the pulley wont spin.

Tom57

I think you mean the Dayco #89154 (idler pulley) could be used in the '95 - '97s. That's the pulley that the '01 - '06 LS's share the common Lexus part #16604-0F010 with the '95 - '97's. The Dayco 89006 is the tensioner pulley in the '01 - '06 (Lexus part #16603-0W030).

Tom57

I see your point.

The '01 - '06 use the exact same pulley plates (outside end of pulley under bolt head covering the bearing) for both tensioner and idler pulleys. Part #1665950022. However, the '96 LS, for example, has plates too, and uses the same pulley plate part #1665950022 for Pulley # 1 (tensioner pulley) as the '01 - '06, but there's a different part # for the idler pulley plate (part #1665950021). Does the idler pulley plate in the '95 - '97 have a slight rim bushing/flange that inserts into the outer end of the bearing?