FrankenJeep Parts Ident plz - Idler pulley bearing replacement

[Jim]

Thread summary as of 4/28/2020

Part number J321-7201 (discontinued), superseded numbers: J3173164 & J3143732 (no source found for either of these)

Bearing: Canada 6203 RS

Gates replacement Pulley / Bearing assembly - direct fit (cut off the "cap" on the old pulley to extract the bolt & re-use the bolt as-is).

Gates DriveAlign Idler Pulley 38038
Product # 78031038
UPC: 0-72053-69559-5

Attribute	Specification
Number of Pulleys	1
Number of Grooves	1
Material	Steel
Contact Surface	V-Grooved
Pulley 1 Flanged	No
Outside Diameter (mm)	94
Bearing Bore Inside Diameter 1 (mm)	17
Width (mm)	19
Contents	Pulley

======================
Hey folks,

In the York air compressor install for 90 YJ (4.2L) the belt routing changed. One of the idler pulleys needs a bearing replacement. The existing pulley does not have a "user serviceable" bearing. I see no part number on the pulley. I'm trying to locate the pulley and could use some help. I have no idea what make/model Jeep I should be searching under - 1985 Wagoneer with Factory air???

The pulley is for the air conditioning belt and is the silver colored top right pulley on the A/C belt in the attached photo (which is not my jeep). Also attached is a pic of the pulley I have (bearing is crimped into the pulley housing). The version in the pulley photo shows what looks like an open-faced pulley with a push-in bearing with a bolt going through the pulley - a different style - not that I care - so long as I can find one that fits (user replaceable bearing a plus).

Searching shows these pulleys as possibilities - though I'll likely need some sort of spacer for the bolt that passes through the bearing ID.

https://www.oreillyauto.com/detail/b.../38038/4347947

https://www.ebay.com/itm/For-1985-Je...ry!80526!US!-1

https://www.ebay.com/itm/Dayco-Drive...EAAOSwFnlebnwr

One step forward... I found a part number for the pulley I have... J321 7201. Now to either find one or to find the replacement. This could be a simple call to the local Jeep dealer to buy it from them (or maybe see what supersedes this model and is current).

Supersessions!! J3173164; J3143732

Any help is appreciated. At this point I am unable to find any source for the two new part numbers - or any picture of either part number.

[FINOCJ]

I think we may need a bit more info....in the diagram with the green line/belt path, this would be the idler pulley in the upper right corner (looking at pic)? Was this pulley not original to your engine set-up? I realize the york compressor was not, but might be helpful to know what was there originally?

[Jim]

Yes, the green path - upper right corner - the silverish pulley with the orangish-red bearing. The silverish pulley was nothing there in the original setup.

The original setup had the alternator approx where the A/C comp is located. For adjustments to the original setup two V-Belts - the alternator adjusted for its belt and the PS pump adjusted for its belt. Each belt rode over the top of the water pump. With the A/C setup, the compressor does not offer a belt adjustment so an adjuster had to be put in somewhere - and that's what this pulley does. Sadly, the A/C belt now does not contact the water pump any more and the PS pump belt is the sole belt to spin the water pump.

The pulley I have is taken as a non-replaceable bearing. The pulley in the picture I believe is a user replaceable bearing and is the style of pulley I'd like to have and is perhaps one of the new part numbers.

The pulley I have came in with the York setup. For the brackets and pulleys I installed for the York compressor upgrade, I do not know what year/model Jeep they came off of (though with part numbers this might be not needed). Early 80's Grand Wagoneer, 258CID motor with FACTORY air (not dealer air and not NO air), with V-belt (serpentine belts were in use at this time) is perhaps the closest I can find for vehicle.

In this picture, item 34 is what I have and is where I found the J321-7201 part number. On that same diagram is a pulley that might work for me - item 38 - but the part number page does not cover 38 so I'm a bit stuck (at least until Jeep opens tomorrow).

Other helpful sites:
Factory Chrysler Parts
https://www.factorychryslerparts.com.../J3217201.html

Mopar Parts Overstock (same site - diff domain name)
https://www.moparpartsoverstock.com/.../J3217201.html

[Spieg]

Have you pulled the spindle out and measured the bearing inner diameter?

[Jim]

No. It's a captive design.

A grinder or, preferably, a lathe, would be needed to remove the folded over cone / the crimped metal on the "inside" (closest to the bracket) that holds the bolt/bearing into the pulley.

I believe it's manufactured in this order:
A bolt is placed through the bearing. A sleeve might be placed between the bolt and the bearing's ID. The bolt/bearing assembly is placed into the pulley. The open face where the bearing is slid into the pulley is bent inward (crimped) to hold the bearing/bolt into the pulley.

If I _had_ to re-use the same pulley, I'd open up the closed side of the pulley to get access to the "bolt head" side. I'd then work to open up / un-fold / un-crimp the metal that holds the bearing into the pulley. I'd then, via the opening in the closed side of the pulley, push the bolt/bearing assembly out of the pulley. Replace the bearing. Reassemble - with the lagging issue of how will the pulley stay on the bearing - would I have enough metal to re-fold / re-crimp a portion of the crimped side or would the bearing/pulley be enough of a press-fit to hold the pulley on the bearing (an internal C-clip might also be involved).

I'm of the belief that the bearing (in the first pic) is user replaceable and is of a press-fit to hold the bearing/pulley together. This pulley might be press-fit but I won't know until I take it apart - and the jeep doesn't move without this pulley (well, not too far as there's no alternator). I don't wish to back myself into a corner just yet. I'd like to find a replacement.

[Jim]

As I'm getting ready to put the jeep together (exhaust work tomorrow - yea! - no more exhaust manifold to down-tube leaks!!) I figured it'd be wise to take some pix while this is easy to get hold of...

Bearing
Canada
6203 RS
? B (I think)

https://www.bearingscanada.com/6203R...2-p/6203rs.htm
https://www.nationalprecision.com/ba...etail/6203-RS/

https://www.motionindustries.com/tax...se/en?q=6203RS

.

[Brian]

Maybe this one too?

https://www.amazon.com/6203RS-Bearin.../dp/B002BBJSPE

[Jim]

Certainly looks like it! Thx.

I'm holding out for the assembly as I'm not certain, if I went bearing only, if I'd end up with a usable pulley. If I come up dry on the assembly, I'll be going bearing only with a rebuild thread. I know I can separate the parts - I just don't know I can put them together where they'll stay together.

This item _really_ catches my eye... Dimensions - OD, Width, Belt sizing... I'm calling to see if they can get one to the store for a good look.
https://www.oreillyauto.com/detail/b.../38038/4347947

I called the store - they'll have it available Monday about Noon. Crossing of fingers.

[Spieg]

My assumption would be that the whole spindle (bolt/sleeve/bearing cap assembly) is simply pressed into the bearing and could be pressed out to replace the bearing and/or pulley, but having it in your hands, I'm sure you have a better feel for how it is put together.
None the less, I bet you could use a micrometer to measure the ID of the bearing as it is here;

[Trevor?]

Jim previously posted:

[Jim]

While I don't have the original / in-use bearing in hand, I do have the likely replacement in hand - and it looks like it'll be a good replacement!

I'll make a post in a day or two... 1) once I know this pulley/bearing assembly is usable and 2) once I pull apart the old unit. Once the old unit is apart, I believe the questions will be answered.

With the new pulley/bearing, the bearing can be pushed through the pulley - a press-fit interface that keeps the two together.

[Jim]

DONE !!! WORKING !!!

That pulley / bearing assembly is a direct fit.

I "sliced off the cap" that I noted in the photo above. This allowed the bolt to be removed from the bad bearing / pulley. The new pulley / bearing has the same bearing (at least close enough - IIRC 6203 LU vs 6203 RS). Direct bolt on.

While I had things apart, I took pix and some measurements as maybe some day another jeeper will be "in search of" information on sourcing parts for their vehicle.

[Jim]

Pix continued...

[Jim]

Now, on the "crimped" side of the old pulley, I did cut away just a small portion of the crimp. I also did try to push out the bearing with the press - no movement (most of the crimp remains, I didn't anticipate movement).

Tomorrow, I'll probably cut off the rest of the crimp and press the old bearing out. With no crimp, would a new bearing press in with enough interference that the bearing / pulley would stay assembled as-is?

[Trevor?]

If I had to wager a guess, i'd say that they crimped the bearing into the pulley because it would be cheaper than a press-fit. Press fits can be tricky to get right, and tool wear would be significant with high volume production. A slip fit and a crimp however would allow larger tolerances, and would still support the axial loads here which are pretty low, and it would take much longer to wear out a set of crimping dies than it would take to wear out the kinds of reamers I would imagine they would use to cut that ID. Also, its probably not a thru-hole. There is likely a step on the other side of the pulley to retain the bearing from that side. That could make it all the more challenging to ream to size. One typically needs to control diameters to tenths of a thou to get press-fits right.

But again, that's just a guess.

[Jim]

I'd agree - low cost manufacture. One side is completely covered - the bearing can not "slip out" that side. The crimp side keeps the bearing from slipping out the cirmped side. Thus my concern - if I were to cut away the crimp, would a replacement bearing (to pulley) have enough of a press-fit that I could trust the parts staying together.

I've had an unexpectedly busy day (with a big curve ball tossed in my lap) and I'm not getting to the garage to cut off the crimp to extract the bearing - to test the snugness of the bearing / pulley interface - tonight.

The orange seal replacement bearing / pulley is designed as a press-fit (it's open on both sides with no crimp on either side). When the next bearing fails, I could see pressing the failed bearing out of the pulley and pressing in a replacement bearing - and having confidence it'd stay together.

[JGRubicon]

Nice! Glad you found the right part!

[Jim]

Here's the pulley, disassembled.

One side has the "cap" (that was removed days ago to pull out the bolt). Today I completed the removal of the crimp. Then I could press the bearing out of the pulley.

[Spieg]

Wow, what a crap design. Never seen anything quite like it. Maybe they enclosed the bearing to help keep dust out?

[Jim]

I'm with Jason - low cost / easy manufacturing with a "the whole unit is a replaceable part" mentality.

I do find it curious - the "enclosed side" of the bearing did not have a seal. Only the exposed side of the bearing was sealed. More cost cutting????