Idler pulley bearing replacement

[Jonathan]

I need some clarification on which parts I may need.

My A/C has been low on Freon for a couple seasons now and thus isn't being used. I don't always run with an A/C belt, but earlier this season I did have one on. I thought I had it good and tight using the tensioning bolt.

At some point I realized it was getting loose but also chewed. As it turns out, one of the pulleys on the tensioner bracket is not rotating true. This may have caused the belt to start to get shredded or it may not have, but the edge of the belt had started to interfere with the edge of the tensioner bracket itself. And it was sharp enough to start shaving off tiny piece by piece of the belt. You can really make a mess that way with the black rubber dust all over as it was shredding it while the engine was running.

I took the belt off and it was still intact, but the one edge was worn down a fair bit. That's when I noticed the pulley was wobbling. I started researching and found a reference on the DMC Store page to a knowledge article mentioning the idler pulley bearing should be replaced at the first sign of problems.

So here's my question:

Before going ahead and taking the pulley apart, am I only going to (probably) need this:

105638 1 7-2-1 Idler pulley bearing $5.63 A/C pulley replacement parts

I listed out a number of other parts all as part of the bigger pulley assembly and wondered if any of these are likely to be damaged as well (from your experience):

SP10376 2 7-2-1 Circlip-internal $2.16 A/C pulley replacement parts
101463 1 7-2-1 Pulley-adjuster $32.40 A/C pulley replacement parts
105470 1 7-2-1 Pulley spindle $22.78 A/C pulley replacement parts
SP10034 1 7-2-1 Washer M12 $0.36 A/C pulley replacement parts
SP10806 1 7-2-1 Locknut M12 $1.89 A/C pulley replacement parts
106257 1 7-2-1 Spacer, idle bracket $0.71 A/C pulley replacement parts
105471 1 7-2-1 Spacer, A/C comp $6.74 A/C pulley replacement parts

I don't mind if you tell me all I will need is the $5.63 idler pulley bearing, but if I am bound to need more than that, I'd just as soon order it all at once.

Thanks.

[David T]

I need some clarification on which parts I may need.

My A/C has been low on Freon for a couple seasons now and thus isn't being used. I don't always run with an A/C belt, but earlier this season I did have one on. I thought I had it good and tight using the tensioning bolt.

At some point I realized it was getting loose but also chewed. As it turns out, one of the pulleys on the tensioner bracket is not rotating true. This may have caused the belt to start to get shredded or it may not have, but the edge of the belt had started to interfere with the edge of the tensioner bracket itself. And it was sharp enough to start shaving off tiny piece by piece of the belt. You can really make a mess that way with the black rubber dust all over as it was shredding it while the engine was running.

I took the belt off and it was still intact, but the one edge was worn down a fair bit. That's when I noticed the pulley was wobbling. I started researching and found a reference on the DMC Store page to a knowledge article mentioning the idler pulley bearing should be replaced at the first sign of problems.

So here's my question:

Before going ahead and taking the pulley apart, am I only going to (probably) need this:

105638 1 7-2-1 Idler pulley bearing $5.63 A/C pulley replacement parts

I listed out a number of other parts all as part of the bigger pulley assembly and wondered if any of these are likely to be damaged as well (from your experience):

SP10376 2 7-2-1 Circlip-internal $2.16 A/C pulley replacement parts
101463 1 7-2-1 Pulley-adjuster $32.40 A/C pulley replacement parts
105470 1 7-2-1 Pulley spindle $22.78 A/C pulley replacement parts
SP10034 1 7-2-1 Washer M12 $0.36 A/C pulley replacement parts
SP10806 1 7-2-1 Locknut M12 $1.89 A/C pulley replacement parts
106257 1 7-2-1 Spacer, idle bracket $0.71 A/C pulley replacement parts
105471 1 7-2-1 Spacer, A/C comp $6.74 A/C pulley replacement parts

I don't mind if you tell me all I will need is the $5.63 idler pulley bearing, but if I am bound to need more than that, I'd just as soon order it all at once.

Thanks.

Typically all you need is the 2 bearings and an "O" ring for the cam cover. If you were running a long time on a bad bearing you could need other parts. You won't know until you take it all apart. It is also possible someone was there before you and reassembled things incorrectly messing up the alignment. You MUST install each bolt, washer, and spacer EXACTLY or the pulleys will not be in proper alignment. Refer to the Parts Manual 7-2-1 for the proper order of the parts. If the belt is chewed up it should be replaced. Don't overtighten the belt, it shortens the life of the bearings. The "O" ring is #3 in 1-1-4

[Jonathan]

Typically all you need is the 2 bearings and an "O" ring for the cam cover. If you were running a long time on a bad bearing you could need other parts. You won't know until you take it all apart. It is also possible someone was there before you and reassembled things incorrectly messing up the alignment. You MUST install each bolt, washer, and spacer EXACTLY or the pulleys will not be in proper alignment. Refer to the Parts Manual 7-2-1 for the proper order of the parts. If the belt is chewed up it should be replaced. Don't overtighten the belt, it shortens the life of the bearings. The "O" ring is #3 in 1-1-4

Thanks David.

"2" bearings if I am doing both pulleys (I think you only need one for each pulley, right)? I only think one of the two is wobbly, but both could be replaced at the same time if necessary.

I hadn't realized I would need that o-ring. I think it is the same one as #24 on the 7-2-1 diagram?

You are likely right about only figuring out what is needed once it comes apart. Also true possibly about it not being exactly installed correctly. I had thought this was one thing on my year one list I had a shop do for me, but now can't find a reference to having bought a replacement bearing for the job. Not sure, but yea, I'll double check it all when apart and get what is missing or damaged.

I can order two bearings and the o-ring and then go from there as needed. I think the car is staying where it is for the remainder of the season so no problem that way.

[David T]

Thanks David.

"2" bearings if I am doing both pulleys (I think you only need one for each pulley, right)? I only think one of the two is wobbly, but both could be replaced at the same time if necessary.

I hadn't realized I would need that o-ring. I think it is the same one as #24 on the 7-2-1 diagram?

You are likely right about only figuring out what is needed once it comes apart. Also true possibly about it not being exactly installed correctly. I had thought this was one thing on my year one list I had a shop do for me, but now can't find a reference to having bought a replacement bearing for the job. Not sure, but yea, I'll double check it all when apart and get what is missing or damaged.

I can order two bearings and the o-ring and then go from there as needed. I think the car is staying where it is for the remainder of the season so no problem that way.

In my Parts Manual 7-2-1 only goes up to part # 22 and does not call out the "O" ring behind the cam cover. You have to go to 1-1-4 to find it. Yes, you always replace the bearings in pairs and there is one each for each pulley (# 3).

[mluder]

I'm not sure you have to replace that o ring... You will have to remove the fixing bolts that hold that plate in place as they also hold the idler pulley assembly. But, you should be able to re-use it unless it's in poor condition. I've had mine apart and back together several times with no ill effect.

+1 on paying attention to the order of install... I'm actually missing some of the spacers and cheated with some over-sized nuts in a few places. Shade tree mechanic.

[David T]

I'm not sure you have to replace that o ring... You will have to remove the fixing bolts that hold that plate in place as they also hold the idler pulley assembly. But, you should be able to re-use it unless it's in poor condition. I've had mine apart and back together several times with no ill effect.

+1 on paying attention to the order of install... I'm actually missing some of the spacers and cheated with some over-sized nuts in a few places. Shade tree mechanic.

Most of the time that cover falls off and the "O" ring plops out.It is almost always dried out and hard and won't seal well anymore. In fact, it is so common to replace that "O" ring, when you order the bearings as a kit from the Delorean venders they will include that "O" ring. Not so good to make substitutions for spacers and washers but obviously better than nothing.

[sdg3205]

I've found the O-ring usually needs a little help from his friend - sensor safe gasket maker - to ensure there are no leaks. Cant risk over torquing those bolts.

[DMC-81]

Hi there, I was just reviving this thread to ask a question:

When replacing the 2 idler pulley bearings, does the old bearing need to be pressed out of the pulley, and the spindle out of the bearing?


Thanks.

[Gfrank]

You won't need a press but you will have to tap it in/out. A socket and hammer will work fine, Have to remove the snap rings

[DMC-81]

Success! Thanks.

I used a brass drift between the spindle and the hammer to avoid damaging the spindle. Also, I removed any surface rust on the spindle shaft which helped make the spindle to bearing removal easier.

[mluder]

Does anyone have the exact specs on the size of the bearings in the idler pulleys?
I need to replace mine this weekend and with no time to wait for delivery from DMC I want to just pick them up locally.
Thanks!

Cheers
Steve

[David T]

Does anyone have the exact specs on the size of the bearings in the idler pulleys?
I need to replace mine this weekend and with no time to wait for delivery from DMC I want to just pick them up locally.
Thanks!

Cheers
Steve

From memory (don't trust it) I think it is a standard 6205. If you take the old ones to an industrial bearing place to match up, they will have them on the shelf, very common. You should get the double shielded type (dirt shields on both sides of the bearing to keep out the dirt and the grease in). They should cost you about $2 each. Try not to get the ones made in China.

[hmcelraft]

There are so many bearings that size and made for so many different applications. The generic ones don't last long at all (made in China). I have had the best luck getting a bearing the 202 size made for high heat. The easiest way to get one is from Hervey. I have two of his on my car now - like forever, and they are still working well. He identifies them as having blue or red seals.

[PJ Grady Inc.]

Thats odd becuse I haven't had good luck with his or any other Chinese sourced bearings. They usually get noisy in 5K to 10K miles and need replacing. Unfortunately there are very few sources left in America or Europe and they are usually at least 5 times the price of the Chinese bearings.You can't get anything non-chinese in the $5- range let alone $2-. Wholesale prices in a US or Euro spec bearing start at $10 or more and none of the other vendors sell them because of the price competition.

BTW 6202 RS is what you want (you have to specify rubber sealed). I'm currently looking for a good quality domestic source but I'm not sure anyone will buy them except my shop customers who don't mind paying extra for that elusive "quality" part.

We used to build quality parts in America but now we consume more than we make. China rules!
Rob



There are so many bearings that size and made for so many different applications. The generic ones don't last long at all (made in China). I have had the best luck getting a bearing the 202 size made for high heat. The easiest way to get one is from Hervey. I have two of his on my car now - like forever, and they are still working well. He identifies them as having blue or red seals.

[mluder]

Thanks for the info everyone...

I replaced mine with ones I bought at NAPA Auto Parts. That was about 2 years ago (almost 10,000 miles) and at the time I balked at the price of the quality ones and went with China. Now they're needing replacement.
Lesson Learned.

Cheers
Steve

[David T]

Thanks for the info everyone...

I replaced mine with ones I bought at NAPA Auto Parts. That was about 2 years ago (almost 10,000 miles) and at the time I balked at the price of the quality ones and went with China. Now they're needing replacement.
Lesson Learned.

Cheers
Steve

You can't even trust Timken anymore and the ones still being made in the US are being counterfeited in China so even if it says Made in USA it is no guarantee.
I think SKF is the only one still making bearings here. I was close, 6205-6202. If you are only buying 2 bearings you can't expect to get much of a price break. The Delorean venders buy by the dozens. Don't forget to replace the "O" ring and make sure you put all of the spacers, washers, and bolts back EXACTLY as it comes apart (hopefully it was correct).

[DMCMW Dave]

You can't even trust Timken anymore and the ones still being made in the US are being counterfeited in China so even if it says Made in USA it is no guarantee.
I think SKF is the only one still making bearings here. I was close, 6205-6202. If you are only buying 2 bearings you can't expect to get much of a price break. The Delorean venders buy by the dozens. Don't forget to replace the "O" ring and make sure you put all of the spacers, washers, and bolts back EXACTLY as it comes apart (hopefully it was correct).

The diagram in the manual is accurate.

And SKF seems to be making these in Thailand now.

[Michael]

The diagram in the manual is accurate.

I know this is an old thread, but I found it looking for assembly info after replacing my idler bearings. The manual/parts diagram shows the pulley spacers(not the cam plate spacers) but the pulley spacers #15 as going behind the pulley bracket on the larger lower bracket, and in front of the bracket on the upper side. This is not correct and it cost me a lot of time and trouble believing the diagrams. The spacer (#15) goes behind both brackets. It didn't make sense to me to have two spacers butt against each other but the manual clearly shows just that. Had I simply took a few pics I would have known this but what did I care? I have the tech manual, I'm golden. SMH

62151

I'm not even discussing how the perspective on the parts diagram makes it look like the pulley shaft goes through the adjustment slot(and to a lesser degree, part #7 is drawn in the wrong location as well):

62152

To recap, the manual is NOWHERE near accurate.

[SS Spoiler]

Don't go by the manual if you take your
transmission apart. The differential shows
the ring gear set up for a mid engine car.
You will end up with a five speed reverse
and one speed forward....ask me how I know.....

[Mark D]

I know this is an old thread, but I found it looking for assembly info after replacing my idler bearings. The manual/parts diagram shows the pulley spacers(not the cam plate spacers) but the pulley spacers #15 as going behind the pulley bracket on the larger lower bracket, and in front of the bracket on the upper side. This is not correct and it cost me a lot of time and trouble believing the diagrams. The spacer (#15) goes behind both brackets. It didn't make sense to me to have two spacers butt against each other but the manual clearly shows just that. Had I simply took a few pics I would have known this but what did I care? I have the tech manual, I'm golden. SMH

62151

I'm not even discussing how the perspective on the parts diagram makes it look like the pulley shaft goes through the adjustment slot(and to a lesser degree, part #7 is drawn in the wrong location as well):

62152

To recap, the manual is NOWHERE near accurate.

I remember changing out my idler pulley bearings a few years ago and basically came to the same determination that the manual is not the best guide. Luckily, I took a bunch of photos before I took everything apart so I could reassemble it back the same way. That seemed to be the better way to reference how the parts should be assembled.

I also remember similar issues with the order and stack-up of various suspension bolts and washers. The manual shows the orientation of bolts and stack of washers one way while while the actual car was assembled much differently from the factory. It's likely that the manual was created early on and changes were made during production such that the manual became obsolete / was never updated to reflect as-built. Either that, or the factory workers should have been following the manual but found their own way of doing things.

[David T]

Refer to the Parts Manual 7-2-1. It is an accurate representation of the parts. The problem with it is that it does not give the sizes of the spacers so you could mix them up. Looking thorough my notes I can't find where I recorded the sizes of the spacers. When you take it apart each spacer should be measured so you can identify them and put them back in the proper locations. Even with pictures and measuring, once you get it back together, step back and look at it to make sure everything lines up.

[Michael]

Refer to the Parts Manual 7-2-1. It is an accurate representation of the parts. The problem with it is that it does not give the sizes of the spacers so you could mix them up. Looking thorough my notes I can't find where I recorded the sizes of the spacers. When you take it apart each spacer should be measured so you can identify them and put them back in the proper locations. Even with pictures and measuring, once you get it back together, step back and look at it to make sure everything lines up.

I am not disputing the accuracy of the parts, I am questioning the assembly order which I have used both the parts manual and the tech manual to show. Spacer #15 (again NOT the 2 differently sized cam plate spacers) is clearly shown (because I circled it in red) going in front of the pulley mounting plate. This is wrong among many other things but I caught those.

Here is the tech manual showing the same mistake(s)


https://www.youtube.com/watch?v=EIOdfJ4OeSE&feature=share&fbclid=IwAR1DFarYZ8f5nRzD-ZR94lM2K-MDbcC-6ZCgy-9UmSvj17hMKQ32zcqqju4

[DMC-81]

I am not disputing the accuracy of the parts, I am questioning the assembly order which I have used both the parts manual and the tech manual to show. Spacer #15 (again NOT the 2 differently sized cam plate spacers) is clearly shown (because I circled it in red) going in front of the pulley mounting plate. This is wrong among many other things but I caught those.

Here is the tech manual showing the same mistake(s)

~Snip~


Agreed. To help future readers, here are pictures of the 2 bracket bolt spacers:

Upper idler pulley bracket bolt with thin spacer (#10) arrangement:
http://dmctalk.org/attachment.php?attachmentid=62139&d=1577203914

Upper idler pulley bracket bolt with outside washer arrangement (lower bolt is the same):
http://dmctalk.org/attachment.php?attachmentid=62140&d=1577204077

Lower idler pulley bracket bolt with thick spacer (#14) arrangement (apologies for pic orientation...rotate to the left):
http://dmctalk.org/attachment.php?attachmentid=62141&d=1577204239

Here are pictures of the pulley stud spacers:

http://dmctalk.org/attachment.php?attachmentid=62144&d=1577207226

http://dmctalk.org/attachment.php?attachmentid=62145&d=1577207430

[Gregadeth]

Some more reference pics here from when I replaced my bearings a couple years ago:
http://dmctalk.org/showthread.php?241-What-have-you-done-to-your-DeLorean-today&p=218157&viewfull=1#post218157

[Michael]

I have scanned and redrawn the tech manual to what I believe is correct. I rescaled the spacers #15, reoriented the cam plate so the proper screws line up to it, repositioned the pulley bolts so they are not out of order, and a few other minor details to make certain parts appear closer to their actual appearance. It's still a tad confusing but in order to draw it correctly I would have to start all over showing the large adjustment bracket in a slightly different perspective. Even with the slight confusion the assembly order is correct (as I remember it) but please if you see something wrong let me know and once completed maybe we can put the revised drawing in the resources section for future owners like me that didn't take pics because they put too much faith in the manual. If everything is correct I will finalize it, draw the center lines correctly and send it to a mod/admin to put it where is needs to be.

62167

[cis6409]

This is brilliant guys, great explanations
And tips.. Will be definitely needing to this once my engine gets nearer completion

Cheers
Shane