Bearing replacement for A/C idler pulley

[Jonathan]

Hey now,

Wanted to ask if anyone had any tips or tricks or advice on replacing the bearing in one or both of the idler pulleys that are on the A/C belt?

I have replacement bearings (2 of them) as I noticed last season the one on the driver's most side was a bit wobbly.

http://store.delorean.com/p-7731-idl...y-bearing.aspx

It looks like I can get at that one without really doing anything to loosen or disassemble anything on the block as these two pulleys are right on the adjustment bracket/tensioner.

Any words of advice or things you learned while doing yours that you'd find valuable to know beforehand and could share? Thanks.

[novadmc]

its easier to take the whole pulley assembly out. when i replaced my bearings on both pulleys i took it all out. its really the only way to easily get to the nuts threaded onto each pulley's bolt

the big things to watch out for are to ensure the order of all the spaces for both the pulleys and for behind the pulley brackets to where they attach to the engine.
additionally, there's an access plate to the timing chain that's held on by 2 of the pulley bracket bolts so be prepared for the possibility of that plate to come off (there's an o-ring behind it). mine was held on with a lot of RTV behind it so it didn't budge luckily.

once out, a impact tool will pop the nuts right off the pulley bolts. then just tap out the bearings and press in the new ones. i didn't have a press so i just placed the old bearing on the new one and then placed a correctly sized socket bit on top of that and used my mallet to hammer the new bearings into the pulleys. not the safest (for the bearings) way to do it, but if done cautiously, its fine.

[David T]

its easier to take the whole pulley assembly out. when i replaced my bearings on both pulleys i took it all out. its really the only way to easily get to the nuts threaded onto each pulley's bolt

the big things to watch out for are to ensure the order of all the spaces for both the pulleys and for behind the pulley brackets to where they attach to the engine.
additionally, there's an access plate to the timing chain that's held on by 2 of the pulley bracket bolts so be prepared for the possibility of that plate to come off (there's an o-ring behind it). mine was held on with a lot of RTV behind it so it didn't budge luckily.

once out, a impact tool will pop the nuts right off the pulley bolts. then just tap out the bearings and press in the new ones. i didn't have a press so i just placed the old bearing on the new one and then placed a correctly sized socket bit on top of that and used my mallet to hammer the new bearings into the pulleys. not the safest (for the bearings) way to do it, but if done cautiously, its fine.

You need to replace the "O" ring behind the cover. Keep track of every washer, bolt and spacer so you can put it all back correctly. Take it all apart to get to the bearings. The wire to the oil pressure sender should be replaced or sleeved. It is often all burnt up and the insulation is missing and if it grounds the light comes on. Among the "while you are there" things is to replace both belts. Inspect the upper right muffler bracket for cracks where it is bent.

[DMCMW Dave]

You need to replace the "O" ring behind the cover. Keep track of every washer, bolt and spacer so you can put it all back correctly. Take it all apart to get to the bearings. .

The o-ring is DMC 102820. Oddball size BTW. I see lots of cars where someone just RTVs the old o-ring. Those always leak.

Be sure to get everything back the way it came off. If you use screws that are too long you'll hit the cam gear. If you get the spacers wrong it will chew up belts.

[novadmc]

The o-ring is DMC 102820. Oddball size BTW. I see lots of cars where someone just RTVs the old o-ring. Those always leak.

Be sure to get everything back the way it came off. If you use screws that are too long you'll hit the cam gear. If you get the spacers wrong it will chew up belts.

I bought the o-ring but never had to use it. now its sitting in a box with my growing list of "ill probably need this eventually" parts.
The plate never budged my guess from inspecting it was rtv around the outter rim of the plate, sandwiching the o ring (im assuming whatever was done, it was done by DeLorean One back in the day when the car was there). no leaks for me pre or post pulley replacement.

that said, i was lucky/the exception to the rule. so yes, if/when the plate comes off when taking the pulley brackets out, replace the o-ring.

[DMC-81]

Hi Jonathan,

I recently refurbished these pulleys and corrected a Macguyver spacer (a filed down nut) installed by the PO to accommodate the spacing for a Volvo water pump pulley. I agree with the comments so far. When you take the assembly apart, take pictures, and I found that you'll need 3 hands to put it back together. The DMC store diagram, or the shop manual helps as well. You'll need good snap ring pliers for the retaining rings on the bearings. Other than that it was pretty straightforward.

Here is a picture of my finished assembly.

image.jpg

Best of luck!

Dana

[novadmc]

You'll need good snap ring pliers for the retaining rings on the bearings. Other than that it was pretty straightforward.

ah yeah, forgot about the snap rings!

also, if any or all of the nuts and bolts are heavily rusted (mine were) soak them overnight in a bottle filled with apple cider vinegar. it does an amazing job of removing rust. then just hit them with a small wire brush and give a light coating of WD40 to help protect them.

here's a before and after of one of the pulley bolt nut and washers after soaking and brushing:
2015-05-03 13.52.22.jpg 2015-05-06 10.27.57.jpg

[Jonathan]

Wow, I'm glad I asked. Thanks for the tips. Nothing is easy on these cars, eh? I looked at the one pulley that is wobbly and figured no sweat, but after reading about how it is likely going to go or the way you should really approach it to do it right, and I think I'm going to put this off for a while. Maybe it's still higher up on the list than my IIABDFI (if it ain't broke don't fix it) items... but this one goes in the list as a NIETRFW (not important enough to risk f&$king with). Ooh, snap ring pliers. Brings back memories of angle drive nuts... and large, angry hammers.

[rdarlington]

Bought the replacement bearings from Hervey and had to replace one within 500 miles. Buyer beware.

[Rodney]

Bought the replacement bearings from Hervey and had to replace one within 500 miles. Buyer beware.

Hi all,

Does anyone have the part # for the bearings ? I am sure I can get them at a parts house.Thanks rk