63 Idler Pulley Question

[Bob B.]

Hi all,

I have a '63 idler pulley and I noticed some grease leaking from the bearing. I don't know if this is normal or if the bearing is supposed to be sealed? Can grease be added by making something to fit over the bearing and putting it in under pressure?

Thanks,

Bob

FYI: These idler pulleys were used on C1 race cars, such as the '60 LeMans cars, starting in 1960.

[Joe L.]

Re: 63 Idler Pulley Question

Hi all,

I have a '63 idler pulley and I noticed some grease leaking from the bearing. I don't know if this is normal or if the bearing is supposed to be sealed? Can grease be added by making something to fit over the bearing and putting it in under pressure?

Thanks,

Bob

FYI: These idler pulleys were used on C1 race cars, such as the '60 LeMans cars, starting in 1960.

Bob-----

These bearings were of a sealed type. I don't know of a way to introduce grease to the bearing but someone may have developed one. The bearing is GM-discontinued but there should still be some around.

[Paul Y.]

Re: 63 Idler Pulley Question

Hi all,

I have a '63 idler pulley and I noticed some grease leaking from the bearing. I don't know if this is normal or if the bearing is supposed to be sealed? Can grease be added by making something to fit over the bearing and putting it in under pressure?

Thanks,

Bob

FYI: These idler pulleys were used on C1 race cars, such as the '60 LeMans cars, starting in 1960.

Bob, they are the same bearing as the water pump. Try a water pump rebuilder for the bearing application.

[Joe L.]

Re: 63 Idler Pulley Question

Bob, they are the same bearing as the water pump. Try a water pump rebuilder for the bearing application.

Paul-----


They are similar to a waterpump bearing but not the same. The vast majority of waterpump bearings have a shaft on both sides of the bearing. The idler pulley bearing has a shaft on only one side of the bearing.

[Paul Y.]

Re: 63 Idler Pulley Question

Paul-----


They are similar to a waterpump bearing but not the same. The vast majority of waterpump bearings have a shaft on both sides of the bearing. The idler pulley bearing has a shaft on only one side of the bearing.

You are right Joe and I seem to remember one time machining that off with a hacksaw. Sort of crude machine work but I believe that I dressed it up with a file. My water pump rebuilder machines them off for me on a lathe I believe. Thanks for the remind.

[Dick W.]

Re: 63 Idler Pulley Question

Bob-----

These bearings were of a sealed type. I don't know of a way to introduce grease to the bearing but someone may have developed one. The bearing is GM-discontinued but there should still be some around.

Once upon a time, I could purchase just the bearing. I cannot remember who manufactured it, but if one was to look at the bearing, I am reasonably sure there is a part number on it. Then you can go to a bearing specialty store and order one.

[Mike M.]

Re: 63 Idler Pulley Question

i have half a dozen bearings with shaft out one end only. seem to recall i got them from a local bearing and tranny shop 20-30 years ago. they need the shaft shortened to work as idler pully bearing/shaft. i9 can bring one to KC'S tech session tomorrow if you can't locate one beforehand. mike

[Joe L.]

Re: 63 Idler Pulley Question

A little more on this:

The original idler pulley bearing used in PRODUCTION and available in SERVICE was GM #907176. This was discontinued in July, 1970 and replaced by GM #908050. In May, 1972 the latter was discontinued and replaced by GM #908076 which was finally discontinued fairly recently.

I don't have an example of the 907176 but I expect that it's virtually the same as the 908050 as far as external configuration goes. I do have an NOS example of the 908050 [not for sale]. I also have examples of the 908076 [not for sale]. However, I believe these are later examples manufactured after New Departure Hyatt ceased producing this type of bearing. The ones I have were manufactured by NSK Bearings. They are an actual GM part, though, as I obtained them through GM.

When these bearings were manufactured by New Departure Hyatt they had a few unique features that are not found in bearings manufactured by others (i.e. NSK, FAG, Koyo, etc.). Since these bearings are similar to the bearings used in waterpumps, the exact same features will be found in New Departure Hyatt-manufactured waterpump bearings. For waterpump bearings, these features are virtually impossible to discern with the pump mounted on the engine and pulleys and fan clutch installed. However, for the idler pulley bearing one or both of the features should be discernible

Pictured below is the New Departure Hyatt-manufactured GM #908050. Note that the bearing end seals are metal. This is a characteristic of NDH-manufactured bearings of this type. No other manufacturer I know of has used or currently uses this type of end seal configuration for this type of bearing assembly. Also note the forward end of the shaft. It has a rough, "chopped off" appearance. No other bearing manufacturer I know of has ever had this sort of configuration for finishing the shaft forward end. The shaft rearward end, however, is more of a machined surface. Once again, keep in mind that the exact same features I have described and depicted here are applicable to NDH-manufactured waterpump bearings (I have many of these but I don't want to go to the trouble of pulling them out because the characteristics I am speaking of are the same as for the idler pulley bearing; only the shaft lengths are different).


DSCN2849.jpgDSCN2850.jpgDSCN2851.jpg

[Joe L.]

Re: 63 Idler Pulley Question

Now some info on the NSK-manufactured 908076. Pictured below is the NSK-manufactured 908076. Note that the bearing end seals are some sort of elastomer or plastic and definitely not metal. This is the type of configuration seen on bearings of this type manufactured by all other manufacturers I know of. The color may vary but the basic configuration is the same. Also note that the forward end of the shaft is surface ground or otherwise machined. All of the other manufacturers of these bearings use this type of finish for the shaft forward end.


DSCN2844.jpgDSCN2845.jpgDSCN2846.jpg



I don't know how this photo of the tire gauge got posted here but I can't seem to delete it so it'll have to remain.