HRC Gears - timing cover clearance problem

javsst

Guys - I have a feeling that somethings not right :) I dry fit the HRC gears into the timing cover that I have and the idler gear is catching the walls of the cavity in the timing cover. Even with assembly lube covering everything, it's notchy. According to the TSM I ought to have about .002 to .004 between the gear and the wall of the cavity. It should spin without any binding, correct? I put assembly lube on the shaft of the main gear before installing, and that appears ok in the timing cover. Stock cover, BTW. Thanks. Steve

jeepsr4ever

Steve check the edge of the gear. Sometimes even the smallest nick can make for a pulse or a tight fit. It is also possible that the gear has a small burr. Run your finger over the gear and see if your fingernail hits an edge. Chances are their is a small burr or nick in one of the gears. Not uncommon

javsst

They do appear to have sharp edges. Should I use a knife to debur, or can I use a fine file? Thanks as always!! Hey! Just realized I'm not a newbie anymore :mrgreen: Steve

jeepsr4ever

A fine file will do it. I will check what we have here to make sure their arent any burrs. Thanks for posting this up, as much as I would like to say everything ships perfect we are getting very busy and sometimes we do make errors.

javsst

Odd. I went over every edge and made sure there were no burrs nor sharp edges on both gears. After cleaning up everything, I've noted both gears are catching in the pump cavity. Also, a .0025 feeler won't even squeek in between the gear and wall.

I'm going to try and get some stock gears around here as a comparison. In the meantime I took a photo of idler gear measurement, which appears to be 1.44.

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javsst

Picked up the oil pump repair kit this morning. Grrrr....... Gear size appears to be identical, which means somethings up with the timing cover. Great...... I'll test fit one more time, but it looks like I'll be ordering a new timing cover. Just bought this one used at Cecil last year. The pump cavity was clean with no scores, but who'd have thought the dimensions would be off.... Steve

BREK

Spend the extra cash and get one of mc's nickel plated covers :lo1l:

jeepsr4ever

Steve if you have some blu'ing dye you can blue your gears in. We paint the edge of each gear and slide them down trying to rotate them (In NI covers). then you can see the shiney area where the ink has been worn away that is the area you need to remove metal. We use stones and files to remove the metal for a nice fit without binding.

javsst

MC - Thanks. Though I'm a little suspicious about this timing cover not even fitting stock gears. Plus, the gears are not just rubbing, they're catching on the openings in the pump cavity. Not much, but it's there. I noted that the cover didn't have any scoring when I bought it. It also looks as though it had been bead blasted, including the pump cavity. I can try to blue the cavity, but it might take a grinder to make it work :) Ah well, guess it's worth a shot since I've got a non-usable cover at this point anyways...... Thanks. Steve

javsst

Well, I'm not liking the looks of this. Lacking blue dye, I used a black sharpie. It's not scraping at the top near as I can tell. I took the .0025 feeler and noted that at the top of the cavity, there's enough clearance, but as you go down towards the bottom, the feeler won't go in. So the walls of the pump cavity appear to be tapered for some reason. This is on all teeth of both the HRC gears and the stock replacement kit. I'm not sure what I'm dealing with at this point, and I'd rather get a new timing cover than try to figure out what's going on with this used cover. MC - looks like I'll be putting in an order shortly :) Steve

jeepsr4ever

Kinda sorry to hear that Steve :wink:

javsst

Ah well, no big deal. Better safe than sorry later! Thanks again!