C4ProjectCar

I replaced the worn distributor gear on my '90 L98 with a Lunati Everwear gear. When I put the new gear on, though, I found that the distributor hardly turned: the gear was snug up against the bottom of the distributor, rather than having ~1/16" clearance like the old gear had. I figured out that although the old and new gears were the same diameter, length, etc, the hole for the roll pin was lower on the new gear by about 1/16", shifting the gear upward by that amount.

This is the gear I bought.

Everything I've seen indicates that this gear should work for my car, and even the tech guy at Lunati had never seen this before. Do you guys have any idea what the problem could be? Did I buy the wrong gear, or maybe did the previous owner install a weird distributor?

Also, if you guys happen to have a spare gear lying around would you mind measuring the distance from the bottom edge of the roll pin hole to the bottom of the gear?

BOOT77

Post a pic of both gears

antfarmer2

Could it be upside down?

s carter

If is the correct part I tend to lean toward the Roll-Pin hole is Miss Drilled, You never Know it could be a Monday morning Hangover part.

I would pull and show to Vendor and have him check his Look up and have him pull another, and Confirm that it is being assemble correctly.

Quick after thought is there anything inside the Distributor out place not allowing it seat, a pinched wire,piece crud, slid up bushing or oil seal?

THE 383 admiral

You mentioned replacing a worn distributor gear. Is the original GM cam installed?
I have witnessed. Aftermarket cam gears. off about 2 deg. major vendors cores. I had a distributor gear shread inside my block. After dis-assembly. i used a known good GM distributor gear. Rolled it across the cam gear. With a pen in the middle. It would bind and stop. With this simple test.
The vendor. Did warranty replace with a billet cam. And also admited they did have a bad batch of cores! Imagine that.

C4ProjectCar

Here ya go. New one on the right.




Not anymore, but it was on our first installation attempt

Unfortunately, I bought it through Summit, so I can't exactly take it back in to have it looked at.

And no, if I put the old gear back on it works just fine. See the above picture and it's pretty obvious the gears are different.

Nope, it's a Lunati Voodoo, and it's new. The old distributor gear and cam gear were both worn from fuel in the oil/lots of miles.


Thanks for the help guys.

PatternDayTrader

I for one am not one bit surprised the purported "replacement" parts are totally useless. I am also not surprised the "tech" guy at lunati is saying they have never seen this before.
At least you noticed that something was actually wrong before you just reassembled it and started driving the car. Your eye for detail probably saved you from a seriously damaged engine.

antfarmer2

send that pic to Summit and start looking for the right one. Or use the old one.

WVZR-1

Eye for detail? You have to ask the right questions to get the right answers!!

Had the OP asked for "design specific dimensions" I'm quite sure they would have been provided OR had he mentioned the "specific dimensions" of what he had in hand they could have been confirmed. Did he offer the Lunati guy a snapshot?

Does the OP have anything to measure with other than offering up the guess?

Did you see the OP's response to "AF2" question?

The only legitimate response to the OP was "Boot77" who mentioned "SHOW ME!

I've an 1103879 distributor here and I ain't gonna knock the gear off but with a less than what I consider spectacular Chinese vernier I get something .196 +/- very little gear edge to pin center.

OP - What method did you use for Lunati contact? Do you have original invoice, original packaging? Might be needed. If you weren't happy with the Lunati response and if you had invoicing I'm quite sure Summit would have confirmed with Lunati themselves dimensions for you, they might have needed or asked to return a call OR offered you an extended wait.

I'd be inclined to think maybe you ordered and received a .50 gear and it actually maybe didn't fit the shaft either. An order error or a Lunati packaging error? Who knows.

Can you measure the shaft ID of the gear to confirm what you've got?

Why the Lunati product? What's special about the usage?

THE 383 admiral

UN-real SO close for "woodworking" It's disturbing. You must examine. every part. from every vendor.

Pride, Quality and Control.

at least 2 of the Three are missing.

PatternDayTrader

I don't really know where your going with this, but it sounds like your blaming the victim.

mtwoolford

For what it's worth, I've always had excellent service from Summit whenever I needed to return a part; give them a call.

WVZR-1

I would expect the OP to have a similar experience, requires invoice etc BUT ...he should certainly have. He doesn't it's shame on him.

**** happens!! That's life. It should certainly be a learning experience for all. BUY it, CHECK IT before INSTALL - anything!!!!

If you can't or aren't prepared to check before an install - DO NOT BUY IT!!

Purchased "local" whatever it might be it's a "toe to toe" discussion.

antfarmer2

and Summit will have the invoice too.

PatternDayTrader

Words to live by.


"Its not my job or my fault" <-- The battle cry of every parts vendor on earth. The sooner a man accepts this as truth, the better off he will be.

PatternDayTrader

You might say there's so much pride that its crowded out the quality and control.

383vett

If the shaft that the actual gear is mounted on is the same diameter in both cases, punch out the small rollpin between the teeth of both gears and switch out the bad one for the good one and you'll be good to go.

WW7

The used gear on the left looks fine, It doesn't look like it has much wear at all., just put it back on...WW

C4ProjectCar

Well this blew up overnight. Thanks for all the replies guys.

Motox,
I'm not blaming Lunati. Mistakes happen, and it seems like errors like this don't slip through often so I'm not surprised the Lunati guy had never seen this before.

AF2,
Thanks for the tip. I'll do that right away and hopefully they'll send me a replacement (Summit seems pretty good with that kind of stuff).

WVZR-1,
Easy there. While I'm not blaming Lunati, this is my first car so, yes, I admit I'm still learning.
But thanks for the measurement. I'll compare that to mine.
I called Lunati, and I have the original packaging. I'm confident either Lunati or Summit will come through on this, as I have had prior positive dealings with both of their customer service departments.
I found the shaft to be .491" through measurement and research, so I ordered that size. I'll have to double-check, but it did not seem too big for the shaft.
I ordered the Lunati gear because I have a Lunati camshaft and I wanted to be positive to avoid compatibility issues. The Lunati gear was inexpensive and well-reviewed as well.

383 Admiral,
Believe it or not, I compared every dimension of those gears other than roll pin hole placement. Don't know why, but it didn't cross my mind. I know now though

383vette,
Huh, didn't even realize they were two pieces. If I could get that to work though that would be great, thanks!

WW7,
Granted I have no frame of reference as to what a worn out distributor gear looks like (except some extreme examples I've seen), but this one looks worn out to me. It doesn't come across in that picture unfortunately. The wear is uneven and I was having issues with timing jumping around at idle, so I thought it might be the cause.

C4ProjectCar

These gears are one-piece, so swapping the shafts isn't an option, but I just got off the phone with Summit and they're replacing it for free. Gotta love Summit.