so monday on my way to work my LT1 hawk just lost all oil pressure out of nowhere. wasnt getting on it, nothing. towed it home and after pulling the intake and removing the drive gear assembly i found that the teeth just straight wore off the gear. now i know thats not normal, and after careful investigation i found that the cam looks great (im sure due to the fact its made of billet steel). what would cause the teeth to wear like this? the motor has nearly 100k miles on that cam, and 150k total miles. i have another drive gear assembly im going to put in its place, but should i be worried about this happening again soon? Tony i know you and some of the other LTx gurus might have an answer for me, or at least im hoping you will. thanks

karl




on a good note i did find out i have a ported intake and some nicely ported heads! on that note i dont know too much about the port work since even though they may look nice, doesnt mean its a good job. although i was always getting some good numbers out of my car for just a hot cam.

 

You need to check the rest of the motor! I had this happen a few weeks ago and have been rebuilding my motor because when that gear got shredded it tore the engine apart with no oil. We are pretty sure we traced the problem to the wrong oil pump. There was a bigger pump than the engine could handle and it stripped the gear

 

Agreed. If its hot cam, there should be no issue with the cam gear. Sounds like a high flow oil pump causing excessive load on the drive stub gear. Its happened countless times on here. Thats the next place to look and yes it will happen again if not corrected.

 

so basically i need to replace the gear with a stronger alloy gear? it does have a high pressure pump. i will be going back to a stock pump once i build a new engine. have not been impressed with the "high pressure" that really hasnt made anymore pressure than the stocker. that didnt even cross my mind when putting it in there. glad you guys pointed it out for me. now to put this back together and see if it hurt the motor.....

 

Where did the metel go from the gear? How long did you drive with no oil pressure? I see a rebuild in your future for sure, same thing happen to me and boom no more engine after tearing the whole thing down and trying to get all the metel fragments out and still was too late. Good luck

 

What exact pump is in the engine? It is the high volume pump that accelerate wear on the gear.

 

He said a high pressure pump but did not note is it was high volume as well. More than likly the pump is the issue. I have in the past used a gear from a MSD distributor and drilled it to fit the cam drive and it worked great. But the plastic body still sucks big time and harron performance charges way to much for there billet drive

 

This seems to be happening more and more.First off,you need to look down the hole and check the gear on the cam,it is probably damaged also and just putting in a new gear/drive will lead to the same failure.Is the drive housing cracked?You need to drop the pan,find out what kind of pump it is,and I would pull a few main and rod caps and check for bearing damage.Chances are you will need all new bearings.

 

I agree with this. Chances are if you just change the pump drive grear and the cam if it's damaged you will end up spinning a bearing or trashing the crank.

 

ok, so here is the deal.... after pulling the drive gear out i got a mirror and a flashlight and looked down in to check the cam gear. it looks great. doesnt appear to have any wear whatsoever on it. took my spare gear drive assembly and coated it with moly lube and installed it. cleaned out my intake and all gasket surfaces and mounted the intake back in place. reinstalled the TB, air box, and all vaccum lines etc.. pulled my coil wire off and cranked her over until i got pressure back on my guage. i then hooked up the coil wire and crossed my fingers. engine fired right up and at first made a little bit of clacking until the lifters pumped up again. i let her idle and circulate oil until she was warm and then took her out for a spin. even at operating temp she is still holding about 25-30lbs of pressure and at 1500 rpms she is getting just north of 40lbs. while out on a drive i went ahead and took the chance of revving her past 6k and had no problems. actually seems to run a bit stronger than before since i cleaned the intake and TB. i have ordered a 396 rotating assembly and will start preparing that in my other black very soon, but for now this bandaid will have to do. the oil pump i used is a high pressure standard volume with a canton pickup and pan. i used the stock type gear back in its place since i put about 35k miles on the other one with the high pressure pump im sure it will last me long enough to build a new motor. i appreciate the help fellas and will let you know when/if this happens again and how many miles the motor lasted with the stock gear. oh, also i had driven about 3 miles with no oil pressure. good ole mobil 1 is what saved my *** i think. i know its not good, but at the time i was beyond irritated.

 

on a good note i did find out i have some pretty good ported heads and intake with trickflow pushrods... that made me happy!

 

Are you sure it is not a high volume pump? You described, but never said the exact model of the pump. I ask, because I don't recall drive gear problems being reported by anyone with a standard volume pump.

 

I had the same thing happen with my stock cam and oil pump drive gear. Pump was a Melling high pressure pump, but not high volume. Was idling through the parking lot when oil pressure dropped instantly from 60-0. Immediately shut it off, coasted into a spot, then had it towed home. Didn't drive it after that. Stock cam gear looks perfect, but the oil pump drive gear is worn out. The metal just seems to be brittle on the oil pump drive gear, seems as if it should be a stronger alloy to me.

Does anyone have any suggestions as to what to replace this gear with, and how? I have a custom LE cam in my 'new' (used 53k) shortblock, and am about to pull the intake to paint it, and if I can put a better gear on that oil pump drive that will last, I would LOVE to do it now.

 

http://ltxtech.com/forums/showthread...il-Pump-drives

 

If the composite body breaking or flexing were causing the problem, the billet unit would be a fix, however, it is the soft metal used on the gear itself that is wearing down. So for this problem a different gear is needed.

 

True. For some reason I thought that came with a newgear. Guess not. I really don't see the point in it now...

 

A motor I am currently rebuilding died from this exact same thing. After tearing it all the way down, there was a HV pump in the car, that is the only culprit I could find. It was a factory cam car.

 

So, since this is happening to so many, what have others done to overcome this problem? Installing a SBC drive gear machined to work is one thing I have heard, but what kind of gear, what needs to be machined, and how to make it work??

 

ok, as i stated in my earlier post it is a HIGH PRESSURE, STANDARD VOLUME pump. the only reason i see that no one has made a harder alloy gear is that it might chew the teeth off the cam, and then the fix isnt so simple. the way i see it is that it took about 35k miles for it to wear mine down, so i should get a good 20k or more before i need to pull the intake and have another look at it. in the mean ill be building my new 396 and will be using a stock pump in it and hoping that i dont run into this again down the road. ill just start buying several gears at a time and alternating between each of my gear drive assemblies and making sure i dont let it happen to a more expensive motor. just glad i could bandaid it till i have to swap my short block.

 

I already acknowledged what you said. However, I asked for the exact pump model number (still not supplied). More than one person has confused one pump from another. Just trying to see if there is a relationship to the very pump you are using.