melton83
I recently installed a matched set of bulltear distributer gears after my previous cam gear got chewed up immediately after my engine rebuild. It’s been running great, and I’ve put about 200+ miles on the bulltear gears, but now my cam gear is all chewed up again. The Distributor gear looks completely normal! Looking at all the parts through the dizzy hole, and looking at the distributor gear, everything looks like it’s covered in plenty of lube, so I don’t know what the hell to do. Does anyone have any advice? My wife’s gotten so fed up with having to share one car that I’m about to just have it towed into the shop where I had my parts machined and have them fix it. Please, any advice would be greatly appreciated!
fifesjeep
Is that the stock timing cover or is it an aftermarket? You could have alignment issues...
melton83
It's the stock timing cover. Both of the dowell pins were inserted through the cover into the block too, so it shoudn't be an alignment issue right?
jeepsr4ever
Thats very strange. Are you sure you were running both our cam and distributor gear. I would take and try to turn the oil pump with a screw driver down the distributor hole to see if its binding in any way. I would say something major is happening.
melton83
Yeah I've tried turning it with a screwdriver, and it's easily done by hand. I'm at my wits end. I'm just going to have it towed to the machine shop today and have them check it out.
mrtazwrench
how about the dizzy, stock? aftermarket? any possable issues with it, the HEI's with issues a while back come to mind. :-|
fifesjeep
How are the gears meshing? When you put the new gears on toss on some gear die clamp the distributor down and rotate the engine by hand... Pull the distributor and see where the witness marks are... You could have it sitting too high or too low, and if you don't have enough shims between the distributor gear and housing this will cause the Distributor shaft to move up and down cause premature wear... Check this stuff... Also, make sure the distributor is a snug fit in the timing cover (No side wobble).
melton83
well I couldnt take it to the shop friday because they were already closed by the time I got out of work.
yes it is an aftermarket HEI distributor. Before installing it though I measured the length from where the dizzy rests on the timing cover to the gear and it was the exact same length as my old dizzy. Also there aren't any shims between the bulltear dizzy gear the the dizzy shaft, because there's no play at all. It's a tight fit. With the dizzy fully seated in the timing cover there is no movement or wobble in the distributor so it seems to be seated right. I going crazy!!
jeepsr4ever
What make of HEI unit is it? Their are a couple that dont sit down all the way allowing the oil pump drive gear to be forced into the oil filter adaptor and that can cause distributor gear damage. It may just be that HEI!!
tufcj
76-cj7
This morning as im pullin into work and my jeep dies......come to find the the gear on my dist is wiped out completely........brand new MSD dist and brand new MSD cam gear. The cam gear looks fine but the dist gear is gone......wut the hell would cause this? Have great oiling.....entire engine was new 5k miles ago along with cam and bearings.... Would cam walk be suspect?
fifesjeep
I can't see where cam walk would be an issue with an AMC... Especially with how the cam bearings are situated... If anything, if the cam were to walk wouldn't it walk away from the distributor gear and into the back plate?
I yanked my distributor HEI just to look at the Gear and I can see definite wear on the top of the gear... I have a few extras... I normally go to the yards and pull the Distributor gears and cam gears if they're good... Looks like I'll be replacing here soon.
tufcj
The MSD gear may not have been compatible with the cam gear you were running. There are factory and a couple of aftermarket sets out there, each with its own unique gear cut. That's why cam and dizzy gears should always be replaced as a matched set, and never mixed from different sources.
There is only about 1/4" of clearance between the cam bolt and the front cover. The lobes and lifters (and a tight chain) all work to pull the cam toward the rear, so the back of the cam gear rides against the block. The only direction the cam can walk is forward (unless the bolt loosens). Check the inside of the timing cover for damage from the bolt. If it has walked that far forward, there may also be damage to the base of the dizzy housing, and the cam lobes and lifters.
Bob
tufcj
76-cj7
well the cam gear was also a brand new MSD so i dont see where matching would be a problem........everything seems fine but come to think of it with the temp being in the teens around here for the past feww weeks and thick oil might be suspect.....
jeepsr4ever
MSD definately does not have a good gear set. Many AMC'ers have trashed theirs.
fifesjeep
I've ordered a few gears from different companies and I have noticed that some cut the gears too deep as other cut them too shallow... Then others will cut them right-on and when they heat treat the gears their dimension change. I figure if I find a set of gears (Junk yard) that look good and have miles on them without any signs of abnormal wearing then they'll work for my use. (Call me cheap :? ... I've been burned a few times with purchasing new gears). :agrue:
76-cj7
Well MC....on that comment about the MSD gears.....i guess i better take advantage of your free shipping....better package me up a set cause im ordering them right now :t:
melton83
OK, i just got a call from the machine shop, and they asked if I had my original distributor from before the rebuild. the one in it now is a ProForm HEI. They want to try switching them and seeing how if that fixes the problem. Before installing I measured the distributor shaft lengths and they were both the same, also I had the matched bulltear gears installed. So do you guys think just switching the distributors would really fix the problem. Oh, they also deteremined that there was no oiling issue, the gears were getting plenty.
melton83
Sorry for the double post, but I just want to be ready. If I do need to get another distributor, any recomendations. I go offroading maybe once or twice a month, but my AMC 304 1976 CJ7 is my daily driver. Just asking because my old distributor is a Mallory unilite without vacuum advance. I would like one with vacuum advance because it should make city driving smoother. Thank you for all the info!
fifesjeep
I don't see how the original is going to help them seeing that both gears were changed... Unless they're going to check the dimensions... How and what did you use to check the distributor dimension(s)?
