BMW Blog

:brickwall
I replaced my dist.drive and cam gear about 4000 miles ago and also put a oiling port in my timing cover due to the gears being shredded. Here I am again, in the same boat that I have sunk in once already:thumbdown::laugh:.

This time the gear located on the cam is shredded to point I can turn my rotor button by hand while the dist. is in the block. What would cause this to happen again? I researched it when I replaced it the first time which lead me to putting the direct oiling on the gears. The gears were covered in oil when I pulled the dist. out this time, so therefore I know my oiling should not be an issue. I am turning to the experts for advice, please help:confused:
was this particular dist replaced 4000k ago? what was the reason for replacing the gear...is there a new cam in it ?? all of this will matter ? I dont think its an oiling issue but a mating/ tolerance issue?? sounds like anyway???
if the cam/bearings are old your cam may be "walking" back and forth which will lunch the dist. gear quickly...
Bad casted timing sets often have slag that covers the oiling channel from the front of the cam, through the fuel pump esentric and through the oil passage cast in the timing gear and into the distributor gear on the cam, the distributor drive gear has 4 small holes that allow the oil to flow and lubricate the dizzy gears.

it could be a bad distributor casting as well, if this began when you replaced with a HEI for example..

anyway on amc's i always remove teh fuel pump and while priming the engine for first startup i watch through the fuel pump mount to see the dist. gears.. the gears should be dripping with oil if everything is proper.
I guess he fixed his problem??????
I would recommend that you do a Jeep Forum search for "distributor gear" postings. JeepHammer went into GREAT detail regarding the Chinese trash that is being sold just a few weeks ago.

Bruce
:brickwall
I replaced my dist.drive and cam gear about 4000 miles ago and also put a oiling port in my timing cover due to the gears being shredded. Here I am again, in the same boat that I have sunk in once already:thumbdown::laugh:.

This time the gear located on the cam is shredded to point I can turn my rotor button by hand while the dist. is in the block. What would cause this to happen again? I researched it when I replaced it the first time which lead me to putting the direct oiling on the gears. The gears were covered in oil when I pulled the dist. out this time, so therefore I know my oiling should not be an issue. I am turning to the experts for advice, please help:confused:

I could be way off base here, but if the fuel pump eccentric isn't in right, the gears fry from lack of oil.

I believe the slot has to be on the outside of the unit.
Sorry I have not been able to reply, I do not have internet at my house. I only get to check it when I get time to stop at my aunt's. I replaced the gears the first time for the very same problem. I did not replace the distributor, only the gears. The gear on the cam is shredded this time to the point I can turn my rotor by hand. The motor was supposedly rebuilt shortly before I bought the jeep, so I can not tell you for sure what has been done in the past. How can I tell if the cam is walking?
I replaced the gears the first time for the very same problem. I did not replace the distributor, only the gears.

I'm assuming you mean you only changed the distributor gear.
If you changed more than the distributor gear, please correct this assumption.

Where did you get that distributor gear?
A place called 'Bulltear' has a horrible track record with their gears, and they don't tell you that using ONLY their HARDENED distributor gear will eat your NON-Hardened cam gear...

Also, lot's of the gears on the current aftermarket have the wrong tooth profile, wrong outside diameter, center hole drilled off center, and the retaining pin hole in the wrong place or drilled off axis in two directions.

The gear on the cam is shredded this time to the point I can turn my rotor by hand.

If your distributor gear isn't showing lots of damage, you have one of the hardened, over sized, and wrong tooth profile gears that are going around. (made in Spain and totally junk)
I'd say this is the direct result of a bad distributor gear, but I'd have to have a good look at the parts first hand to swear to it...


The motor was supposedly rebuilt shortly before I bought the jeep, so I can not tell you for sure what has been done in the past.

A 'Rebuilt' engine isn't worth paying extra for, simply because you don't know what was done to it.

A reputable shop will give the owner 'Transferable' warranty...
A fly by night shop won't transfer the warranty to the new owner.
Never pay extra for an engine unless you see the receipts and contact the shop that did the work to find out what was done, and if the warranty is transferable...
If you don't do the leg work, then pay for the jeep as if it has any old 20+ year old engine in it.

How can I tell if the cam is walking?

That will be obvious when you take the front cover off to replace the distributor drive gear.
I'd also replace the distributor driven gear (distributor gear) at the same time with one that isn't going to eat up your parts again...

MSD has some very good gears (Better than stock!),
MSD p/n 8005 for distributor,
MSD p/n 8007 for cam.
DO NOT expect to get these high quality, well made gears for the $19.95 those junk gears are selling for!
They cost considerably more, but are well worth the extra money...