First off, I've never had to replace a distributor drive gear, so I'm wondering what I'm getting myself into. I know how to go about getting it out, but what I want to know is if the gear is attached to the oil pump driveshaft? If so do I need to pull the pan and take the oil pump off when I put the gear and driveshaft back in? (I read somewhere that the pan needs to come off.) I am also having trouble finding a replacement part. I've looked and I found a drive gear with the shaft attached and another without the shaft. The magnum in my pickup was running strangely so I checked my distributor and sure enough the drive gear teeth have worn down. It has a lot of play in it I can turn the gear back and forth before it engages the cam. So can anyone help me out? I'm getting some conflicting parts searches.
5.2 magnum distributor drive gear replacement questions.
- Thread starter alpha13
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The replacement part is the gear on the shaft. The oil pan does not have to come off. Twist the intermediate shaft out with a BIG flat top screw driver. If the gear is stubron, wack the top of the driver with a mallet. The shock value is what your after to loosen it up.
That is always how I have done it.
That is always how I have done it.
the oil pump driveshaft is what has the gear on it. not the dist. you can purchase with or without a gear i believe.
the distributor lifts out, the gear/driveshaft usually stay in place.
assuming it's the same as an LA. I lift mine out with a magnet.
The roll pin gets pushed out.
old gear off
new gear on
new roll pin installed (i usually take this opportunity to install a solid pin and "peen" it)
make sure the bronze cam bushing is in good shape. or replace it.
make sure when you drop the gear in, it does in the correct position for the engine (usually #1 TDC is the best reference point) this also prevents the 180 out problem.
the distributor lifts out, the gear/driveshaft usually stay in place.
assuming it's the same as an LA. I lift mine out with a magnet.
The roll pin gets pushed out.
old gear off
new gear on
new roll pin installed (i usually take this opportunity to install a solid pin and "peen" it)
make sure the bronze cam bushing is in good shape. or replace it.
make sure when you drop the gear in, it does in the correct position for the engine (usually #1 TDC is the best reference point) this also prevents the 180 out problem.
the hex end goes in the pump. the top of the gear has a keyway where the distributor shaft sits. again not the position before removal and reinstall. for this one you obviously replace the whole thing, not just the gear.
http://www.jegs.com/i/Mopar+Performance/312/P3690715/10002/-1
http://www.jegs.com/i/Mopar+Performance/312/P3690715/10002/-1
So if I wanted t replace the whole thing how would I get the oil.pump to line up with the shaft when I go to put it in? Will I have enough shaft to be able to insert it and spin it til it connects with the pump then seat the gears?
Unless someone interrupts me to tell me the magnum is different. (and please feel free to do so if it is) I have never had to get at the oil pump to drop in the intermediate shaft. the allen shaft is slightly tapered...and they just slide into the pump, while rotating downward on the cam helix.
mopar jimmie
Mopar Jimmie
Take a good look at the block bushing , there were alot of issues in the early magnums with dist drive bushing wear, there is a dealer essential tool for removing and replaceing it
This is listed for every SB, magnum included, from 60 something to 99
http://www.oreillyauto.com/site/c/detail/SPO0/2246166/02339.oap#compatibilityTab_
and here it is on rock auto for much cheaper.
https://www.rockauto.com/en/catalog...5689,engine,oil+pump+intermediate+shaft,14256
i would take that as the shaft is the same from LA to MAG...and i can't see you having a problem dropping it in, as i have 100 times.
worst case scenario, put a small taper on the end, and grease it.
thats about all the help i can be.lol I went straight from LA's to 5.7 Hemi's...so i have never torn down a mag engine.
http://www.oreillyauto.com/site/c/detail/SPO0/2246166/02339.oap#compatibilityTab_
and here it is on rock auto for much cheaper.
https://www.rockauto.com/en/catalog...5689,engine,oil+pump+intermediate+shaft,14256
i would take that as the shaft is the same from LA to MAG...and i can't see you having a problem dropping it in, as i have 100 times.
worst case scenario, put a small taper on the end, and grease it.
thats about all the help i can be.lol I went straight from LA's to 5.7 Hemi's...so i have never torn down a mag engine.
Yeah I read about the bushing wear and the fact that I might have to get that replaced. But if I can get away with just the gear for now I will do that. I haven't had the gear out and haven't had a chance to look at the bushing yet. So it seems this will be easier than I anticipated, which is good. I just want the Damn thing to run decent. I'm sure it needs a timing chain too but I'm kinda looking forward to getting rid of this truck as soon as I can as I have bills to pay and I don't need two trucks.
Well, I went out just now and managed to get the gear out. Came out pretty easily. Turn the gear with a screwdriver clockwise and it pops up, then work a wire under the gear and pull it out or use a strong magnet like someone else mentioned. It does look like the bushing could use a replacement, but the teeth on the drive gear were pretty tapered down and the actual drive shaft itself was showing signs of wear. I didn't put calipers on it but I could feel the taper on the shaft from where it's been rubbing at least a few thousandths of an inch. I'm hoping between the new gear and shaft it will take up most of the slack to make it run at least decent. I was having this missing problem right after I bought the truck and replaced the distributor because the shaft had some wobble and then my problem went away. Then over the last two years It gradually came back. So I'm hoping this will clear up most of my problem at least for another 20k or so then I get to do a timing chain! Wahoo! I will stay updated, I'm going to the parts store in the morning.
Well I got the new one in and everything went together great. It ran fine for the first ten minutes and then started the same symptoms again.... I'm going to check out my crank sensor and see if that fixes the problem. Thanks for the help though guys!!
magnummopar
Well-Known Member
You mentioned truck...if this engine is in a Ram or Dakota, and its injected, then when you pulled the distributor, you have now changed the cam to crank timing. This can lead to the engine running like crap. The only way to set the timing on a magnum FI enigne is with the Dodge DRB III scan tool that the dealer has. If you notice that turning the distributor while engine is running makes no difference, thats because the cam and crank sensor have to be "synced" to get timing correct.
Another thing you didnt mention is just how many miles are on this engine. For a magnum to wear the gear like that they had to use chicken crap for oil or it has 250K on the odo.
On the 92 dakota the service bulletin for indexing the distributor correctly is as follows. Bring engine to top dead center and then locate the V8 timing mark on the balancer.(magnum v6 and v8 engines use the same balancer) approximately 17.5 degrees after TDC. Bring the engine around to the v8 mark. Now backprobe the distributor cam sensor with a multimeter(positive wire is in the middle of the three I think grey with black trader, negative is I believe blue with a grey tracer). Loosen the distributor clamp. Turn on ignition to run position but do not crank the engine. With the multimeter turned on, slowly turn the distributor until the reading changes from either 0 or 5 volts either side of this point as close as possible. Then lock down the distributor. I've done it several times on a couple different magnums that were running strangely, cleared the missing right up. I will see if I can find the service bulletin or a link to it.
Oh yeah, this engine only has 160,000 according to the odometer. I bought the pickup cuz it was super cheap. Only problem with it was the tranny wouldn't shift into overdrive and had a tranny leak. So I replaced the OD solenoid and everything worked great for a little while. Then it started running weird so I replaced all the wires and plugs and distributor because it had some wobble in the shaft. Put it back together and it ran like a top for about another year and then one day out of the blue started running strange and missing. I Reindexed the distributor and it didn't work. So I started my investigation. Found out the distributor gear had a lot of play, the bushing is shot too.( go figure) So I wanted to replace itso I knew for sure that it wasn't distributor wobble caused by the gear. The new gear took up a lot of the slack. And it started and ran great for about 10 minutes til it warmed up. I'm guessing O2 sensor as well, but I'm not sure yet. I'm going to check everything for vacuum leaks and check my plenum for oil in case the leak is in my manifold.
mopar jimmie
Mopar Jimmie
The situation you have here is the dist drive gear was worn by a bad drive bushing , this bushing makes a big difference on a magnum . If you have access to the the dealer essential tool the gear is super easy to to replace and only takes about 15 minutes .
I'm going to have to replace the bushing. Unfortunately I don't have the tools. But I read somewhere that someone tapped it with a long 9/16tap then threaded in a piece of all thread put on a pipe cap and used some washers and a nut to pull it off. I am going to check out the tool as well. I'm not sure I want to drive to the dealer to get it done cuz it will probably cost upwards of $200 bucks.
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