Oil Pump Drive Assembly Replacement

Worst that can happen is you'll be off a few degrees on the sync and it won't run. I'm on my 3rd one now. I replaced the last myself in the dealer lot right beside the shop area and after putting the new one in, used their computer to re-sync it. Kind of funny as they tried but had no idea what they were doing. They held the computer and I adjusted it. Spec is +/- something like 6 degrees. I was off a bit even though it appeared everything was good. Wouldn't start. Moved it a bit, got it to fire, but was stumbling all over itself. With the computer hooked up, you can see it only takes a MINUTE adjustment to swing 10 degrees or more on the computer, easily putting you over the 15 degree limit to where it won't run. I was able to carefuly adjust it down to .8 degrees or something like that, and it fired and ran fine.

To replace is very easy-just unhook the connector plug, then there's one bolt holding a cap plate down on the block itself. Pull that and the entire unit slides right out.

As you're putting in a brand new unit, it might be easier to get the engine to top dead center first. If you do, do NOT pull the little white plug holding the unit in place-that's the timing/adjustment ring thing and if you're off on there, total sync will be out and it won't run. If you don't have a scan tool or way to visually see the degrees you're off, Good Luck is all I can say. Many folks have been able to get it within spec to run, but honestly, I don't know how-the marker used will definitely be more than the degree limit variation to fire or not if you are off. I'd highly recommend doing it in the dealer lot just in case you need the computer to sync properly. Otherwise, it could be an expensive tow bill.

Best of Luck,

Mike

That is precisely what I don't understand with the pics, lining up the new one to the old and so forth from the research I've done in other areas. After seeing what I saw and doing just that, I was off on the initial install. I don't understand how they're getting it within spec by just the pictures. I did the setup myself using the dealer scan tool and just a very MINISCULE movement of the gear would throw it out of sync so it didn't run.

If you want to try the pen mark and get it to work that way, then by all means, pull the white safety pin, rotate it to where you think it should be-based off the other research you've done, and try it out. You might get lucky and it will fire without issue. Mine didn't. With the pin in place, the sensor itself is showing TDC and "KNOWS" where it's supposed to be. If you put it in anywhere other than that, it doesn't know where "HOME" or TDC is so it's off. That's why the pen trick with lining it up exactly where the old was comes to play-at least to the best of my understanding. When I did this, I was off, it wouldn't run and we had to put it back to to TDC to find "home" to sync things up.

I've read everything I can find, including the 80+ page thread on JF as well as others there. This has been MY experience with the 3rd gear. By all means, do what you feel comfortable with, I'm just saying have a "plan B" if you're unsuccessful. There is no way to tell where sync is without the dealer computer.

So, with the pin in the new setup, that is "home" for the sensor. That is TDC for the engine. If you want to try lining it up, pull that pin and adjust to where your old was. One thing to mention is when folks were simply "checking" the gear, they were lining up the pen marks and putting the same one back in. You're installing a NEW setup. Do whatever you feel comfortable with.

Best of Luck,

Mike

cgork said:

Nevermind. That didn't make sense at all. How about this one. Isn't the new one set up exactly the same as the old one? I read on the other forums to just orient the new one exactly like the old one. Taking pics even, before removing the old one. If that works, then I have to remove the alignment "before" I install and the instructions say not to do that. Maybe I should do some more research on this all works so I undrstand the ins and outs better.

Click to expand...

It's a very simple deal. It is a go or no go deal. If you want, turn your engine with the old unit in to where the alignment holes line up. A long allen wrench or skinny screw driver will fit in there. As you look down at the unit from the passenger side wheel the alignment hole is about at the 8:00 area. Of course turning the engine over is a hard deal. I have done 2 of these so far. Mine I did not turn over I just scribed reference points in it. My brother in laws unit was all lined up and a allen wrench slipped right in.

I say scribe cause those sharpie pen marks can wipe off if you clean anything. I actually did use a sharpie, but as soon as I had it out I scribed lines in it with a sharp screw driver. I suggest marking the old unit (before you loosen the mounting bolt of course) in two places 20-30 degrees from each other. Then remove it. If you are putting in a new unit, and I think you are, then align the holes. Of course don't turn the engine over once it's out. The old unit scribed can go back in and if the marks are lined up you are good to go. Ditto with the new unit. Even if the unit is sitting 90 degrees off of where it sat before if the marks are lined up it you are good to go.

As you pull the unit out and put it in it will turn as the gear will do this. As long as the mark is lined up---okay.

I strongly suggest you do the grease zerk deal.

Make sure the gasket is on and looks good.

The hardest trick is getting both the assembly and shaft in same position when re-installing...or if installing a new unit by using the TDC marks on tone ring (aluminum top ring on shaft) on a pretty close place to where previous unit was at. Always remember that you need to START with the shaft (and your marks on inside) slightly ahead in a COUNTER-CLOCKWISE position so that when the unit slides into place it turns clock wise and lines up your marks perfectly.

A scribe is 100x better than sharpie as mentioned..and this only works if you have not turned engine over at all after removal.

It's my understanding that the earlier unit's (smaller tone/indicator ring) need a much more precise accuracy (within 5 degrees) than the newer units with a different computer and lesser degree of accuracy (within 15 degrees) in order for the computer to compensate and fire on time.

I also know that the signal sent on the older style is 50/50..on or off 180 degrees apart..the later models use 3 sets of 2 to send same signal..set 120 degrees apart...and yet the spark plugs fire twice as set up by coil rail since 1998 dropping of cap and rotor.