what cause the oil pump drive gears to strip out?

[5sp. mini]

I have not had this happen but chucks had 2 and franks at sdac15. does it happen to the 2.2 or more com. on the 2.5? or is it a comm. block thing. 2 out of 3 of mine are 88 2.2 only one 2.5.AL

[87glhs232]

I have not had this happen but chucks had 2 and franks at sdac15. does it happen to the 2.2 or more com. on the 2.5? or is it a comm. block thing. 2 out of 3 of mine are 88 2.2 only one 2.5.AL

I'm not really sure. I had it happen to me a couple times consecutively on a motor. The first time I thought maybe the oil pump had seized because when I took it out the pump was pretty hard to turn. So I replaced the pump and the shaft and made sure to clean all the little bits out before reassembly. It happened again only 20 minutes into running the motor. Well, it did'nt completely destroy them, but BAD noises started, so I shut it down, dropped the pan and the pump and sure enough, galling and a few chips on the oil pump gear. I decided to give it one more pump since the shaft looked good. Nope...killed the shaft and pump AGAIN. So I replaced the motor.

Here's my theory...and I'm sticking to it unless there's a better one.

My pump siezed, chewing the gears on the pump and shaft. This put extra stress on the shaft bearings causing misalignment or out of roundness. The new shaft in turn never had a chance.

Oh, and it was a 2.2 non-common.

[turbovanman²]

I have seen a few motors apart and its age, worn or dirty pump etc. I just did Will Martins engine and I made him buy a known good shaft, why, his old one has pitted teeth on the shaft, he brought me another one, same. Now use a new oil pump on a worn shaft with the hardening gone and what do you get-a gear eater. Ditto for using a used pump on a worn shaft-different mesh patterns and then you give them 2 diff surfaces to ride on, they will eat each other apart. You can clearly see the pitted teeth if you inspect the shaft gear.

Josh's first failure looks like normal wear and tear, then the junk got left in the system and took out his oil pump and shaft again.

TIII's from what I have read on here seam to have a weak shaft so owners just replace the pump and shaft from our 8V engines.

[87glhs232]

After the first occurance, I bought a new pump and a shaft from Cindy, since I had no other source at the time. Gear teeth looked good. Prolly was junk still in there.

[BadAssPerformance]

The tolerance is pretty open on those gears. I had one skip in my '87 CSX w/o damaging the teeth on the intermeduiate shaft or the oil pump. Heard of others having that happen to their motors too.

[Dave]

The oil pumps just get all old and crudded up and just start dying out and not spinning as loosely as they should and it just decides to jump a tooth I think then all hell breaks less and it just tears up the teeth.

[inmyshadow]

I've stripped out both intermediate shafts and oil pump gears plenty of times. Mine was caused by oil starvation after I pulled my balance shafts.

I've been told it could be bad intermediate shaft bearings is one of the causes behind stripped gears.

[turbovanman²]

I've stripped out both intermediate shafts and oil pump gears plenty of times. Mine was caused by oil starvation after I pulled my balance shafts.

I've been told it could be bad intermediate shaft bearings is one of the causes behind stripped gears.

That would make sense if you don't put a windage tray in or the shallower oil pan.

[MiniMopar]

Mine went slowly. The car started idling really bad, knocked and pinged all the time and just ran terrible. Eventually I removed the timing belt cover and noticed that the timing belt was very loose, though it hadn't jumped time. I tightened it and it helped, but about a week later the gears gave out.

I think the loose belt was making the cam timing jump all over the place and it was taking the intermediate shaft with it. The constant backlash killed the gears. The teeth were chewed up on both sides, not just the forward side.

That's my theory, anyway. The bearings were nice and tight as far as I could tell. I got a "new" shaft from Cindy, but it wasn't really a new part. I looked like a good used part. It was in a Mopar tube, all wrapped up professional-like. Anyway, I've put about 10k on it since then and it's been fine.

[turbovanman²]

That's my theory, anyway. The bearings were nice and tight as far as I could tell. I got a "new" shaft from Cindy, but it wasn't really a new part. I looked like a good used part. It was in a Mopar tube, all wrapped up professional-like. Anyway, I've put about 10k on it since then and it's been fine.

Yeah, I heard a rumour that the NEW Mopar shafts are simply remanned shafts. What a rip,

[86Shelby]

I'll just resurrect this thread instead of starting a new one...

Is there anything in particular that could be done to a used shaft, specifically the gears so that it will wear nicely with a new oil pump? The gears look fabulous, journal surfaces are perfect. I can't find anything wrong with it other than it has mileage on it.

I've already been through one shaft/pump failure on my R/T and don't want to revisit it any time soon.

[MiniMopar]

Well, if you buy into my theory, just make sure the timing belt tension is correct. Mine got sloppy because I set the tension using the tool on a new belt. New belts stretch, so now I add a little weight to it if it is new.

[turbovanman²]

If the teeth look good, you should be fine. If your really paranoid, get them cryo treated or even coated?

[BadAssPerformance]

Well, if you buy into my theory, just make sure the timing belt tension is correct. Mine got sloppy because I set the tension using the tool on a new belt. New belts stretch, so now I add a little weight to it if it is new.

...or use the tool, then use it again in 500 miles... LOL, i do what Russ does.. if it is too tight it will sing for you to let ya know

[BadAssPerformance]

If the teeth look good, you should be fine. If your really paranoid, get them cryo treated or even coated?

Or just get a new shaft?

[86Shelby]

No actual 'new' shafts available. I looked at a reman shaft at the dealer. The teeth were polished and they felt smooth but still had a wear pattern.

[BadAssPerformance]

Someone has to have one in their parts pile... good luck getting it for cheap tho.

[86Shelby]

I've thought about having the gear portion soda blasted to get rid of the wear patterns. NOT sand or other harsh material, more like soda, walnut shells, etc. thoughs on this?

I haven't had a problem with the shaft in my GLHT, with nearly 20k on it. But if/when it gives out the engine will stop running. I consider myself lucky that I caught the oil pressure guage botom out on the R/T.

[Dave]

I know my dad got one from the dealer. The bearings were acutally more than the shaft.

When I blew mine out it was because the stock oil pump failed.

[Directconnection]

Junkyard part from a known good running car... dime a dozen at a pick 'n pull type yard.