Jeep Strokers

Last month, I dropped in a newly built stroker, and I am working through the break-in. After the first 30-minute cam break-in, I drained the oil (Driven BR30) and changed the filter. The oil coming out looked just like the new oil going in, which was encouraging. I use a FilterMAG and cut the filter open to find some very fine metal, but nothing I would consider out of the ordinary for the first run. After that, I proceeded to fill it with more BR30 and a fresh filter, and after seating the rings, I drove normally along local routes (mix of country back roads and small-town driving) with minimal idle time and no sustained high-speed driving. Unfortunately, when I drained the oil, it was very dark, and there was even more metal in the filter. Within a mile of driving, I had a loud squeal around 2k RPM that we thought was the idler pulley, so I replaced that and the belt, but the issue came back once the engine was warmed up and seemed to be when it was under load, not in neutral or park. This evening, I pulled the OPDA out and found extreme wear on the teeth. The unit was a new Crown Automotive that went in with the engine. My next steps are to pull the pan and see what it looks like inside. Has anyone seen one fail this quickly, and if so, what would cause that?

That degree of distributor gear wear could be caused by the cam walking inside the block.

Thank you for the quick reply.

I am looking through the forums and so far all of the threads I am seeing regarding cam walk are with the older button and spring style retention. Any thoughts on the newer style cams that use the retainer plate?

I’ve seen that type of wear from use of high volume pumps on big block Chevys. You running a high volume pump? What kind of oil pressure you getting on the guage at idle? I specifically chose a cam that use the cam retainer plate in my build because I didn’t want cam walk.

It is a Melling standard volume pump, I did not see any need to go with a high volume, especially given the potential risks involved.

Warm, idling 6-700RPM I am seeing 14-20psi from an AEM gauge mounted in a sandwich adaptor between the block and filter.

I’d check for cam walk for sure. By any chance does it have a double roller timing chain? Also make sure you have the right timing cover because I believe there is one with the bump and ones without the bump.

I will be pulling the engine to check for walk and to check for damage. It does not have a double-roller chain, instead it is one of the single-roller style from Russ. Since this is a 2005 I am running the factory cam retainer plate and timing cover (without bump) with a matching comp cam.

If you are running cam retainer plate you shouldn’t have cam walk at all unless the plate came loose.

That is my understanding as well. Everything was properly torqued, so I would not expect it to have come loose.

Guessing/hoping yours is an updated version of the Crown unit? I had a distributor fail on a beach trip once and it started making the squealing sounds you refer to. I was terrified after pulling the distributor and i couldn't turn it by hand. The shaft had galled the aluminum housing and was trying to seize. It had nife-edged all the gear teeth in the process, WAY worse than your pic. Found a jeep dealer in OBX and they had a distributor in stock, so i picked it up, mucho $$, and all was well. Needless to say that experience made me an oil-pump drive nazi, and i keep a close eye on it ever since, lol

https://wranglertjforum.com/threads/wha ... e-mine.80/

I also intalled a not-perfect oil pump way back when it was still a 4.0 that had terrible mesh of the rotor vanes in the pump. Wasn't pronounced when I primed it by hand, but with the engine running you could hear it 'growling' if you stood anywhere near the Rt front wheeel. That prompted my 1st dizzy drive gear change. I was able to score a factory replacement gear back then, now it's pretty much Crown & Omix-Ada. These gears are ALL designed to be a little softer than the cam gear teeth, so it'll trash the more easily serviced part in the event of a failure. "SOME" level of wear pattern will happen on these, because basically that little roll-pin secured gear has to take the brunt of any misalignment or deviation in tolerance from true, as the assembly runs. Mass production parts will always have some variance. That factory gear i got back then i still believe had the best properties. It was Green and lasted almost perfectly another 35k miles on a wore out 4.0 w/ a hi-volume pump, to get me thru while i was in college. I think the newer batches are maybe even a little softer cause almost all of my cam changes since have produced gears with similar wear patterns as the pic you posted. Sorry for the novel here! So verify there is no binding on the distributor shaft, that it turns smooth w/ out any hangs or tight spots. While it's out, get a Clean long reach flat head screw driver and CAREFULLY engage the oil pump drive slot and turn it slowly Clockwise to feel if the oil pump is binding. If it hasn't been run in a day or so you should be able to turn it a little before it re-primes and makes it too hard to do by hand. I Will Not recommend you to use anything but hand effort for this. Some folks are comfortable drilling the oil pump in this manner, but its risky w/out a proper priming tool (keep an old dizzy shaft & make one). If everything checks out smooth, its possible that this is just your engines wear pattern for that gear. Keep an eye on it, i had one that looked like it was on its way out and then stayed that way unchanged, until the cam wiped 30k miles later. Just trying to help, know these things can be frustrating. Good luck w/ it!

All, thank you for your recommendations. I pulled the engine earlier this year and found the cam retainer plate was still properly torqued and had not moved. I do not see a spec in the FSM, what is an acceptable amount of movement for the cam front to rear?

The most disturbing part of this is I wiped another (second) crankshaft due to the rear thrust surface wearing down. I did not have the bushing that locates the torque converter in the rear of the crank, but I was able to locate one for this go-round. Aside from that bushing possibly, what else could be a cause for this issue?

unlimitedrubicon wrote: ↑August 13th, 2022, 7:03 am
The most disturbing part of this is I wiped another (second) crankshaft due to the rear thrust surface wearing down. I did not have the bushing that locates the torque converter in the rear of the crank, but I was able to locate one for this go-round. Aside from that bushing possibly, what else could be a cause for this issue?

What transmission do you have and what crankshaft are you using?

Are there OE Jeep automatics that require a pilot bushing?

Torque converter spacing is the usual suspect in this scenario.

It is the factory 42RLE automatic transmission. When I built the engine the first time it was a scat stroker crank, the second was another aftermarket, and this time will be an eagle. I did not see any reference to a bushing online, nor does the FSM or factory parts guide list anything for it. However, the factory crank did have a bushing in it, and I was able to find the replacement cross reference from another Jeep forum and have one to install this time. The pilot bearing for a manual seems to be common knowledge, but the bushing for these Jeeps seems to be a great unknown. I even recall finding postings when I did this years ago stating it wasn’t needed.

If this is the final fix that would be great, and probably the best $20 I could spend on the engine.