3.3 rocker arm shaft pedestal breakage [Archive] - Dodge Talk Community Forum


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shelbydodgeimp
10-11-2005, 10:32 PM
Ok, I know some of you all have heard of the pedestal breakage problem on early 3.3's top end.

The 1990 and 1991 model year 3.3/3.8's would have the pedestals (what the rocker arm shaft mounts to) snap off the heads.

Anyway I have heard about this alot, never actually seen it with my own eyes. Tonight I found a Dynasty on eBay with this happened (1991 Dynasty).

http://f3.grp.yahoofs.com/v1/IG5MQ0xcgPORCt6-nEJhiKGD6rWtpNCXRspSrEmQtUm9h84XpQp-DBSnQsM3uhB2ASuSdMtzk0NZENenBv4R/broken33rockershaft.JPG

I have never heard of this happening on any newer 3.x engine, the later heads design resolved the issue.

Just goes to show that if you rebuild an early 3.3- go with the newest top end parts that will bolt right on- the changes chrysler makes, are made for a reason.

Anyway, the easy fix for this is to grab the late 1993/early 1994 3.3 heads with the matching unshrouded style cam and just bolt it on.

But figure this is of interest to the 3.x minivan users from the 1990-1991 era on the board!

shelbydodgeimp
10-11-2005, 10:34 PM
FYI this is a fairly rare occurance, most 3.3s of those two years will never have this happen. It just happens enough for it to be noticed and talked about.

96Grand
10-11-2005, 11:08 PM
Happened to me in March of this year... the shaft on the rear head broke at the left side near the left rear cylinder head bolt. Snapped the bolt & a couple rockers got mangled... sounded like marbles in the engine... with a loud knocking sound... when it happened.

It was a bitch... I went ahead & sent the front head to the machine shop to be overhauled just to be safe. I also did a complete engine tune up & replaced all the gaskets & a bunch of other shit at the same time since it was all torn apart anyway.

I took pics but I dunno what I did w/ them... maybe on one of my other computers... if I can find them I'll post them for you guys. Anyone needs tips or pointers about this repair contact me... I did mine myself & I could walk you through it.

Note: My van is a 96 Grand w/ 3.8 and it had 182,000 miles on it when this happened.

:rck:

shelbydodgeimp
10-11-2005, 11:13 PM
Wow, never heard of such a recent case. Musta been a lot rarer after 1991.

tchase
10-11-2005, 11:18 PM
And we didn't even know it was common:
http://i8.photobucket.com/albums/a20/tchase/3.jpg

This was actually out of an intrepid, not sure what year but early.

96Grand
10-11-2005, 11:23 PM
I read up on dodge's recalls for my van when this happened... and sure enough there was something that I saw regarding this same issue on an old recall alert... if I can find it again I'll post it.

:rck:

shelbydodgeimp
10-11-2005, 11:29 PM
Hmm, I wonder if one could just spry more oil on the rocker arms and shaft via a 2nd oil pump or something.

There's gotta be some preventative measures besides bigger top end oiling bores.

96Grand
10-11-2005, 11:42 PM
I figured the same thing... my problem must have been a classic "no oil" situation... but... when I took it all apart... all the parts were perfectly lubricated & wet w/ oil... not barely wet or partially wet... fully wet... the way they should be.

That's what lead me to believe that there might have been recalls on the shaft or head bolts or heads themselves. The breakeage was very violent & was unlike anything I had seen prior... I have seen breakages like this in the past where there is a no oil situation... but not when fully wet.

Strange huh?

shelbydodgeimp
10-11-2005, 11:52 PM
Here's a thought going by an allpar thread on this...

what if the early 3.3s that had this happen, did so due to an oiling problem, and the later 3.3s that have this occur- do so as the result of a casting problem?

Compare those two pics, your pic looks much more uniform and symetrical.

shelbydodgeimp
10-12-2005, 12:09 AM
FYI I just did a search on 3.3 recalls and didnt find anything pertaining to the valvetrain, oiling system, etc.

I found stuff on the early ABS systems, on late 90s 3.3s lots of fuel injector stuff... but nothing related to this.

Not that this says anything, Chrysler hasnt recalled some of the obviously flawed A604's out there.

96Grand
10-12-2005, 02:19 PM
For some reason those pics didn't show for me until today... but that looks exactly the same as what mine looked like except the breakage was on the far left... other than that... exactly the same thing.

Note: Mine was a 1996 3.8 w/ 182,000 miles at time of breakage.

:rck:

shelbydodgeimp
10-12-2005, 03:22 PM
Aparently the breakage on the newer 3.3/3.8s is always on the rear bank.

If it were an oiling problem, since both heads are the same design- shouldnt the front bank also be subjectiable to this problem?

I am starting to suspect that:
-1990/1991 instances were an oiling problem (could happen on either bank)
-newer 3x's could be a casting problem (or something going on during the production stage of the rear bank heads).

Since its only the rear bank thats breaking on the newer ones, what else could cause it other than a casting problem?

Perhaps they're using the molds too long before discarding them. I know from some factories I've been in, with alumnium molds usually the factory will stamp a serial number on the mold so that if later on down the line, some parts are failing, they can trace it back to the mold to rule it out as having defects/aged/etc.

This doesnt happen very often, I never come across 3.3s in the yards with the heads removed (like would happen if this is a common problem).... using a bad mold too long past its life span might be able to do this.

Just a thought I guess.

tchase
10-13-2005, 10:09 AM
Sorry guys I was slightly mistaken before. The engine in the pic I posted is out of a '93 Concorde, the replacement was from an intrepid.

shelbydodgeimp
10-13-2005, 03:16 PM
I talked to a guy with a Dynasty who had the breakage, he had a shop (for about $60) tap the heads and use long grade8 bolts to attach the rocker arm assembly to the heads, bolt went clear threw the heads to the side of the heads that mates with the block.

Perfect fix, he never had any problems later. I suppose one could use this bolt method as a preventative repair if they ever have their 3.3 heads out for some reason.

96Grand
10-14-2005, 12:46 PM
Aparently the breakage on the newer 3.3/3.8s is always on the rear bank.

If it were an oiling problem, since both heads are the same design- shouldnt the front bank also be subjectiable to this problem?


I thought the exact same thing... but from what I have learned it's only occuring on the rear heads on these models... very odd... but leans more toward a casting problem.

One other thing I realized was... at the time of the actual breakage of mine... I was travelling up a pretty long steep hill... and I think that maybe that's what is causing the breakage's to occur in the rear heads... due to heavier load while going up a very steep incline.

Another major thought occured to me. Wouldn't this incline cause the no-oil situation to occur in the rear head??? Wow... never thought about that one til' right now. This would explain the fact that only the rear heads are being damaged... no oil getting to the rear head on a steep incline... is it even possible?

:rck:

shelbydodgeimp
10-14-2005, 01:45 PM
Wouldnt going up an incline be more likely to effect the oil of the front bank?

gas28man
10-14-2005, 02:03 PM
It all depends on the design of the passages, drainback, pickups, etc.

Rick

96Grand
10-15-2005, 10:29 PM
Lets say... with a 96 grand caravan w/ 3.8 liter engine... can this really happen or not? Let me know what you guys come up with... I will look into it also.

:rck:

shelbydodgeimp
10-15-2005, 11:15 PM
*can* the 96 3.8 rockers break? Sure. Is it likely? No.

Can it be prevented or fixed after the fact with the grade-8 bolt methd? Definately.

Or are you asking about steep hills playin into the "cause"?

96Grand
10-17-2005, 09:39 AM
On the 96's w/ 3.8's... is it possible for the oil to be pulled away from the oil pickup and cause a no-oil to the rear rockers situation while going up a steep incline?

Is it possible that there could have been too much load while going up a steep incline and this caused the breakage?

Mine broke during these conditions... although having normally wet rockers... just a thought.

I guess I am trying to rule out a casting problem & determine what may have been the most likely cause.

That's what I am getting at... just trying to put two and two together.. I'm not an expert on the subject by any means.



:rck: