Replaced with used engine, breaks flex plates, 2000 3.0lv6

[theant]

Shortly after having mechanic replace my engine (blown radiator, head gasket, too much time sitting with water in it) replaced with a used 70-kilomiles engine replacing my 170kmiles, both 3.0l V6.

First "rattle out of the box" was said to be too long of bolts they used on the flex plate.

Fixed that but started making noise and then it broke the flex plate.

Replaced that with a new flexplate.

After a few hundred miles, a complete tear around the bolts and so no connection between motor and Torque Converter. Flexplate replaced under warranty.

By now I have a decent idea from past experience that the current flexplate is breaking too from the all too familiar loud knock at idle. It seems to go away under load/acceleration or driving.

Is it possible that the engine they put in is incompatible with my transmission?

Would a competition (thicker) flexplate be a good fix?

Could it be alignment between engine and tranny? I do not know about the dowels. Hope they didn't lose them.

As far as I know the tranny is original, I guess 4spd.

There s a plate missing from the bell housing that allows me to see the flexplate gear teeth if I look in the passenger front wheel well. Can we get new covers? I think they're just thin aluminum and might be able to make one.

tia

 

[adsm08]

Does this one have a spacer like the 2.9 and 4.0? If so that is the likely culprit.

 

[theant]

Unfortunately... I did not do the work myself. I will this time.

I read some about the spacer. Is it one that fits around the center and all bolts go through it? I think they called it a "spreader". My interpretation being was that it helped distribute the pressure from the bolt heads further, making it less likely to tear.

I need to get my tranny ID number and look at the exploded diagram.

I also want to see what engine he put in there. Maybe it is a mismatch with my tranny, don't know.

Does this one have a spacer like the 2.9 and 4.0? If so that is the likely culprit.

 

[adsm08]

There is no "mismatch" between the engine and trans. It's not like they made one 3.0 block for the 4R44 and another for the 5R44, it doesn't work that way.

The flex plate spacer was used because a manual trans flywheel is thicker. Using the spacer put the flex plate in the same spot as a flywheel, allowing for the use of the same bolts, among other things. On the 2.9 and 4.0 there were issues with the spacer wearing over time and so it wouldn't hold itself centered properly, and this would cause stress and tearing on the flex plate. But not every engine used them. I have had the trans out of a few Triton F-150s and can't remember ever seeing one.

 

[85_Ranger4x4]

I think my parts book (which only goes up to '89) shows the "spreader" you mention for '86+ 3.0 engines.

Looks like it acts as one big washer with size holes for the TC bolts to go thru on the tranny side of the flexplate. Base part number is 6A366.

Things might have changed since yours is quite a bit newer than my book but that is what I found.

 

[theant]

Your reply is masterfully done, thanks!

I did not know what may have transpired before I got the truck in terms of mods, engine, and/or transmission changes but you make plenty of sense on the engine/tranny match. I was wondering if they had variations between my V6 in truck vs. some models of vehicles because I see people moving engines between vehicle models in forums. Regardless, I would suspect all I have is original equipment so I feel more confident on that front, thanks.

heh, on a side note, when they pulled my old engine they pulled the water pump and there were no vanes on the impeller, just a flat disk with ridges where the blades should have been! It is possible that a very small amount of water flow existed in that state just from motion and surface tension but I assume it says a lot about the cooling ability of that design. I never had reason to suspect a bad water pump and the blown head gasket was on me and my stupidity, pushing too hard when my temp gauge went up. I didn't know it but I had blown the bend of the top neck of my radiator. I replaced the radiator but the motor quickly deteriorated from the head gasket. That had to be the EASIEST radiator I ever changed! Love the old mechanical fans!

Sorry about the off topic, my middle initial is "D" which has to be for "Digression", "Diversion" or "Distraction" but it does make me an analytical, variable aware sort.

Regarding potentially missing spreader and/or spacer; after the mechanic (actually his lackeys doing the work) swapped engines for me, I found a loose bolt on the bell housing, leaking, loose fitting at the radiator from the tranny, a disconnected ground wire, and some other piddlin' stuff that as me expecting I may find a missing spacer and/or spreader when I split block from xmission.

Again, I will look at the library more closely once I get the type of transmission so I can look at the exploded view.

Is there any merit in my comment I left on a "competition" flex plate? As I infer after only cursory reading, a "competition" flex plate might be thicker and possibly remove the need for the spacer, assuming mine requires one now. Comments?

Again, great job of filling in the blanks in my mind on the details and nature of engine/transmission mating.

There is no "mismatch" between the engine and trans. It's not like they made one 3.0 block for the 4R44 and another for the 5R44, it doesn't work that way.

The flex plate spacer was used because a manual trans flywheel is thicker. Using the spacer put the flex plate in the same spot as a flywheel, allowing for the use of the same bolts, among other things. On the 2.9 and 4.0 there were issues with the spacer wearing over time and so it wouldn't hold itself centered properly, and this would cause stress and tearing on the flex plate. But not every engine used them. I have had the trans out of a few Triton F-150s and can't remember ever seeing one.

 

[theant]

Thanks for the part number! I will look also for the spacer p/n just in case I need it.

I think my parts book (which only goes up to '89) shows the "spreader" you mention for '86+ 3.0 engines.

Looks like it acts as one big washer with size holes for the TC bolts to go thru on the tranny side of the flexplate. Base part number is 6A366.

Things might have changed since yours is quite a bit newer than my book but that is what I found.

 

[85_Ranger4x4]

Thanks for the part number! I will look also for the spacer p/n just in case I need it.

That should get you close, I don't know what the prefix is for a 2000 Ranger though.

 

[adsm08]

The spacer, if it should be there, cannot be missing. It would make two things happen.

1) The bolts for the flex plate would bottom out before getting tight.

2) The flex pate would be so far into the wrong spot that the torque converter studs wouldn't engage it.

 

[theant]

ummm, the throw out bearing was a joke, OK?

Hmmm, I remember the first reason for noise on the flexplate was "bolts were too long"

Sounds like they lost the spacer, went back in with shorter bolts. So if they put shorter ones in maybe broke flex plates from that? Obviously to you all, I am also not totally familiar with the parts in there. While I have it apart I'll be sure to replace the throw out bearing

I'll let you all know what I find when I get it apart. I hope I haven't screwed anything else up like seals.

You all have been great!!! I'm learning tons. I just never encountered such problems in the past and for that matter, never had an engine replaced. I am almost 60 years old and ave been through many cars and fixed almost everything on all of them ad of course friends and family.

The spacer, if it should be there, cannot be missing. It would make two things happen.

1) The bolts for the flex plate would bottom out before getting tight.

2) The flex pate would be so far into the wrong spot that the torque converter studs wouldn't engage it.

 

[85_Ranger4x4]

The spacer, if it should be there, cannot be missing. It would make two things happen.

1) The bolts for the flex plate would bottom out before getting tight.

2) The flex pate would be so far into the wrong spot that the torque converter studs wouldn't engage it.

From what I see the spacer wouldn't effect the flex plate location, it goes between the flex plate bolt heads and the flex plate, not the flex plate and crankshaft.

But again my book only goes to '89...

 

[adsm08]

From what I see the spacer wouldn't effect the flex plate location, it goes between the flex plate bolt heads and the flex plate, not the flex plate and crankshaft.

But again my book only goes to '89...

The ones I am thinking of are for the Cologne engines, and as I said, I don't know if they were ever used on a 3.0, but the arrangement was crank, spacer, flex plate, bolts.

Even if the spacer went on the outside (seems pointless to me) it would still keep them from getting tight.

 

[theant]

I know what you are talking about and that is a possible problem.

Point pressure from bolt heads, that is, just pressure under the contact area between bolt head and plate may be inadequate to prevent shearing the plate.

I read thickness may be less than adequate under strain... like when it is supposed to flex. Other wear or problems could increase stress on the plate like alignment with transmission or engine (whichever it bolts to) bearing end play, starter motor/gear, and as I also read problems with the harmonic balancer permitting too much wobble on the crank. Metal fatigues over time, which could be a problem, except I have a new plate in there, (actually there have been two) and finally, it could be an old one broke and then I got a couple of bad new flex plates.

The part you are talking about effectively extends the bolt head contact area across what is effectively a hard metal "washer" that "spreads" pressure from all of the bolt heads across a greater area, thus extending the flexing material out toward the edge of the spreader and between the bolts. It may be difficult to visualize but the bolt holes are like perforation on continuous, folding computer paper making an easy place to tear. The spreader is like tape over the perforation keeping shear from happening along the perforation line.

It is an important component that the mechanic may have left out. The "long bolts" the mechanic blamed for my first problem with the flex plate may indicate that spreader was left out. It is also why I asked about a "competition" flex plate which may be thicker and harder for greater shear strength from harder alloys or heat/quench hardening. If designed to be light weight for rapid acceleration it may be thicker but more vulnerable to bending, flexing, shearing, or breaking depending on the properties of the metal.

After all of that physics drivel, that part may be missing as might be the spacer, assuming called for. Either or both could may contribute to breaking plates.

I realize you and maybe most here know all of this but but it is good to intuitively understand for many things mechanical. I think about our sons learning here. I mean no insult to those veterans of "the choir" here. Many cannot get these ideas but those who do have that "mechanical genius".

I fall far short in knowledge among the giants here helping me in this part of the drive train and respect them! Thanks to you and to all!

From what I see the spacer wouldn't effect the flex plate location, it goes between the flex plate bolt heads and the flex plate, not the flex plate and crankshaft. I will know more when I see the drawings and compare that to what I see when open her up but help here prepares me better to understand what I see when I get there, THANKS AGAIN!

But again my book only goes to '89...

 

[theant]

Got that, thanks! I have read of this but like you not sure whether it is this engine/xmission combination. I will pass on what I learn.

I have no idea what engine it is. I looked for identifying marks on the engine block but could not see any. (surely it is not a plate that was knocked off or painted over...).

I expect to see a number cast into the block somewhere, probably under an exhaust header or something

I did get a pic of the tranny marks and will look them up later.

Thanks!

The ones I am thinking of are for the Cologne engines, and as I said, I don't know if they were ever used on a 3.0, but the arrangement was crank, spacer, flex plate, bolts.

Even if the spacer went on the outside (seems pointless to me) it would still keep them from getting tight.

 

[85_Ranger4x4]

No idea what their reasoning is, but that is what the picture shows. It looks like something that could be called a spreader.

Might just be a cheap way to reinforce the flexplate without making it thicker.