4 spun rod bearings 2.4 hybrid

[sophat34]

well the moter had 2020 miles on it. I took it back to the shop that assembled the long block because I didnt feel like tearing it apart again. turns out that all four rod bearing were shot and had spun in the rods. any idea how this could happen, it seems like they were starved for oil but the car has always had good oil pressure. its a 7 bolt 97 galant block and crank with paulter rods and ross pistons at 9:1 any help on this one is really appreciated

 

[TheBear]

not enough oil clearance between bearings and crank journals that the rods ride on would still have high oil pressure, but not thick enough of an oil film between the bearing and journal to lubricate it enough. have them turn the crank and get the correct undersize bearing

 

[Nanan]

not enough oil clearance between bearings and crank journals that the rods ride on would still have high oil pressure, but not thick enough of an oil film between the bearing and journal to lubricate it enough. have them turn the crank and get the correct undersize bearing

Sounds right to me. When you get your new bearings take them to the machine shop and have them cut the crank to the bearings.

 

[blue1]

sounds like someone stuffed up somewhere and you you didn't assemble it, that only leaves one person. you are at their mercy to see if they are going to admit to the bad build or blame the type of polish you used on the car!! (joke) see what they come up with as their finding to the bearing failure and keep us posted and who it was that did do the build, so others can be weary of who they use!

 

[sophat34]

the shop that did it is actualy being very helpful so far. they realize that it was there fault. the car is at there shop and they took the pan off to see what was wrong. all they have asked so far is for me to come and help pull the motor this weekend which I have no problem with because I really dont like other people working on my car to begin with. I just wish I knew how to assemble a motor.

 

[blue1]

you seem to have a good shop looking after you, once they do fix the problem with yours it would possibly be an idea to post them on, its hard to find good reliable shops, and the thing is the problem that you had will never happen to any other of their customer cars.

 

[Suparata]

What could they have done that it took 2000 miles to go bad?
Spun rod bearings mean damaged rods most of the time to the point of being junk.
This whole story is weird so keep us posted what and why it happened, what’s the damage and how things go.

 

[TSIfreek]

What could they have done that it took 2000 miles to go bad?
Spun rod bearings mean damaged rods most of the time to the point of being junk.
This whole story is weird so keep us posted what and why it happened, what’s the damage and how things go.

Yea Mitch is right. When a rod bearing goes it welds itself to the crankshaft (bearings) and the
rod keeps spinning and gets red hot to the point were all the heat treatment (strength) of the rod is lost and its junk. You can tell right away if a rod bearing spun by looking at the big end of the rods and they will be discolored black (just the big end were it got so hot). If not the rods may still be ok. Let the builder make that call.
How did you prime the oil pump?? Was the oil pump packed with vasoline or was it dry??
Ask what the bearing clearances were set to and the torque put on the rod bolts and lube that was used.
If all 4 bearings failed its more than likely to tight of clearance and oil starvation occured but 2000 miles seams a little weird to me as well. If its to tight they will spin in 10 miles. Make sure the problem is found before the motor is put back together. Keep us posted.

 

[sophat34]

when I looked at the rods, there was no discoloration at all. they are chromoly rods if that has any thing to do with it. I am wondering if they just didnt torque the rod caps on. the berings turned inside of the rod. number one wasnt bad but it got progresively worse as u went towards number 4. number 4 has significant marks on the inside of the rod cap from the bearing spining. for priming the motor I am not sure what they did as far as packing the oil pump. I made sure that I had oil pressure befor I started the motor. cranked till pressure then stopped and repeated 3 times. with plugs out and ignition disconected. thats what really gets me that it ran for this long like this. there was copper all over the bottom of the oil pan, but it was stuck to it so it wasnt comming out when I drained the oil. I am wondering if one of the oil passages got colged. wich direction does oil feel threw the crank? when I was talking with the shop owner we both agreed that something went wrong and that it wasnt the driving that did it. what really gets me is that every thing else in the motor is fine so far. wrist pins are fine and all the other bearings are fine. they said that they will machine down the rod cap to make the hole smaller then boar it round to the size that it needs to be. does that weaken the rod at all? he told me no but I dont know much about that.

 

[TSIfreek]

The oil flows from 1 to #4 rod bearing. As far as machining the rods it depends on how much they take off. Pauter rods are very strong to begin with so I dought you will have a problem. Still no definate answer to why this happened. If you had a cloged passageway the crank bearings would be trashed as well because the rod bearings get the oil supply from the crank bearing oil. Any chance we can get picks of the bearings and rods?

 

[sophat34]

I am pulling the motor with them on saterday morning. I will get some pics and post them.

 

[sophat34]

well, only rod bearings 1 and 4 were bad. but...the thrust bearings were almost gone. the middle one ground its way in to the side of the crank about 1/8 of an inch. not sure if this is crank walk but if it is, I have a new theory. we looked every thing over, on the presure plate there was a ring worn in from the throw out bearing. the 2g's dont have an adjustable clutch cylinder. if the shift fork is pressed against the throw out bearing there would be a constant presure on the pressure plate which would keep a load on the thrust bearings and lead to premature failure. the stronger the pressure plate the more the load would be and the greater the chance of the bearings failing. some one shoot me down if I am wrong on this.

 

[TSIfreek]

I thought I saw how to adjust the 2gs on RRE web site? If its a 6 bolt I dought its crankwalk like the 7 bolts. The 6 bolts get a much better oil supply to the trust bearings so I would rule this out as a maybe but more so on not alighning the thust bearings when they were installed to begin with or having to tight of crankshaft end play. How far away are you from rockford??

 

[sophat34]

I am about 20 min north of madison, the motor and shop are in fond du lac. thats about an hour and a half strait up hwy 41. it is a 7 bolt, its a 97 galant block and crank. I know I should have done a 6 but I couldnt find any at the time.

 

[snox135]

You can adjust the clutch on 2g's. You have to adjust the pedal. You are right thou you add to much pressure on it.

Poynette is about 1 to 1 1/2 hours from Rockford. Not too far off I-90 past Madison.

 

[sophat34]

I did adjust the peddle I had about 1/4 inch of free play, the aluminum fly wheel that is on the car is thicker than the stock so it sticks out further. there isnt an adjustment on the rod that pushes the shift fork. I am thinking that if I can move the whole assembly back just a small amount to give the fork a minimal amount of free play I can prevent this from happenieng again. I used to live in rockford long time ago when byron was being built.

 

[TSIfreek]

If you would bet on this being the problem thats fine. Check your flywheel step height

 

[snox135]

I would check your step height. I'm not 100% sure, but I think you are supposed to have an inch of free play in the pedal.

 

[AutoMods]

Sophat,

Brand new pressure plates have ring shaped marks where paint is rubbed off on the pp fingers appearing as though wear/contact has been made around the TOB contact area. They are like that new from the manufacturers, perhaps from testing or some kind of break in.

I wouldn't put the motor back together until your shop has a good idea of what caused the problem or take it to another shop.

 

[ltho98]

Or you could have had the same unfortunate luck that I had and find out you had a clogged oil cooler after spinning a bearing twice.