138 Grey motor crank thrust bearings and stuff - URGENT

[stapla]

Hi All,

Does anyone have any new crank bearings, crank thrust bearings and a maybe even a new crank ? Motor could be a 138. Engine number is B320XXX which I understand is FB/EK 138 ??

Mechanic checked motor yesterday and diagnosted too much crank float. Strange, since the motor has only done little work. They don't have time to remove engine so I had to do it myself. Lucky for sick days

Today I pulled out the engine. I supposed to be traveling from adelaide to NSW - leaving next friday 26th in this car.

Dropped engine off to engine builder this arvo. Hopefully the engine builder will be able to sort issue quickly but parts are likely to be a problmem

Plan B is a reco motor from HM GEM, Southcots @ $3200 exchange. Ouch. At least they have stock (australia wide apparently as they did a batch recently)

History.

Since recently installing fresh motor I had a strange clutch noise when pedal was pressed.

As usual I thought clutch thrust bearing or spigot bush - strange since thrust bearing was new.

Dropped past a clutch specialist and they had a quick listen. They thought it wasn't clutch thrust bearing. This was because noise didn't start when slack was taken up and when thrust bearing touched pressure plate. Noise started when clutch pedal was about 1/4 down, and then all the way to the floor. They thought if its not clutch thrust, then it must be spigot.

A 2nd, more serious, noise started a couple days ago. It was louder, sounded like it was coming from the dissy, internal oil pump area but I'm a bit deaf. Sounded bit like a whurring of gears.

This noise was there when it was idling, and revving - irrespective of gear position or clutch. I swapped dissy as a remote chance but no luck - problem still there

Off to the mechanic who couldn't find much apart from the crank problem. They think the clutch noise is related to crank problem. Movement is around 1 to 2 mm. Apparently should be just a few thou. Too much more and crank hits the block.

The only thing I can think that might have caused too much crank end float is me fitting the flywheel inspection plate, while gearbox and motor were in car. I needed to bang it in. Not sure if it was around the wrong way. Which way do they go anyway ? Bumps to the rear / outside ?

Apart from that I'm not sure what might cause the issue with a fresh motor.

At least the problem didn't happen half way across the hay plains !!

Hopefully better news tomorrow.

Cheers
Peter.

[FB MAD]

Greys will have some crank end float and yes, about 1 mm would be found in a lot of well used grey's but 2 mm would be at the extreme edge of acceptability in my opinion but would/could probably still be found in a running engine with no obvious noises.

Your description is well described and it would appear from that description that it would "appear" to be a crank thrust bearing problem however I agree with Tim that it could also be caused by something outside of the current diagnosis square including stupid silly little things.

Did the people that came to the conclusion that it was most likely crankshaft end float measure the amount of end float that was happening by using a dail guage and if so what was that reading??

Excessive crank float "kinks" or "binds" the conrods causing them to sort of operate slightly sideways in simple terms and causes excessive rod bearing wear and/or excessive piston pin/bush wear and eventually leads to a sort of rattling/knocking noise of sorts among other possible problems depending on engine design.

Not sure whether a grey crank would float enough to actually hit the block but don't have a bottom end sitting in my lap ATM to confidently say it wouldn't so it's possibility??

I have a genuine GMH FB shop manual here so will see if it lists accepted crankshaft end float so you have a starting point there.

Again, it most certainly does sound,by your description to be an end float problem but as always there may be an alternative cause as well??

Would be interested in the engines post-mortem results from the engine coroner

[FB MAD]

Well the 1 mm crank end float I've seen in a lot of greys is well out of the GMH accepted tolerance.

Shop manual says .003 to .008 ( 3 to 8 thousanths of an inch ) and is measured at the crank thrust bearing itself with a feeler guage.

Obviously the grey is very tolerant when running outside recommended GMH running specifications and I'm sure that a lot of greys would have left the engine plant and fitted to new cars with crank end float outside the factory "blue print" specs anyway.

[stapla]

Unfortunately no good news today. Engine builder says crank float is 40 thou'. Crank is damaged and main bearing.

The cause ?? Well engine guy thinks a mis adjusted clutch could cause it. He thinks if thrust bearing was always under load it would put pressure on crank. I'm doubtful it could happen so quick.

Secondly I know the clutch was adjusted ok (few mm's freeplay).

This motor lasted about 4hrs and 150kms.

Shopping list plan A

Main bearings - Big End Bearings - 2nd hand crank reground.

Shopping list plan B

New reco 138 motor.

[stapla]

Hi Sunnytim,

Yes it was the same guy that assembled the motor but he didn't fully recondition it. I'm a bit stuck with warranty unless I can prove they assembled it incorrectly.

History

Motor was purchased 30 years ago recond from GEM engines. It has never done any KM's.

It was fitted to the car and run every few months or so to keep fresh. Eg reverse out of shed and run for 10mins etc. In last 10 years or so motor wasn't run at all.

I wasn't sure if they go rusty or whatever, so I gave the engine to a business that builds race engines. I was paying them to check everything with the motor

They ripped it apart, acid dipped it, new gasket kits, seals etc. They replaced cam bearings and also did valve seats. I paid them $1300 and they said internals were in new cond. The oil pump was brand new, cam and maybe crank new. They were surprised as many recond places don't go to those lengths these days.

They claim that they checked the crank end float when they refitted the crank.

I guess I'm just gunna have to wear it.

I'm not sure if I should fix this motor, or just bite the bullet and buy a HM Gem exchange engine off the shelf. I fear that there is a good chance the same problem will happen again with the old motor since we haven't really conclusively got a root cause.

Cheers
Peter.

[bootlegger]

They probably dont exist for grey engines. But you can buy thicker thrust main bearings for chevs to take out excessive end float. I had the other problem in my last race engine. Not enough end float. I had to surface grind some off the thrust.

[FB MAD]

Unfortunately no good news today. Engine builder says crank float is 40 thou'. Crank is damaged and main bearing.

The cause ?? Well engine guy thinks a mis adjusted clutch could cause it. He thinks if thrust bearing was always under load it would put pressure on crank. I'm doubtful it could happen so quick.

Secondly I know the clutch was adjusted ok (few mm's freeplay).

This motor lasted about 4hrs and 150kms.

Shopping list plan A

Main bearings - Big End Bearings - 2nd hand crank reground.

Shopping list plan B

New reco 138 motor.

I rebuilt a crossflow 250 XD Falcon engine ( mid '90's ) that my father had owned the car from new.It had 185000 km's on the clock.On dismantling it had very worn crank thrust bearings and this had also worn the thrust bearing running face on the crankshaft which stuffed it.It was a C4 auto so with this engine,a maladjusted clutch wasn't the cause of this.It wasn't rebuilt because of the worn/stuffed crank and thrust bearings, it was rebuilt simply because it was down on compression and tired.Was an otherwise quiet running engine with the stuffed crank/bearings only being discovered on pulldown.

The suspician that an incorrectly adjusted clutch could be the cause of failed thrust bearings is correct in that it does place pressure on the crank and thrust bearings if the clutch pressure plate thrust bearing is bearing down hard on the pressure plate diafragm fingers constantly.Usually the clutch thrust bearing would fail before a crank thrust bearing I'd say in this case.

However to say that a thrust bearing/crankshaft has failed after minimal miles seems to me to point to someone not checking measurements/parts condition on engine dismantling and re-assembly at sometime during the previous rebuild/rebuilds with a crank that has wear problems.

I don't think an incorrectly adjusted clutch over very minimal miles would have been the cause of the current problem.Perhaps if it had been incorrectly adjusted for some thousands of miles then the finger of blame could be attributed to that.

Crankshaft and thrust bearing wear happens over a long time period, not over a very short amount of miles unless an obvious cause like no oil supply or some apparent incorrect assembly of parts helps the failure process along a bit.

It doesn't seem like you are going to be able to completely prove that one of the previous engine builders hasn't done their job properly as they are unlikely to admit it but to me it appears to point to that.

[stapla]

It doesn't seem like you are going to be able to completely prove that one of the previous engine builders hasn't done their job properly as they are unlikely to admit it but to me it appears to point to that.

I think this is very close to the truth.

Crank is stuffed. Main Bearings stuffed. Unable to get satisfactory response from engine builder apart from incorrectly preloaded clutch might have caused it.

Local clutch experts think this is B/S to happen in 4 hrs of driving no mater what clutch adjustment. I know the freeplay was ok on clutch cause I did it myself.

Engine builder wanted another $1000 for 2nd hand crank, machining and bearings. No guarantee it wouldn't happen again.

I lost confidence in the engine itself and the builder. I'm not confident that whatever caused the issue won't happen again at my expense.

I have decided to buy an off the shelf motor. $3400 later I picked up the motor today. I wanted a 132 FC motor but they only had a B prefix FB-EK 138. On the positive side I think they are spec'd for a little more power. Engine supplier said they modify the grey for red motor oil pump gears, red motor valves and a couple other upgrades. They are having trouble getting grey motor parts and therefore are forced to modify them.

Also I purchased a new harmonic balancer, completely new clutch kit and spigot. Flywheel is getting machined.

I have 6 days to paint motor, fit motor, test car and drive 1000 km's to Wagga, and then a few km's more to orange a few days later.

Fingers crossed.

[FB MAD]

It doesn't seem like you are going to be able to completely prove that one of the previous engine builders hasn't done their job properly as they are unlikely to admit it but to me it appears to point to that.

I think this is very close to the truth.

Crank is stuffed. Main Bearings stuffed. Unable to get satisfactory response from engine builder apart from incorrectly preloaded clutch might have caused it.

Local clutch experts think this is B/S to happen in 4 hrs of driving no mater what clutch adjustment. I know the freeplay was ok on clutch cause I did it myself.

Engine builder wanted another $1000 for 2nd hand crank, machining and bearings. No guarantee it wouldn't happen again.

I lost confidence in the engine itself and the builder. I'm not confident that whatever caused the issue won't happen again at my expence.





.

He's having a lend of you if he thinks $1000 is a fair price for a re-ground crank and new bearings.

Grey head with red valves will flow a little better but the grey's small intake ports aren't made for high airflow.There will be some improvement in power output.

Agree with the clutch experts with the cause not being the clutch adjustment wrong,just hasn't done enough miles for this to be the cause of the problem.

Methinks the engine bloke has made a boo boo.

If you are after a very close colour for your grey motor the Power Plus spray can number 427 is pretty much close to the original one.

[stapla]

I think it was around $200 odd for B/E and main undersize bearings. $240 for 2nd hand crank. $200 odd or so for crank journal grinding. Gaskets and something else.

Cheers
Peter.

[FB MAD]

I think it was around $200 odd for B/E and main undersize bearings. $240 for 2nd hand crank. $200 odd or so for crank journal grinding. Gaskets and something else.

Cheers
Peter.

The price for the bearings would be about right,dunno what charge crank grinding is now,haven't had it done for ages so maybe $200 would be OK but $240 for a 2nd hand crank is way more than what one should cost.