6.2 locked up

[bsalbrig]

A little background: Around october last year I cracked my transfer case and adapter on my M1028; so I decided to swap in a 4spd. I just got everything together and my engine wont turn over. I drove the truck to the spot where I worked on it. The engine was running great as it has since I got it. I didnt try to turn the engine over until I installed my flywheel and it wouldnt crank so I thought dead batteries. I thought nothing of it so I went ahead with the install, figured I would drag the truck down the road and make it start. I was able to make the engine turn a little but when I drop the clutch the tires will lock up (4th gear Hi). I cant figure out what would cause this engine to lock up unless there is a problem with my flywheel. I bought it from Rock Auto (RHINOPAC Part # 16765, Custom; Casting # 14050525) The flywheel fit on the engine ok. I laid the flywheel and flexplate on top of each other and they were the same size. The starter even engages the teeth properly.


Could the flywheels balance area be hitting something on my engine block. I have never heard what was the problem with the wrong flywheel.

By the way the swap went really well except for this one problem. My original crossmember fit the new combo there were even holes in my frame for the new location, there were already bolts in place for my clutch pivot linkage and all the holes on the cab were marked for the clutch rod. I just need to shorten my front driveshaft or have it remade (I might now be too steep of an angle for my current driveshaft).

I used a 78 model SM465-NP205 10spline with a one ton rear cv yoke and the newer style gm front drive flange.

 

[T_F_E]

I usually roll start vehicles in 2nd not 4th.

 

[jakwi]

I'm certainly not an expert, but if it ran great before and now it doesn't I'd have to believe that it is something to do with your swap. I know it sucks, but I think the thing to do is to separate the tranny and engine enough to see if it will turn over by hand ( you might have to pull the glow plugs to eliminate the compression) without the tranny involved. If it turns over fine then reevaluate your fly wheel clutch arangement. I certainly wouldn't try to drag start it any more, at this point you need to figure out what the problem is because there is definately a problem. Anyway keep us updated and good luck I'm curious to hear what the end result is.

I swapped a tranny on a jeep wrangler one time, and some how missed the fact that I hadn't tightened the clutch all the way down to fly wheel. The engine would start but it would grind if I tried to put it into gear. I ended up pulling the tranny almost all the way out to tighten it up. It really sucked since I basically had to do the whole job over. But in the end it worked great.

"when you have eliminated the impossible, whatever remains, however improbable, must be the truth?" Arthur Conan Doyle

 

[Blood_of_Tyrants]

I see two possibilities.

1) engine hydro locked. Solution, remove glow plugs and see if it cranks. If it does, it will probably force fuel/water/oil out of the offending cylinders.

2. Interference with flywheel. Remove inspection plate and look.

 

[bsalbrig]

Well I am planning on taking it out tomorrow if I can make it fit into my shop. I am tired of working out in the cold. When I put it in my trans jack cylinder wasnt working so I got creative with ratchet straps (dont want to do that again). I bought a new hydraulic cylinder so it should go pretty easy.

The reason I used 4th was because it requires less torque to turn the engine over. I was hoping to free it up then use the starter to crank it. It looked pretty funny with my M151 pulling a vehicle three times it size.


I tried to crank the engine once just the flywheel was on and it wouldnt. It about has to be something wrong with it.

 

[4bogginchevys]

flex plate bolt too long?

 

[Goose2448]

My Fist thought was Hydro lock. Any rain when working on it?

 

[Matt65]

Do you have any pics of your transmission swap? Have thought about doing the same thing one day.

 

[bsalbrig]

bought new arp flywheel studs when I put it in. I will try to remove glowplugs tomorrow before I take it apart. I never took the air filter housing off but now that I think of it, the engine was leaning backward for a long time and the opening on the air filter was pointed toward the drivers side headlight so it might have been a slight downhill path into the intake. I did keep the hood on it the whole time though.


If it is hydro-locked, how strong are the rods?

 

[bsalbrig]

I will get some pics at some point. It was fairly easy; everything just bolts together. All the holes are there. I think if you found a later 80s trans and transfer case you could use the same driveshafts. I bought a half ton transmission first and later found a one ton that has the bigger output yoke. The half ton would have worked just as well. I used a mechanical linkage because a friend gave me a 2wd truck with one (it ran well). I hated to take it apart for the pedals but it would have cost too much to buy all the parts.

 

[ida34]

They thing you changed was flex plate to flywheel. Was the flywheel for the 6.2? I would say your flywheel is wrong or damaged in some way that is causing it to contact the block. You say you tried to turn it over with only the flywheel? Was that with the bell housing on? If it did not turn with the bell housing off then the flywheel is contacting the engine block somewhere. Loosen the fly wheel just a little then see if the engine turns.

I just checked and your numbers match up to a 6.2 flywheel. I would still check for interference first.

 

[Tanner]

hmmm... there * shouldn't * be anything on flywheel that contact block; wonder if flywheel to crank bolts are too long? Agree that cylinder(s) could be flooded with water/fuel & you're trying to compress liquid.

'Tanner'

 

[ida34]

Shouldn't is the operative word there. As a pilot we learn when the engine starts to cut out you reverse what you just did first since this is the most likely cause of the engine cutting out. Same principal. If you loosen the fly wheel just a little and the engine turns you will know there is something wrong with it. At any rate, good luck with it.

 

[Tanner]

Shouldn't is the operative word there. As a pilot we learn when the engine starts to cut out you reverse what you just did first since this is the most likely cause of the engine cutting out. Same principal. If you loosen the fly wheel just a little and the engine turns you will know there is something wrong with it. At any rate, good luck with it.

Chuck - I'm just going from memory on the manual trans flywheel that I bolted to my 6.2; there was nothing on 'engine block' side of flywheel to interfere with it rotating...

OP will find out what's wrong in a day or so -

'Tanner'

 

[bsalbrig]

I am going to give the hydro lock theory a try but I worry that if it does have water in my cylinder first it has been in there a long time and will probably have caused problems, second that I tried to turn it over with great force and could have been rods.


The truck did sit for a while for me to acquire parts between the time that I drove it to where I worked on it and when I installed the flywheel and tried to crank it.

 

[woodyNla]

I would look at the backside of the flywheel/crank with the dust cover off. Sounds like you may have too long of a flywheel bolts installed and they are hitting the block casting.

 

[Tanner]

I would look at the backside of the flywheel/crank with the dust cover off. Sounds like you may have too long of a flywheel bolts installed and they are hitting the block casting.

That's been brought up -

'Tanner'

 

[tonka tester]

i doubt the motor is seized. im going with the hardware on the clutch interferance. i had a m1008 sit for over eight years...without starting, or turning over...i just put a little oil down the cylinders, and it fired right up, and runs great

 

[bsalbrig]

Well I got it out and back together today. The interference was the tooth ring on the flywheel to the starter. It had already rubbed a little out of the starter. I took a angle grinder to my starter and got enough space for it to fit. I put it all back together and it fired right up. I will post pics later. Only took about 5hrs to take it out and get it back in with the trans jack.

I did however find a new problem. The glowplug in the front left cylinder was broken off at some point prior to me removing it.

I have had DI engines apart before but not IDI. I assume that the combustion chambers would hold the glowplug tip from falling into the cylinder. I inserted a unbroken glowplug and didnt hit a piece from the other. Maybe motorpool broke it off and removed the piece. I dont think I can do anything about it but ignore it.