Oshkosh Snow plow W/ frozen motor

[73m819]

I would let soak with marvel and auto trans fluid, and forget for a while, just me, but I would NOT use coke because I would be afraid of etching from the acid, don't think I would use the jack, because you can NOT get the feel for movement, with a bar, you get a hands on feel, check the top end, if good close it up after dumping m/o on everything, if the top is stuck then work each part after a soak, check what is in the pan, drain a bit, if a bunch of, water comes out, drop the pan , check if the mains and rod caps were in water, if good oil comes out, leave it up, WHAT H/S motor do you have, I have a book that covers the 400, 470, 480

 

[BBoomerBootCamp]

Thanks Ron, it's the 1091, big boy I'd say. can't wait to feed it's gas habit, if I'm so lucky

 

[73m819]

all 3 in my info are the same just each is a bit bigger , all use the same valve adjust, timing, points, ect

 

[scoutmanadam]

i have had good luck with brake fluid to as a penetration agent. that and a bar will do most jobs, slow and steady

 

[wdbtchr]

I've had good luck with Kroil in stuck tractor engines. I think I might give the jack thing a try if I ever have another one. I've been lucky using a bar, only sheared off the woodruf key in the front pulley so far.

 

[maxim]

Went to pick up a jeep I found for $100. We had to pull it out from behind a house and told the guy That was steering to JUST STEER IT. Well he decided to put it in gear 'to see if it would turn over'. Pushed the connecting rods through 3 pistons.....Don't ever pull it.

 

[BBoomerBootCamp]

I plan to link this thread to Alex at Idaho Motor Pool, he can sort out his best choices that way. I was going to ask him to pull the pan and valve cover to do a visual inspection, at which point if he has some ATF and old diesel he could put the pan back on and fill the crank with that combo. Its obvious with this size of cubic inches theres allot more surface area in the cylinders to rust and stick, any treatment will involve patience and a little extra time. It also would make sence that turning this big motor may require a bit more force than say a 235 chevy. So having said all that all the feedback so far has good merit.
Thanks to all,
Mark

 

[73m819]

I have freed up froze big cat motors, with the long soak and a LONG bar, or a toque multiplier, the trick is take your time and FEEL and WATCH the movement

 

[dburd72]

Any update ?

 

[DOCUSN1]

KROIL

 

[BBoomerBootCamp]

Sent this tread to Alex up at Idaho Motor Pool. Last time we spoke he made it pretty clear that he would not return to the Oshkosh till the middle of December. All I can add to the process would be that he reads the feedback and the motor turns over, like magic.

 

[73m819]

Great

 

[JimM37]

Mark,
Glad you got it at Alex's place he's a good guy. I have always used a witches brew of AeroKroil,PB Rustbuster and Marvel get nice pools of the aerosols on top of the pistons and dump the marvel in up to the bottom of the plug holes.Before you remove the pan I would remove one of the oil filters and cut it open and look for "trinkets"if there's alot of metal in the filter. things could get ugly.The filters should be a Wix 51503 or a NAPA 1241 of its the old sock type try a Fram C299.Then take the cover off the timing gear on top of the engine and see if the camshaft timing chain is still on the sprocket and not bunched up in the block.That is a easy gasket to make. Remember you're not going to just run down to O'Rieley's or Auto-Zone and get hard parts for this animal.So the less you disturb the better.and last pull the pan and check the rods and make sure nothing is askew.If the rods look like they are where they are supposed to be then try the jack thing that Spike recommended.The crank has large throws so it shouldn't be a big deal.
later.

 

[Speedwoble]

I have *heard* to fill the cylinders with penetrating oil and place a largepry-bar/lever/wrench on the end of the motor, then hang a bunch of weight off of the end of it. Then walk away and forget it. If you are lucky, one day you will walk by and realize the weight is lower than when you started, thus meaning the motor has moved...

 

[trukhead]

If you have a mild dry stuck engine the soaking is ok but if you have some thing that has had a mouse nest in a cylinder and water down another cylinder, no amount of soaking is going to remove flaking rust and mouse fluff and associated rust from urine. The parts the force get applied to will break long before the stuck parts and rust will displace. I'd poll the heads and see what is not stuck after doing the belts and accessories.

 

[Jbrowning22]

If you have a mild dry stuck engine the soaking is ok but if you have some thing that has had a mouse nest in a cylinder and water down another cylinder, no amount of soaking is going to remove flaking rust and mouse fluff and associated rust from urine. The parts the force get applied to will break long before the stuck parts and rust will displace. I'd poll the heads and see what is not stuck after doing the belts and accessories.

Way easier to buy one of those fiber optic cameras to stick down the plug holes to have a look, than it is to pull the heads.

 

[dburd72]

stuck engine

Any progress ?

 

[plym49]

X2 on not using force. You can introduce some heat. If needed, hook up a hot water circuit through some fittings on the block. Warming the block even to 120 degrees will help the MMO brew infiltrate. Infiltration is what it is all about. Many witches brews have been tried and they all will work, some better than others in a given situation. You can cut ATF with acetone or lacquer thinner, for example.

If you need to force the motor, better to do it via a piston than at the nose of the crank. Weld a grease fitting to an old spark plug, select a cylinder on the power stroke, and pump away with your grease gun.

Time is your friend and so is heat. I am not advocating an open flame around that motor; hot water flowing through the block works wonders.

 

[dodgedougak]

Ditto on slow and easy. I also hate to put too much pressure on the pulley or crank end. I have done quite a few stuck ship/boat engines. There is a tremendous amount of surface area where the rings touch the bore! Just a skim of rust between those rings and the bore will stop you dead. I would soak them using one of the suggested penetrant cocktails. Then if it does not want to move with easy barring, i would pull the head. Use a 4X4 block and a big hammer to tap on the pistons at TDC. You don't have to swing hard, just tap enough to give the oil a chance to work it's way down. A little at a time maybe tapping some each day for a few days. The air pressure trick (which will work in some cases) will push but not shock the piston. Like tapping the head of a stuck bolt, the slight impacts will help the penetrant get down the threads. I know pulling the head sounds like a pain, but in the end it may save the engine and even be quicker. Ever try to drill out the pulley bolt on the crank nose?

 

[BBoomerBootCamp]

I must say you guys have brought some really good ideas to the table, and I thank you all. I am confident that Alex will get this fine example of Oshkosh Truck breathing fire again. I have not spoke with him in over a month now, I will ring him up in the next week, I curious to know too. I've made a choice to give the whole thing a bit of space, Alex is doing me a large and I do not want to micro manage the situation. It is a busy time of year for many and when we spoke last month he was filling a large order of Green iron do out in mid December.
Now if any of you guys that might live a stones through away from Idaho Motor Pool would happen to say drop by and lend a hand to the cause, well I'd say I owe you a huge debt of gratitude.
Merry X-mas and a happy New Year to all