Bobcat 731 Engine Removal

[77XJ6L]

I recently purchased my 1st bobcat and I'm taking the engine apart as it has a damaged connecting rod. I've removed everything from the motor and I can't get it to come out. I've tried almost everything. Any Tips, Tricks??

 

[77XJ6L]

I`m having trouble separating the engine and transmission for removal from the bobcat. It`s a 731 deutz diesel engine. The service manual says to remove bolts and slide engine out the back.

 

[Tazza]

I`m having trouble separating the engine and transmission for removal from the bobcat. It`s a 731 deutz diesel engine. The service manual says to remove bolts and slide engine out the back.

Remove the 4 bolts holding the engine to the frame and simply slide it out the back. I have done this before without any issues.
The manual is spot on. The grease in the coupler between the pump and motor may be a little hard and sticky preventing it from moving? It should simply slide out and disengage from the pump.
If you have problems still, let me know.

 

[77XJ6L]

Remove the 4 bolts holding the engine to the frame and simply slide it out the back. I have done this before without any issues.
The manual is spot on. The grease in the coupler between the pump and motor may be a little hard and sticky preventing it from moving? It should simply slide out and disengage from the pump.
If you have problems still, let me know.

I tried pulling it out with a come along wrapped around a tree. This motor will not budge. I even tried removing the universal joint behind the tranny, but had no luck trying to loosen the bolts. Where exactly should the motor and tranny separate, so I could use a pry bar to help it along?

 

[OldMachinist]

I tried pulling it out with a come along wrapped around a tree. This motor will not budge. I even tried removing the universal joint behind the tranny, but had no luck trying to loosen the bolts. Where exactly should the motor and tranny separate, so I could use a pry bar to help it along?

Someone may have added some additional mounting hardware sometime during its life. I'd try a pry bar under the engine in several places to try and see where it's still attached.

 

[77XJ6L]

Someone may have added some additional mounting hardware sometime during its life. I'd try a pry bar under the engine in several places to try and see where it's still attached.

All nuts and bolts are removed. Engine moves from side to side and up and down, it just will not slide out. Can you tell me where it disconnects from the tranny.

 

[OldMachinist]

All nuts and bolts are removed. Engine moves from side to side and up and down, it just will not slide out. Can you tell me where it disconnects from the tranny.

I looked in the 741 service manual and it says the engine should just slide out like Tazza said. I don't have a 731 manual to see if anything is different. I'd have to assume that the u-joint is just siezed on the pump shaft. You might have to use some penitrating oil and some leverage to get it to bust loose.

 

[77XJ6L]

I looked in the 741 service manual and it says the engine should just slide out like Tazza said. I don't have a 731 manual to see if anything is different. I'd have to assume that the u-joint is just siezed on the pump shaft. You might have to use some penitrating oil and some leverage to get it to bust loose.

What I need to know is where does the engine separate from the transmission. If I know where they separate I can pry them apart.

 

[OldMachinist]

What I need to know is where does the engine separate from the transmission. If I know where they separate I can pry them apart.

This is the only image I found that shows the u-joint that connects the engine to the pump. The splined end of the U-joint slips on the pump shaft. You'll have to lift the cab and look or feel down behind the pump to figure out where to pry.

 

[77XJ6L]

What I need to know is where does the engine separate from the transmission. If I know where they separate I can pry them apart.

I appreciate the image you sent. This will help alot. I have already removed the seat and I think I can try to separate the spline from there. Actually this area is right below the tanks, diesel and hydraulic, which I would rather not remove if at all possible. Thanks for your assistance and I will keep you updated on my progress.

 

[OldMachinist]

I appreciate the image you sent. This will help alot. I have already removed the seat and I think I can try to separate the spline from there. Actually this area is right below the tanks, diesel and hydraulic, which I would rather not remove if at all possible. Thanks for your assistance and I will keep you updated on my progress.

There is a grease fitting on the u-joint that greases the spline maybe if you can pump some grease in there it might loosen up.

 

[Tazza]

There is a grease fitting on the u-joint that greases the spline maybe if you can pump some grease in there it might loosen up.

The 743 and 731 mounting to the pump is exactly the same, so the image OldMachinist posted is what you should see. There will be 4 bolts holding the U-Joints to the fly wheel, but gaining access won't be easy with it still all connected together. It sounds like the coupling has rusted to the spline.
The other thing i can think of is to pull it like you have tried by putting tension on the engine and coupling then using a bar strike the U-Joints to try and shock it off. Sometimes shocking it will let it release. A bit of grease in the grease nipple won't hurt.

 

[brettk1]

The 743 and 731 mounting to the pump is exactly the same, so the image OldMachinist posted is what you should see. There will be 4 bolts holding the U-Joints to the fly wheel, but gaining access won't be easy with it still all connected together. It sounds like the coupling has rusted to the spline.
The other thing i can think of is to pull it like you have tried by putting tension on the engine and coupling then using a bar strike the U-Joints to try and shock it off. Sometimes shocking it will let it release. A bit of grease in the grease nipple won't hurt.

if you can try to remove the grease nipple and spray penetrating oil (I use Creeper from Sea Foam) into the nipple hole let it soak overnight .

 

[77XJ6L]

if you can try to remove the grease nipple and spray penetrating oil (I use Creeper from Sea Foam) into the nipple hole let it soak overnight .

Thanks everyone for all the help.....I unbolted the flywheel and the motor pulled right out. What a PITA but atleast the motor is out. Now the fun starts. I lost a bearing on the connecting rod and it scored the rod and the crank. So i'm gonna have someone machine the crank and connecting rod and get oversized bearings. I called the Bobcat dealer and they said a new crank is around $5000 and a new Duetz Motor is $5400 is that true?

 

[Tazza]

Thanks everyone for all the help.....I unbolted the flywheel and the motor pulled right out. What a PITA but atleast the motor is out. Now the fun starts. I lost a bearing on the connecting rod and it scored the rod and the crank. So i'm gonna have someone machine the crank and connecting rod and get oversized bearings. I called the Bobcat dealer and they said a new crank is around $5000 and a new Duetz Motor is $5400 is that true?

I don't know if you can even get that model engine still. Call around, my 731 had an engine from a dynapac roller as the old one was worn out.
I'd get the crank ground and see how it comes up. Worst case, there will be places that can spray hard facing metal to the crank, then get it ground back, but thats a last resort if it won't clean up at the maximum over size bearing you can get.
Glad you got it removed, it should simply have slid off, at least now you can get better access to get it off.

 

[OldMachinist]

I don't know if you can even get that model engine still. Call around, my 731 had an engine from a dynapac roller as the old one was worn out.
I'd get the crank ground and see how it comes up. Worst case, there will be places that can spray hard facing metal to the crank, then get it ground back, but thats a last resort if it won't clean up at the maximum over size bearing you can get.
Glad you got it removed, it should simply have slid off, at least now you can get better access to get it off.

There was a post awhile back where a member found somebody that supplies parts for Duetz engines. Look at the 9th post in this thread.
http://www.skidsteerforum.com/DesktopDefault.aspx?tabid=54&frmView=ShowPost&PostID=28399

 

[77XJ6L]

There was a post awhile back where a member found somebody that supplies parts for Duetz engines. Look at the 9th post in this thread.
http://www.skidsteerforum.com/DesktopDefault.aspx?tabid=54&frmView=ShowPost&PostID=28399

I found a guy in NC who does all the machine work for the Bobcat dealers in the NC area and he can machine my connecting rod and crank for $240 which is awesome. But he told me since I lost a bearing and had metal in the oil system that I should buy a new oil cooler. So I called Bobcat and quoted a new Cooler for $1400....Is there a Way I can clean out my old one or buy an aftermarket one meant for cars. I mean an oil cooler is an oil cooler correct?

 

[skidsteer.ca]

I found a guy in NC who does all the machine work for the Bobcat dealers in the NC area and he can machine my connecting rod and crank for $240 which is awesome. But he told me since I lost a bearing and had metal in the oil system that I should buy a new oil cooler. So I called Bobcat and quoted a new Cooler for $1400....Is there a Way I can clean out my old one or buy an aftermarket one meant for cars. I mean an oil cooler is an oil cooler correct?

Is there some reason you could not put a inline hydraulic filter in the return line for xx hours until it flushes out? There can't be much pressure there? maybe 100 psi, temp maybe 300f max. Get the non bypass type and change the filter a couple times. Maybe 200 to $300
Ken

 

[Tazza]

Is there some reason you could not put a inline hydraulic filter in the return line for xx hours until it flushes out? There can't be much pressure there? maybe 100 psi, temp maybe 300f max. Get the non bypass type and change the filter a couple times. Maybe 200 to $300
Ken

There will be places that can clean oil coolers out. I asked about servicing a compressor by a dealer and they said they get the oil cooler acid cleaned. If they do it here, there will be people that do it over there too. They may have ways to get all the particles out. I like the idea of an inline oil filter though. Not sure how you would plumb it in, but its not a bad idea. Worst case, i'd clean EVERYTHING and run petrol throught the oil cooler to try and wash any metal out. Petrol is good as when it dries there is residue and compressed air should be able to pick up any rubish and push i out.
As for the particles, any that are left over, the oil filter should catch those. I don't know the oil flow, but usually its pickup, pump, filter, oil cooler then around the engine. So any metal should be collected by the filter. Yes, i know it goes through the oil pump un-filtered which seems silly....

 

[oiu789]

Thanks everyone for all the help.....I unbolted the flywheel and the motor pulled right out. What a PITA but atleast the motor is out. Now the fun starts. I lost a bearing on the connecting rod and it scored the rod and the crank. So i'm gonna have someone machine the crank and connecting rod and get oversized bearings. I called the Bobcat dealer and they said a new crank is around $5000 and a new Duetz Motor is $5400 is that true?

What was holding it from not sliding out? Was the splines rusted up or what?