Bobcat 743 V2203 install broke rear crankshaft bolts

[antfarmer2]

My flywheel did not have them either but did not mess with it if your ser# is under 5000 there is another filter if over your good sound like your doing the same thing as me........ pick it up and do a push pull on the wheels hope there is no play

And think you have about 10 more hp now get a cheap laser tack from ebay 10 bucks to make sure not to over rev your new engine

 

[KC743]

And think you have about 10 more hp now get a cheap laser tack from ebay 10 bucks to make sure not to over rev your new engine

Good idea! I just ordered one off ebay for 14 dollars including shipping. Better safe than sorry. I did transfer all the throttle linkage from old engine to new engine in hopes is would be close. : )

 

[antfarmer2]

Good idea! I just ordered one off ebay for 14 dollars including shipping. Better safe than sorry. I did transfer all the throttle linkage from old engine to new engine in hopes is would be close. : )

Where are you and what kind of hydro fluid are you using

 

[KC743]

Where are you and what kind of hydro fluid are you using

I'm in Kansas City. I used AW46.

 

[antfarmer2]

Where are you and what kind of hydro fluid are you using

Did you put a new hydro seal in?

 

[antfarmer2]

Did you put a new hydro seal in?

I have done a lot of research and most use 10-30 10-40 to 15-40 to 20-40 depending on where they live

 

[antfarmer2]

I have done a lot of research and most use 10-30 10-40 to 15-40 to 20-40 depending on where they live

Watch for it loosing hydro fluid into the chain case that is what my po used and what happend to mine

 

[KC743]

I have done a lot of research and most use 10-30 10-40 to 15-40 to 20-40 depending on where they live

I did not put a new seal in the hydro pump. I may Consider a different oil next change. I am going to run it and let the air bleed off and change one more time too ensure no water is in the system. Thanks for the advice!

 

[antfarmer2]

I did not put a new seal in the hydro pump. I may Consider a different oil next change. I am going to run it and let the air bleed off and change one more time too ensure no water is in the system. Thanks for the advice!

10 min and easy for the seal I dropped shipped it over the phone from bobcat came fast will save a bite in the ass

 

[jerry]

I did not put a new seal in the hydro pump. I may Consider a different oil next change. I am going to run it and let the air bleed off and change one more time too ensure no water is in the system. Thanks for the advice!

Just curious why remove the thermostat? If the thermostat is working and it is say a 195 the temp should not ever go much over unless the rad is not adequate. If the radiator is not adequate it will over heat regardless of the thermostat. Diesels do run better warm.

 

[KC743]

Good idea! I just ordered one off ebay for 14 dollars including shipping. Better safe than sorry. I did transfer all the throttle linkage from old engine to new engine in hopes is would be close. : )

The only reason I removed the thermostat was that most forums said the 743 was notorious for overheating. I was ok with leaving it in since I put a new radiator in with fresh antifreeze. Just trying to be over cautious. If you guys think I should put a new one back in, I will. : )

 

[jerry]

The only reason I removed the thermostat was that most forums said the 743 was notorious for overheating. I was ok with leaving it in since I put a new radiator in with fresh antifreeze. Just trying to be over cautious. If you guys think I should put a new one back in, I will. : )

I'd go with what ever Tazza recommends, he's been around them for awhile. Otherwise try the no thermostat plan. Here in minnesota it would not work if you wanted to heat the cab.

 

[antfarmer2]

I'd go with what ever Tazza recommends, he's been around them for awhile. Otherwise try the no thermostat plan. Here in minnesota it would not work if you wanted to heat the cab.

I am waiting to see what Tazza has to say too but he is down under and has never had temps this low

 

[Tazza]

I am waiting to see what Tazza has to say too but he is down under and has never had temps this low

I haven't heard of them over heating, the issue is always a cooling systme fault that causes them to over heat. The issue is when they do over heat, they crack heads.
I'd advise against removing the thermostat. You want the engine to be nice and warm, even more so in colder times of the year. Engines are designed to work most efficiently at set temperatures, if they don't get there they can actually sludge up the oil.
I'd use blue loctite on the crank and u-joint bolts, it's servicable, so you can get them out later if needed.
I don't believe the u-joints are to blame for this one, if they were locked up, you'd get a vibration, not a lockup that could break those bolts. Hopefully you can get the bolts out at a reasonable price..... Sounds like there were installed with loctite too. Make sure you get a suitable grade bolt to replace them with too, i don't want to hear they sheared off again

 

[KC743]

I haven't heard of them over heating, the issue is always a cooling systme fault that causes them to over heat. The issue is when they do over heat, they crack heads.
I'd advise against removing the thermostat. You want the engine to be nice and warm, even more so in colder times of the year. Engines are designed to work most efficiently at set temperatures, if they don't get there they can actually sludge up the oil.
I'd use blue loctite on the crank and u-joint bolts, it's servicable, so you can get them out later if needed.
I don't believe the u-joints are to blame for this one, if they were locked up, you'd get a vibration, not a lockup that could break those bolts. Hopefully you can get the bolts out at a reasonable price..... Sounds like there were installed with loctite too. Make sure you get a suitable grade bolt to replace them with too, i don't want to hear they sheared off again

Thanks Tazza!! I will put a new thermostat in and be sure to use blue Loctite. The engine goes to the shop Monday. Keeping my fingers crossed they get all the bolts out and clean the threads. I am using the flywheel off my v1702 and the 6 factory bolts from it and I will send the other flywheel back with the core engine. Thanks to all who has helped!!

 

[KC743]

Thanks Tazza!! I will put a new thermostat in and be sure to use blue Loctite. The engine goes to the shop Monday. Keeping my fingers crossed they get all the bolts out and clean the threads. I am using the flywheel off my v1702 and the 6 factory bolts from it and I will send the other flywheel back with the core engine. Thanks to all who has helped!!

So I put a 180 degree thermostat back in and reinstalled engine. Fired right up and hydraulics good. Bolts had to be loose, fractured or over torqued on the flywheel. The machinist said he had never seen any bolts in so tight. It took him 5 hours and walking away multiple times. Lol I know that frustration. On the downside I did not replace the rear main seal before reinstalling and now have to pull engine again as there is oil coming from the backside of the engine area and its darker so I know it is engine oil not hydraulic which is brand new and clean. Thank you for all the help and I look forward to sharing my experiences as I continue this overhaul.

 

[antfarmer2]

So I put a 180 degree thermostat back in and reinstalled engine. Fired right up and hydraulics good. Bolts had to be loose, fractured or over torqued on the flywheel. The machinist said he had never seen any bolts in so tight. It took him 5 hours and walking away multiple times. Lol I know that frustration. On the downside I did not replace the rear main seal before reinstalling and now have to pull engine again as there is oil coming from the backside of the engine area and its darker so I know it is engine oil not hydraulic which is brand new and clean. Thank you for all the help and I look forward to sharing my experiences as I continue this overhaul.

Since you having fun pulling the engine again change the hydro seal

 

[antfarmer2]

Since you having fun pulling the engine again change the hydro seal

Also I would warm the flywheel bolts a bit to loosen the locktight

 

[KC743]

Also I would warm the flywheel bolts a bit to loosen the locktight

Thank you antfarmer2 for the suggestions. I think I will do both as suggested. I sure don't want to pull it again. Would a propane torch get them warm enough or would I need to take to someone with a real torch. Also as the hydraulics have been being used I am finding small leaks. One on the bucket and the right ram is starting to leak at the seal. Another day another project. I am going to get the flat faced couplers to upgrade the auxiliary hydraulics since the old ones are leaking pretty good. If anyone has replaced those any suggestions would be helpful. I am also looking to replace the two round headlights for the front. My dealer is only open Monday thru Friday so I will check with them at the time I order seals.

 

[antfarmer2]

Thank you antfarmer2 for the suggestions. I think I will do both as suggested. I sure don't want to pull it again. Would a propane torch get them warm enough or would I need to take to someone with a real torch. Also as the hydraulics have been being used I am finding small leaks. One on the bucket and the right ram is starting to leak at the seal. Another day another project. I am going to get the flat faced couplers to upgrade the auxiliary hydraulics since the old ones are leaking pretty good. If anyone has replaced those any suggestions would be helpful. I am also looking to replace the two round headlights for the front. My dealer is only open Monday thru Friday so I will check with them at the time I order seals.

I like map gas yellow tank better than propane but it does not have to be to hot for big bolts with blue locktight just a bit harder than lock washers but will help