Can we talk about the Detroit Bull Gear?

BabyGator · May 2, 2017

catmechanic07 said: ↑

Are you kidding me? Bull gears are "bullet proof"? HAHAHA!

Here's the deal: You replace just bearings, your on your own! End of story. You buy a reman bull gear assembly, you SHOULD have dealer backing if they install. The bull gear can be installed in 1 day if they have competent tech's.

Easiest way: Remove radiator. Remove fan hub, acc drive, cam gear cover, damper and pulley. You SHOULD remove the oil pan so you have something solid to put a bottle jack against to raise the engine. If you don't want to, good luck and remove the front 2 bolts that go into the front cover. Remove the bolts for the front engine mount. Raise the engine just enough to clear the engine mount for removal. Remove the front mount. Now is a good time to remove the front seal. Its a royal pain to pull the front cover with the seal in. Remove all bolts in the front cover including 2 that hold the water pump on and the stud for the air compressor (there may be a bolt on the compressor towards the block as well. Pry the front cover off at the specified locations, looks like deep splits in the cover. Try to keep it clean but buff the red sealant off now before you install new parts. Use the flywheel to turn the engine over so the bolts line up with the holes in the bull gear. After the bull gear is removed, remove the idler gear (top left), remove the cam gear. Clean the front end with mineral spirits and dry with compressed air. Now, turning the engine by the flywheel in direction of rotation, put the timing mark at TDC. Timing mark on new bull gear (either a straight line or "V" mark) will determine which mark to use on the crank gear. With that done, install the idler gear and cam gear. When sealing the cam gear, use new O-ring and "football" gasket. When you install cam gear, use grey gasket maker where the football gasket seals on the cam cap splits. If you don't.....it WILL leak there! Now, leave the idler gear loose enough to where you can move it by hand but snug. "Eye" the timing marks on them and get them close. You cam now hold the bull gear up and align all the timing marks. ALL marks MUST line up at this point. You can tighten the bull gear to specs now (I think its 50ftlbs but not 100%). Now you need to set your back lashes. On used gears I think its .006-.012 allowance. Once backlash is achieved, tighten the idler nuts to 80 ftlbs. Your done with gears! Now, buff the front cover mating surface and apply red antirobic cream to the mating surfaces and spread it out evenly. Place the front cover on and remember, the sealer cures with the lack of air so you have limited time to get the bolts in and torqued. Front cover bolts torque to 50ftlbs. You WILL need a seal installer, yes you can tap it in but take a good chance of the seal leaking. Install the seal and front engine mount. Make sure to use grey gasket maker on the splits of the front and rear structure when installing the oil pan as well. Install the rest of your front cover components and radiator! ALL DONE!!!
Click to expand...

catmechanic07 said: ↑

Are you kidding me? Bull gears are "bullet proof"? HAHAHA!

Here's the deal: You replace just bearings, your on your own! End of story. You buy a reman bull gear assembly, you SHOULD have dealer backing if they install. The bull gear can be installed in 1 day if they have competent tech's.

Easiest way: Remove radiator. Remove fan hub, acc drive, cam gear cover, damper and pulley. You SHOULD remove the oil pan so you have something solid to put a bottle jack against to raise the engine. If you don't want to, good luck and remove the front 2 bolts that go into the front cover. Remove the bolts for the front engine mount. Raise the engine just enough to clear the engine mount for removal. Remove the front mount. Now is a good time to remove the front seal. Its a royal pain to pull the front cover with the seal in. Remove all bolts in the front cover including 2 that hold the water pump on and the stud for the air compressor (there may be a bolt on the compressor towards the block as well. Pry the front cover off at the specified locations, looks like deep splits in the cover. Try to keep it clean but buff the red sealant off now before you install new parts. Use the flywheel to turn the engine over so the bolts line up with the holes in the bull gear. After the bull gear is removed, remove the idler gear (top left), remove the cam gear. Clean the front end with mineral spirits and dry with compressed air. Now, turning the engine by the flywheel in direction of rotation, put the timing mark at TDC. Timing mark on new bull gear (either a straight line or "V" mark) will determine which mark to use on the crank gear. With that done, install the idler gear and cam gear. When sealing the cam gear, use new O-ring and "football" gasket. When you install cam gear, use grey gasket maker where the football gasket seals on the cam cap splits. If you don't.....it WILL leak there! Now, leave the idler gear loose enough to where you can move it by hand but snug. "Eye" the timing marks on them and get them close. You cam now hold the bull gear up and align all the timing marks. ALL marks MUST line up at this point. You can tighten the bull gear to specs now (I think its 50ftlbs but not 100%). Now you need to set your back lashes. On used gears I think its .006-.012 allowance. Once backlash is achieved, tighten the idler nuts to 80 ftlbs. Your done with gears! Now, buff the front cover mating surface and apply red antirobic cream to the mating surfaces and spread it out evenly. Place the front cover on and remember, the sealer cures with the lack of air so you have limited time to get the bolts in and torqued. Front cover bolts torque to 50ftlbs. You WILL need a seal installer, yes you can tap it in but take a good chance of the seal leaking. Install the seal and front engine mount. Make sure to use grey gasket maker on the splits of the front and rear structure when installing the oil pan as well. Install the rest of your front cover components and radiator! ALL DONE!!!
Click to expand...

catmechanic07 said: ↑

Are you kidding me? Bull gears are "bullet proof"? HAHAHA!

Here's the deal: You replace just bearings, your on your own! End of story. You buy a reman bull gear assembly, you SHOULD have dealer backing if they install. The bull gear can be installed in 1 day if they have competent tech's.

Easiest way: Remove radiator. Remove fan hub, acc drive, cam gear cover, damper and pulley. You SHOULD remove the oil pan so you have something solid to put a bottle jack against to raise the engine. If you don't want to, good luck and remove the front 2 bolts that go into the front cover. Remove the bolts for the front engine mount. Raise the engine just enough to clear the engine mount for removal. Remove the front mount. Now is a good time to remove the front seal. Its a royal pain to pull the front cover with the seal in. Remove all bolts in the front cover including 2 that hold the water pump on and the stud for the air compressor (there may be a bolt on the compressor towards the block as well. Pry the front cover off at the specified locations, looks like deep splits in the cover. Try to keep it clean but buff the red sealant off now before you install new parts. Use the flywheel to turn the engine over so the bolts line up with the holes in the bull gear. After the bull gear is removed, remove the idler gear (top left), remove the cam gear. Clean the front end with mineral spirits and dry with compressed air. Now, turning the engine by the flywheel in direction of rotation, put the timing mark at TDC. Timing mark on new bull gear (either a straight line or "V" mark) will determine which mark to use on the crank gear. With that done, install the idler gear and cam gear. When sealing the cam gear, use new O-ring and "football" gasket. When you install cam gear, use grey gasket maker where the football gasket seals on the cam cap splits. If you don't.....it WILL leak there! Now, leave the idler gear loose enough to where you can move it by hand but snug. "Eye" the timing marks on them and get them close. You cam now hold the bull gear up and align all the timing marks. ALL marks MUST line up at this point. You can tighten the bull gear to specs now (I think its 50ftlbs but not 100%). Now you need to set your back lashes. On used gears I think its .006-.012 allowance. Once backlash is achieved, tighten the idler nuts to 80 ftlbs. Your done with gears! Now, buff the front cover mating surface and apply red antirobic cream to the mating surfaces and spread it out evenly. Place the front cover on and remember, the sealer cures with the lack of air so you have limited time to get the bolts in and torqued. Front cover bolts torque to 50ftlbs. You WILL need a seal installer, yes you can tap it in but take a good chance of the seal leaking. Install the seal and front engine mount. Make sure to use grey gasket maker on the splits of the front and rear structure when installing the oil pan as well. Install the rest of your front cover components and radiator! ALL DONE!!!
Click to expand...

BabyGator · May 2, 2017

GrapeApe said: ↑

You can check and adjust lash on the adjustable gear with the cover in place. There are 2 access covers that need to be removed. 1 is the cam gear cover, the other is part of the bracket that the fan hub bolts to.
Click to expand...

It's the bull gear for sure, we've got all the bolts of the cover except for this one #### bolt for the air compressor that's way up close to the block any advice on how to get this one bolt out?!?! This is the only thing keeping me from getting the cover off so i can replace thw gear

BabyGator · May 2, 2017

OUTLAW-7 said: ↑

I have never seen a failure to wear on the gear, only after bearings start to fail then the gear wobbles and destroys itself and everything around it. I don't know if it's common knowledge but, you can actualy replace just the 2 bearings and races from with new timken bearings from auto parts stores! I have seen gears with well over 2 million miles on them after the bearings were changed at 1 million miles. I'll see if I can find the part number if you guys are interested.
Click to expand...

Outlaw 7 you still follow

BabyGator · May 2, 2017

CatMechanic you still follow this thread cause we are following your instructions and we have hit a issue could you please message us thanks

William8 · May 2, 2017

BabyGator said: ↑

It's the bull gear for sure, we've got all the bolts of the cover except for this one #### bolt for the air compressor that's way up close to the block any advice on how to get this one bolt out?!?! This is the only thing keeping me from getting the cover off so i can replace thw gear
Click to expand...

A socket, an extra long extension, and holding your mouth juuuuust right! Lol.

It's a pain, but put the socket on an extra long extension and go at it from the rear of the compressor.

And bullgears suck. I've just replaced the second one in two months at a certified Detroit shop. Long story, read in previous posts.

benjamin260_6 · May 3, 2017

BabyGator said: ↑

It's the bull gear for sure, we've got all the bolts of the cover except for this one #### bolt for the air compressor that's way up close to the block any advice on how to get this one bolt out?!?! This is the only thing keeping me from getting the cover off so i can replace thw gear
Click to expand...

That on isn't a hex bolt. It takes a 5/16" hex key.

GrapeApe · May 3, 2017

BabyGator said: ↑

It's the bull gear for sure, we've got all the bolts of the cover except for this one #### bolt for the air compressor that's way up close to the block any advice on how to get this one bolt out?!?! This is the only thing keeping me from getting the cover off so i can replace thw gear
Click to expand...

If you're talking about one of the bolts that also hold the air compressor on, an extension long enough to go past the compressor. Some have a bracket on the back of the compressor that you have to remove 1st to get a straight shot at it. When doing a front cover, I just pull the compressor.

BabyGator · May 5, 2017

catmechanic07 said: ↑

Are you kidding me? Bull gears are "bullet proof"? HAHAHA!

Here's the deal: You replace just bearings, your on your own! End of story. You buy a reman bull gear assembly, you SHOULD have dealer backing if they install. The bull gear can be installed in 1 day if they have competent tech's.

Easiest way: Remove radiator. Remove fan hub, acc drive, cam gear cover, damper and pulley. You SHOULD remove the oil pan so you have something solid to put a bottle jack against to raise the engine. If you don't want to, good luck and remove the front 2 bolts that go into the front cover. Remove the bolts for the front engine mount. Raise the engine just enough to clear the engine mount for removal. Remove the front mount. Now is a good time to remove the front seal. Its a royal pain to pull the front cover with the seal in. Remove all bolts in the front cover including 2 that hold the water pump on and the stud for the air compressor (there may be a bolt on the compressor towards the block as well. Pry the front cover off at the specified locations, looks like deep splits in the cover. Try to keep it clean but buff the red sealant off now before you install new parts. Use the flywheel to turn the engine over so the bolts line up with the holes in the bull gear. After the bull gear is removed, remove the idler gear (top left), remove the cam gear. Clean the front end with mineral spirits and dry with compressed air. Now, turning the engine by the flywheel in direction of rotation, put the timing mark at TDC. Timing mark on new bull gear (either a straight line or "V" mark) will determine which mark to use on the crank gear. With that done, install the idler gear and cam gear. When sealing the cam gear, use new O-ring and "football" gasket. When you install cam gear, use grey gasket maker where the football gasket seals on the cam cap splits. If you don't.....it WILL leak there! Now, leave the idler gear loose enough to where you can move it by hand but snug. "Eye" the timing marks on them and get them close. You cam now hold the bull gear up and align all the timing marks. ALL marks MUST line up at this point. You can tighten the bull gear to specs now (I think its 50ftlbs but not 100%). Now you need to set your back lashes. On used gears I think its .006-.012 allowance. Once backlash is achieved, tighten the idler nuts to 80 ftlbs. Your done with gears! Now, buff the front cover mating surface and apply red antirobic cream to the mating surfaces and spread it out evenly. Place the front cover on and remember, the sealer cures with the lack of air so you have limited time to get the bolts in and torqued. Front cover bolts torque to 50ftlbs. You WILL need a seal installer, yes you can tap it in but take a good chance of the seal leaking. Install the seal and front engine mount. Make sure to use grey gasket maker on the splits of the front and rear structure when installing the oil pan as well. Install the rest of your front cover components and radiator! ALL DONE!!!
Click to expand...

A thousand Thank yous for this post! We've followed it step by step and she's running again!!! 3 days total to tear down and fix but that was due to waiting on parts! So glad we stopped when we heard the tale tale metal on metal! 3 daye lost is better than 3 weeks!

William8 · May 16, 2017

BabyGator said: ↑

A thousand Thank yous for this post! We've followed it step by step and she's running again!!! 3 days total to tear down and fix but that was due to waiting on parts! So glad we stopped when we heard the tale tale metal on metal! 3 daye lost is better than 3 weeks!
Click to expand...

Yeah I wish I would have stopped. But the shop foreman at Interstate Power Systems Cedar Rapids told me to go ahead and run it for a day, see what happens....Shelled out my gearbox and my head, then wouldn't warranty the work they did six months before. I've been running my truck now for two weeks, everything they touched leaks oil....And they don't want to talk to me about it.

allan5oh · May 17, 2017

That's funny because I did my own bullgear 3 years ago and nothing leaks, I didn't even have the front seal installer.

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