Bottom End Longevity
Thread Starter
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Cruiser
Joined: Jul 2016
Posts: 241
Likes: 33
From: Syracuse IN
Bottom End Longevity
My '75 FXE has 20,000 on the odometer, and knowing its history before I received it I don't believe it to have been abused.
It leaks from practically every seam with exception of the lower case. Enough that on a day ride I find oil on the back of my shirt and the saddlebags have a nice coat. So I plan to have the top end freshened and replace the leaky gaskets with Cometic.
The entire top end, with exception of the pistons and cylinders, will be new.
Since it will be in the shop anyway, do I need to think about the bottom end? I know that it has had the crank balanced, but don't know when, nor whether the original or new bearings were installed.
The bottom case does not appear to leak. Should I go ahead and freshen the bottom end as well, or am I good for another 20K or longer?
It leaks from practically every seam with exception of the lower case. Enough that on a day ride I find oil on the back of my shirt and the saddlebags have a nice coat. So I plan to have the top end freshened and replace the leaky gaskets with Cometic.
The entire top end, with exception of the pistons and cylinders, will be new.
Since it will be in the shop anyway, do I need to think about the bottom end? I know that it has had the crank balanced, but don't know when, nor whether the original or new bearings were installed.
The bottom case does not appear to leak. Should I go ahead and freshen the bottom end as well, or am I good for another 20K or longer?
Seasoned HDF Member
Joined: Jul 2014
Posts: 8,590
Likes: 3,361
From: Cental, MI
my old Geezer Glide sits at about 50K... from the MoCo... I sure would Not sweat the bottom end...even yet.
Now... a top end rebuild... I would Never do a Valve job without Rings..., nor Rings without a valve job...
Find a good Indy... Not an automotive, nor Tractor shop... a real Harley Indy is the answer to all of your Questions... Period.. ie, you cannot "plan" on reusing pistons if ya don't know for sure that yer bore is Straight, and Round... Only Car and Tractor folks do such things....
Now... a top end rebuild... I would Never do a Valve job without Rings..., nor Rings without a valve job...
Find a good Indy... Not an automotive, nor Tractor shop... a real Harley Indy is the answer to all of your Questions... Period.. ie, you cannot "plan" on reusing pistons if ya don't know for sure that yer bore is Straight, and Round... Only Car and Tractor folks do such things....
Thread Starter
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Cruiser
Joined: Jul 2016
Posts: 241
Likes: 33
From: Syracuse IN
Everything will be new with exception of the pistons and cylinders.
Keeping the stock 74 cube bore and stroke.
Have new Hastings rings on hand, but hadn't considered possibility of issue with pistons/bores.
Will build that into the budget as well.
Thanks RP
Keeping the stock 74 cube bore and stroke.
Have new Hastings rings on hand, but hadn't considered possibility of issue with pistons/bores.
Will build that into the budget as well.
Thanks RP
Club Member
Joined: Mar 2009
Posts: 66,110
Likes: 51,396
From: Niles Canyon Ca.
Stock 74 lower end can go a 100K if the oils been changed regular and hasn't been beat to death, as long as the rods check out I'd leave it alone. I'd do 3 uppers before I'd have to crack the cases on mine. Johjzjz will chime in, ask him how to check the rods he explains it better than I do.
Last edited by TwiZted Biker; Mar 1, 2019 at 09:20 AM.
Seasoned HDF Member
Joined: Oct 2005
Posts: 7,495
Likes: 3,705
From: Santa Klaus County, Cali
Got over 80K on my 84 FLH. Did the top end at 62K. Ended up going 30 over with new pistons, rings and bore. Spend the couple extra to do the complete top end. You won't regret it.
Seasoned HDF Member
Joined: Jul 2014
Posts: 8,590
Likes: 3,361
From: Cental, MI
Stock 74 lower end can go a 100K if the oils been changed regular and hasn't been beat to death, as long as the rods check out I'd leave it alone. I'd do 3 uppers before I'd have to crack the cases on mine. Johjzjz will chime in, ask him how to check the rods he explains it better than I do.
I hope so... I was taught the "Pull and Smack" method long ago... just a bit subjective... but, never let me down...I am more than willing to learn better methods...
Seasoned HDF Member
Joined: Nov 2006
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From: la la land jerzey
ok if you can take the front rod in your fingers and twist it like a bottle cap both directions and it does not have any movement / play - that lower unit is good for another 10 / 12 years - if it has just a small bit of movement in the twist 5 years almost not felt but something is in the twist
you know the answer to this if you can twist it back and forth an 1/32 both ways or more have it re done < seen them come in with 1/4 inch both ways but the breather valve - oil pump and all the shafts are hurt including the cam and every bushing
what happens with the movement is the out side edges of the roller bearings are worn, one or two tenths of one thousand, and you can feel it then after that what happens is the oil pressure bleads off and leans out the crank pin and roller bearings of its correct flow - this causes a very rapid wear on the hardened crank pin and rollers - rod races ect ect
you know the answer to this if you can twist it back and forth an 1/32 both ways or more have it re done < seen them come in with 1/4 inch both ways but the breather valve - oil pump and all the shafts are hurt including the cam and every bushing
what happens with the movement is the out side edges of the roller bearings are worn, one or two tenths of one thousand, and you can feel it then after that what happens is the oil pressure bleads off and leans out the crank pin and roller bearings of its correct flow - this causes a very rapid wear on the hardened crank pin and rollers - rod races ect ect
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Seasoned HDF Member
Joined: Oct 2007
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From: Decatur, Alabama
That oil on your shirt might be caused by the chain oiler dripping too much oil on the chain.
carl
carl
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Road Master
Joined: Nov 2018
Posts: 873
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From: FLORIDA
I think they make oil pumps now without the chain oiler it'll kill your t-shirt
Seasoned HDF Member
Joined: Jul 2014
Posts: 8,590
Likes: 3,361
From: Cental, MI
ok if you can take the front rod in your fingers and twist it like a bottle cap both directions and it does not have any movement / play - that lower unit is good for another 10 / 12 years - if it has just a small bit of movement in the twist 5 years almost not felt but something is in the twist
you know the answer to this if you can twist it back and forth an 1/32 both ways or more have it re done < seen them come in with 1/4 inch both ways but the breather valve - oil pump and all the shafts are hurt including the cam and every bushing
what happens with the movement is the out side edges of the roller bearings are worn, one or two tenths of one thousand, and you can feel it then after that what happens is the oil pressure bleads off and leans out the crank pin and roller bearings of its correct flow - this causes a very rapid wear on the hardened crank pin and rollers - rod races ect ect
you know the answer to this if you can twist it back and forth an 1/32 both ways or more have it re done < seen them come in with 1/4 inch both ways but the breather valve - oil pump and all the shafts are hurt including the cam and every bushing
what happens with the movement is the out side edges of the roller bearings are worn, one or two tenths of one thousand, and you can feel it then after that what happens is the oil pressure bleads off and leans out the crank pin and roller bearings of its correct flow - this causes a very rapid wear on the hardened crank pin and rollers - rod races ect ect
Help me here...