HarleyTechTalk

Technical Forums => Milwaukee-Eight => Topic started by: les on September 28, 2020, 08:41:01 AM

Title: Lifter cuff bolts breaking, is it still happening?
Post by: les on September 28, 2020, 08:41:01 AM
I've got a 131" crate engine in my engine bench.  I'm going to install the S&S lifter cuffs.  Are the OEM bolts still snapping off, or has H-D fixed the bolt and thread locker problem on later engines?
Title: Re: Lifter cuff bolts breaking, is it still happening?
Post by: les on September 28, 2020, 05:53:15 PM
Ok, I'll ask another way.  Has anyone broken a lifter cuff bolt on a 2019 or 2020?
Title: Re: Lifter cuff bolts breaking, is it still happening?
Post by: KiwiRob on September 28, 2020, 11:41:07 PM
Recently installed a big bore 124 piston and cylinder kit to my 2019 107 fat boy, along with a cam and lifters change. Removed the stock cuff bolts with no problem. - Rob
Title: Re: Lifter cuff bolts breaking, is it still happening?
Post by: les on September 29, 2020, 05:33:08 AM
Quote from: KiwiRob on September 28, 2020, 11:41:07 PM
Recently installed a big bore 124 piston and cylinder kit to my 2019 107 fat boy, along with a cam and lifters change. Removed the stock cuff bolts with no problem. - Rob

Thanks, Rob.  That's encouraging.  So, it felt like normal blue loctite when you removed the bolts, right?  Because when I removed bolts on a 2017 (that I broke the bolt) I could tell that the loctite just didn't feel right.
Title: Re: Lifter cuff bolts breaking, is it still happening?
Post by: KiwiRob on September 29, 2020, 11:22:23 AM
It felt a normal blue loctite removal. I've since come across a tip from Fuelmoto, where they use a heat gun to heat the area around the cuff for removing bolt. - Rob
Title: Re: Lifter cuff bolts breaking, is it still happening?
Post by: Jamie Long on September 29, 2020, 12:17:46 PM
Based on the motors we see here nothing appears to have changed with the tappet cuff bolts, the Motor Company does not want these bolts to come out. Simply apply a little heat and it's no issue.
Title: Re: Lifter cuff bolts breaking, is it still happening?
Post by: les on September 30, 2020, 05:08:19 AM
So, I'm not going to be taking the cam chest apart.  I plan to use a propane torch and try to give it a little heat from the top.  Will the torch damage the black powder coating of the engine around the lifter blocks?  Or, should I try to use the heat gun from the top?  I don't know how susceptible the plastic cuffs are to direct heat.
Title: Re: Lifter cuff bolts breaking, is it still happening?
Post by: Sunny Jim on September 30, 2020, 04:17:32 PM
Use a heat gun! As in 'very hot hairdryer'
Title: Re: Lifter cuff bolts breaking, is it still happening?
Post by: les on October 01, 2020, 10:04:58 AM
Quote from: Sunny Jim on September 30, 2020, 04:17:32 PM
Use a heat gun! As in 'very hot hairdryer'

Ok.
Title: Re: Lifter cuff bolts breaking, is it still happening?
Post by: Rokinrider on October 01, 2020, 04:29:19 PM
I used a heat gun and they came out like nothing.
Title: Re: Lifter cuff bolts breaking, is it still happening?
Post by: Hillside Motorcycle on October 02, 2020, 04:16:46 AM
We really haven't seen any odd issues here.
Title: Re: Lifter cuff bolts breaking, is it still happening?
Post by: les on October 02, 2020, 04:23:46 AM
Quote from: Rokinrider on October 01, 2020, 04:29:19 PM
I used a heat gun and they came out like nothing.

So, you're talking about using the heat gun from the top, right?  Not from the underside (inside the cam chest) of the lifter blocks.
Title: Re: Lifter cuff bolts breaking, is it still happening?
Post by: les on October 02, 2020, 10:49:58 PM
I used the heat gun from the top, on low setting because that was plenty hot.  I directed it down into the channel next to the bolt hole.  I held it there the entire time I was slowly turning the bolts out.  I expected the rear bolt to come out easier because the channel was winder with better access, but that bolt came out the hardest.  My hand was shaking the entire time I was removing the bolts, because I've already been through a broken lifter cuff bolt.  It ain't fun.

Everything went smooth, but taking those two bolts out is not a job I ever look forward to.  Thanks for the comments and help.
Title: Re: Lifter cuff bolts breaking, is it still happening?
Post by: KiwiRob on October 03, 2020, 12:21:51 AM
I must have been lucky when I did mine. Anyway, if I have to do it again on another M8, I'll definitely use a heat gun. - Rob
Title: Re: Lifter cuff bolts breaking, is it still happening?
Post by: sfmichael on October 05, 2020, 07:16:44 PM
Quote from: les on October 02, 2020, 10:49:58 PM
I used the heat gun from the top, on low setting because that was plenty hot.  I directed it down into the channel next to the bolt hole.  I held it there the entire time I was slowly turning the bolts out.  I expected the rear bolt to come out easier because the channel was winder with better access, but that bolt came out the hardest.  My hand was shaking the entire time I was removing the bolts, because I've already been through a broken lifter cuff bolt.  It ain't fun.

Everything went smooth, but taking those two bolts out is not a job I ever look forward to.  Thanks for the comments and help.

:up: :baby:
Title: Re: Lifter cuff bolts breaking, is it still happening?
Post by: cmashark on June 05, 2021, 06:41:47 AM
I will cut the pushrods, pull lifter blocks, and lifter cuffs while the engine is at full operating temp.  Then I take a nap for an hour or 2 and then go back out and finish the job. Never had one that was difficult to remove in the 8 or so M8 cam swaps I've done. At full operating temp, the top of the case, where the cylinder spigots are, typically measures 330 degrees at full operating temp.
Title: Re: Lifter cuff bolts breaking, is it still happening?
Post by: les on June 10, 2021, 04:56:52 AM
Quote from: Sunny Jim on September 30, 2020, 04:17:32 PM
Use a heat gun! As in 'very hot hairdryer'

Sunny, I did another one using the heat gun with success.  I hold it on low setting for about 5 minutes, then switch back and forth between high and low heat while slowly removing the bolt.

Now, how do I solve the problem of my hands shaking from nervousness while I'm removing the bolt?   :hyst:
Title: Re: Lifter cuff bolts breaking, is it still happening?
Post by: Hossamania on June 10, 2021, 05:51:39 AM
Quote from: les on June 10, 2021, 04:56:52 AM
Quote from: Sunny Jim on September 30, 2020, 04:17:32 PM
Use a heat gun! As in 'very hot hairdryer'
Now, how do I solve the problem of my hands shaking from nervousness while I'm removing the bolt?   :hyst:

A couple of cocktails to calm the nerves...