I plan on replacing all the studs and am going to do all the stud holes at the same time.I have the helicoil sets but may invest in the time cert tool as it appears to be a better choice. Rocker boxes are dry as they have had the factory gaskets replaced and found to be true at this time. I’ve had this bike about 7 years and am still finding problems that previous owner(s) caused during previous repairs. I have slightly over 60 k on it now. I rode every day until I retired and still try to ride at least 3 days a week. I was leaning toward the cosmetic gaskets so that recommendation was appreciated.
Are you just really bored or do you subscribe to the governmental policy of if it ain't broke fix it till it is?
The only reason to pull the studs is if you have a problem with them and then you just have to fix the problem child not all of them.
I look on replacing the studs now as pm. I don’t want to do this repair again anytime soon. Factory procedure makes me believe that they are torque to yield as that has been the case every time I have had fasteners that required torque then turn a number of degrees. I also have a stud removal tool making the task a little easier. Government procedure is ironic as I worked for TXDOT for 15 years in the main shop before leaving to teach full time.
I look on replacing the studs now as pm. I don’t want to do this repair again anytime soon. Factory procedure makes me believe that they are torque to yield as that has been the case every time I have had fasteners that required torque then turn a number of degrees. I also have a stud removal tool making the task a little easier. Government procedure is ironic as I worked for TXDOT for 15 years in the main shop before leaving to teach full time.
If you go with James or Cometic steel gaskets you will seek up on 42 flbs of torque and no extra in degrees.
A buddy of mine has an evo with over 250k and he hasn't changed a stud yet so I'm not real sure that should fall under the pm list.
FWIW I haven't talked to an engine builder yet that changed studs unless there was a problem with one and I'm talking multiple rebuilds on the same motor.
On the other hand it's your motor and if it makes you happy go for it.
That’s the kind of info I can use. If shops that can’t afford comebacks don’t replace I may rethink my plan. I will go with the cosmetic gaskets, factory rocker box gaskets( already have a set) plan has always been to have machine shop true up the cylinders. Just great to hear from others success stories and even better to see that my ideas have been used by others with good results.
The stud to case threads on old EVO's has an interference fit, I wouldn't disturb them if they're OK.
When you get the rocker boxes off, grab a torque wrench set to 40 foot pounds and see if each head bolt will hold solid, backoff first and then retorque, then you know if and which studs are pulled, you don't want to find that out later.
Definitely don't use helicoils, I know people used timeserts with success and some not so much, I don't like any inserts, I'd probably rip it all apart and weld and drill if I was to get one repaired., or just replace, probably with aftermarket.
I like to spray the MLS gaskets with light coat of coppercoat.on Evo's, never a leak.
I’m preparing to replace the leaking head gasket on the rear cylinder(second time) and decided to do both cylinders and eliminate the base gasket and rocker box seeps. At the risk of starting another thread like the oil threads I am trying to find the best brand of gasket sets or combination of different brands. Next I’m on to methods to rethread the stud holes. All info is welcomed. Maybe I should say my bike is a 1989 FLTC.
For gaskets;
OEM harley
Cometic MLS series
James
In that order and james as a last resort, You've already gotten some excellent advice on the stud situation.
I agree with Texashill and Schex...if it aint broke...
Your dilemma will be if one or two come out when taking things apart (like mine did). Mine was collar up.
The question is, just put back the ones that came loose collar up or collar down? I was really nervous about that interference fit that Schex mentions and putting the original studs back in with those interference threads, as those interference threads in the block looked like threads that have been fatigued or stressed. I also questioned it on another forum, and got the "you must replace and your a cheap azz rickhead loser if you don't" because of metal fatigue, stretch, etc...to me the concern was integrity of the threads in the block and studs pulling out of the block more than anything else and not the actual stud condition/strength.
When you put them back, they need to be installed at the correct height (if you reinstall collar up), if you install them collar down, then you need to replace them because of the interference thread on the old stud now being up. The head bolt will not thread onto the interference threads. If any come out, I would suggest you replace them with new and collar down. Red loctite at 10 ft lbs after making sure block threads and stud threads are clean and dry.
I also researched about "stud stretch" and metal fatigue for the studs on our bikes only, and did not find any direct info from Moco saying "you must replace the studs" when taking cylinders off. I am not saying studs don't fatigue or stretch, what I am saying is the same and Texalhill and Shcex, if it aint broke...
I hope your studs all stay in place during disassembly and it is a nonissue...see link below regarding stud install instructions, if you go that way and note the difference in the threads interference vs standard..
The trouble is, of course, the studs (and studs and bolts) stretch and loses their elasticity.
Once that happens the clamping force is just a static pull and not good enough to hold, and or they shear off.
The other problem is the constant movement from the static pull wears out the threads in the case.
Now there are bigger problems.
ARP and others make quality replacements.
The trouble is, of course, the studs (and studs and bolts) stretch and loses their elasticity.
Once that happens the clamping force is just a static pull and not good enough to hold, and or they shear off.
The other problem is the constant movement from the static pull wears out the threads in the case.
Now there are bigger problems.
ARP and others make quality replacements.
11-08-2018 | 07:19 PM
