Flat washers under flywheel bolts?
#2677226
07/13/19 11:40 PM
07/13/19 11:40 PM
|
Joined: Mar 2003
Posts: 9,099 Rogue River, OR
Jeremiah
OP
master
|
OP
master
Joined: Mar 2003
Posts: 9,099
Rogue River, OR
|
Question for the group-
Why don't all flywheel bolts have washers? Every flywheel I have ever r&r'd looked ugly where the washerless bolts contacted.
Is there any reason I should not be running flat washers here? I always use red locktite on the bolts per SOP.
Thanks for any insight on this topic.
|
|
|
Re: Flat washers under flywheel bolts?
[Re: 340Cuda]
#2677301
07/14/19 11:26 AM
07/14/19 11:26 AM
|
Joined: Feb 2005
Posts: 20,159 PA.
pittsburghracer
"Little"John
|
"Little"John
Joined: Feb 2005
Posts: 20,159
PA.
|
The last ARP flywheel/flexplate bolts I bought specifically said not to use washers with them.
I have no idea why. It’s been 30 years since I messed with a 727 or 904 but if I remember right they use thin headed bolts because of how close they come to the engine block. If you use a washer it would probably hit when you went to turn it.
1970 Duster Edelbrock headed 408 5.984@112.52 422 Indy headed small block 5.982@112.56 mph 9.42@138.27
Livin and lovin life one day at a time
|
|
|
Re: Flat washers under flywheel bolts?
[Re: lancer493]
#2677350
07/14/19 04:15 PM
07/14/19 04:15 PM
|
Joined: Jan 2003
Posts: 5,762 Hot Rod Ridge
FastmOp
master
|
master
Joined: Jan 2003
Posts: 5,762
Hot Rod Ridge
|
I sheared grade 8 bolts a few months ago. I noticed on the ARP bolts they have a nice flat land under the head that looks pretty nice and was bigger then the land on the grade 8 bolts ATI sends with their flywheel and spacer kit. Plus the ARP bolts are 41something chrome moly.
ATI has issues with the flex plate they sell. I reused my old one because the converter bolt pattern is wrong on the new one.
Last edited by FastmOp; 07/14/19 04:16 PM.
|
|
|
Re: Flat washers under flywheel bolts?
[Re: FastmOp]
#2677375
07/14/19 06:15 PM
07/14/19 06:15 PM
|
Joined: Dec 2004
Posts: 10,552 Rittman Ohio
fourgearsavoy
I Live Here
|
I Live Here
Joined: Dec 2004
Posts: 10,552
Rittman Ohio
|
If the OP is talking about an actual "flywheel" and not a flex plate you need to be careful the bolt heads don't contact the damper springs of the clutch disc like Cab said. I like the ARP bolts with a flange built in because they are easier on the flywheel. You might be able to get away with some thin hardened AN washers but double check it. Gus
64 Plymouth Savoy 493 Indy EZ's by Nick at Compu-Flow 5-Speed Richmond faceplate Liberty box Dana 60
|
|
|
Re: Flat washers under flywheel bolts?
[Re: Jeremiah]
#2677384
07/14/19 06:58 PM
07/14/19 06:58 PM
|
Joined: Dec 2006
Posts: 2,105 Byron, NY
W.I.N. Racing
top fuel
|
top fuel
Joined: Dec 2006
Posts: 2,105
Byron, NY
|
The main reasons are washers that thin will either be too soft and squeeze out or too hard(brittle) and break both conditions will cause flywheel/Flex plate to fail.
Last edited by W.I.N. racing; 07/14/19 07:11 PM.
'01 P1500, Blown/Inj BAE,/Veney ,Bruno/CS2,Dana 60 '01 Dodge 3500 S Cummins Auto, Fresh air kit, 4" Exhaust, '05 Dodge Magnum R/T - Too Much to list '60 Willys CJ5 '01 International LPX - Project,DT466, Allison '64 Plymouth Valiant, Inj 528 Hemi, 2spd
|
|
|
Re: Flat washers under flywheel bolts?
[Re: Stanton]
#2677439
07/14/19 10:34 PM
07/14/19 10:34 PM
|
Joined: Aug 2003
Posts: 43,124 Bend,OR USA
Cab_Burge
I Win
|
I Win
Joined: Aug 2003
Posts: 43,124
Bend,OR USA
|
Millions have been built with no washers. All the flywheel bolt manufacturers DON'T supply washers. Good enough for me !!! Keep in mind that the major auto makers look at saving parts of a penny per car, they are not worried about the motor or car after the warranty runs out When it comes to high performance race parts I want to be as safe as possible, especially in the cars I build, drive and race and have to pay for the race parts Jeremiah, 55 Ft Lbs. on the stock Mopar 7/16 flywheel bolts with red Locktite
Last edited by Cab_Burge; 07/15/19 08:19 PM.
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
|
|
|
Re: Flat washers under flywheel bolts?
[Re: Cab_Burge]
#2677510
07/15/19 09:00 AM
07/15/19 09:00 AM
|
Joined: Oct 2005
Posts: 8,862 Ontario, Canada
Stanton
Don't question me!
|
Don't question me!
Joined: Oct 2005
Posts: 8,862
Ontario, Canada
|
Millions have been built with no washers. All the flywheel bolt manufacturers DON'T supply washers. Good enough for me !!! When it comes to high performance race parts I want to as safe as possible, especially in the cars I build, drive and race and have pay to for the race parts Don't you think ARP would have tossed the idea around ?!?!?
|
|
|
Re: Flat washers under flywheel bolts?
[Re: Stanton]
#2677628
07/15/19 01:03 PM
07/15/19 01:03 PM
|
Joined: Aug 2003
Posts: 43,124 Bend,OR USA
Cab_Burge
I Win
|
I Win
Joined: Aug 2003
Posts: 43,124
Bend,OR USA
|
[quote=Stanton]Millions have been built with no washers. All the flywheel bolt manufacturers DON'T supply washers. Good enough for me !!! Don't you think ARP would have tossed the idea around ?!?!? I'm sure ARP did do a lot of thinking on the Mopar Flywheel and flex plate bolts they sale, hence the thin heads on both
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
|
|
|
Re: Flat washers under flywheel bolts?
[Re: JACK1440]
#2678179
07/17/19 08:03 AM
07/17/19 08:03 AM
|
Joined: Oct 2004
Posts: 3,097 back in Georgia
dthemi
master
|
master
Joined: Oct 2004
Posts: 3,097
back in Georgia
|
Because flywheels flex and can break hardened washers. Then you have projectiles, and a loose crank bolt.
I don't know if this is correct, but I use thread locker on the threads, and carefully brush a very small amount of lube on the flywheel where the bolt head contacts it. Torquing is smoother, and does less damage to the wheel.
Last edited by dthemi; 07/17/19 08:14 AM.
|
|
|
Re: Flat washers under flywheel bolts?
[Re: jlatessa]
#2678238
07/17/19 10:04 AM
07/17/19 10:04 AM
|
Joined: Feb 2005
Posts: 20,159 PA.
pittsburghracer
"Little"John
|
"Little"John
Joined: Feb 2005
Posts: 20,159
PA.
|
Just be very very careful with lube and loc-tite. They do not get along well together at all.
1970 Duster Edelbrock headed 408 5.984@112.52 422 Indy headed small block 5.982@112.56 mph 9.42@138.27
Livin and lovin life one day at a time
|
|
|
Re: Flat washers under flywheel bolts?
[Re: pittsburghracer]
#2678240
07/17/19 10:09 AM
07/17/19 10:09 AM
|
Joined: Aug 2009
Posts: 1,317 Ohio
jlatessa
pro stock
|
pro stock
Joined: Aug 2009
Posts: 1,317
Ohio
|
Noted, thanks...
Joe
Edit, By the way, I ALWAYS clean the threads, both male and female with brake clean before applying thread lockers.
Last edited by jlatessa; 07/17/19 10:13 AM.
|
|
|
Re: Flat washers under flywheel bolts?
[Re: dthemi]
#2678395
07/17/19 06:33 PM
07/17/19 06:33 PM
|
Joined: Dec 2004
Posts: 10,552 Rittman Ohio
fourgearsavoy
I Live Here
|
I Live Here
Joined: Dec 2004
Posts: 10,552
Rittman Ohio
|
Because flywheels flex and can break hardened washers. Then you have projectiles, and a loose crank bolt.
I don't know if this is correct, but I use thread locker on the threads, and carefully brush a very small amount of lube on the flywheel where the bolt head contacts it. Torquing is smoother, and does less damage to the wheel. I thought I was the only one that done that When I build rear ends the shur-grip gets ARP lube under the head and red on the treads,the same for ring gear bolts Gus
64 Plymouth Savoy 493 Indy EZ's by Nick at Compu-Flow 5-Speed Richmond faceplate Liberty box Dana 60
|
|
|
Re: Flat washers under flywheel bolts?
[Re: Cab_Burge]
#2678495
07/17/19 11:39 PM
07/17/19 11:39 PM
|
Joined: Mar 2003
Posts: 9,099 Rogue River, OR
Jeremiah
OP
master
|
OP
master
Joined: Mar 2003
Posts: 9,099
Rogue River, OR
|
I try to use thin harden flat washers with thin head bolts, make sure the clutch anti chatter springs don't touch the bolt heads after torqueing before using it that way Don't worry there are not clutch hub springs. Those are for sissies! I have used a thin wave washers before but as mentioned a few of them came out intact however they were lightly lubricated for install. I always torque everything and a big 10-4 on the locktite. I have run solid mounts for years and a dab of red seems to be necessary in many places you would not normally have to address.
|
|
|
Re: Flat washers under flywheel bolts?
[Re: 340Cuda]
#2678496
07/17/19 11:41 PM
07/17/19 11:41 PM
|
Joined: Mar 2003
Posts: 9,099 Rogue River, OR
Jeremiah
OP
master
|
OP
master
Joined: Mar 2003
Posts: 9,099
Rogue River, OR
|
The last ARP flywheel/flexplate bolts I bought specifically said not to use washers with them.
I have no idea why. Yet they sell flywheel bolts with flat washers for the high end HEMI stuff. Hence my question. More of a curiosity than anything I guess.
|
|
|
Re: Flat washers under flywheel bolts?
[Re: lancer493]
#2678499
07/17/19 11:43 PM
07/17/19 11:43 PM
|
Joined: Mar 2003
Posts: 9,099 Rogue River, OR
Jeremiah
OP
master
|
OP
master
Joined: Mar 2003
Posts: 9,099
Rogue River, OR
|
I 'think' the small amount of distortion created by tightening the hardened bolts,with their specifically sized and machined area under the head, may help to create a locating effect that is normally accomplished with a dowel or tapered cone. Both of the last 2 would add additional machining steps and cost.I think a hard steel washer would elimate that 'freebie' effect mentioned in the beginning,as it 'may' act as a bushing between the 2 mating surfaces. Not sure if a dowel is included in the equation. That spinning flywheel creates some serious energy there,especially when try to move a 4000lb vehicle with sticky tires. Conical lug nuts on a street car comes to mind.Nothing textbook here, purely speculation and observation. Just my thoughts. Bill The bushing example makes good sense. I guess I didn't really think too far into how much heat gets built up in the flywheel.
|
|
|
Re: Flat washers under flywheel bolts?
[Re: fourgearsavoy]
#2678500
07/17/19 11:46 PM
07/17/19 11:46 PM
|
Joined: Mar 2003
Posts: 9,099 Rogue River, OR
Jeremiah
OP
master
|
OP
master
Joined: Mar 2003
Posts: 9,099
Rogue River, OR
|
If the OP is talking about an actual "flywheel" and not a flex plate you need to be careful the bolt heads don't contact the damper springs of the clutch disc like Cab said. I like the ARP bolts with a flange built in because they are easier on the flywheel. You might be able to get away with some thin hardened AN washers but double check it. Gus You know I'd never have a car with a flex plate! I think I'll stick with the lube under the head, loctite on the threads and torque 'em down. Now instead of being nervous about the lack of washers I am paranoid they will cause problems.
|
|
|
Re: Flat washers under flywheel bolts?
[Re: FastmOp]
#2678502
07/17/19 11:48 PM
07/17/19 11:48 PM
|
Joined: Mar 2003
Posts: 9,099 Rogue River, OR
Jeremiah
OP
master
|
OP
master
Joined: Mar 2003
Posts: 9,099
Rogue River, OR
|
I sheared grade 8 bolts a few months ago. I noticed on the ARP bolts they have a nice flat land under the head that looks pretty nice and was bigger then the land on the grade 8 bolts ATI sends with their flywheel and spacer kit. Plus the ARP bolts are 41something chrome moly.
ATI has issues with the flex plate they sell. I reused my old one because the converter bolt pattern is wrong on the new one. Always ARP. You should see the bolts that I got from one of the vendors. They are grade 8 with the heads ground down. Very scary especially when I ordered them with all of the face plated 9310 gears. Nothing leaves my shop wearing hardware store bolts, especially on the rotating assembly. ACE is not the place for flywheel bolts.
|
|
|
Re: Flat washers under flywheel bolts?
[Re: Stanton]
#2678504
07/17/19 11:57 PM
07/17/19 11:57 PM
|
Joined: Mar 2003
Posts: 9,099 Rogue River, OR
Jeremiah
OP
master
|
OP
master
Joined: Mar 2003
Posts: 9,099
Rogue River, OR
|
Millions have been built with no washers. All the flywheel bolt manufacturers DON'T supply washers. Good enough for me !!! Millions have not been built with 750hp moving 3600lbs through a solid disc clutch/aluminum flywheel to plant sticky 10.5" slick tires at 5000 rpm. That begs the question. Some of the flywheel bolt manufactures that cover the entire motorsports spectrum *do* offer flywheel bolts with washers: Example #1Example #2Example #3I though maybe I was missing something.
|
|
|
Re: Flat washers under flywheel bolts?
[Re: Stanton]
#2678505
07/17/19 11:58 PM
07/17/19 11:58 PM
|
Joined: Mar 2003
Posts: 9,099 Rogue River, OR
Jeremiah
OP
master
|
OP
master
Joined: Mar 2003
Posts: 9,099
Rogue River, OR
|
Millions have been built with no washers. All the flywheel bolt manufacturers DON'T supply washers. Good enough for me !!! When it comes to high performance race parts I want to as safe as possible, especially in the cars I build, drive and race and have pay to for the race parts Don't you think ARP would have tossed the idea around ?!?!? Yes, I actually do think ARP has tossed this idea around lol.
|
|
|
Re: Flat washers under flywheel bolts?
[Re: Jeremiah]
#3047770
06/03/22 11:06 PM
06/03/22 11:06 PM
|
Joined: Jun 2022
Posts: 1 Pueblo, CO USA
Darkbreeze
member
|
member
Joined: Jun 2022
Posts: 1
Pueblo, CO USA
|
Sorry to necro, but for anybody who might still come across this thread, which they will because I did while looking for something else, I feel like it's important to correct misinformation even though I realize none of it was given intentionally. The bottom line is, none of the answers is actually correct in this thread for about 95%, maybe more, of applications. The reason being, about 95% of manufacturers use PLACE BOLTS, which you can read about at the following link and I guarantee none of you ever heard of them otherwise they'd have been mentioned in this thread, on critical fastener locations like flywheel bolts, oil pump bolts, camshaft retainer bolts, etc. https://www.earnestmachine.com/sites/default/files/products/imported/BHP.pdfYou will be able to identify Place Bolts by the undercut in the bottom of the head and the six cut out lines in the top of the bolt head. This design allows the bolt to create far more clamping power than a standard bolt, even when using a lock washer. If you remove a place bolt on any application that is the ONLY kind of bolt that should go back in that application location. Generally these are used on applications where the bolt is not particularly long, since longer bolt bodies are able to provide their own additional clamping spring tension, and where they are both difficult to get to if a bolt were to come loose AND would be likely to create a catastrophic end result if they did. Did not intend to step on anybody's toes, but sometimes, like I did, you might go half your career AFTER professional schooling, and have never heard of them, until somebody slapped me upside the head with that information. Hopefully, some of you here or others who come along later, will be better informed for the info. Good luck.
|
|
|
Re: Flat washers under flywheel bolts?
[Re: Jeremiah]
#3047861
06/04/22 01:28 PM
06/04/22 01:28 PM
|
Joined: Jan 2012
Posts: 2,631 Stuttgart, Arkansas
rickseeman
master
|
master
Joined: Jan 2012
Posts: 2,631
Stuttgart, Arkansas
|
I'm into bolts. Nice article. I've paid for flywheel bolts twice from "Mopar vendors" and received regular Grade 8 bolts at a big price. These guys make me very mad sometimes.
2011 Drag Pak Challenger
|
|
|
Re: Flat washers under flywheel bolts?
[Re: Cab_Burge]
#3048062
06/05/22 03:00 PM
06/05/22 03:00 PM
|
Joined: Sep 2018
Posts: 166 West Palm Beach, Florida
Craig J
member
|
member
Joined: Sep 2018
Posts: 166
West Palm Beach, Florida
|
I try to use thin harden flat washers with thin head bolts, make sure the clutch anti chatter springs don't touch the bolt heads after torqueing before using it that way Just adding photos for reference since I am in the middle of trying to undo numerous mistakes on a car I bought last year. Even without washers they bolt heads can hit... the previous owner tried to add clearance by using a hand grinder on the heads of the flywheel bolts, but it was not enough.
|
|
|
Re: Flat washers under flywheel bolts?
[Re: Craig J]
#3048064
06/05/22 03:13 PM
06/05/22 03:13 PM
|
Joined: Dec 2004
Posts: 10,552 Rittman Ohio
fourgearsavoy
I Live Here
|
I Live Here
Joined: Dec 2004
Posts: 10,552
Rittman Ohio
|
I try to use thin harden flat washers with thin head bolts, make sure the clutch anti chatter springs don't touch the bolt heads after torqueing before using it that way Just adding photos for reference since I am in the middle of trying to undo numerous mistakes on a car I bought last year. Even without washers they bolt heads can hit... the previous owner tried to add clearance by using a hand grinder on the heads of the flywheel bolts, but it was not enough. That happens when people use a flywheel that has been cut a few too many times Gus
64 Plymouth Savoy 493 Indy EZ's by Nick at Compu-Flow 5-Speed Richmond faceplate Liberty box Dana 60
|
|
|
Re: Flat washers under flywheel bolts?
[Re: Craig J]
#3048169
06/05/22 10:58 PM
06/05/22 10:58 PM
|
Joined: Dec 2004
Posts: 10,552 Rittman Ohio
fourgearsavoy
I Live Here
|
I Live Here
Joined: Dec 2004
Posts: 10,552
Rittman Ohio
|
Yep only good for an engine run stand now. Gus
64 Plymouth Savoy 493 Indy EZ's by Nick at Compu-Flow 5-Speed Richmond faceplate Liberty box Dana 60
|
|
|
Re: Flat washers under flywheel bolts?
[Re: moparx]
#3048206
06/06/22 08:54 AM
06/06/22 08:54 AM
|
Joined: Jan 2006
Posts: 8,162 USA
360view
Moparts resident spammer
|
Moparts resident spammer
Joined: Jan 2006
Posts: 8,162
USA
|
interesting article breeze. thank you sir ! i learned something, so you can say you taught an old dog. Me too. Glad to learn the automotive term “Place Bolts”. In mining they are commonly called “Double A” like the link to earnest machine has typed on the right. I understand the undercut head because in Mech Engr education class time is spent on “Stress Concentration Analysis”. I now am wondering about whether the six cut marks on the upper head surface are “cosmetic” just for human eyes to see or are functional in that they affect either stress concentration or act similar to “toothed lock washers.”
|
|
|
Re: Flat washers under flywheel bolts?
[Re: 360view]
#3048280
06/06/22 01:01 PM
06/06/22 01:01 PM
|
Joined: Sep 2003
Posts: 19,355 north of coder
moparx
"Butt Crack Bob"
|
"Butt Crack Bob"
Joined: Sep 2003
Posts: 19,355
north of coder
|
i'm almost betting the cut marks allow the bolt head to deform somewhat, affecting the clamping force. just guessing this, as it seems this type of bolt head is only found in certain applications. if it were just cosmetic, why take the time to add this feature ? just my observation over the years. i have no degree in anything, just [mostly] self taught skills from the school of hard knocks.
|
|
|
Re: Flat washers under flywheel bolts?
[Re: moparx]
#3048309
06/06/22 01:51 PM
06/06/22 01:51 PM
|
Joined: Jan 2003
Posts: 16,923 NC
440Jim
I Live Here
|
I Live Here
Joined: Jan 2003
Posts: 16,923
NC
|
i'm almost betting the cut marks allow the bolt head to deform somewhat, affecting the clamping force. From the Earnest technical bulletin that "Darkbreeze" linked.
|
|
|
Re: Flat washers under flywheel bolts?
[Re: 440Jim]
#3048891
06/08/22 01:07 PM
06/08/22 01:07 PM
|
Joined: Sep 2003
Posts: 19,355 north of coder
moparx
"Butt Crack Bob"
|
"Butt Crack Bob"
Joined: Sep 2003
Posts: 19,355
north of coder
|
i'm almost betting the cut marks allow the bolt head to deform somewhat, affecting the clamping force. From the Earnest technical bulletin that "Darkbreeze" linked. thanks for kicking my butt when i needed it Jim ! after reading the bulletin, i immediately forgot what i read ! i need to get some of those supplements advertised on late night tv. i think those products are meant to kill the spiders that make the cobwebs in my noggin. i have now printed the bulletin, so i have no excuse to forget what it contains. [except forgetting where i put the print out. ]
|
|
|
|
|