Flywheel Bolt Problem (Major)

[Jocko_51_B3B]

My 218 is mostly together and this morning I was in the process of mounting the flywheel and torquing the flywheel bolts to 55 ft-lbs per the shop manual when I started to feel the last bolt give out. Sure enough, the bolt thread had stripped out. I guess it was just an old worn out bolt that I should have replaced before installing the crankshaft. Has anyone else had this happen and what would be the best way to fix this problem? I'm sure the original style bolts are unavailable. Would any grade-8 hardware store bolts be OK if I grind off one corner of the head to make them fit? Last but not least, why on earth did Dodge not design the flywheel to be bolted on from the flywheel side??? What a pain.

 

 

Edited December 17, 2018 by Jocko_51_B3B

[Young Ed]

I don't think you can substitute a hardware store bolt in place. The shank needs to be a tight fit and the head is D shaped with one side going against the inner side so it can't rotate. 

[Don Coatney]

My application is a bit different than yours. I have a Desoto engine, P-15 flywheel, T-5 transmission. The critical thing is finding bolts with a shoulder long enough to go inside both the flywheel and the end of the crankshaft. The bolts pictured below are what I used. If you do not use bolts with the long shoulder you run the risk of shearing off the bolts as the threads are not as strong as the shoulder. These bolts were too long so I had to cut them to length. As you can see I installed the bolts with the nuts on the engine side

 

 

 

 

 

[Merle Coggins]

I would think that if you can find bolts with the proper diameter and length shank, as Don mentioned, then you could probably make them into a clipped head bolt with a grinder. Then you'll have to drop the pan and rear main bearing cap to replace them.

If I were to go through all of this trouble, I'd be replacing all 4 of them.

Edited December 17, 2018 by Merle Coggins

[Old CWO]

I have not personally had one of these apart but from the photo it appears to me that you are dealing with a stud, not a bolt. and I agree with Merle; replace them all.  A wheel stud of suitable dimensions should be available from a "real" auto parts store.

 

 

[wayfarer]

MaMopar did plenty of 'odd' things, this is but one of them.  Because the studs are too long to go out the engine side in one piece you will need a new plan: 

Since the flywheel registers on the OD of the crank flange  and the bolts are only there to hold the whole mess together

then I'd do something like Don shows in his photos. Cut the existing bolt flush to the face and drive them out.

[Dodgeb4ya]

Factory Flywheel bolts....................... 1/2 cut head

Edited December 17, 2018 by Dodgeb4ya

[tom'sB2B]

Vintage Power Wagon sells them for $5 a piece ?

[JBNeal]

Those flywheel studs are most likely installed at the factory on the crankshaft so that they act as pilot studs when the flywheel is being serviced in the vehicle... as DC has shown, a properly sized bolt with adequate shank can be modified and installed, with the downside that bolt modifications will remove any metal coatings that protect against corrosion.  Also shown is that the fasteners need not be grade 8 nor stainless steel, as the original flywheel studs were neither...this is a Dodge flathead, not a Titan rocket

[48Dodger]

That's it....the next race truck I build will be called "The L6 Dodge Titan Rocket"

 

48Boom!

[Jocko_51_B3B]

I called Vintage Power Wagon yesterday and they said they have NOS flywheel mounting bolts so I ordered four. Major problem solved.

I decided to replace the clutch cover plate bolts too. I've checked several sources including VPW and no one seems to have ready-to-go replacements so I'll have to use some longer shoulder bolts and cut them down to 1 inch. The closest I've found to the originals are 1/4 inch too long. My thanks to all who posted replies!

 

Edited December 20, 2018 by Jocko_51_B3B
Better wording.

[Dodgeb4ya]

The original clutch cover plate/pressure plate bolts were shouldered for accurate placement on the flywheel.

[wayfarer]

12 hours ago, Dodgeb4ya said:

The original clutch cover plate/pressure plate bolts were shouldered for accurate placement on the flywheel.

...some folks seem to miss small details like this and only wonder why the factories do 'odd' stuff...

[ggdad1951]

41 minutes ago, wayfarer said:

...some folks seem to miss small details like this and only wonder why the factories do 'odd' stuff...

 

the engineer ALWAYS has a reason...whether it makes sense or not! 

 

[Plymouthy Adams]

knowing how it works is the first step to GETTING IT TO WORK

[Todd B]

12 minutes ago, ggdad1951 said:

 

the engineer ALWAYS has a reason...whether it makes sense or not! 

 

Mark is the only engineer I know that doesn’t have to where Velcro shoes. 

[Jocko_51_B3B]

My original clutch cover (pressure plate) bolts were shoulder bolts so I made sure my replacements had shoulders of the same length. Only thing I had to do was shorten the new ones to match the original bolt length - one inch from bottom of bolt head to the end of threads.

Edited January 9, 2019 by Jocko_51_B3B
elaboration

[wayfarer]

On 12/20/2018 at 10:02 AM, ggdad1951 said:

 

the engineer ALWAYS has a reason...whether it makes sense or not! 

 

...as an retired engineer I have some experience in that department.

Many times projects were not guided by sensible requirements.....

[kencombs]

 

4 hours ago, wayfarer said:

...as an retired engineer I have some experience in that department.

Many times projects were not guided by sensible requirements.....

Ya mean like marketing, sales and accounting????

[lonejacklarry]

I have been bitten several times over the years with factory  "orginal" hardware vs the hardware that came on an old vehicle.  Previous owner changes over the years with a 60+ year old vehicle are very possible.

[Jocko_51_B3B]

The flywheel bolts I received from VPW were perfect. Since my engine was still on the workbench when the old bolt stripped, all I had to do was put it back on the engine stand, turn it upside down, and then remove the oil pan and the rear main bearing to make room for the replacement bolts.

Edited January 9, 2019 by Jocko_51_B3B