Thread Lock?????

[Tarrbabe]

About a year ago I swapped from the standard torque converter in my step-side to a 2300 stall. I had this converter laying around and decided to try it out as the stock converter was making noise, the 2300 is the stock converter from a 340 Duster I had and had been in the garage for over 10 years. In the past year I've put about 4000 miles on it and it has worked very well till recently. A few days back I drove the truck for about half hour as I hadn't driven it for about a month. As I got near home I heard a new sound. After checking everything out, it turns out the bolts from the flex plate to the converter are loose. I will replace them if I detect any damage but I wondered if anyone uses thread lock on them? I'm also worried about why they came loose. I didn't install them, as I had a local shop do it for me. The engine, a 318, runs very good and no vibration that I can detect. Of course the 3.91 gears keep it rev'ed pretty well when I drive it. I have even made several trips to east Tennessee with it which kept the rpm up for several hours each round trip. Is it a good idea to use thread lock on these?

Thanks.

[TK]

Well, I have always just put them on dry, and have never, ever ever had one come loose. I think the tranny shop may have not tightened them good enough?
You might want to install new bolts, and torque them to whatever spec they are supposed to be. (I dunno, I never have torqued them either...........)

[TK]

Hey, wait, was the 340 a steel crank, or a cast crank 340?

Cast crank 340 uses a external balanced converter..........

[Shaun]

Yes. I use the red loc-tite on the tq converter to flexplate. Just make sure they(and the holes) are clean beforehand.
318's usually are smooth all across the board. A 340 tq converter shouldn't cause vibration. Have you changed anything else?

[TK]

Originally Posted by Shaun

Yes. I use the red loc-tite on the tq converter to flexplate. Just make sure they(and the holes) are clean beforehand.
318's usually are smooth all across the board. A 340 tq converter shouldn't cause vibration. Have you changed anything else?

Ohhh, your one of THOSE..............I bet you throw away the cork gasket for the intake manifolds too................and use RTV on your pumpkin covers......................

(Insert california joke here)

[Shaun]

One of THOSE?

Ya had to crack the california cap didn't ya?
I use the paper gaskets with the tin on the 448 and on the 360,I use the front and back rubber/cork with a dab on the corners,but my manifolds fit!!! Some don't have much of a choice!
When I change my oil in the 742 I just get the back way up in the air and I drain it out!!

[TK]

Well.............yeah, I was born there, and that gives me the right to talk smack.

And my manifolds always fit.............even when the heads are milled, and the deck is milled......

[Tarrbabe]

was a 72 and yes it is a steel crank. I still have it. I have witnessed other cars loosing these bolts but never a Mopar. I've only checked one so far and it would only turn about an inch at the end of the wrench to tighten it so I'm sure the others will need attention also. I know I caught this really early in the problem. The tc is the only thing I changed when it was worked on and no it don't have any balance weights on it. If I remember right, I looked up the numbers and the 318 is a 78 model and of course the trans is a 727.

[TK]

Well, all 318's are internal, so your OK.

I would replace the bolts, and try again, loctite up to you, I never do, but then again, I have some strange idea's!

[peg leg]

I use Loctite blue on my TC bolts, and torque to the shank spec, which I do not recall. Big help!
Ron

[dodger1]

My '80 FSM sez 30 lb/ft torque on converter - flexplate bolts. Elsewhere it sez 270 lb/in. No mention of threadlocker. I use it anyway. Confused yet?

[John Kunkel]

For the life of me I have never figured out how the factory got away with no locks on the converter bolts but I always use red Loctite.

[Tarrbabe]

for the info. Like I stated, I've seen this before but not on a Mopar.

[aarracer]

Hey

Did you grease the converter nose/stub before installing it?
Does the converter pull up tight to the flex plate? A must as some converters stock or not hit the flexplate to crankshaft bolts causing stress in the plate and potentially causing this problem as well as potentially cracking the flex plate.
Loctite is $4, saves alot of greif!

Cheers

AARRACER

[wilks3]

I used locktite on bellhousing, flywheel, pressure plate, 4-speed and starter bolts because most everything there is too damn heavy to mess with twice. I'm 50, I can't put those 4-speeds in by myself anymore. Just my .02

[RR3834bbl]

You bet! About a day after I started my rebuilt 69 440 engine, it started making a sound like the water pump was going out. Come to find out, the flex plate bolts were backing out. Red Loctite and I never heard that scary sound again. I know there will be about a dozen smart guys who will say that I didn't tighten the bolts well enough, but that's just not the case. I'm one of those who will check and double check torque specs a few times just to make sure one bolt was not missed. And it's not like I had a vibration issue either. The engine was balanced from the crank pulley to the torque converter so things spun nice and smooth. The Loctite is cheap insurance, I'll aways use it on the flex plate bolts.

[Tarrbabe]

After sitting for a number of years in the garage ( there was no rust ) but I polished the surface with polishing cloth to ensure smoothness and lubed it with trans fluid. Converter moved freely back and forth with no binding or interference. While I had the trans out I should have replaced the clutch units and the bushing in the pump as it takes about 5 seconds before pressure is enough to move the truck after sitting overnight. After that it is fine. The stupid thing is I had a fresh re-built unit sitting there and decided not to replace it. I also chose that time to replace the valve body to a stock unit. The one I took out shifted so violently I found it offensive. It felt like getting rear-ended. Still have that valve body to use in the Dart if I ever get around to it. I have no idea what changes have been made to the valve body but it shifts harder than any I have seen.

[Tarrbabe]

I'm trying to post a pix of one of my 4 bolts............

[TK]

Originally Posted by wilks3

I used locktite on bellhousing, flywheel, pressure plate, 4-speed and starter bolts because most everything there is too damn heavy to mess with twice. I'm 50, I can't put those 4-speeds in by myself anymore. Just my .02

Starter?




You know guys, I am not sure about all of ya's, I have never had any of this stuff come loose, and I have been driving and working on these things for 13 years now...........

[Tarrbabe]

a 15" breaker bar to get the starter loose.

[TK]

If you have ever had to fish a starter bolt, loctited in ...........???

Woweeewooooo!

[MrChemist]

I use the blue locktite and pound the converter bolts on with my impact…no issues, except when I swapped converters last year. Had to get the impact back in there to get the bolts off

[dodgedart360]

Another obvious problem I have experienced is the bolts were a shade too long, they looked like they were hard up but were infact bottomed out. Check each bolt in the hole before putting through the flex plate, saves alot of grief later and no I have never used a thread sealer. Also check the convertor threads to make sure they haven't been damaged.

[wilks3]

Worked on these things for 35+ years, and have had starter bolts come loose, not alot but some. The motor was on engine cradle when installing flywheel and all other assorted stuff, the starter bolts did,and will always will, get the blue loctite.
I'd rather do it once than fix it twice. My choice.

[Jacksdad]

Lost a converter and flex plate on my Charger to a couple of bolts backing out and smacking the back of the block hard enough to tear one of them out. Definitely threadlocking the next ones I install. I can't see any harm in using Loctite and it beats the hell out of lying on your back retightening bolts...or worse.

[Tarrbabe]

Locktite Red and a new set of bolts from Mr. Gasket. New bolts come with flat washers to help distribute the pressure.

Thanks.

[aarracer]

Be carefull.

Stock converter bolts have a much thinner head than standard cap screws.

By adding a washer you may find your converter bolts will strike the block.

double check before startup!

Cheers

AARRACER

[Tarrbabe]

The Mr. Gasket bolts have the flat washers included to spread the clamping force over a larger area. They even have a space at the head of the bolt with one thread missing to allow for the washer. When I first went to the parts store, they checked the size of the bolt and come out with the correct thread size but the head size was just 1/2 inch that were grade 8. The original bolt head is thinner and 9/16 inch to spread the force over a larger area. The Mr. Gasket are only grade 5 like the original but the 9/16 head, plus the washer to spread the clamping force over an even greater area. I see this as very important because of the tight fit and only 4 small bolts to transfer that much power. The Mr. Gasket bolts cost me about $9 but I feel good about the product, plus I used the ThreadLock Red.
Don't have it together yet, let alone to put some time on the set-up but I'm hoping for the best. If it fails I'll let everyone know.
I caught this very early. One bolt required about 1/16 turn to snug. 2 were loose but less than the first. The 4th bolt was still very tight. Like I said, I heard something different, not felt it. It pays to listen to your car/truck. My truck has two very old glasspacks on it so you would think it would be loud. But I have two small and almost new catalitic converters in front of them. Not loud, but you can hear it. The exhaust was built by some drunk. I'd hate to let anyone see that mess.

[dodger1]

I believe most of the load on these bolts is in shear as opposed to tension so one or more coming the least bit loose will have the flexplate flexing in unintended ways. Loctite for me!!

[Tarrbabe]

Drove it about 2 miles and started to hear the NOISE again. Back on the ramps to look at it soon.\
I can't beleive it's the same problem.