Loose Flex Plate Bolts

[scottmandu]

So from now on all LMTV's that come through my shop will get the flex plate bolts replaced torqued and lock-tighted. The US army must not own torque wrenches as this has happened with great frequency.

 

[1951M1078]

Is that a pull the tran's thing ?

 

[scottmandu]

Is that a pull the tran's thing ?

It depends on what else was damaged. We are pulling the trans to fix an oil leak. (maybe rear main seal.. Maybe not after this discovery.

 

[1951M1078]

What I meant to say was can they be changed without pulling the tran's ?

 

[scottmandu]

What I meant to say was can they be changed without pulling the tran's ?

Yes there is an inspection plug they are accessed through.

 

[Suprman]

I remember another thread on this. I have one truck with a mil reman 3116 it drips a bit from the rear seal I believe. Prob put together wrong at rebuild unfortunately.

 

[1951M1078]

So it the flex-plate to converter not the flex-plate to crank ?

 

[scottmandu]

So it the flex-plate to converter not the flex-plate to crank ?

Correct

 

[Awesomeness]

I just pulled my flexplate bolts yesterday. Half of them were loose, and the other half I was able to easily loosen with a standard length 3/8"-drive ratchet (8" long?).

 

[Adventure Driven]

Anyone by chance have a photo of the access point to check these bolts? Just when I thought my to do list was getting shorter, arrrrrg

And How does one turn the crank? and tighten each bolt to what torque?

Seth

 

[Awesomeness]

Anyone by chance have a photo of the access point to check these bolts? Just when I thought my to do list was getting shorter, arrrrrg
And How does one turn the crank? and tighten each bolt to what torque?
Seth

The inspection port is documented in the 34-2 manual, under the engine replacement topic. It's a large (1.5"?) pipe plug on the upper passenger side of the bellhousing (about the 2 o'clock position, behind the exhaust pipe). The manual says to turn the crank by turning the alternator pulley, but I already had my alternator off. So I took the fan clutch off, and loosely reinstalled the bolts, and used a crowbar in between the bolts to easily turn the engine. I haven't got that far, but I'm assuming the later portion of the topic, which details reinstallation of the new engine, lists the torque.

 

[Floridianson]

Anyone by chance have a photo of the access point to check these bolts? Just when I thought my to do list was getting shorter, arrrrrg

And How does one turn the crank? and tighten each bolt to what torque?

Seth

I guess I need to check mine. I found the plug on the passenger side half way around the housing facing forward. How did you guys rotate the engine. I thought using the start inhibitor switch and just bumping it? Did anyone find the TQ. specs?

 

[Awesomeness]

I had the fan clutch off when I did it, so I just used a crowbar between the fan clutch bolts to turn it. The manual says to turn the engine with the alternator pulley, which I've done too. Just put a big ratchet on the alternator pulley bolt, and as long as your belts are tight you can rotate the engine with it (make sure you are turning clockwise... tightening the bolt).

 

[Adventure Driven]

Here is how we fixed ours

https://youtu.be/jnKev0FuLCc

 

[TNriverjet]

Here is how we fixed ours

https://youtu.be/jnKev0FuLCc

Thanks Seth, now I have another item on the list. Admittedly, I enjoy laying under the truck and appreciating the sheer size of components. I am actually looking forward to this one.

As a side note, while trying to repair the stuck fan clutch, I grabbed the fan to see if it would turn. I actually pulled hard enough that the engine turned over. I was surprised how easily it rotated (relative to what I was anticipating). I will probably turn mine manually when I get to tightening flywheel bolts.

 

[scottmandu]

Thanks Seth, now I have another item on the list. Admittedly, I enjoy laying under the truck and appreciating the sheer size of components.

I too appreciate the sheer size of the components parts of the LMTV, until I have to drop a transmission that weighs as much as a compact car.

 

[snowtrac nome]

Scott I have done it once in the past its a pretty uncomfortable feeling having that much weight that far in the air on top a transmission jack

 

[TNriverjet]

INCORRECT INFO READ POSTS BELOW FOR TORQUE SPECS ON BOLTS DISCUSSED IN THIS THREAD
It looks like TM 34-2 states in section 3-10 on page 3-86 that flexplate mounting bolt torque is to be 76-94 ft.lbs. See attached screenshot of that section/page.

 

[Awesomeness]

It looks like TM 34-2 states in section 3-10 on page 3-86 that flexplate mounting bolt torque is to be 76-94 ft.lbs. See attached screenshot of that section/page.

View attachment 689323

That's the wrong torque (more correctly, those are the wrong bolts, not the ones being described here), but you're on the right track. A couple pages forward or back from that is where it talked about the flexplate bolts to the ring gear. I just had to install them a couple weeks ago, when I changed engine, and I was surprised that they weren't actually that high a torque rating. I think they are like 40-50 ft-lbs, or something around there.

EDIT: It's under Engine Assembly Replacement, step 43, on page 3-41 of that manual. "Tighten six bolts (54) to 37-45 lb-ft (61-67 N*m)."

 

[TNriverjet]

Thanks Awesomeness. Mods, feel free to edit/remove my post #18 above as it appears to be incorrect information. Sorry for the confusion

This information on page 3-42 of the 34-2 TM appears to be the correct torque information we were seeking. Only 18-22 ft-lbs. Apparently they aren't supposed to be very tight... Does that look like what you remembered Awesomeness?