LMTV FMTV CAT3116 Engine Front Cover Failure & Cause

[f8617]

This is a common & expensive CAT 3116/3126 engine failure point, which is easily prevented by proper fastening of the air compressor bracket.

Fix/PM: before selling (ie GP) or driving your LMTV / FMTV roll under the truck's oil pan, driver's side, and look at the air compressor bracket-- confirm all the bolts are in & tight.

Pix: CAT 3116 Engine Front Cover Break & Missing/loose/improper-sized Air Compressor Bracket Bolts

 

[Smike740]

Yep had the same issue, compressor brkt was loose/cracked and the front housing was cracked although not as bad as yours pictured. I installed a used front housing and cover and had to repair the compressor support bracket by welding.

I will definitely routinely check the bracket fasteners to make sure they are tight, when I put everything back together I used loctite.

 

[sandcobra164]

Once the newer trucks get released with the C7 Cat, another failure point will be noted. There is lack of loctite or proper torque on the air compressor driving gear nut. It doesn't harm the cover but the truck will not build air or have power steering when it happens. Either way, it involves removing the front cover and that job is somewhat a pain.

 

[DTinNC]

Hello
Just wondering if anyone has their old (cracked) front housing. I'm looking to repair a cracked one and then replace the one that's cracked on my engine.

Thanks for your time

 

[charlesrg]

Hello
Just wondering if anyone has their old (cracked) front housing. I'm looking to repair a cracked one and then replace the one that's cracked on my engine.

Thanks for your time

I’m working on removing mine this week. So far stuck with the single piece camshaft .

 

[country]

Hello
Just wondering if anyone has their old (cracked) front housing. I'm looking to repair a cracked one and then replace the one that's cracked on my engine.

Thanks for your time

we have some parts engines lplease email dave@easternsurplus.net

 

[DTinNC]

I’m working on removing mine this week. So far stuck with the single piece camshaft .

My disclaimer is that I have never seen the plate... But I've heard that the sprocket may be able to be pulled off and then perhaps heated to get back on. There's a JustAnswers thread somewhere (or akin to that site).

 

[charlesrg]

My disclaimer is that I have never seen the plate... But I've heard that the sprocket may be able to be pulled off and then perhaps heated to get back on. There's a JustAnswers thread somewhere (or akin to that site).

I don't think that heating up the camshaft in place would allow to remove the sprocket. I might put the whole engine on fire.
I'm working on creating a parts list to have the front cover replaced

 

[DTinNC]

I don't think that heating up the camshaft in place would allow to remove the sprocket. I might put the whole engine on fire.
I'm working on creating a parts list to have the front cover replaced

Sorry - The heat is to place the sprocket back onto the shaft after using a puller to remove. But I haven't personally laid hands on it.

 

[charlesrg]

You are right, the manual shows the parts being separated. Just not sure if it can be done while in place.

 

[DTinNC]

You are right, the manual shows the parts being separated. Just not sure if it can be done while in place.
View attachment 934174

I have a hydraulic three arm puller that I bought at harbor freight. May be worthwhile for you. An electric heat gun may also help and they're relatively inexpensive. Sorry you're having a tough time with it... I assume that mine will be tough as well.

 

[charlesrg]

I have a hydraulic three arm puller that I bought at harbor freight. May be worthwhile for you. An electric heat gun may also help and they're relatively inexpensive. Sorry you're having a tough time with it... I assume that mine will be tough as well.

Experienced Cat mechanic said:

“It is possible to just remove the cam gear from the cam shaft. But to be honest, the heat and puller needed most often causes the gear to come loose later on the engine.”

https://www.justanswer.com/medium-and-heavy-truck/8xl9y-need-change-timing-cover-3126-cat-1999-3126-going.html

 

[DTinNC]

Experienced Cat mechanic said:

“It is possible to just remove the cam gear from the cam shaft. But to be honest, the heat and puller needed most often causes the gear to come loose later on the engine.”

https://www.justanswer.com/medium-and-heavy-truck/8xl9y-need-change-timing-cover-3126-cat-1999-3126-going.html

Good article. Thanks.

 

[Skyhawk13205]

This guy pulled his cam gear, did not look easy.

 

[DTinNC]

Experienced Cat mechanic said:

“It is possible to just remove the cam gear from the cam shaft. But to be honest, the heat and puller needed most often causes the gear to come loose later on the engine.”

https://www.justanswer.com/medium-and-heavy-truck/8xl9y-need-change-timing-cover-3126-cat-1999-3126-going.html

Found this PDF that seems to have decent disassembly info. The steps are interlaced all over in different sections (typical though). I hope that this helps (not sure if DoD TMs are better/worse).