84 M1009 Torque Converter

[AZDeuce]

Gentlemen:

This morning on my way to work, everytime I'd take off from a stop, my Blazer made a weird grinding noise upon taking off, but quieted down within a 100 yrds distance or so, until the next stop. I figured it was the rear end, and figured if it let go, I could continue on in front wheel drive.

Not a good call!

On the way home this evening, at one stop sign, when I tried to move, I heard all kinds of racket, but the vehicle never moved. OH-OH! I bet the torque converter bolts came loose/busted etc. This can't be good! (I've read this is a common CUCV problem).

I called my son he picked me up, we went back to the house, and picked up my M35A2 Deuce, and my military tow bar, came back hooked up the CUCV, and towed her home.

I'll tear into her tomorrow (weather permitting) , but I was wondering if any of you have suffered a similar fate? If so what am I up against?

I'm ASSuming the flex plate is ok, because I can still start the engine. Can I EASY-OUT the broken bolts and install new ones and I'm good, or am I looking at a MAJOR disaster?

I had the transmission rebuilt, and installed it myself over 3 1/2 years ago, if I remember correctly there was a torque spec on the torque converter bolts, and I torqued them.. Next time I'll use some LOCK-TITE!!

Not being to automatic transmission savy, If the bolts came loose would the loose torque converter damage anything, in or on the transmission?

I don't know a whole lot about automatic transmissions, so I'm hopin I didn't ruin anything expensive, or anything that would require me to pull the transmission out. What do you all think?

Thanks - AZ Deuce

 

[Chevytruck]

got pics of the damage?

might help some of us figure out where this converter is for future reference

if that happened to me, i'd check the internals for damage
you never know what can happen

although i'm not an expert on this either
just trying to help

 

[kennyw]

I've seen many flexplates fail, but never heard of the torque converter bolts going. Did you install a diesel torque converter with 6 bolts or a gas version with 3 bolts?

 

[jj]

KennyW you raise an interesting question, namely, does six mount lugs on the torque convertor automatically (NO pun intended) make it a Diesel convertor? And if so, what happens if you install a six lug (possibly Diesel only) convertor in a TH-400 behind a gasoline engine? I do not have enough knowledge about the workings of automatics to even make an UNeducated guess. Anybody have any ideas?

 

[AZDeuce]

Gentlemen:

About 4 years ago, I lost the engine, and installed a surplus HUMMV engine, after swapping all the extrnal parts including the CUCV flex plate.

I can't remember if I got a new torque converter, or just re-used the original one. But I "think" I got a new one, and it had more than 3 bolts. I'll find out this afternoon.

I read posts on the old mil-veh site 4-5 years ago about the torque converters coming loose, they clamed this was a fairly common occurance. Except for the broken bolts, and the mounting surfaces hitting each other as they spun around, I can't imagine what other problems/damage could occur. (as if that ain't enough) The rear of the torque converter should be supported by the transmssion.....correct?

I won't know until later today when it warms up some what I'm looking at, I'll report back when I know more.

As for pictures I wish I could post some, I finally bought a nice digital camera last year, but, still haven't figured out how to send/post photos on my webtv yet! Yeah, yeah, I know....buy a real computer. Someday, but I've been spendng all my "excess" income preparing for obamageddon, and supporting a bad MV habit......but I can quit anytime I want to........the problem is I just don't want to!

Later - AZ Deuce

 

[AZDeuce]

UPDATE: 1245 Hrs, 12-27-08

I was WRONG about the torque converter.

I jacked up the front end, and put her on jackstands, got under, and pulled the pan beneath the torque converter. To my surprise everything looked like it did, when I put it together several years ago.

And in response to the previous posts, YES, it was a NEW torque converter, and yes, it is attached to the flex plate with 6 bolts. But that's no longer is my concern. (at least I don't think so).

After some lunch I plan to get the rear end jacked up, and on jackstands, then start her up, and see where the noise is coming from.
If necessary I can put her in gear and listen from underneath, fairly safely.

I'm hoping it is the rear end and not the transmission, or transfer case. Just out of curiosity, does the M1009 have one of those transfercases that has a chain in it?

If so, what does a chain sound like when it lets go?

My truck was sounding like a "bearing without grease" upon accelerating from a stop, but it stop making noise after about a hundred yards or so..........Beats me!!??

I thought about locking in the hubs, and putting her into 4WD to see if I could drive it home, but the noise seemed to be coming from the transmission area, and I remembered the old posts, regarding torque converters coming loose from the flex plate, and didn't want to tear up the torque converter.

But now that isn't the issue, and I have her up in the air, I could lock in the hubs, put her in 4WD, and see if the front end works.

I would ASSume if the front end works, then the transmission, transfer case are not the problem, and I'm looking at the rear end as the culprit.

In all my years of driving I have never had a transmission, transfercase, or rear end, go out on me, so this is all new to me.

I'll report back this evening on my latest findings.

Thanks

 

[kennyw]

I've had a crank snap on a 6.2L and it made a horrific metal grinding noise that sounded like a transmission going out.

Do you get the noise when in park at idle? Or only when driving/trying to drive?

Put it up on 4 jackstands and start turning everything over by hand. The NP208 tcase does have a chain so it is one possibility. Also, check your transmission fluid and smell it. If it smells burnt then it could be the transmission. If you smell burnt fluid, pull the pan and inspect.

 

[kennyw]

KennyW you raise an interesting question, namely, does six mount lugs on the torque convertor automatically (NO pun intended) make it a Diesel convertor? And if so, what happens if you install a six lug (possibly Diesel only) convertor in a TH-400 behind a gasoline engine? I do not have enough knowledge about the workings of automatics to even make an UNeducated guess. Anybody have any ideas?

I know all small block gas motors use 3 bolts and all 6.2L diesels use 6. Not sure about big blocks, but they could have 6 as well.

The stall speed is lower on a diesel converter than a gas version, but I have run a diesel transmission behind a 350 gas motor and could not tell the difference while driving.

 

[jj]

Thanks for the response Kenny. This has had me puzzled for some time. I had the TH400 in my 79 gasser rebuilt three years ago because i got tired of the oil slick underneath it. Yeah, i know, i could have bought a lot of DexronIII for $954, but anyway, the convertor that came out had three mounting lugs, the new convertor that came with the overhaul had six lugs. So i thought maybe it was a Diesel convertor. I cannot really tell any difference in the vehicle performance either. Since buying my 1009, though, i've toyed with the idea of finding a 6.2, military or otherwise, to drop in place of the 350. The truck is a 10k gvw, so it already has a four core radiator, and the hydraulic brake booster. If i've already got a Diesel compatible torque convertor, then the balance of the project is just plumbing and wiring details. The difference in fuel economy between the 350 now in it and what i see in the 1009 is a major factor. Although, not the factor it was six months ago.

 

[AZDeuce]

kennyw:

Thanks for the responses.

UPDATE: 1523 HRS, 12-27-08

I jacked up the rear end, and had the entire vehicle off the ground on jackstands. I started her up she seemed normal until I put her in Reverse or Drive then it made all kinds of hideous noise.

I climbed out to see if the rear tires were moving, they were not. I started towards the rear end, but realized the rear drieshaft wasn't turning, so I bent down under the center of the truck, and all the noise seemed to be coming from the transmission or the transfer case.

I got back in the truck stepped on the brake, and tried to put the transmission in park, it would not engage in park and you could hear it grinding as I tried. so I just shut it off and put it in Park, but it didn't feel ike it went into Park. But it must have, because I was able to re-start it, after I got out and flipped in the frt hubs.

Once the hubs were engaged, with the engine running, I tried engaging 4WD High, the shifter didn't want to move, I shut her off, and was able to get her in 4WD High, I then tried to shift the transfer to Neutral, with the truck running, and in gear. Couldn't get her to go, she just made grinding noises, I put the tranmission in Neutral (wouldn't go in park), and tried again, still the transfer case just ground everytime I tried to pull it down into Neutral.

All the time this was going on the transmission/transfer kept making unfriendly noises.

I shut the truck off and was able to easily get her into Neutral.....hmmmm. I started her back up, and tried to pull the transfer case into 4WD Low, I heard a comforting thud, and got out to see all 4 wheels moving, the right side seemed to be moving faster than the left side, I think this is correct for a limited slip type differential.

The offending noises had STOPPED!

Once I had all the wheels turning, I stepped on the brakes, and got all the wheels to stop, and was able to put her in PARK!

What in the World!!??

I then tried her in 4WD High, and 2WD, and all the tires spun when they were supposed to, and didn't when they weren't supposed to. The truck now engaged in Park, Reverse, Neutral, and Drive as GM intended.

I took it off the jackstands, and took her for a ride she behaved normally.

WHAT IN THE WORLD!!

I hate when vehicles heal theirselves, seems like what ever the infliction was, it will come back to haunt you at the most inconvienent time!

So all seems ok with the world once again,
.......UNTIL...............

I did check the transmssion fluid, it looks as clean as the day I put it in there, and does not smell burnt.

At this point I'm dazed and confused to what just happened, but it seems to have healed itself. Beats me.

I'm off Monday, so maybe I'll take her on a road trip, with the wife behind me in a chase car.........just in case.......

 

[jj]

Man, i feel your pain. This situation would drive me to a dark shelter and the fetal position. Clearly SOMETHING WAS WRONG. But now it isn't. The suspense of waiting for it to rear it's ugly head again would be BAD. And as Mr. Murphy has pointed out, it will re-appear at the least opportune time. Good Luck.

 

[canopy2k]

It sounds to me like you may have accidentally knocked your transfer case shifter out of position. My M1009 made a very similar noise when I was out 4 wheeling. I had it in 4l, hit a bump, my dog fell forward and knocked the shift lever out of place. Made a terrible sound, and I couldnt shift it, or the transmission, until I turned the engine off.

 

[AZDeuce]

Canopy2k

I hope it was something that easy, it was definitely some kind of connection between the transmission, and the transfer case. I plan on driving her tomorrow, so we'll see if she works, or strands me on the side of the road again.

Thanks for that info.

 

[HAWKMAN]

Hope all goes well for you with smooth sailing

 

[Somemedic]

Need some followup AZ