Engine/Transmission (1994 - 1998) A clutch disaster waiting to happen!!!

[FATCAT]

Well, my saga of getting a new NV4500 transmission from Quad 4X4 with the Torque King main shaft is almost over. I hope to pick up my truck early next week. (would have been done today, but I thought I ordered the new gear shifter for the transmission, but didn't and the 1997 shifter does not work with the new NV4500 transmission).



Anyway, the shop doing the work, when puting in Q4X4's TK pilot bearing, reviewd my SB Con OFE clutch and strongly recommended I put in a new clutch. Now ... the clutch lining was fine, but the hub is where the problems all lie. When I stoped by Blue Chip Diesel (southern NH) tonight, I got a good look at my clutch hub and saw how the springs have bottomed out and pounded the hub rivits (holding the two sides of the hub apart) to half their diameter!!!!



Please bear with me, I'm not a machanic, but, the inner portion of the hub that holds the springs in place pound the rivits all away around the hub. I probably was only a few thousand miles away from a complete hub failure!

I am having a new 6-speed Luk clutch installed ... very, very heavy duty where the inner disk that holds the springs is away from the rivits and has more and thicker springs to hold the shock.



I was very supprised at the design of the SB clutch friction disk setup. I can't believe that they have not relized this as a potential failure point.

I wish I had pictures of this to make it clear, but would like to inform anyone with this clutch that the next time you have to remove the transmission, inspect your clutch closely.



Its not like I have crazy power in the truck or beat the hell out of it, (just occationally), but was not pleased to see how this happened and how it could easly be avoided in their design.



Just an FYI.

 

[bmoeller]

Do you back trailers a lot? Or slip it when starting out, forward or reverse? Sounds like it to me. If that is the case, I'm not surprised it happened.



IIRC, the SB clutch is based off of a LuK clutch, with SB's linings on the disc.

 

[FATCAT]

Do you back trailers a lot? Or slip it when starting out, forward or reverse? Sounds like it to me. If that is the case, I'm not surprised it happened.



IIRC, the SB clutch is based off of a LuK clutch, with SB's linings on the disc.

I back my two trailers up quite a bit, especially my Hydro-dump when it is loaded. I can't but help to slip the clutch when backing up, especially up hill with a load. I don't slip the clutch when going forward. My old clutch lining was just fine, its the design of the hub and the proximity of the rivits to the inner arms that hold the springs (whatever the technical name of that thing is).

The springs were not strong enough and would bottom out allowing the rivits to be hammered.

The new Luk clutch I saw that is to be in stalled into my truck has the rivits outside of the reach of that inner spring arms and the springs are larger and there are more of them ... this is the one used in the 6 speeds.

 

[Woodenhead]

Get a kit to enable you to run your transfer case in low range but stay in 2 wheel drive. Backing up was hell with my FE until I installed this kit. Now it's great, just let the clutch out and back up real slow with no shaking.



Mike

 

[FATCAT]

Get a kit to enable you to run your transfer case in low range but stay in 2 wheel drive. Backing up was hell with my FE until I installed this kit. Now it's great, just let the clutch out and back up real slow with no shaking.



Mike

That is definitely my next mod (after I get out of the poor house with this new transmission and clutch). I think Quad 4X4 sells something like that.

When I do have a real heavy load I have to back up, I try to use 4WD low, but it always rips up the lawn and it looks like hell.

 

[gitchesum]

Was this a 13" upgraded clutch or the 12. 25" clutch disc?



I know that Peter no longer sells a 12. 25" Con OFE or Con FE due to the very problem your experiencing. The hub just isn't strong enough. That's why all the Con OFE/FE's are now 13" clutches.



I had the same problem and Peter made it all right in the end. Give him a call Monday and explain the situation to him. He'll make sure you get fixed up.

 

[FATCAT]

Was this a 13" upgraded clutch or the 12. 25" clutch disc?



I know that Peter no longer sells a 12. 25" Con OFE or Con FE due to the very problem your experiencing. The hub just isn't strong enough. That's why all the Con OFE/FE's are now 13" clutches.



I had the same problem and Peter made it all right in the end. Give him a call Monday and explain the situation to him. He'll make sure you get fixed up.

Yes I believe it was a 12 1/4" disk. It was about 2 1/2 years old.

This time I will go with the Luk Pro Gold for a change. It is a 13"

 

[DWitcher]

Well you guys won't believe but I just took a look at a 12. 25 Con OFE that a friend of mine gave me that only has around 4000 miles on it since new and the rivits that FATCAT was having problems with are beyond 50% gone at the hub on this clutch. I guess we'll be calling South Bend too.

 

[FATCAT]

Well you guys won't believe but I just took a look at a 12. 25 Con OFE that a friend of mine gave me that only has around 4000 miles on it since new and the rivits that FATCAT was having problems with are beyond 50% gone at the hub on this clutch. I guess we'll be calling South Bend too.

Scary looking ain't it! You could just imagine driving the truck in the not too distant future and BANG there goes your hub!

 

[rubberneck]

Like said earlier, this is why peter has gone to the 13 x 1. 25 con series, the hub on the 13 inch clutch is much better. when i put the ofe in my 98 12valve, peter told me not to bother with the 12 inch because of the weight i tow. he told me that even with mild power (as the truck had at the time) they had torn up the hubs when towing really heavy. that truck grosses 24 k routinely. 3 years to date on it and going strong. Im glad i listened to him after hearing this.

 

[NIsaacs]

Scary looking ain't it! You could just imagine driving the truck in the not too distant future and BANG there goes your hub!

Yup! I used a 12" Chevy clutch in my Ford CTD conversion and have lost at least 6 clutch disks in 150,000 miles, all heavy towing, the hub fails and you just stop. I have tried all types of heavy duty disks with failure every time. I now have one from Heath Diesel, advertised for 600 hp, but have not installed it yet, just looking at it, it will fail too! The best clutch disk I have found is the factory one used in the P-series Chevy with the 4-bt and 4spd, however they fail too, just takes longer.





"NICK"

 

[Woodenhead]

That is definitely my next mod (after I get out of the poor house with this new transmission and clutch). I think Quad 4X4 sells something like that.

When I do have a real heavy load I have to back up, I try to use 4WD low, but it always rips up the lawn and it looks like hell.

I know Quad sells the manual pull cable kit that replaces the front axle vacuum disconnect. I've got the vacuum switch that just switches around the vacuum lines, it's a really simple install and just means another switch in the cab.



Mike

 

[FATCAT]

I know Quad sells the manual pull cable kit that replaces the front axle vacuum disconnect. I've got the vacuum switch that just switches around the vacuum lines, it's a really simple install and just means another switch in the cab.



Mike

Which system is that Woodenhead?

 

[Bloomy]

The same thing happened with my OFE. Peter explained everything as to why it happened and as stated before that is why he doesn't sell it anymore. He also took very good care of me when I purchased a DD from him. Here is a picture of my popped hub.

 

[Signal73]

I just had a SBC con O installed, is this the same as the ofe you guys are having all the trouble with?

http://www.southbendclutch.com/organic.html

 

[FATCAT]

I just had a SBC con O installed, is this the same as the ofe you guys are having all the trouble with?

http://www.southbendclutch.com/organic.html

Did you have your flywheel redrilled for a larger diameter clutch?

Do you know if the Con O you got is a 12. 25" or 13"?



If it is advertised as 400hp/900tq, you should be OK. If like everyone said above that SouthBend doesn't and hasn't sold the 12. 25" clutch for some time, then you should be OK.

 

[Woodenhead]

Which system is that Woodenhead?

I bought mine from Piers. It's listed here part way down the page under performance accessories as "2 Low Diff Switch Kit" for $85. 00. I think it's a BD product.



Mike

 

[gitchesum]

You can still geta Con O in the 12. 25" hub.



My guess would be that the disc isn't strong enough to cause the kind of hub damage that is being seen on the OFE's an FE's

 

[Signal73]

OK, yeah I do have the 400/900TQ one, but Im pretty sure nothing was redrilled so its gotta be the 12¼ hub. I just had it put in about a month ago. Do you guys think I may have this prob. down the road also?

 

[DWitcher]

Scary looking ain't it! You could just imagine driving the truck in the not too distant future and BANG there goes your hub!

Damn scary! I'm glad that I found it and this thread before the install