Engine/Transmission (1998.5 - 2002) clutch failure related to boxes?

[rodmeyer]

could some one help me out. I've read a lot about clutches not being able to handle boxes maybe even just ez or va's. why then can you run 80 or 100 hp injectors and stock clutch will survive?I know i've done it. pulling heavy to. I'am talking injectors and boost module which I ran. so here s the deal. right now I run dd2s boost module 80hpmaybe 90 . I do have the ho. and bullydog propane which is 80hp. I've run this combo all summer pulling a 5000lb camper and a 8000lb horse trailer. no clutch slipage and low egts. the only think I whated was some more low end, so I purchased a va. love it, lots of low end,but now clutch slips. your saying of course you've added 65 more hp. but wait. when I ran dd2s and turn the propane I kicked in 80 hp no slipage. I might add I was still carfull and only floored it above 2000rpms. don't get me wrong. I knew I would need a clutch sooner or latter,my question is why would a 65 hp box slip your clutch and 80hp of fuel,injectors or propane won't?these test were all at above 2000rpms even with the va. could it be the timing on boxes

 

[jwilliams3]

Low end fueling from the BOX.



--Justin

 

[JR2]

Your propane and injectors add the HP when you have the TC locked and you have some RPM's. The EZ and VA add torque off the line at low RPM.





JR2

 

[rodmeyer]

thats why I said in my first post that I could slip it in higher rpms. above 2000. I know the low end it would slip,that would be normal. with the propane above 2000rpms I can't slip the clutch but with the va I can. whats up with that? propane being more hp.

 

[Steve St.Laurent]

Something to keep in mind is that once you slip the stock clutch ONCE it will slip much sooner thereafter. In other words if you slipped it once at low RPM with the box you may find that it'll now slip at higher rpm with the propane or injectors. A clutch slips due to torque and you'll make a lot more torque with a box than with injectors. The stock clutch does do a pretty good job of "healing" after a slip but it takes a couple of weeks of driving without slipping it for that to happen.

 

[rodmeyer]

thanks steve,now that makes sence. its more torque what slips the clutch. so are you saying you get more torque with a box even above 2000rpms?and less torque with injectors?just trying to make sence of all this and how each is different from one another,I love them both.

 

[Snow man]

rod,the timing boxes add about 175 ft lbs of torque very quickly,they bring it in fast,and this slips clutches. this is just my opinion,but you are asking for trouble by running both the timing box,and propane/dd2's. The timing box+ the propane together may be deadly for your head gasket.

 

[rodmeyer]

snowman,tell me more,as I just received the va and really love it but don't want to damage head gaskets either. I'd pick the va over the propane if I had to. I have the bullydog kit and its turned in 1 1/2 turns just what they say. am I still going to have problems? I thought it was to much boost that blew gaskets?what do I know. thanks

 

[Snow man]

There are those who know much more than I do about this,but i was told by some people who have used propane a lot that it effectively advances the timing a bit,combine this with the VA which advances it a bit more can put a lot of extra stress on the head gasket. The ETH;'s blow gaskets more than the std output as it is due to the higher compression they run. I was told that if you ran propane,with no oringed block or head,to run a pump wire box,that does not advance the timing,to keep the head gasket intact. I blew mine with just a B1 turbo hitting 53 psi spikes,and 49 psi average high boost.

 

[smittybuilt]

rod glad to see you are enjoying the va box. sounds like all you need now is a good clutch.

 

[RustyJC]

I've been towing our 13,500 lb 36' 5th wheel RV very successfully with the stock injectors and Edge EZ. A couple of weekends ago MDW and I installed DD2's. The first thing I noticed is that, with the Edge EZ hooked up, the DD2's made a bunch of torque right now - turbo spoolup was very quick, and the stock clutch (which had never slipped loaded) was being taxed to hold the quick application of torque even when the truck was unloaded.



We had to take a trip towing the RV this past weekend, so I unplugged the EZ's data link cable but left the MAP cabling plugged in - the EZ was effectively just acting as a boost fooler. This really softened up the torque rise, and I never slipped the clutch with the DD2's. I'm sure I would have if the EZ's data link cable had been plugged in. As an aside, towing with the DD2's and the EZ data link cable unplugged, I only saw max EGT's around 1200 degF with 32 PSIG boost. Smoke was almost undetectable (not the case with the EZ hooked up with the jumper on either setting #2 or #3!)



I have a SBC Con OFE sitting on the workbench ready to go in. At least in my case, upgrading the clutch is necessary if I'm going to tow with the EZ fully functional and the DD2's installed.



Rusty

 

[plongson]

Slipping clutch..

What do your clutches feel like when they slip?? I just returned from a week trip to the Sierra's in eastern CA. At the higher altitudes (8k to 9k feet) , I couldn't get enough boost to keep the EGT's under control, so I back off of shift down. But when I got to the lower elevations (2k to 3k feet) I could get 30+lbs. boost and barely 1100°+ on steep grades. At that HP and torque I felt a jerking feeling and not a sense of the clutch slipping in the traditional sense. Do your clutches jerk when they slip or what???

 

[RustyJC]

I suppose if one were to slip the clutch enough, it would eventually get to that "slick, free-wheeling" feeling some of us remember from our old gasser days - like driving on ice and having the rear tires break loose, except when the clutch slips, the tach moves but the speedometer doesn't!



In my truck, however, I've only "borderline" slipped the a couple of times. It's more of a ratcheting, juddering sensation, like the clutch is intermittently grabbing and slipping.



Rusty

 

[plongson]

Originally posted by RustyJC





In my truck, however, I've only "borderline" slipped the a couple of times. It's more of a ratcheting, juddering sensation, like the clutch is intermittently grabbing and slipping.



Rusty

That is what I was feeling, and that is what I thought was happening. Fortunately it only happens under HEAVY load and steep grades... Unfortunately... it limits the use of the mighty Cummins. Guess I better start saving for a new clutch