TOB clearance with pressure plate

[MalcolmV8]

Hey Guys,

Anyone have any tips or experience with TOBs to share? What is the correct way to set them up? some say have slight pressure on the pressure plate at all times and others say to have it slightly off the pressure plate.
Currently on my 03 Cobra the TOB is slightly off the pressure plate. I installed a Spec 3+ clutch last year and used their included TOB and put it slightly preloaded on the pressure plate. Within about a thousand miles or less it started making horrible sounds. Right from the get go the clutch pedal had vibration on slight pedal pressure and I think it's because the clutch fingers are not all at an even height. I then adjusted it off the pressure plate but when you lightly depress the clutch pedal to make contact with the pressure plate it makes horrible noises. Usually sitting in the car I can't really tell but pull up next to a car or wall where sounds can echo and you hear it real loud. Sounds horrible.

Just ordered a new ford racing TOB and will install it next week but really need to know the correct way to set it up.

Thanks
Malcolm

[cgrey8]

It all depends on the clutch and the TOB. Some clutches are designed for preload. Others are not and will wear prematurely if preloaded.

The Windsor clutches for GTs and most performance setups are designed for preload because I believe the cable clutch setup is designed to maintain a preload...at least that's what I've heard. I'm glad because I was forced to run my King Cobra with preload on the TOB to get it to disengage completely. It didn't require much...1/8", at most 1/4". The amount of preload required, I was able to attain pushing the fork with my thumb while I ran the nut on the pushrod to the fork with my other hand. Point I'm trying to make is the preload pressure on the bearing isn't that much. I've got over 40k on the truck, driving it every day, and the clutch and TOB has never been an issue. I actually expected to have to adjust it from time to time, but I haven't had to do a thing to it. It's smooth on the disengagement and doesn't wabble or vibrate up the pedal. Disengagement is strong & smooth with no excessive slip or grab. I can't say anything bad about the King Cobra clutch for a stock or mildly modified Windsor.

Now once the HP gets into the 350+HP range, I believe the King Cobra begins to hit its limits and it begins showing signs of slipping. But the power output of the engine shouldn't have anything to do with the TOB or its ability to perform.

As it relates to your 03 Cobra, I have no clue what the TOB requires.

[MalcolmV8]

Hey Chris,

How are some clutches designed for preload? what happens if you don't preload on them? I will try and call Spec on Monday and see what their recommendation is. I'm just so annoyed with the whole clutch and shifting of the car right now.
I ordered an MGW shifter for the tranny which from the cobra forums is an awesome shifter that works really well. I have a pro 5.0 in there now and it sucks. I also need to try different oils. It seemed like the T56 shifted great on Dexron III which was factory spec but lately it sucks and I'm not sure if its the clutch or what. I tried GM syncromesh and all that did was blow $60 plus. It actually shifted worse even though some on the forums swear it makes their tranny shift better although others reported the same results as me. One guy claims he called borg warner and they told him to use GM syncromesh so who knows. Now I see a ton of people on the forums claiming pennzoil syncromesh makes a big difference and makes it shift nice so I guess I'll give it a shot. Not much to loose at this point.
I also found an interesting mod where you remove this bolt on the top right side of the tranny. When you pull it out it has a ball and spring behind it. You apparently shim it with two washers and put it back and the tranny shifter will feel so much softer and smoother because shimming it reduces pressure on the "indent" I think they called it. I'll try that mod too.

While I have the tranny out I may also replace the clutch with something else. I've never liked the Spec clutch as it shuddered really bad when I first got it. Absolutely horrible to drive. It's smoothed out a ton now but still shudders under low rpms when moving slowly like at a gas station or pulling in to the garage. You basically have to bump the rpms quite a bit like you're about to do a super fast pull off but you're just barely moving. I hate it. It's like you're showing off or something and revving really high to barely move around parking lots and gas stations and stuff. Not to mention my neighbors love it when I come home at midnight and pulling in the garage and gassing it nice and loud lol.
I'm still trying to research and find a clutch though that can handle 600 rwhp and drives like stock. The Spec 3+ I have in there now is good to 800 hp at the motor. It just blows for a street driven daily driver although some love it. I'm personally more picky about it.

I also ordered a new clutch cable in case my original has stretched some and is the reason it won't shift sometimes. It's like the shifter hits a brick wall at times. Like I'll nail it hard in 2nd and then go to shift fast into 3rd and shifter just jams hard like it hit a stop and refuses to go in gear. I have to blip the throttle and release level, clutch in/out and suddenly it goes in. HIGHLY annoying. Doesn't do it all the time but still. Also in regular driving I'm noticing it can be quite notchy and I'm not sure which mod over time caused it to get so bad.

I've also installed a firewall adjuster (adjust tension on clutch cable) and an aftermarket quadrant with three different cable hooking positions.

Anyhow the saga continues. Hopefully I get this sorted out soon. I just ordered Nitto NT05 tires for all four corners which should make the car stick to the road like glue both straight line and in corners and can't wait to test it out.... with a properly working clutch/tranny setup.

Later
Malcolm

[cgrey8]

Best I can figure, it's the quality of the TOB that makes it designed for preload or not. I remember years ago, TOBs would burn out fairly quickly if you had them preloaded. But like I said, others actually advertise that they are designed to tolerate preload. If the TOB isn't designed to be run with preload, then it'll fail fairly quickly on a daily driver because it is being spun any time the engine is spinning.

I remember back a few years ago, someone was recommending a centerforce dual-plate clutch to get a strong, but stock-like feel on the pedal. They are rather pricey, but it sounds like that would be OK with you if it'd work as promised.

I can't say anything to the fluid. I originally ran Mobil1 ATF in my T5 and I thought changing the fluid would make it shift better when I heard from you and others that the Mobil1 ATF didn't shift well. I replaced it with standard Castrol DextronIII/Mercon ATF and I never noticed a difference. It's coming up on time to replace it again. I'm trying to replace the tranny fluid every OTHER oil change...and I only change my fluid every 9-10kmiles. I run synthetic and I run the engine so light that I don't expect there's an issue with it. Add to it, I keep thinking I'll be replacing that engine, so it's not like I need it to last another 100kmiles...just another 20-30k if that. I'm watching eBay for deals on things like engines, roller rockers, injectors, etc in hopes of finding a steal. Once I finally get an engine, I'll be in high gear getting it torn apart so I can start porting the heads and intake. Then it'll be back slow-go as I get more money to do the block and head work. But that's a whole-nuther discussion.

[MalcolmV8]

I tried Mobil 1 ATF in the T5 in my 95 Mustang GT once and it wasn't good. It wouldn't shift into gear very well. I read that the full syn oil was to slippery and not allowing the syncros to do their job. What ever the reason I swapped back to dex III or what ever it was (been a while) and it shifted much better. Actually now that I think about it I think I ran GM syncromesh in the T5 and it shifted well but gosh it's been so long I don't remember exactly.

[Dave]

TOB pre-load, remember this discussion way back when Chris was setting up his slave cylinder. thought for sure I had found the dimensions in the '93' shop manual but looking again, not to be found. In about four places they do mention, the TOB is designed to be constant running. Found some info on a Miata site (using the 5.0L) where they were going thru the same problems. Think the engineers would rather have the bearing constantly running with the force applied than have the bearing be non-moving and have to accelerate to engine speed, it's brought up in below comments.
That MGW shifter is supposted to be the best shifter around, just havent gotten mine yet. Them tires have also gotten some high reviews for aggressive street driving. Hope you figure out the latest problem.
Snowed last night!


"Understand that you still want the tob in constant contact with the fingers. Without preloading anything, that will be the case. When the pedal is released, there is nothing to move the tob away from the fingers except fluid traveling back to the master and that takes some force. If there were play, the bearing would need to accelerate to 6000rpm or whatever you shift at instantly, wearing the fork and tob. Also, play is the noise you hear until the pedal is lightly pressed. In addition, any play would have to be taken up when the pedal is pressed before anything happened. The modern ballbearing tob is designed to turn all the time with a thrust load, like wheelbearings. It should be replaced at every clutch change."

http://www.youtube.com/watch?v=7Ehbef-5mFE


Video finally answers my question about total movement at the lever. Them guys with the "Monster Miatas" seen to have been having the same slave/master cylinder problems a lot of swappers have had
Dave

[MalcolmV8]

Dave,

Thanks for the info. I will try and setup the new FMS TOB with a small amount of preload and see how that goes. Still debating on what to do with the clutch though. That low rpm shudder when trying to move the car annoys the heck out of me. A Mcleod twin disk clutch is supposed to be smooth as stock and hold 800+ hp and have lighter than stock pedal effort but their cheapest one is $700. Trying to decide what is worse. Having the shudder at low RPMs or spending $700 to get rid of it lol and possibly find other things I hate about it.

Malcolm

EDIT: mcleod clutch, not ram.

[Dave]

I'll have to go back and look thru the shuddering problem. think I remember reading it can happen with the clutch our or depressed, depending on the cause.
Dave

[MalcolmV8]

Dave the Spec clutches are very aggressive and known for having some shuddering issues. When you first install them they shudder the living daylights out of the car as you try and drive. It is supposed to be reduced after 500 ~ 1000 miles and it does. However some say it goes away completely and that's what I was hoping for. Mine never did go away completely it was something I thought I could live with when purchasing it but after getting it I have to say it sucks really bad and I hate it.

[MalcolmV8]

Ah guess I forgot to report back here. A couple weekends ago I pulled the tranny and replaced the TOB and lone behold it made a HUGE difference to the shudder the clutch had while engaging. The difference was night and day. I couldn't believe how much a TOB can affect a clutch shuddering like that.
I also switched to pennzoil syncromesh and got the MGW shifter and I'm very very happy. The T56 shifts like butter now for the most part and is much more enjoyable to drive with.