rear end suggestions

[jymontoya]

^that is what frightens me...

the one occasion i do slap a drag radial on it and BOOM! its toast....

im going with the trac-lok but with extra clutches and pack stacking. we will see if it helps...

That worked for me for a while on my 304whp '97 Cobra... until I added slicks on the track... Then, the diff just wouldn't put the power where needed and I had to adapt my driving to compensate. I'd guess that if you're staying away from slicks on the track, you'll be OK for a while on the beefed up Trac-lok.

 

[MountainMichael]

^that is what frightens me...

the one occasion i do slap a drag radial on it and BOOM! its toast....

im going with the trac-lok but with extra clutches and pack stacking. we will see if it helps...

Anyone have a link to a thread about the different stack/spring arrangement? I have a FRPP carbon clutch set on the way for the stock trac-lok.

Yeah, I've been searching and can't find it.

Thanks,

Micke

 

[MountainMichael]

doh.. just stumbled across it and Kevin actually posted the info here:

http://www.s197forum.com/forum/showthread.php?t=29762&highlight=traction+lok

 

[kevinatfms]

it should go:
SHIM, friction, steel, friction, steel, friction, steel, friction, SHIM

the rear finally let go this past weekend to the point where i cant even drive it 5 min down the road. box of marbles in back...LOL.

 

[MountainMichael]

Hi, Kevin. Sorry to hear your diff grenaded. Thanks for info on 4 friction setup/stack. Saw some saying not to mix stock friction in to do the above with the carbon kit I ordered.. if true:

Would you think I should maybe use the FRPP carbon kit as is? If yes, a video in one thread suggests this arrangement for 3 frictions per side:

Gear - steel - friction - steel - steel - friction - steel - friction - shim

His reasoning is: He believes having a friction against late model gear has very poor contact area; less than 40 percent due to narrow and uneven surface on late gears. He thinks that poor friction contact area on the gear causes a lot of slippage/noise/failures, or that was how I took his meaning.

My 06 is supercharged but doesn't get raced. I'm doing this to get rid of a diff clutch set that squawks badly on tight turns. Double dose of friction modifier and new Amsoil 75w140 reduced it but still squawky and I think making excessive metal. Don't want to ruin the gears and bearings over a bad clutch set polluting the gear oil with flakes. This car apparently didn't get the TSB for "groaning" LSD and flaking metal plates. 24,000 miles on car and stock diff.

Two other things: Explorer forums insist the carrier doesn't need to come out at all. Can do clutches with carrier in place "easily"..? Various other suggestions about compressing S spring in a vise; constraining it compressed with steel wire or hose clamp; then install; cut wire; ends the S spring installation fight supposedly.

Your thoughts?

Input greatly appreciated.

Thanks!

Micke

 

[MountainMichael]

S spring installation vid - needle nose vise grips

This short vid looks like it might work. 'Course, I hear the new FRPP S spring is pretty tall...

http://www.youtube.com/watch?v=O_TqMuV_MeA&list=UUCeGcd4EW_5ttOhw4GRZv3w&index=2&feature=plcp

 

[MountainMichael]

One guy's opinion for 3 friction clutch stack

This is the same guy's take on how he thinks the clutch stack should be for use with 3 frictions. He says he believes that this 3 friction stack works as well as various 4 friction stacks.

There is some Q&A after the videos I found to be informative.

http://www.youtube.com/watch?v=0GsLDg3C6Hc&list=UUCeGcd4EW_5ttOhw4GRZv3w&index=9&feature=plcp

 

[MountainMichael]

Ratech seems to sell an 8.8 traction-lok clutch kit that has 8 frictions as delivered. Part number 1808.

Started a thread (linked below) to learn if anyone has used it; is it good? is it garbage? I don't think it is carbon, but appears a lot of people don't like the FRPP carbon clutches anyway..?

http://www.s197forum.com/forum/showthread.php?p=1409994#post1409994

 

[MountainMichael]

it should go:
SHIM, friction, steel, friction, steel, friction, steel, friction, SHIM

the rear finally let go this past weekend to the point where i cant even drive it 5 min down the road. box of marbles in back...LOL.

Too many people like 4 frictions per side for it to be "the same" as the guy in the vid suggests, so I'm doing this in the order you spec'd. The Ratech 1808 kit that may or may not have 8 frictions is out of stock at Summit until mid-July, so that is out for me. So I just ordered a 2nd frpp carbon kit. gd money pit.

Again, info appreciated.

m

 

[kevinatfms]

i am going to go back with the regular clutch packs as i have blown out the carbon packs too easily. the setup that lasted the longest was my regular frictions with the air gap closed to .45. im hoping with this setup and an extra friction it will hold and last a bit longer than before. i will be going with the friction/steel/friction style stacking of plates as i believe the steel/steel to make it slip will not work with what i am doing with the car, it will just produce excessive slip.

i have ordered the clutch kit(B kit) and i have a few extra shims laying around from my old job. once i get it all ill try to do a full write up but since i will be doing it on my back in my fathers garage(where all my tools are) its gonna be a PITA.

also check the spring height, i am going to use an old F150/Bronco full size 8.8 s-spring(part number:f3tz-4214-a)which should be thicker to help produce more lock up.

 

[kevinatfms]

oh and the Ratech kit frictions may be 8 plates but i would believe they may be thinner than the factory plates. im sticking with the factory plates since i have had bad issues with Ratech parts before. the metal seems to be much cheaper and thinner in their case shims so im sure they use the same for the clutch pack kits.

 

[MountainMichael]

Kevin,

Thanks for valued input. I found some good build guides for the 8.8 that reminded me of some tricks I'd forgotten. I'll be doing the upgrade with the diff carrier in the car, so some unwanted gymnastics in store for me as well.

Clarification on air gap: Did you mean .0045" or 4 and a half thousandths between axle and cross pin?

Your level of racing experience far exceeds anything I've done or will do with my street car's trac-lok. I am carefully considering what you've had to say. I will give strong consideration to returning the carbon kits and just using a 4700-b kit along with 2 of my used frictions.

The warning about Ratech shims being trash is good to know; I will forgo those. I agree with you; if Ratech can't get simple shims right, why on earth would we trust their frictions??

Do you think the F150 heavier S spring (pn appreciated!) is advisable in my street car? It won't be raced and really only ends up burning rubber maybe 5 to 10 times a years. It will probably never have slicks on it.

Micke

 

[MountainMichael]

Went with standard clutches. Tousley Ford -

Ok, now I'm keeping the shipping companies in business with wasted shipping charges... jk

At least thanks to some excellent input, I'll be getting things about as right as I can as trac-lok's go. I've decided to return the carbon kits.

I called Steve at Tousley Ford to check stock on several things. I had bought all the cam chain guides and arms from them back when I did the TSS pump upgrade and they saved me a bunch of money on those and shipped fast.

Steve was super as usual today and gave me the usual 'stang forums discount.

Notes: The thinnest clutch shims he saw listed were .025"; he had 4 in stock for cheap so I ordered them. Unknown if I'll need them, but for a little over a buck each, I want them on hand in case either stack is too tall. I further reason that when I run a shim on the gear as Kevin suggested, this should be thinner than any of the stock shims making the top splines more likely to be engaged? Guesswork but I live in the middle of nowhere, so I can't just pop in to the dealer.

Next, he says that S spring PN IS a truck number but he claims it is the identical part to what is in the 2005 and later 'stang or any 31 spline app. No criticism intended on this; I would not know if his assertion on this is correct or not. Still, I've heard of S springs being cracked or worn or just fatigued over time, it was cheap, so I ordered the one he had in stock.

He had one 4700-b kit in stock, so I ordered it. Had there been 2 in stock, I might have ordered 2 so I'd have all brand new frictions. But what the hell.

Another cool thing: For the regular shipping most charge, I was able to get the parts sent 2nd day. Steve says they will easily get it shipped today.

So I'm still on for bathing in gear oil this weekend.


I don't usually do plugs, but I continue to be impressed with Tousley.


Micke

 

[kevinatfms]

the airgap is .0045 according to my gauge. this should bring the total lockup quicker compared to the factory air gap of .0060 -.0065.

as for the s-spring part number, im not 100% sure as i dont have the f150 spring yet but since they are different part numbers im going to guess that they may be different somehow. im gonna stick the f150 spring in it one way or another just to be sure. ill have both in my hands by the week to make a final inspection of both to see if either is more "beefy" than the other.

as for your car, do what you feel is best. i was taken away from grabbing one of the more expensive diffs due to the abuse i put on my car. im sure other people do the same but i seem to break things that most people feel are "unbreakable" in the stupidest ways possible. im sticking with the trac-lok for now as my budget allows, in the future when the trac-lok decides to quit on me i will be going with some type of helical type diff(t2r or true-trac) as i will be road racing more once i finally get married(Oct.) and will have more disposable income.

 

[MountainMichael]

Kevin,

First off, congrats on your wedding date!

Next, valuable info. It totally tracks IMHO and that's what I'm going to do, too.

I consider your extensive track experience with the traction-lok highly valuable; ya' prevented a lot of wasted money and time for me.

Road racing is obviously hell on diff clutches, so the best build practices you suggested will probably last forever in my street car. I mean, the thing only has 25,000 miles on it now!

Sincere thanks,

Micke

 

[MountainMichael]

Mods: If this link ISN'T ok, no offense intended and go ahead and kick it out; mea culpa in advance.

This is an 8.8 traction-lok rebuild sticky from another 'stang forum. It got moved around a lot and is kinda' hard to find. I found it to be lengthy, but very good and it reminded me of several tricks I had forgotten or never knew. Offered for first timer trying to do their trac-lok rebuild.

The original pics got wiped out somehow, so the OP posts them again way down about halfway through this lengthy thread. Maybe just scroll down to pics as most of the important text is repeated there anyway:

http://www.moddedmustangs.com/forums/5-0-mustangs/58740-trac-lok-rebuild-how.html

 

[kevinatfms]

I have gone through soooo many differentials in cars its rediculous. i have rebuilt my own more than i can count due to the heat/stress i put on the rear. im hoping it lasts for one more season.

one big thing i do notice is that i autocross quite a bit more than other road course junkies due to the fact im over 2 hrs from my local tracks(VIR, NJMP, summit) so the autocross is my fix when i cant get to the track. im assuming the aggressiveness of a tight course is whats really hurting the rear over and over...
i wonder if strano has an input on this as im sure he may very well have the same issues i am having???

 

[MountainMichael]

I can't remember if it was strano or not, but one of the road racing champs swears by the Eaton POSI type carrier. Says he doesn't like the true trac for several reasons and that newer Torsens and T2's are melting down; like as in, those spiral gears are way too soft and are shredding way prematurely.

Too bad, that. Torsen was really supposed to be great for road racing back when they didn't melt down, no?

Maybe strano will jump in and clarify anything I've misstated.

Autocross? Yeah, I'm guessing that would be about the worst abuse imaginable for diff clutches! It seems likely IMHO that the Eaton POSI clutches might not even hold up to that, I don't know.

Here's hoping you find something that lasts!

 

[kevinatfms]

yukon gear just came out with a new posi trac unit called the dura grip($325) that may be worth checking out once this goes south...it looks to be the same spring/clutch combo as the eaton posi type carriers for a few hundred cheaper and it is rebuildable.

on american muscle:
http://www.americanmuscle.com/yukon...kon-31spline-88-posi-NoFitment&adtype=pla&kw=

 

[MountainMichael]

Good to know; great cost savings! If you try one out, please update us. If it lasts thru your intense AutoX usage, would probably last a lifetime for many of us!

With your usage and if utilizing clutch type, clutches lasting the life-of-the-car is probably out, right? If so, what do you think a reasonable goal is? Maybe 2 years on a rebuild or..?

Are there kevlar clutches for some diff types? Might be too noisy for street but might tolerate constant heat abuse of racing better?

Just some thoughts. I obviously don't know a lot about racing differentials.